Groundwater quality in the Santa Barbara Coastal Plain, California

USGS Publications Warehouse

Davis, Tracy A.; Belitz, Kenneth

2016-10-03

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California established the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Santa Barbara Coastal Plain is one of the study units.

Groundwater quality in the Klamath Mountains, California

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.

2014-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Klamath Mountains constitute one of the study units being evaluated.

Ground-water data collected in the Missouri River Basin units in Kansas during 1949

USGS Publications Warehouse

Berry, Delmar W.

1950-01-01

Ground-water studies in the Missouri River Basin were begun by the United States Geological Survey during the fall of 1945 as a part of the program for development of the resources of the basin by the U.S. Bureau of Reclamation and other Federal Agencies. The studies of the ground-water resources in the part of Kansas that lies within the Basin have been coordinated with the cooperative program of ground-water studies already being carried on in Kansas by the Federal Geological Survey and the State Geological Survey of Kansas with the cooperation of the Division of Sanitation of the Kansas State Board of Health and the Division of Water Resources of the Kansas State Board of Agriculture. Areas in which ground-water data have been collected under the Missouri Basin program include the Almena Unit in Norton and Phillips Counties; the Bostwick Unit in Jewell, Republic, and Cloud Counties; the Cedar Bluff Unit in Ellis, Rush, and Trego Counties; the Glen Elder Unit in Mitchell County; the Webster Unit in Osborne County; and the Wilson Unit in Lincoln County. Most of the ground-water data presented in this report were collected during 1949. Most of the data collected in these areas prior to the end of 1947 were presented in a report that was mimeographed in September 1948 and most of the data collected during 1948 were presented in a report that was mimeographed in November 1949. This report is the third of a series of annual reports on ground-water data collected in the Missouri Basin units in Kansas. These annual reports are a means of more promptly releasing for administrative use the data collected each year. Data that are included in the annual reports for a given area will be assembled later in a report on the geology and hydrology of that area. An index of the data collected and presented in the 1947, 1948, and 1949 reports is given in table 1.

Ground-water data collected in the Missouri River Basin units in Kansas during 1948

USGS Publications Warehouse

Berry, Delmar W.

1950-01-01

Ground-water studies in the Missouri River Basin were begun by the U.S. Geological Survey during the fall of 1945 as a part of the program for development of the resources of the basin by the U.S. Bureau of Reclamation and other Federal agencies. The studies of the ground-water resources in the part of Kansas that lies within the basin have been coordinated with the cooperative program of ground-water studies already being carried on in Kansas by the Federal Geological Survey and the Kansas State Geological Survey with the cooperation of the Division of Sanitation of the Kansas State Board of health and the Division of Water Resources of the Kansas State Board of Agriculture.Areas in which ground-water data have been collected under the Missouri Basin program include the Almena Unit in Norton and Phillips Counties; the Bostwick Unit in Jewell, Republic, and Cloud Counties; the Cedar Bluff Unit in Ellis and Trego Counties; the Glen Elder Unit in Mitchell County; the Kanopolis Unit in McPherson and Saline Counties; the Kirwin Unit in Phillips, Smith, and Osborne Counties; the St. Francis Unit in Cheyenne County; the Webster Unit in Osborne County; and the Wilson Unit in Lincoln County.Most of the ground-water data presented in this report were collected during 1948. Most of the data collected in these areas prior to the end of 1947 were presented in a report mimeographed in September 1948. This report and the previous report are the first two of a series of annual reports on ground-water studies in the Missouri Basin units in Kansas. These reports are a means of more promptly releasing for administrative use the data collected each year. Data for a given area that are included in the annual reports will be assembled later in a report on the geology and hydrology of that area.

Conceptual understanding and groundwater quality of selected basin-fill aquifers in the Southwestern United States

USGS Publications Warehouse

Thiros, Susan A.; Bexfield, Laura M.; Anning, David W.; Huntington, Jena M.

2010-01-01

The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey has been conducting a regional analysis of water quality in the principal aquifer systems in the southwestern United States (hereinafter, “Southwest”) since 2005. Part of the NAWQA Program, the objective of the Southwest Principal Aquifers (SWPA) study is to develop a better understanding of water quality in basin-fill aquifers in the region by synthesizing information from case studies of 15 basins into a common set of important natural and human-related factors found to affect groundwater quality.The synthesis consists of three major components:1. Summary of current knowledge about the groundwater systems, and the status of, changes in, and influential factors affecting quality of groundwater in basin-fill aquifers in 15 basins previously studied by NAWQA (this report).2. Development of a conceptual model of the primary natural and human-related factors commonly affecting groundwater quality, thereby building a regional understanding of the susceptibility and vulnerability of basin-fill aquifers to contaminants.3. Development of statistical models that relate the concentration or occurrence of specific chemical constituents in groundwater to natural and human-related factors linked to the susceptibility and vulnerability of basin-fill aquifers to contamination.Basin-fill aquifers occur in about 200,000 mi2 of the 410,000 mi2 SWPA study area and are the primary source of groundwater supply for cities and agricultural communities. Four of the principal aquifers or aquifer systems of the United States are included in the basin-fill aquifers of the study area: (1) the Basin and Range basin-fill aquifers in California, Nevada, Utah, and Arizona; (2) the Rio Grande aquifer system in New Mexico and Colorado; (3) the California Coastal Basin aquifers; and (4) the Central Valley aquifer system in California. Because of the generally limited availability of surface-water supplies in the arid to semiarid climate, cultural and economic activities in the Southwest are particularly dependent on supplies of good-quality groundwater. Irrigation and public-supply withdrawals from basin-fill aquifers in the study area account for about one quarter of the total withdrawals from all aquifers in the United States.Many factors influence the quality of groundwater in the 15 case-study basins, but some common factors emerge from the basin summaries presented in this report. These factors include the chemical composition of the recharge water, consolidated rock geology and composition of aquifer materials derived from consolidated rock, and land and water use. The major water-quality issues in many of the developed case-study basins are increased concentrations of dissolved solids, nitrate, and VOCs in groundwater as a result of human activities.The information presented and the citations listed in this report serve as a resource for those interested in the groundwater-flow systems in the NAWQA case-study basins. The summaries of water-development history, hydrogeology, conceptual understanding of the groundwater system under both predevelopment and modern conditions, and effects of natural and human-related factors on groundwater quality presented in the sections on each basin also serve as a foundation for the synthesis and modeling phases of the SWPA regional study.

Groundwater quality in the Sierra Nevada, California

USGS Publications Warehouse

Fram, Miranda S.; Belitz, Kenneth

2014-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project (PBP) of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Sierra Nevada Regional study unit constitutes one of the study units being evaluated.

Groundwater quality in the western San Joaquin Valley, California

USGS Publications Warehouse

Fram, Miranda S.

2017-06-09

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Western San Joaquin Valley is one of the study units being evaluated. 

Groundwater quality in the North San Francisco Bay shallow aquifer, California

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.

2018-02-23

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The North San Francisco Bay Shallow Aquifer constitutes one of the study units being evaluated.

Groundwater quality in the Mojave area, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Four groundwater basins along the Mojave River make up one of the study areas being evaluated. The Mojave study area is approximately 1,500 square miles (3,885 square kilometers) and includes four contiguous groundwater basins: Upper, Middle, and Lower Mojave River Groundwater Basins, and the El Mirage Valley (California Department of Water Resources, 2003). The Mojave study area has an arid climate, and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). Land use in the study area is approximately 82 percent (%) natural (mostly shrubland), 4% agricultural, and 14% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Victorville, Hesperia, and Apple Valley (2010 populations of 116,000, 90,000 and 69,000, respectively). Groundwater in these basins is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in the Mojave study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in the Mojave study area are completed to depths between 200 and 600 feet (18 to 61 meters), consist of solid casing from the land surface to a depth of 130 to 420 feet (40 to 128 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the mountains to the south, mostly through the Mojave River channel. The primary sources of discharge are pumping wells and evapotranspiration.

Groundwater quality in the Central Sierra Nevada, California

USGS Publications Warehouse

Fram, Miranda S.; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. Two small watersheds of the Fresno and San Joaquin Rivers in the Central Sierra Nevada constitute one of the study units being evaluated.

Groundwater quality in the Bear Valley and Lake Arrowhead Watershed, California

USGS Publications Warehouse

Mathany, Timothy; Burton, Carmen; Fram, Miranda S.

2017-06-20

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Bear Valley and Lake Arrowhead Watershed study areas in southern California compose one of the study units being evaluated.

Ground-water levels in intermontane basins of the northern Rocky Mountains, Montana and Idaho

USGS Publications Warehouse

Briar, David W.; Lawlor, S.M.; Stone, M.A.; Parliman, D.J.; Schaefer, J.L.; Kendy, Eloise

1996-01-01

The Regional Aquifer-System Analysis (RASA) program is a series of studies by the U.S. Geological Survey (USGS) to analyze regional ground-water systems that compose a major portion of the Nation's water supply (Sun, 1986). The Northern Rocky Mountains Intermontane Basins is one of the study regions in this national program. The main objectives of the RASA studies are to (1) describe the groundwater systems as they exist today, (2) analyze the known changes that have led to the systems present condition, (3) combine results of previous studies in a regional analysis, where possible, and (4) provide means by which effects of future ground-water development can be estimated.The purpose of this study, which began in 1990, was to increase understanding of the hydrogeology of the intermontane basins of the Northern Rocky Mountains area. This report is Chapter B of a three-part series and shows the general distribution of ground-water levels in basin-fill deposits in the study area. Chapter A (Tuck and others, 1996) describes the geologic history and generalized hydrogeologic units. Chapter C (Clark and Dutton, 1996) describes the quality of ground and surface waters in the study area.Ground-water levels shown in this report were measured primarily during summer 1991 and summer 1992; however, historical water levels were used for areas where more recent data could not be obtained. The information provided allows for the evaluation of general directions of ground-water flow, identification of recharge and discharge areas, and determination of hydraulic gradients within basin-fill deposits.

Groundwater-flow budget for the lower Apalachicola-Chattahoochee-Flint River Basin in southwestern Georgia and parts of Florida and Alabama, 2008–12

USGS Publications Warehouse

Jones, L. Elliott; Painter, Jaime A.; LaFontaine, Jacob H.; Sepúlveda, Nicasio; Sifuentes, Dorothy F.

2017-12-29

As part of the National Water Census program in the Apalachicola-Chattahoochee-Flint (ACF) River Basin, the U.S. Geological Survey evaluated the groundwater budget of the lower ACF, with particular emphasis on recharge, characterizing the spatial and temporal relation between surface water and groundwater, and groundwater pumping. To evaluate the hydrologic budget of the lower ACF River Basin, a groundwater-flow model, constructed using MODFLOW-2005, was developed for the Upper Floridan aquifer and overlying semiconfining unit for 2008–12. Model input included temporally and spatially variable specified recharge, estimated using a Precipitation-Runoff Modeling System (PRMS) model for the ACF River Basin, and pumping, partly estimated on the basis of measured agricultural pumping rates in Georgia. The model was calibrated to measured groundwater levels and base flows, which were estimated using hydrograph separation.The simulated groundwater-flow budget resulted in a small net cumulative loss of groundwater in storage during the study period. The model simulated a net loss in groundwater storage for all the subbasins as conditions became substantially drier from the beginning to the end of the study period. The model is limited by its conceptualization, the data used to represent and calibrate the model, and the mathematical representation of the system; therefore, any interpretations should be considered in light of these limitations. In spite of these limitations, the model provides insight regarding water availability in the lower ACF River Basin.

Data on ground-water quality in the Carson River basin, western Nevada and eastern California, 1987-90

USGS Publications Warehouse

Whitney, Rita

1994-01-01

The U.S. Geological Survey collected and analyzed water samples from June 1987 through February 1990 as part of a study of the ground-water quality in the Carson River Basin. The Carson River Basin is one of seven national pilot projects conducted by the Geological Survey as part of a National Water-Quality Assessment Program. The data from the sampling program include analyses of 110 different constituents and properties of ground water in 400 separate samplings of 230 domestic, public-supply, irrigation, and shallow monitoring wells and one spring. The water-quality data include: field measurements, major constituents, nutrients, minor constituents, radionuclides, stable isotopes, and synthetic organic compounds.

Potential for using the Upper Coachella Valley ground-water basin, California, for storage of artificially recharged water

USGS Publications Warehouse

Mallory, Michael J.; Swain, Lindsay A.; Tyley, Stephen J.

1980-01-01

This report presents a preliminary evaluation of the geohydrologic factors affecting storage of water by artificial recharge in the upper Coachella Valley, Calif. The ground-water basin of the upper Coachella Valley seems to be geologically suitable for large-scale artificial recharge. A minimum of 900 ,000 acre-feet of water could probably be stored in the basin without raising basinwide water levels above those that existed in 1945. Preliminary tests indicate that a long-term artificial recharge rate of 5 feet per day may be feasible for spreading grounds in the basin if such factors as sediment and bacterial clogging can be controlled. The California Department of Water Resources, through the Future Water Supply Program, is investigating the use of ground-water basins for storage of State Water Project water in order to help meet maximum annual entitlements to water project contractors. (USGS)

Water levels prior to January 1, 1954 in observation wells, in Nebraska: part 1. Adams through Howard Counties

USGS Publications Warehouse

Keech, C.F.; Case, R.L.

1954-01-01

During the fall of 1945, as part of the program for the development of the resources of the Missouri River basin, the United States Geological Survey began a new series of groundwater investigation in Nebraska.  Those studies were coordinated with the already existing program of ground-water studies that was begun in 1930 by the U.S. Geological Survey in cooperation with the Conservation and Survey Division of the University of Nebraska. Most of the water-level measurements in this report were obtained and compiled as part of the Missouri Basin Development Program.

Groundwater ages and mixing in the Piceance Basin natural gas province, Colorado

USGS Publications Warehouse

McMahon, Peter B.; Thomas, Judith C.; Hunt, Andrew G.

2013-01-01

Reliably identifying the effects of energy development on groundwater quality can be difficult because baseline assessments of water quality completed before the onset of energy development are rare and because interactions between hydrocarbon reservoirs and aquifers can be complex, involving both natural and human processes. Groundwater age and mixing data can strengthen interpretations of monitoring data from those areas by providing better understanding of the groundwater flow systems. Chemical, isotopic, and age tracers were used to characterize groundwater ages and mixing with deeper saline water in three areas of the Piceance Basin natural gas province. The data revealed a complex array of groundwater ages (50,000 years) and mixing patterns in the basin that helped explain concentrations and sources of methane in groundwater. Age and mixing data also can strengthen the design of monitoring programs by providing information on time scales at which water quality changes in aquifers might be expected to occur. This information could be used to establish maximum allowable distances of monitoring wells from energy development activity and the appropriate duration of monitoring.

Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

USGS Publications Warehouse

Feinstein, D.T.; Hunt, R.J.; Reeves, H.W.

2010-01-01

A regional groundwater-flow model of the Lake Michigan Basin and surrounding areas has been developed in support of the Great Lakes Basin Pilot project under the U.S. Geological Survey's National Water Availability and Use Program. The transient 2-million-cell model incorporates multiple aquifers and pumping centers that create water-level drawdown that extends into deep saline waters. The 20-layer model simulates the exchange between a dense surface-water network and heterogeneous glacial deposits overlying stratified bedrock of the Wisconsin/Kankakee Arches and Michigan Basin in the Lower and Upper Peninsulas of Michigan; eastern Wisconsin; northern Indiana; and northeastern Illinois. The model is used to quantify changes in the groundwater system in response to pumping and variations in recharge from 1864 to 2005. Model results quantify the sources of water to major pumping centers, illustrate the dynamics of the groundwater system, and yield measures of water availability useful for water-resources management in the region. This report is a complete description of the methods and datasets used to develop the regional model, the underlying conceptual model, and model inputs, including specified values of material properties and the assignment of external and internal boundary conditions. The report also documents the application of the SEAWAT-2000 program for variable-density flow; it details the approach, advanced methods, and results associated with calibration through nonlinear regression using the PEST program; presents the water-level, drawdown, and groundwater flows for various geographic subregions and aquifer systems; and provides analyses of the effects of pumping from shallow and deep wells on sources of water to wells, the migration of groundwater divides, and direct and indirect groundwater discharge to Lake Michigan. The report considers the role of unconfined conditions at the regional scale as well as the influence of salinity on groundwater flow. Lastly, it describes several categories of limitations and discusses ways of extending the regional model to address issues at the local scale. Results of the simulations portray a regional groundwater-flow system that, over time, has largely maintained its natural predevelopment configuration but that locally has been strongly affected by well withdrawals. The quantity of rainfall in the Lake Michigan Basin and adjacent areas supports a dense surface-water network and recharge rates consistent with generally shallow water tables and predominantly shallow groundwater flow. At the regional scale, pumping has not caused major modifications of the shallow flow system, but it has resulted in decreases in base flow to streams and in direct discharge to Lake Michigan (about 2 percent of the groundwater discharged and about 0.5 cubic foot per second per mile of shoreline). On the other hand, well withdrawals have caused major reversals in regional flow patterns around pumping centers in deep, confined aquifers - most noticeably in the Cambrian-Ordovician aquifer system on the west side of Lake Michigan near the cities of Green Bay and Milwaukee in eastern Wisconsin, and around Chicago in northeastern Illinois, as well as in some shallow bedrock aquifers (for example, in the Marshall aquifer near Lansing, Mich.). The reversals in flow have been accompanied by large drawdowns with consequent local decrease in storage. On the west side of Lake Michigan, groundwater withdrawals have caused appreciable migration of the deep groundwater divides. Before the advent of pumping, the deep Lake Michigan groundwater-basin boundaries extended west of the Lake Michigan surface-water basin boundary, in some places by tens of miles. Over time, the pumping centers have replaced Lake Michigan as the regional sink for the deep flow system. The regional model is intended to support the framework pilot study of water availability and use for the Great Lakes Basin (Reeves, in press).

User guide for the PULSE program

USGS Publications Warehouse

Rutledge, A.T.

2002-01-01

This manual describes the use of the PULSE computer program for analysis of streamflow records. The specific instructions included here and the computer files that accompany this manual require streamflow data in a format that can be obtained from U.S. Geological Survey (USGS) sites on the World Wide Web. The program is compiled to run on a personal computer that uses a Microsoft Windows-based operating system. This manual provides instructions for use of Microsoft Excel for plotting hydrographs, though users may choose to use other software for plotting. The program calculates a hydrograph of ground-water discharge to a stream on the basis of user-specified recharge to the water table. Two different formulations allow recharge to be treated as instantaneous quantities or as gradual rates. The process of ground-water evapotranspiration can be approximated as a negative gradual recharge. The PULSE program is intended for analyzing a ground-water-flow system that is characterized by diffuse areal recharge to the water table and ground-water discharge to a stream. Program use can be appropriate if all or most ground water in the basin discharges to the stream and if a streamflow-gaging station at the downstream end of the basin measures all or most outflow. Ground-water pumpage and the regulation and diversion of streamflow should be negligible. More information about the application of the method is included in Rutledge, 1997, pages 2-3. The program can be used in conjunction with ground-water-level data. If a well is open to the surficial aquifer, observed water-level rises in the well can be used to evaluate the timing of recharge. Such evaluation is most effective if there are numerous water-level observation wells in the basin. Water levels in observation wells can also be used to evaluate the rate of ground-water discharge estimated by the PULSE program. The results of such an evaluation may be problematic, however, because the relation between ground-water level and ground-water discharge may not be unique. Departures from the linear model of recession occur because of areal variation in transmissivity and because of the longitudinal component of ground-water flow (parallel to the stream). If the PULSE program is used to estimate ground-water recharge, the recession index should not be obtained from periods of extreme low flow, and the calibration process should include plotting flow on the linear scale in addition to plotting flow on the log scale.

Summary appraisals of the Nation's ground-water resources; Great Basin region

USGS Publications Warehouse

Eakin, Thomas E.; Price, Don; Harrill, J.R.

1976-01-01

Only a few areas of the Great Basin Region have been studied in detail sufficient to enable adequate design of an areawide groundwater development. These areas already have been developed. As of 1973 data for broadly outlining the ground-water resources of the region had been obtained. However, if large-scale planned development is to become a reality, a program for obtaining adequate hydrologic and related data would be a prerequisite. Ideally, the data should be obtained in time to be available for the successively more intensive levels of planning required to implement developments.

Investigation of possible effects of surface coal mining on hydrology and landscape stability in part of the Powder River structural basin, northeastern Wyoming

USGS Publications Warehouse

Bloyd, R.M.; Daddow, P.B.; Jordon, P.R.; Lowham, H.W.

1986-01-01

The effects of surface coal mining on the surface- and groundwater systems in a 5,400 sq mi area in the Powder River Basin, Wyoming, that includes 20 major coal mines were evaluated using three approaches: A surface water model, a landscape-stability analysis, and a groundwater model. A surface water model was developed for the Belle Fourche River basin. The Hydrological Simulation Program-Fortran model was used to simulate changes in streamflow and changes in dissolved-solids and sulfate concentrations. Simulated streamflows resulting from less than average rainfall were small, changes in flow from premining to during-mining and postmining conditions were less than 2.5%, and changes in mean dissolved-solids and sulfate concentrations ranged from 1 to 7%. A landscape-stability analysis resulted in regression relations to aid in the reconstruction of reclaimed drainage networks. Hypsometric analyses indicate the larger basins are relatively stable, and statistical data from these basins may be used to design the placement of material within a mined basin to approximate natural, stable landscapes in the area. The attempt to define and simulate the groundwater system in the area using a groundwater-flow model was unsuccessful. The steady-state groundwater-flow model could not be calibrated. The modeling effort failed principally because of insufficient quantity and quality of data to define the spatial distribution of aquifer properties; the hydraulic-head distribution within and between aquifers; and the rates of groundwater recharge and discharge, especially for steady-state conditions. (USGS)

Ground-water data collected in the Missouri River Basin units in Kansas during 1953

USGS Publications Warehouse

Mason, B.J.

1954-01-01

Ground-water studies in the Missouri River basin were begun by the United States Geological Survey during the fall of 1945 as a part of a program for the development of the resources of the basin by the United States Bureau of Reclamation and other Federal Agencies. The studies of the ground-water resources in the part of Kansas that lies within the Missouri River basin have been coordinated with the cooperative program of ground water studies which were already being made in Kansas by the U. S. Geological Survey, the State Geological Survey of Kansas, the Division of Sanitation of the Kansas State Board of Health, and the Division of Water Resources of the Kansas State Board of Agriculture.Areas in which ground-water data have been and are being collected are the following: Almena unit in Norton and Phillips Counties; Bostwick unit in Jewell, Republic, and Cloud Counties; Cedar Bluff unit in Ellis, Rush, and Trego Counties; Glen Elder unit in Mitchell County; Kanopolis unit in Ellsworth, McPherson, and Saline Counties; Kirwin unit in Phillips, Smiths and Osborne Counties; St. Francis unit in Cheyenne County; Webster unit in Osborne County; and Wilson unit in Lincoln County. (See fig. 1.) Data relating to the Ladder Creek project in Greeley, Gove, Lane, Logan, Scott, Wallace, and Wichita Counties will be published later in a separate report.

Methods to characterize environmental settings of stream and groundwater sampling sites for National Water-Quality Assessment

USGS Publications Warehouse

Nakagaki, Naomi; Hitt, Kerie J.; Price, Curtis V.; Falcone, James A.

2012-01-01

Characterization of natural and anthropogenic features that define the environmental settings of sampling sites for streams and groundwater, including drainage basins and groundwater study areas, is an essential component of water-quality and ecological investigations being conducted as part of the U.S. Geological Survey's National Water-Quality Assessment program. Quantitative characterization of environmental settings, combined with physical, chemical, and biological data collected at sampling sites, contributes to understanding the status of, and influences on, water-quality and ecological conditions. To support studies for the National Water-Quality Assessment program, a geographic information system (GIS) was used to develop a standard set of methods to consistently characterize the sites, drainage basins, and groundwater study areas across the nation. This report describes three methods used for characterization-simple overlay, area-weighted areal interpolation, and land-cover-weighted areal interpolation-and their appropriate applications to geographic analyses that have different objectives and data constraints. In addition, this document records the GIS thematic datasets that are used for the Program's national design and data analyses.

California Groundwater Units

USGS Publications Warehouse

Johnson, Tyler D.; Belitz, Kenneth

2014-01-01

The California Groundwater Units dataset classifies and delineates areas within the State of California into one of three groundwater-based polygon units: (1) those areas previously defined as alluvial groundwater basins or subbasins, (2) highland areas that are adjacent to and topographically upgradient of groundwater basins, and (3) highland areas not associated with a groundwater basin, only a hydrogeologic province. In total, 938 Groundwater Units are represented. The Groundwater Units dataset relates existing groundwater basins with their newly delineated highland areas which can be used in subsequent hydrologic studies. The methods used to delineate groundwater-basin-associated highland areas are similar to those used to delineate a contributing area (such as for a lake or water body); the difference is that highland areas are constrained to the immediately surrounding upslope (upstream) area. Upslope basins have their own delineated highland. A geoprocessing tool was created to facilitate delineation of highland areas for groundwater basins and subbasins and is available for download.

Wyoming groundwater-quality monitoring network

USGS Publications Warehouse

Boughton, Gregory K.

2011-01-01

A wide variety of human activities have the potential to contaminate groundwater. In addition, naturally occurring constituents can limit the suitability of groundwater for some uses. The State of Wyoming has established rules and programs to evaluate and protect groundwater quality based on identified uses. The Wyoming Groundwater-Quality Monitoring Network (WGQMN) is a cooperative program between the U.S. Geological Survey (USGS) and the Wyoming Department of Environmental Quality (WDEQ) and was implemented in 2009 to evaluate the water-quality characteristics of the State's groundwater. Representatives from USGS, WDEQ, U.S. Environmental Protection Agency (USEPA), Wyoming Water Development Office, and Wyoming State Engineer's Office formed a steering committee, which meets periodically to evaluate progress and consider modifications to strengthen program objectives. The purpose of this fact sheet is to describe the WGQMN design and objectives, field procedures, and water-quality analyses. USGS groundwater activities in the Greater Green River Basin also are described.

Groundwater quality in the Yuba River and Bear River Watersheds, Sierra Nevada, California

USGS Publications Warehouse

Fram, Miranda S.; Jasper, Monica; Taylor, Kimberly A.

2017-09-27

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Program’s Priority Basin Project assesses the quality of groundwater resources used for drinking water supply and increases public access to groundwater-quality information. In the Yuba River and Bear River Watersheds of the Sierra Nevada, many rural households rely on private wells for their drinking water supplies. 

Groundwater quality in the Mokelumne, Cosumnes, and American River Watersheds, Sierra Nevada, California

USGS Publications Warehouse

Fram, Miranda S.; Shelton, Jennifer L.

2018-03-23

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Program’s Priority Basin Project assesses the quality of groundwater resources used for drinking water supply and increases public access to groundwater-quality information. In the Mokelumne, Cosumnes, and American River Watersheds of the Sierra Nevada, many rural households rely on private wells for their drinking-water supplies.

Risk assessment of groundwater level variability using variable Kriging methods

NASA Astrophysics Data System (ADS)

Spanoudaki, Katerina; Kampanis, Nikolaos A.

2015-04-01

Assessment of the water table level spatial variability in aquifers provides useful information regarding optimal groundwater management. This information becomes more important in basins where the water table level has fallen significantly. The spatial variability of the water table level in this work is estimated based on hydraulic head measured during the wet period of the hydrological year 2007-2008, in a sparsely monitored basin in Crete, Greece, which is of high socioeconomic and agricultural interest. Three Kriging-based methodologies are elaborated in Matlab environment to estimate the spatial variability of the water table level in the basin. The first methodology is based on the Ordinary Kriging approach, the second involves auxiliary information from a Digital Elevation Model in terms of Residual Kriging and the third methodology calculates the probability of the groundwater level to fall below a predefined minimum value that could cause significant problems in groundwater resources availability, by means of Indicator Kriging. The Box-Cox methodology is applied to normalize both the data and the residuals for improved prediction results. In addition, various classical variogram models are applied to determine the spatial dependence of the measurements. The Matérn model proves to be the optimal, which in combination with Kriging methodologies provides the most accurate cross validation estimations. Groundwater level and probability maps are constructed to examine the spatial variability of the groundwater level in the basin and the associated risk that certain locations exhibit regarding a predefined minimum value that has been set for the sustainability of the basin's groundwater resources. Acknowledgement The work presented in this paper has been funded by the Greek State Scholarships Foundation (IKY), Fellowships of Excellence for Postdoctoral Studies (Siemens Program), 'A simulation-optimization model for assessing the best practices for the protection of surface water and groundwater in the coastal zone', (2013 - 2015). Varouchakis, E. A. and D. T. Hristopulos (2013). "Improvement of groundwater level prediction in sparsely gauged basins using physical laws and local geographic features as auxiliary variables." Advances in Water Resources 52: 34-49. Kitanidis, P. K. (1997). Introduction to geostatistics, Cambridge: University Press.

Isotopic composition and elemental concentrations in groundwater in the Kuiseb Basin and the Cuvelai-Etosha Basin, Namibia

NASA Astrophysics Data System (ADS)

Kgabi, Nnenesi A.; Atekwana, Eliot; Ithindi, Johanna; Uugwanga, Martha; Knoeller, Kay; Motsei, Lebogang; Mathuthu, Manny; Kalumbu, Gideon; Amwele, Hilma R.; Uusizi, Rian

2018-05-01

We assessed environmental tracers in groundwater in two contrasting basins in Namibia; the Kuiseb Basin, which is a predominantly dry area and the Cuvelai-Etosha Basin, which is prone to alternating floods and droughts. We aimed to determine why the quality of groundwater was different in these two basins which occur in an arid environment. We analysed groundwater and surface water for the stable isotope ratios of hydrogen (δ2H) and oxygen (δ18O) by cavity ring-down spectroscopy and metals by inductively coupled plasma mass spectrometry. The δ2H and δ18O of surface water in the Cuvelai-Etosha Basin plot on an evaporation trend below the global meteoric water line (GMWL) and the local meteoric water line (LMWL). The δ2H and δ18O of some groundwater samples in the Cuvelai-Etosha Basin also plot on the evaporation trend, indicating recharge by evaporated rain or evaporated surface water. In contrast, the δ2H and δ18O of groundwater samples in the Kuiseb Basin plot mostly along the GMWL and the LMWL, indicating direct recharge from unevaporated rain or unevaporated surface water. Fifty percent of groundwater samples in the Cuvelai-Etosha Basin was potable (salinity < 1 ppt) compared to 79 % in the Kuiseb Basin. The high salinity in the groundwater of the Cuvelai-Etosha Basin does not appear to be caused by evaporation of water (evapo-concentration) on surface prior to groundwater recharge, but rather by the weathering of the Kalahari sediments. The low salinity in the Kuiseb Basin derives from rapid recharge of groundwater by unevaporated rain and limited weathering of the crystalline rocks. The order of abundance of cations in the Kuiseb Basin is Na > K > Ca > Mg vs. Na > Mg > Ca > K for the Cuvelai-Etosha Basin. For metals in the Kuiseb Basin the order of abundance is Fe > Al > V > As > Zn vs. Al > Fe > V> As > Zn for the Cuvelai-Etosha Basin. The relative abundance of cations and metals are attributed to the differences in geology of the basins and the extent of water-rock interaction. Our results show that the quality of groundwater in Cuvelai-Etosha Basin and Kuiseb Basin which vary in the extent of aridity, is controlled by the extent of water-rock interaction at the surface and in the groundwater aquifer.

Groundwater quality in the shallow aquifers of the Madera–Chowchilla and Kings subbasins, San Joaquin Valley, California

USGS Publications Warehouse

Fram, Miranda S.; Shelton, Jennifer L.

2018-01-08

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Program’s Priority Basin Project assesses the quality of groundwater resources used for drinking-water supply and increases public access to groundwater-quality information. Many households and small communities in the Madera– Chowchilla and Kings subbasins of the San Joaquin Valley rely on private domestic wells for their drinking-water supplies.

Comparing Budget-based and Tracer-based Residence Times in Butte Basin, California

NASA Astrophysics Data System (ADS)

Moran, J. E.; Visser, A.; Esser, B.; Buck, C.

2017-12-01

The California Sustainable Groundwater Management Act of 2014 (SGMA) calls for basin-scale Groundwater Sustainability Plans (GSPs) that include a water budget covering a 50 year planning horizon. A nine layer, Integrated Water Flow Model (IWFM) developed for Butte Basin, California, allows examination of water budgets within 36 sub-regions having varying land and water use, to inform SGMA efforts. Detailed land use, soil type, groundwater pumping, and surface water delivery data were applied in the finite element IWFM calibration. In a sustainable system, the volume of storage does not change over a defined time period, and the residence time can be calculated from the water storage volume divided by the flux (recharge or discharge rate). Groundwater ages based on environmental tracer data reflect the mean residence time of groundwater, or its inverse, the turnover rate. Comparisons between budget-based residence times determined from storage and flux, and residence times determined from isotopic tracers of groundwater age, can provide insight into data quality, model reliability, and system sustainability. Budget-based groundwater residence times were calculated from IWFM model output by assuming constant storage and dividing by either averaged annual net recharge or discharge. Calculated residence times range between approximately 100 and 1000 years, with shorter times in subregions where pumping dominates discharge. Independently, 174 wells within the model boundaries were analyzed for tritium-helium groundwater age as part of the California Groundwater Ambient Monitoring and Assessment program. Age distributions from isotopic tracers were compared to model-derived groundwater residence times from groundwater budgets within the subregions of Butte Basin. Mean, apparent, tracer-based residence times are mostly between 20 and 40 years, but 25% of the long-screened wells that were sampled do not have detectable tritium, indicating residence times of more than about 60 years and broad age distributions. A key factor in making meaningful comparisons is to examine budget-based and tracer-based results over transmissive vertical sections, where pumping increases turnover time.

Hydrogeologic framework and groundwater conditions of the Ararat Basin in Armenia

USGS Publications Warehouse

Valder, Joshua F.; Carter, Janet M.; Medler, Colton J.; Thompson, Ryan F.; Anderson, Mark T.

2018-01-17

Armenia is a landlocked country located in the mountainous Caucasus region between Asia and Europe. It shares borders with the countries of Georgia on the north, Azerbaijan on the east, Iran on the south, and Turkey and Azerbaijan on the west. The Ararat Basin is a transboundary basin in Armenia and Turkey. The Ararat Basin (or Ararat Valley) is an intermountain depression that contains the Aras River and its tributaries, which also form the border between Armenia and Turkey and divide the basin into northern and southern regions. The Ararat Basin also contains Armenia’s largest agricultural and fish farming zone that is supplied by high-quality water from wells completed in the artesian aquifers that underlie the basin. Groundwater constitutes about 40 percent of all water use, and groundwater provides 96 percent of the water used for drinking purposes in Armenia. Since 2000, groundwater withdrawals and consumption in the Ararat Basin of Armenia have increased because of the growth of aquaculture and other uses. Increased groundwater withdrawals caused decreased springflow, reduced well discharges, falling water levels, and a reduction of the number of flowing artesian wells in the southern part of Ararat Basin in Armenia.In 2016, the U.S. Geological Survey and the U.S. Agency for International Development (USAID) began a cooperative study in Armenia to share science and field techniques to increase the country’s capabilities for groundwater study and modeling. The purpose of this report is to describe the hydrogeologic framework and groundwater conditions of the Ararat Basin in Armenia based on data collected in 2016 and previous hydrogeologic studies. The study area includes the Ararat Basin in Armenia. This report was completed through a partnership with USAID/Armenia in the implementation of its Science, Technology, Innovation, and Partnerships effort through the Advanced Science and Partnerships for Integrated Resource Development program and associated partners, including the Government of Armenia, Armenia’s Hydrogeological Monitoring Center, and the USAID Global Development Lab and its GeoCenter.The hydrogeologic framework of the Ararat Basin includes several basin-fill stratigraphic units consisting of interbedded dense clays, gravels, sands, volcanic basalts, and andesite deposits. Previously published cross sections and well lithologic logs were used to map nine general hydrogeologic units. Hydrogeologic units were mapped based on lithology and water-bearing potential. Water-level data measured in the water-bearing hydrogeologic units 2, 4, 6, and 8 in 2016 were used to create potentiometric surface maps. In hydrogeologic unit 2, the estimated direction of groundwater flow is from the west to north in the western part of the basin (away from the Aras River) and from north to south (toward the Aras River) in the eastern part of the basin. In hydrogeologic unit 4, the direction of groundwater flow is generally from west to east and north to south (toward the Aras River) except in the western part of the basin where groundwater flow is toward the north or northwest. Hydrogeologic unit 6 has the same general pattern of groundwater flow as unit 4. Hydrogeologic unit 8 is the deepest of the water-bearing units and is confined in the basin. Groundwater flow generally is from the south to north (away from the Aras River) in the western part of the basin and from west to east and north to south (toward the Aras River) elsewhere in the basin.In addition to water levels, personnel from Armenia’s Hydrogeological Monitoring Center also measured specific conductance at 540 wells and temperature at 2,470 wells in the Ararat Basin using U.S. Geological Survey protocols in 2016. The minimum specific conductance was 377 microsiemens per centimeter (μS/cm), the maximum value was 4,000 μS/cm, and the mean was 998 μS/cm. The maximum water temperature was 24.2 degrees Celsius. An analysis between water temperature and well depth indicated no relation; however, spatially, most wells with cooler water temperatures were within the 2016 pressure boundary or in the western part of the basin. Wells with generally warmer water temperatures were in the eastern part of the basin.Samples were collected from four groundwater sites and one surface-water site by the U.S. Geological Survey in 2016. The stable-isotope values were similar for all five sites, indicating similar recharge sources for the sampled wells. The Hrazdan River sample was consistent with the groundwater samples, indicating the river could serve as a source of recharge to the Ararat artesian aquifer.

Field trip guidebook to the hydrogeology of the Rock-Fox River basin of Southeastern Wisconsin

USGS Publications Warehouse

Holt, C. L. R.; Cotter, R.D.; Green, J.H.; Olcott, P.G.

1970-01-01

On this trip we will examine some hydrogeologic characteristics of glacial features and emphasize ground-water management within the Rock-Fox River basin. Field stops will include the hydrogeology of a classical glacial terrane--the Kettle moraine--and the management of ground-water resources for industrial, municipal, agricultural, and fish-culture purposes. Descriptions of the geology, soils, water availability and characteristics, water quality, water use, and water problems within the basin are given in the accompanying U.S. Geological Survey Hydrologic Atlas (HA-360). This atlas is a product of the cooperative program of University Extension--the University of Wisconsin Geological and Natural History Survey.

Status of groundwater quality in the San Fernando--San Gabriel study unit, 2005--California GAMA Priority Basin Project

USGS Publications Warehouse

Land, Michael; Kulongoski, Justin T.; Belitz, Kenneth

2012-01-01

Groundwater quality in the approximately 460-square-mile San Fernando--San Gabriel (FG) study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study area is in Los Angeles County and includes Tertiary-Quaternary sedimentary basins situated within the Transverse Ranges of southern California. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA FG study was designed to provide a spatially unbiased assessment of the quality of untreated (raw) groundwater in the primary aquifer systems (hereinafter referred to as primary aquifers) throughout California. The assessment is based on water-quality and ancillary data collected in 2005 by the USGS from 35 wells and on water-quality data from the California Department of Public Health (CDPH) database. The primary aquifers were defined by the depth interval of the wells listed in the CDPH database for the FG study unit. The quality of groundwater in primary aquifers may be different from that in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. This study assesses the status of the current quality of the groundwater resource by using data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifers of the FG study unit, not the treated drinking water delivered to consumers by water purveyors.

Evaluation of the Source and Transport of High Nitrate Concentrations in Ground Water, Warren Subbasin, California

USGS Publications Warehouse

Nishikawa, Tracy; Densmore, Jill N.; Martin, Peter; Matti, Jonathan

2003-01-01

Ground water historically has been the sole source of water supply for the Town of Yucca Valley in the Warren subbasin of the Morongo ground-water basin, California. An imbalance between ground-water recharge and pumpage caused ground-water levels in the subbasin to decline by as much as 300 feet from the late 1940s through 1994. In response, the local water district, Hi-Desert Water District, instituted an artificial recharge program in February 1995 using imported surface water to replenish the ground water. The artificial recharge program resulted in water-level recoveries of as much as 250 feet in the vicinity of the recharge ponds between February 1995 and December 2001; however, nitrate concentrations in some wells also increased from a background concentration of 10 milligrams per liter to more than the U.S. Environmental Protection Agency (USEPA) maximum contaminant level (MCL) of 44 milligrams per liter (10 milligrams per liter as nitrogen). The objectives of this study were to: (1) evaluate the sources of the high-nitrate concentrations that occurred after the start of the artificial-recharge program, (2) develop a ground-water flow and solute-transport model to better understand the source and transport of nitrates in the aquifer system, and (3) utilize the calibrated models to evaluate the possible effect of a proposed conjunctive-use project. These objectives were accomplished by collecting water-level and water-quality data for the subbasin and assessing changes that have occurred since artificial recharge began. Collected data were used to calibrate the ground-water flow and solute-transport models. Data collected for this study indicate that the areal extent of the water-bearing deposits is much smaller (about 5.5 square miles versus 19 square miles) than that of the subbasin. These water-bearing deposits are referred to in this report as the Warren ground-water basin. Faults separate the ground-water basin into five hydrogeologic units: the west, the midwest, the mideast, the east and the northeast hydrogeologic units. Water-quality analyses indicate that septage from septic tanks is the primary source of the high-nitrate concentrations measured in the Warren ground-water basin. Water-quality and stable-isotope data, collected after the start of the artificial recharge program, indicate that mixing occurs between imported water and native ground water, with the highest recorded nitrate concentrations in the midwest and the mideast hydrogeologic units. In general, the timing of the increase in measured nitrate concentrations in the midwest hydrogeologic unit is directly related to the distance of the monitoring well from a recharge site, indicating that the increase in nitrate concentrations is related to the artificial recharge program. Nitrate-to-chloride and nitrogen-isotope data indicate that septage is the source of the measured increase in nitrate concentrations in the midwest and the mideast hydrogeologic units. Samples from four wells in the Warren ground-water basin were analyzed for caffeine and selected human pharmaceutical products; these analyses suggest that septage is reaching the water table. There are two possible conceptual models that explain how high-nitrate septage reaches the water table: (1) the continued downward migration of septage through the unsaturated zone to the water table and (2) rising water levels, a result of the artificial recharge program, entraining septage in the unsaturated zone. The observations that nitrate concentrations increase in ground-water samples from wells soon after the start of the artificial recharge program in 1995 and that the largest increase in nitrate concentrations occur in the midwest and mideast hydrogeologic units where the largest increase in water levels occur indicate the validity of the second conceptual model (rising water levels). The potential nitrate concentration resulting from a water-level rise in the midwest and

PUMa - modelling the groundwater flow in Baltic Sedimentary Basin

NASA Astrophysics Data System (ADS)

Kalvane, G.; Marnica, A.; Bethers, U.

2012-04-01

In 2009-2012 at University of Latvia and Latvia University of Agriculture project "Establishment of interdisciplinary scientist group and modelling system for groundwater research" is implemented financed by the European Social Fund. The aim of the project is to develop groundwater research in Latvia by establishing interdisciplinary research group and modelling system covering groundwater flow in the Baltic Sedimentary Basin. Researchers from fields like geology, chemistry, mathematical modelling, physics and environmental engineering are involved in the project. The modelling system is used as a platform for addressing scientific problems such as: (1) large-scale groundwater flow in Baltic Sedimentary Basin and impact of human activities on it; (2) the evolution of groundwater flow since the last glaciation and subglacial groundwater recharge; (3) the effects of climate changes on shallow groundwater and interaction of hydrographical network and groundwater; (4) new programming approaches for groundwater modelling. Within the frame of the project most accessible geological information such as description of geological wells, geological maps and results of seismic profiling in Latvia as well as Estonia and Lithuania are collected and integrated into modelling system. For example data form more then 40 thousands wells are directly used to automatically generate the geological structure of the model. Additionally a groundwater sampling campaign is undertaken. Contents of CFC, stabile isotopes of O and H and radiocarbon are the most significant parameters of groundwater that are established in unprecedented scale for Latvia. The most important modelling results will be published in web as a data set. Project number: 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060. Project web-site: www.puma.lu.lv

Groundwater quality in the San Diego Drainages Hydrogeologic Province, California

USGS Publications Warehouse

Wright, Michael T.; Belitz, Kenneth

2011-01-01

More than 40 percent of California's drinking water is from groundwater. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The San Diego Drainages Hydrogeologic Province (hereinafter referred to as San Diego) is one of the study units being evaluated. The San Diego study unit is approximately 3,900 square miles and consists of the Temecula Valley, Warner Valley, and 12 other alluvial basins (California Department of Water Resources, 2003). The study unit also consists of all areas outside defined groundwater basins that are within 3 kilometers of a public-supply well. The study unit was separated, based primarily on hydrogeologic settings, into four study areas: Temecula Valley, Warner Valley, Alluvial Basins, and Hard Rock (Wright and others, 2005). The sampling density for the Hard Rock study area, which consists of areas outside of groundwater basins, was much lower than for the other study areas. Consequently, aquifer proportions for the Hard Rock study area are not used to calculate the aquifer proportions shown by the pie charts. An assessment of groundwater quality for the Hard Rock study area can be found in Wright and Belitz, 2011. The temperatures in the coastal part of the study unit are mild with dry summers, moist winters, and an average annual rainfall of about 10 inches. The temperatures in the mountainous eastern part of the study unit are cooler than in the coastal part, with an annual precipitation of about 45 inches that occurs mostly in the winter. The primary aquifers consist of Quaternary-age alluvium and weathered bedrock in the Temecula Valley, Warner Valley, and Alluvial Basins study areas, whereas in the Hard Rock study area the primary aquifers consist mainly of fractured and decomposed granite of Mesozoic age. The primary aquifers are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. Public-supply wells typically are drilled to depths between 200 and 700 feet, consist of solid casing from the land surface to a depth of about 60 to 170 feet, and are perforated, or consist of an open hole, below the solid casing. Water quality in the shallow and deep parts of the aquifer system may differ from water quality in the primary aquifers. Municipal water use accounts for approximately 70 percent of water used in the study unit; the majority of the remainder is used for agriculture, industry, and commerce. Groundwater accounts for approximately 8 percent of the municipal supply, and surface water, the majority of which is imported, accounts for the rest. Recharge to groundwater occurs through stream-channel infiltration from rivers and their tributaries, infiltration in engineered recharge basins, and infiltration of water from precipitation and irrigation. The primary source of discharge is water pumped from wells.

Identifying the groundwater basin boundaries, using environmental isotopes: a case study

NASA Astrophysics Data System (ADS)

Demiroğlu, Muhterem

2017-06-01

Groundwater, which is renewable under current climatic conditions separately from other natural sources, in fact is a finite resource in terms of quality and fossil groundwater. Researchers have long emphasized the necessity of exploiting, operating, conserving and managing groundwater in an efficient and sustainable manner with an integrated water management approach. The management of groundwater needs reliable information about changes on groundwater quantity and quality. Environmental isotopes are the most important tools to provide this support. No matter which method we use to calculate the groundwater budget and flow equations, we need to determine boundary conditions or the physical boundaries of the domain. The Groundwater divide line or basin boundaries that separate the two adjacent basin recharge areas from each other must be drawn correctly to be successful in defining complex groundwater basin boundary conditions. Environmental isotope data, as well as other methods provide support for determining recharge areas of the aquifers, especially for karst aquifers, residence time and interconnections between aquifer systems. This study demonstrates the use of environmental isotope data to interpret and correct groundwater basin boundaries giving as an example the Yeniçıkrı basin within the main Sakarya basin.

Building science-based groundwater tools and capacity in Armenia for the Ararat Basin

USGS Publications Warehouse

Carter, Janet M.; Valder, Joshua F.; Anderson, Mark T.; Meyer, Patrick; Eimers, Jo L.

2016-05-18

The U.S. Geological Survey (USGS) and U.S. Agency for International Development (USAID) began a study in 2016 to help build science-based groundwater tools and capacity for the Ararat Basin in Armenia. The growth of aquaculture and other uses in the Ararat Basin has been accompanied by increased withdrawals of groundwater, which has resulted in a reduction of artesian conditions (decreased springflow, well discharges, and water levels) including loss of flowing wells in many places (Armenia Branch of Mendez England and Associates, 2014; Yu and others, 2015). This study is in partnership with USAID/Armenia in the implementation of its Science, Technology, Innovation, and Partnerships (STIP) effort through the Advanced Science and Partnerships for Integrated Resource Development (ASPIRED) program and associated partners, including the Government of Armenia, Armenia’s Hydrogeological Monitoring Center, and the USAID Global Development Lab and its GeoCenter. Scientific tools will be developed through this study that groundwater-resource managers, such as those in the Ministry of Nature Protection, in Armenia can use to understand and predict the consequences of their resource management decisions.

U.S. Geological Survey activities in New Mexico 1995

USGS Publications Warehouse

Livingston, Russell K.

1995-01-01

The report provides an overview of the USGS in New Mexico, including activities of the Water Resources, Geologic, and National Mapping Divisions. Some USGS projects address hydrologic and geologic hazards, such as flood discharges, landslides, and land subsidence. Recent environmental assessments include participation in the Kirtland Air Force Base Installation Restoration Program, erosion on the Zuni Reservation, and ground-water contamination in eastern Bernalillo County. Water availability studies have focused on ground-water depletion in the Albuquerque Basin, recharge in the Roswell Basin, and the water resources of Taos County. Irrigation drainage in the San Juan River area and trace metals in a reach of the Rio Grande have been investigated. The National Water-Quality Assessment (NAWQA) program has two study units partly located in New Mexico. Energy and mineral resource assess- ments include gas resources in the San Juan Basin and environmental impacts of mining in the Mimbres Resource Area. The USGS is studying the extent of suitable habitat for Mexican Spotted Owls. Also discussed are cartographic/thematic products and Geographical Information Systems; surface-water, ground-water, and water-quality data-collection net- works; and reports published from 1993 to 1995.

Study plan for the regional aquifer-system analysis of alluvial basins in south-central Arizona and adjacent states

USGS Publications Warehouse

Anderson, T.W.

1980-01-01

The U.S. Geological Survey has started a 4-year study of the alluvial basins in south-central Arizona and parts of California , Nevada, and New Mexico to describe the hydrologic setting, available groundwater resources, and effects of historical development on the groundwater system. To aid in the study, mathematical models of selected basins will be developed for appraising local and regional flow systems. Major components necessary to accomplish the study objectives include the accumulation of existing data on groundwater quantity and quality, entering the data into a computer file, identification of data deficiencies, and development of a program to remedy the deficiencies by collection of additional data. The approach to the study will be to develop and calibrate models of selected basins for which sufficient data exist and to develop interpretation-transfer techniques whereby general predevelopment and postdevelopment conceptual models of the hydrologic system in other basins may be synthesized. The end result of the project will be a better definition of the hydrologic parameters and a better understanding of the workings of the hydrologic system. The models can be used to study the effects of management alternatives and water-resources development on the system. (USGS)

Assessing the groundwater fortunes of aquifers in the White Volta Basin, Ghana: An application of numerical groundwater flow modeling and isotopic studies

NASA Astrophysics Data System (ADS)

Oteng, F. M.; Yidana, S. M.; Alo, C. A.

2012-12-01

Effective development and informed management of groundwater resources represent a critical opportunity for improved rural water supply in Ghana and enhanced livelihoods particularly in the northern part of the White Volta Basin, a region already prone to a myriad of water-related infirmities. If adequately developed, the resource will form a sufficient buffer against the effects of climate change/variability and foster food security and sustainable livelihoods among the largely peasant communities in the region. This research presents the results of a preliminary assessment of the hydrogeological conditions and recharge regimes of the aquifers in the Northern parts of the White Volta Basin, Ghana. Results of estimates of groundwater recharge through the conventional isotopic and mass balance techniques are presented. Details of the groundwater flow pattern and preliminary delineation of local and regional groundwater recharge areas are presented from initial simulations of the hydrogeological system with a robust groundwater flow simulation code, MODFLOW, in the Groundwater Modeling System, GMS, version 7.1. The stream flow and evapotranspiration components of the program were activated to incorporate surface flow processes, so that the resulting model represents the conditions of the entire hydrological system. The results of this study form a platform for detailed numerical assessment of the conditions of the aquifers in the area under transient conditions of fluctuating rainfall patterns in the face of climate change/variability.

Groundwater quality in the Antelope Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic systems. The primary sources of discharge are pumping wells and evapotranspiration near the dry lakebeds.

Groundwater quality in Coachella Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Coachella Valley is one of the study areas being evaluated. The Coachella study area is approximately 820 square miles (2,124 square kilometers) and includes the Coachella Valley groundwater basin (California Department of Water Resources, 2003). Coachella Valley has an arid climate, with average annual rainfall of about 6 inches (15 centimeters). The runoff from the surrounding mountains drains to rivers that flow east and south out of the study area to the Salton Sea. Land use in the study area is approximately 67 percent (%) natural, 21% agricultural, and 12% urban. The primary natural land cover is shrubland. The largest urban areas are the cities of Indio and Palm Springs (2010 populations of 76,000 and 44,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Coachella Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Coachella Valley are completed to depths between 490 and 900 feet (149 to 274 meters), consist of solid casing from the land surface to a depth of 260 to 510 feet (79 to 155 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Salton Sea and Imperial Valley areas.

Hybrid-optimization algorithm for the management of a conjunctive-use project and well field design

USGS Publications Warehouse

Chiu, Yung-Chia; Nishikawa, Tracy; Martin, Peter

2012-01-01

Hi-Desert Water District (HDWD), the primary water-management agency in the Warren Groundwater Basin, California, plans to construct a waste water treatment plant to reduce future septic-tank effluent from reaching the groundwater system. The treated waste water will be reclaimed by recharging the groundwater basin via recharge ponds as part of a larger conjunctive-use strategy. HDWD wishes to identify the least-cost conjunctiveuse strategies for managing imported surface water, reclaimed water, and local groundwater. As formulated, the mixed-integer nonlinear programming (MINLP) groundwater-management problem seeks to minimize water delivery costs subject to constraints including potential locations of the new pumping wells, California State regulations, groundwater-level constraints, water-supply demand, available imported water, and pump/recharge capacities. In this study, a hybrid-optimization algorithm, which couples a genetic algorithm and successive-linear programming, is developed to solve the MINLP problem. The algorithm was tested by comparing results to the enumerative solution for a simplified version of the HDWD groundwater-management problem. The results indicate that the hybrid-optimization algorithm can identify the global optimum. The hybrid-optimization algorithm is then applied to solve a complex groundwater-management problem. Sensitivity analyses were also performed to assess the impact of varying the new recharge pond orientation, varying the mixing ratio of reclaimed water and pumped water, and varying the amount of imported water available. The developed conjunctive management model can provide HDWD water managers with information that will improve their ability to manage their surface water, reclaimed water, and groundwater resources.

Assessing the groundwater salinization in closed hydrologic basins due to overdraft

NASA Astrophysics Data System (ADS)

Guo, Z.; Pauloo, R.; Fogg, G. E.

2016-12-01

Population growth and the expansion of agriculture, coupled with climate uncertainties, have accelerated groundwater pumping and overdraft in alluvial aquifers worldwide. In many agricultural basins, the low rate of replenishment is far exceeded by the rate of groundwater pumping in overdrafted aquifers, which results in the substantial water table declines and in effect contributes to the formation of a "closed" basin. In fact, even modest amounts of groundwater system drawdown that do not produce what is construed as overdraft, can result in most of the groundwater discharge occurring as evapotranspiration via irrigation practices, converting the basin to a closed groundwater basin. Moreover, in past decades, extreme weather conditions (i.e., severe drought in California for the past five years) have resulted in substantially reduced surface water storage. This increases demand for groundwater to supplement low surface water supplies, and consequently, drives groundwater overdraft, and hence, groundwater salinization. In these newly closed basins, just as in other naturally closed basins such as Death Valley and the Great Salt Lake, groundwater salinity must increase not only due to evaporation, but also due to rock water interactions in the groundwater system, and lack of a natural outlet for the groundwater. In this study, the water balance and salt balance in closed basins of the Central Valley, California are computed. Groundwater degradation under the current overdraft conditions is further investigated using simple models that are developed by upscaling more complex and heterogeneous transport models. The focus of this study is to determine the applicability of these simple models to represent regional transport without explicitly including the large-scale heterogeneity inherent in the more complex models. Groundwater salinization processes, including salt accumulation caused by evapotranspiration of applied irrigation water and rock-groundwater interactions are simulated, and the time scales under which groundwater salinity may pose a threat to societies is estimated. Lastly, and most importantly, management strategies to mitigate groundwater salinization are examined.

Geohydrology, geochemistry, and groundwater simulation (1992-2011) and analysis of potential water-supply management options, 2010-60, of the Langford Basin, California

USGS Publications Warehouse

Voronin, Lois M.; Densmore, Jill N.; Martin, Peter; Brush, Charles F.; Carlson, Carl S.; Miller, David M.

2013-01-01

Groundwater withdrawals began in 1992 from the Langford Basin within the Fort Irwin National Training Center (NTC), California. From April 1992 to December 2010, approximately 12,300 acre-feet of water (averaging about 650 acre-feet per year) has been withdrawn from the basin and transported to the adjacent Irwin Basin. Since withdrawals began, water levels in the basin have declined by as much as 40 feet, and the quality of the groundwater withdrawn from the basin has deteriorated. The U.S. Geological Survey collected geohydrologic data from Langford Basin during 1992–2011 to determine the quantity and quality of groundwater available in the basin. Geophysical surveys, including gravity, seismic refraction, and time-domain electromagnetic induction surveys, were conducted to determine the depth and shape of the basin, to delineate depths to the Quaternary-Tertiary interface, and to map the depth to the water table and changes in water quality. Data were collected from existing wells and test holes, as well as 11 monitor wells that were installed at 5 sites as part of this study. Water-quality samples collected from wells in the basin were used to determine the groundwater chemistry within the basin and to delineate potential sources of poor-quality groundwater. Analysis of stable isotopes of oxygen and hydrogen in groundwater indicates that present-day precipitation is not a major source of recharge to the basin. Tritium and carbon-14 data indicate that most of the basin was recharged prior to 1952, and the groundwater in the basin has an apparent age of 12,500 to 30,000 years. Recharge to the basin, estimated to be less than 50 acre-feet per year, has not been sufficient to replenish the water that is being withdrawn from the basin. A numerical groundwater-flow model was developed for the Langford Basin to better understand the aquifer system used by the Fort Irwin NTC as part of its water supply, and to provide a tool to help manage groundwater resources at the NTC. Measured groundwater-level declines since the initiation of withdrawals (1992–2011) were used to calibrate the groundwater-flow model. The simulated recharge was about 46 acre-feet per year, including approximately 6 acre-feet per year of natural recharge derived from precipitation runoff and as much as 40 acre-feet per year of underflow from the Irwin Basin. Between April 1992 and December 2010, an average of about 650 acre-feet per year of water was withdrawn from the Langford Basin. Groundwater withdrawals in excess of natural recharge resulted in a net loss of 11,670 acre-feet of groundwater storage within the basin for the simulation period. The Fort Irwin NTC is considering various groundwater-management options to address the limited water resources in the Langford Basin. The calibrated Langford Basin groundwater-flow model was used to evaluate the hydrologic effects of four groundwater-withdrawal scenarios being considered by the Fort Irwin NTC over the next 50 years (January 2011 through December 2060). Continuation of the 2010 withdrawal rate in the three existing production wells will result in 70 feet of additional drawdown in the central part of the basin. Redistributing the 2010 withdrawal rate equally to the three existing wells and two proposed new wells in the northern and southern parts of the basin would result in about 10 feet less drawdown in the central part of the basin but about 100 feet of additional drawdown in the new well in the northern part of the basin and about 50 feet of additional drawdown in the new well in the southern part of the basin. Reducing the withdrawals from the three existing production wells in the central part of the basin from about 45,000 acre-feet to about 32,720 acre-feet would result in about 40 feet of additional drawdown in the central basin near the pumping wells, about 25 feet less than if withdrawals were not reduced. The combination of reducing and redistributing the cumulative withdrawals to the three existing and two proposed new wells results in about 40 feet of additional drawdown in the central and southern parts of the basin and about 70 feet in the northern part of the basin. These results show that reducing and redistributing the groundwater withdrawals would maintain the upper aquifer at greater than 50 percent of its predevelopment saturated thickness throughout the groundwater basin. The scenarios simulated for this study demonstrate how the calibrated model can be utilized to evaluate the hydrologic effects of different water-management strategies.

U.S. Geological Survey Middle Rio Grande Basin Study; Proceedings of the first annual workshop, Denver, Colorado, November 12-14, 1996

USGS Publications Warehouse

Bartolino, James R.

1997-01-01

Approximately 40 percent (about 600,000 people) of the total population of New Mexico lives within the Middle Rio Grande Basin, which includes the City of Albuquerque. Ongoing analyses of the central portion of the Middle Rio Grande Basin by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque and other cooperators have shown that ground water in the basin is not as readily accessible as earlier studies indicated. A more complete characterization of the ground-water resources of the entire Middle Rio Grande Basin is hampered by a scarcity of data in the northern and southern areas of the basin. The USGS Middle Rio Grande Basin Study is a 5-year effort by the USGS and other agencies to improve the understanding of the hydrology, geology, and land-surface characteristics of the Middle Rio Grande Basin. The primary objective of this study is to improve the understanding of the water resources of the basin. Of particular interest is to determine the extent of hydrologic connection between the Rio Grande and the Santa Fe Group aquifer. Additionally, ground-water quality affects the availability of water supplies in the basin. Improving the existing USGS- constructed ground-water flow model of the Middle Rio Grande Basin will integrate all the various tasks that improve our knowledge of the various components of the Middle Rio Grande water budget. Part of this improvement will be accompanied by extended knowledge of the aquifer system beyond the Albuquerque area into the northern and southern reaches of the basin. Other improvements will be based on understanding gained through process-oriented research and improved geologic characterization of the deposits. The USGS will study the hydrology, geology, and land-surface characteristics of the basin to provide the scientific information needed for water- resources management and for managers to plan for water supplies needed for a growing population. To facilitate exchange of information among the many USGS scientists working in the Middle Rio Grande Basin, yearly technical meetings are planned for the anticipated 5-year study. These meetings provide an opportunity to present research results and plan new field efforts. This report documents the results of research presented at the first technical workshop held in Denver, Colorado, in November 1996. The report is organized into this introduction, five chapters that focus on USGS investigations in progress in the Middle Rio Grande Basin, and three appendixes with supplemental information. The first chapter provides an overview of the USGS program in the basin. The second chapter describes geographic data and analysis efforts in the basin. The third chapter details work being done on the hydrogeologic framework of the basin. The fourth chapter describes studies on ground-water availability in the basin and is divided into three areas of research: ground-water/surface-water interaction, ground-water flow and aquifer properties, and recharge. The fifth chapter is devoted to an overview of New Mexico District Cooperative Program studies in the basin. Finally, the appendixes list publications and presentations made during the first year of the study and 1996 workshop attendees. The report concludes with a list of selected references relevant to the study. The information in this report presents preliminary results of an evolving study. As the study progresses and individual projects publish their results in more detail, the USGS hopes to expand the scientific basis needed for management decisions regarding the Middle Rio Grande Basin.

Upper Illinois River basin

USGS Publications Warehouse

Friedel, Michael J.

1998-01-01

During the past 25 years, industry and government made large financial investments that resulted in better water quality across the Nation; however, many water-quality concerns remain. Following a 1986 pilot project, the U.S. Geological Survey began implementation of the National Water-Quality Assessment (NAWQA) Program in 1991. This program differs from other national water-quality assessment studies in that the NAWQA integrates monitoring of surface- and ground-water quality with the study of aquatic ecosystems. The goals of the NAWQA Program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers (water-bearing sediments and rocks), (2) describe how water quality is changing over time, and (3) improve our understanding of the primary natural and human factors affecting water quality.The Upper Illinois River Basin National Water- Quality Assessment (NAWQA) study will increase the scientific understanding of surface- and ground-water quality and the factors that affect water quality in the basin. The study also will provide information needed by water-resource managers to implement effective water-quality management actions and evaluate long-term changes in water quality.

Hydrogeology and numerical simulation of the unconsolidated glacial aquifer in the Pootatuck River Basin, Newtown, Connecticut

USGS Publications Warehouse

Carlson, Carl S.; Mondazzi, Remo A.; Bjerklie, David M.; Brown, Craig J.

2010-01-01

A study of the groundwater and stream-aquifer interaction in the Pootatuck River Basin, Newtown, Connecticut, was conducted to analyze the effect of production wells on the groundwater levels and streamflow in the Pootatuck River as part of a cooperative program between the U.S. Geological Survey and Newtown, Connecticut. This study will help address concerns about the increasing competition for water for human uses and protection of aquatic habitat. The groundwater-flow model developed in the study was designed for use as a tool to assist planners in assessing the effects of potential future development, which will change the amount and distribution of recharge available to the groundwater system. Several different techniques were used to investigate the interconnection between the stream and the aquifer. Temperature, groundwater levels, stream stage, and stable-isotope data collected during aquifer tests at the principal production wells in the Pootatuck River Basin, as well as groundwater-flow simulations of the system, indicate that more than half of the water pumped from the wells comes from the Pootatuck River. This finding potentially has a large effect on approaches for protecting the water quality of the pumped water. Increases in the amount of impervious surface from future development will reduce and redistribute recharge to the groundwater system. The simulation of future development scenarios showed a decrease in the simulated base flow in the main stem of the Pootatuck River and in all of the 26 simulated subbasins, with some of the subbasins showing a decrease of more than 20 percent when new development had 85 percent impervious area. The groundwater-flow model and particle tracking were used to determine areas that contribute recharge to the five production wells available for use in the Pootatuck River Basin. These areas included narrow portions of the aquifer that extended beyond the immediate upgradient areas, probably because of deeper groundwater-flow paths.

An appraisal of the ground-water resources of the Juniata River Basin, Pennsylvania

USGS Publications Warehouse

Seaber, Paul R.; Hollyday, Este F.

1966-01-01

This report describes the availability, quantity, quality, variability, and cost of development of the ground-water resources in the Juniata River basin, one of the larger sub-basins of the Susquehanna River basin. The report has been prepared for and under specifications established by the Corps of Engineers, U. S. Army, and the Public Health Service, Department of Health, Education, and Welfare.A comprehensive study of the water and related land resources of the Susquehanna River basin was authorized by the Congress of the United States in October 1961, and the task of preparing a report and of coordinating the work being done by others in support of the study was assigned to the Corps of Engineers. The comprehensive study is being conducted by several Federal departments and independent agencies in cooperation with the States of New York, Pennsylvania, and Maryland. The Public Health Service under its authority in the Federal Water Pollution Control Act (P. L. 660) initiated a comprehensive water quality control program for the Chesapeake drainage basin, which includes the Susquehanna River basin.

Optimizing conjunctive use of surface water and groundwater resources with stochastic dynamic programming

NASA Astrophysics Data System (ADS)

Davidsen, Claus; Liu, Suxia; Mo, Xingguo; Rosbjerg, Dan; Bauer-Gottwein, Peter

2014-05-01

Optimal management of conjunctive use of surface water and groundwater has been attempted with different algorithms in the literature. In this study, a hydro-economic modelling approach to optimize conjunctive use of scarce surface water and groundwater resources under uncertainty is presented. A stochastic dynamic programming (SDP) approach is used to minimize the basin-wide total costs arising from water allocations and water curtailments. Dynamic allocation problems with inclusion of groundwater resources proved to be more complex to solve with SDP than pure surface water allocation problems due to head-dependent pumping costs. These dynamic pumping costs strongly affect the total costs and can lead to non-convexity of the future cost function. The water user groups (agriculture, industry, domestic) are characterized by inelastic demands and fixed water allocation and water supply curtailment costs. As in traditional SDP approaches, one step-ahead sub-problems are solved to find the optimal management at any time knowing the inflow scenario and reservoir/aquifer storage levels. These non-linear sub-problems are solved using a genetic algorithm (GA) that minimizes the sum of the immediate and future costs for given surface water reservoir and groundwater aquifer end storages. The immediate cost is found by solving a simple linear allocation sub-problem, and the future costs are assessed by interpolation in the total cost matrix from the following time step. Total costs for all stages, reservoir states, and inflow scenarios are used as future costs to drive a forward moving simulation under uncertain water availability. The use of a GA to solve the sub-problems is computationally more costly than a traditional SDP approach with linearly interpolated future costs. However, in a two-reservoir system the future cost function would have to be represented by a set of planes, and strict convexity in both the surface water and groundwater dimension cannot be maintained. The optimization framework based on the GA is still computationally feasible and represents a clean and customizable method. The method has been applied to the Ziya River basin, China. The basin is located on the North China Plain and is subject to severe water scarcity, which includes surface water droughts and groundwater over-pumping. The head-dependent groundwater pumping costs will enable assessment of the long-term effects of increased electricity prices on the groundwater pumping. The coupled optimization framework is used to assess realistic alternative development scenarios for the basin. In particular the potential for using electricity pricing policies to reach sustainable groundwater pumping is investigated.

Modeling Effects of Groundwater Basin Closure, and Reversal of Closure, on Groundwater Quality

NASA Astrophysics Data System (ADS)

Pauloo, R.; Guo, Z.; Fogg, G. E.

2017-12-01

Population growth, the expansion of agriculture, and climate uncertainties have accelerated groundwater pumping and overdraft in aquifers worldwide. In many agricultural basins, a water budget may be stable or not in overdraft, yet disconnected ground and surface water bodies can contribute to the formation of a "closed" basin, where water principally exits the basin as evapotranspiration. Although decreasing water quality associated with increases in Total Dissolved Solids (TDS) have been documented in aquifers across the United States in the past half century, connections between water quality declines and significant changes in hydrologic budgets leading to closed basin formation remain poorly understood. Preliminary results from an analysis with a regional-scale mixing model of the Tulare Lake Basin in California indicate that groundwater salinization resulting from open to closed basin conversion can operate on a decades-to-century long time scale. The only way to reverse groundwater salinization caused by basin closure is to refill the basin and change the hydrologic budget sufficiently for natural groundwater discharge to resume. 3D flow and transport modeling, including the effects of heterogeneity based on a hydrostratigraphic facies model, is used to explore rates and time scales of groundwater salinization and its reversal under different water and land management scenarios. The modeling is also used to ascertain the extent to which local and regional heterogeneity need to be included in order to appropriately upscale the advection-dispersion equation in a basin scale groundwater quality management model. Results imply that persistent managed aquifer recharge may slow groundwater salinization, and complete reversal may be possible at sufficiently high water tables.

Delineation of the Pahute Mesa–Oasis Valley groundwater basin, Nevada

USGS Publications Warehouse

Fenelon, Joseph M.; Halford, Keith J.; Moreo, Michael T.

2016-01-22

This report delineates the Pahute Mesa–Oasis Valley (PMOV) groundwater basin, where recharge occurs, moves downgradient, and discharges to Oasis Valley, Nevada. About 5,900 acre-feet of water discharges annually from Oasis Valley, an area of springs and seeps near the town of Beatty in southern Nevada. Radionuclides in groundwater beneath Pahute Mesa, an area of historical underground nuclear testing at the Nevada National Security Site, are believed to be migrating toward Oasis Valley. Delineating the boundary of the PMOV groundwater basin is necessary to adequately assess the potential for transport of radionuclides from Pahute Mesa to Oasis Valley.The PMOV contributing area is defined based on regional water-level contours, geologic controls, and knowledge of adjacent flow systems. The viability of this area as the contributing area to Oasis Valley and the absence of significant interbasin flow between the PMOV groundwater basin and adjacent basins are shown regionally and locally. Regional constraints on the location of the contributing area boundary and on the absence of interbasin groundwater flow are shown by balancing groundwater discharges in the PMOV groundwater basin and adjacent basins against available water from precipitation. Internal consistency for the delineated contributing area is shown by matching measured water levels, groundwater discharges, and transmissivities with simulated results from a single-layer, steady-state, groundwater-flow model. An alternative basin boundary extending farther north than the final boundary was rejected based on a poor chloride mass balance and a large imbalance in the northern area between preferred and simulated recharge.

Evaluation of baseline ground-water conditions in the Mosteiros, Ribeira Paul, and Ribeira Fajã Basins, Republic of Cape Verde, West Africa, 2005-06

USGS Publications Warehouse

Heilweil, Victor M.; Earle, John D.; Cederberg, Jay R.; Messer, Mickey M.; Jorgensen, Brent E.; Verstraeten, Ingrid M.; Moura, Miguel A.; Querido, Arrigo; Spencer,; Osorio, Tatiana

2006-01-01

This report documents current (2005-06) baseline ground-water conditions in three basins within the West African Republic of Cape Verde (Mosteiros on Fogo, Ribeira Paul on Santo Antão, and Ribeira Fajã on São Nicolau) based on existing data and additional data collected during this study. Ground-water conditions (indicators) include ground-water levels, ground-water recharge altitude, ground-water discharge amounts, ground-water age (residence time), and ground-water quality. These indicators are needed to evaluate (1) long-term changes in ground-water resources or water quality caused by planned ground-water development associated with agricultural projects in these basins, and (2) the feasibility of artificial recharge as a mitigation strategy to offset the potentially declining water levels associated with increased ground-water development.Ground-water levels in all three basins vary from less than a few meters to more than 170 meters below land surface. Continuous recorder and electric tape measurements at three monitoring wells (one per basin) showed variations between August 2005 and June 2006 of as much as 1.8 meters. Few historical water-level data were available for the Mosteiros or Ribeira Paul Basins. Historical records from Ribeira Fajã indicate very large ground-water declines during the 1980s and early 1990s, associated with dewatering of the Galleria Fajã tunnel. More-recent data indicate that ground-water levels in Ribeira Fajã have reached a new equilibrium, remaining fairly constant since the late 1990s.Because of the scarcity of observation wells within each basin, water-level data were combined with other techniques to evaluate ground-water conditions. These techniques include the quantification of ground-water discharge (well withdrawals, spring discharge, seepage to springs, and gallery drainage), field water-quality measurements, and the use of environmental tracers to evaluate sources of aquifer recharge, flow paths, and ground-water residence times.In the Mosteiros Basin, measured well and spring discharge is about 220,000 cubic meters per year. For the Ribeira Paul Basin, measured well discharge, spring discharge, and ground-water seepage to springs is about 1,600,000 cubic meters per year. Ribeira Fajã Basin is the driest of the three basins with a precipitation rate of about half that of the other two basins. The only measurable ground-water discharge from this basin is from Galleria Fajã, estimated to be about 150,000 cubic meters per year. Measured discharge for all three basins does not include submarine outflow or agricultural/phreatophyte consumptive use (Paul Basin, only) and is assumed to be less than total ground-water discharge.Ground-water ages indicate that recharge to wells and springs occurred from more than 50 years ago at some locations to within the past decade at other sites. Ground water in Paul is younger than that in the other two basins, indicating that recharge generally occurred within the past 50 years. Ground water at all the dateable sites using tritium/helium in both the Mosteiros and Ribeira Fajã Basins show that recharge occurred more than 50 years before the sampling dates. Ground-water tritium/helium age dating was not possible at some sites in Mosteiros and Ribeira Fajã Basins because of the presence of helium in the aquifer derived from the mantle or aquifer matrix. However, this helium was useful for accurate age dating of the unaffected ground-water sites.Dissolved gases indicate that most ground-water recharge occurs at mid and high altitudes within all three basins; calculated recharge altitudes ranged from 700 to more than 2,000 meters. In the Mosteiros and Ribeira Fajã Basins, recharge altitudes are much higher than the wells and springs. This suggests that it may take many years for artificial recharge to result in a beneficial impact on the aquifer in areas where the agricultural projects are implemented. Recharge altitudes in Paul Basin also were generally higher than their respective ground-water discharge sampling sites except for one spring, Seladinha. This spring, in combination with generally younger ground-water ages in Paul, indicates the existence of some short flow paths where artificial recharge may possibly enhance available water resources within a few years.The salinity of wells and springs is generally low in the Ribeira Paul and Ribeira Fajã Basins, but somewhat higher in Mosteiros Basin. Specific-conductance measurements of wells and springs in Ribeira Paul and Ribeira Fajã ranged from about 200 to 700 microsiemens per centimeter at 25 degrees Celsius. Although the Monte Vermelho spring in Mosteiros Basin also has very low salinity (200 microsiemens per centimeter at 25 degrees Celsius), water from the wells along the coastal plain has specific-conductance measurements of as much as 16,000 microsiemens per centimeter at 25 degrees Celsius. These higher values indicate some brackish water intrusion. Additional ground-water development of the Mosteiros coastal plain may exacerbate this situation.

Hydrogeologic framework and selected components of the groundwater budget for the upper Umatilla River Basin, Oregon

USGS Publications Warehouse

Herrera, Nora B.; Ely, Kate; Mehta, Smita; Stonewall, Adam J.; Risley, John C.; Hinkle, Stephen R.; Conlon, Terrence D.

2017-05-31

Executive SummaryThis report presents a summary of the hydrogeology of the upper Umatilla River Basin, Oregon, based on characterization of the hydrogeologic framework, horizontal and vertical directions of groundwater flow, trends in groundwater levels, and components of the groundwater budget. The conceptual model of the groundwater flow system integrates available data and information on the groundwater resources of the upper Umatilla River Basin and provides insights regarding key hydrologic processes, such as the interaction between the groundwater and surface water systems and the hydrologic budget.The conceptual groundwater model developed for the study area divides the groundwater flow system into five hydrogeologic units: a sedimentary unit, three Columbia River basalt units, and a basement rock unit. The sedimentary unit, which is not widely used as a source of groundwater in the upper basin, is present primarily in the lowlands and consists of conglomerate, loess, silt and sand deposits, and recent alluvium. The Columbia River Basalt Group is a series of Miocene flood basalts that are present throughout the study area. The basalt is uplifted in the southeastern half of the study area, and either underlies the sedimentary unit, or is exposed at the surface. The interflow zones of the flood basalts are the primary aquifers in the study area. Beneath the flood basalts are basement rocks composed of Paleogene to Pre-Tertiary sedimentary, volcanic, igneous, and metamorphic rocks that are not used as a source of groundwater in the upper Umatilla River Basin.The major components of the groundwater budget in the upper Umatilla River Basin are (1) groundwater recharge, (2) groundwater discharge to surface water and wells, (3) subsurface flow into and out of the basin, and (4) changes in groundwater storage.Recharge from precipitation occurs primarily in the upland areas of the Blue Mountains. Mean annual recharge from infiltration of precipitation for the upper Umatilla River Basin during 1951–2010 is about 9.6 inches per year (in/yr). Annual recharge from precipitation for water year 2010 ranged from 3 in. in the lowland area to about 30 in. in the Blue Mountains. Using Kahle and others (2011) data and methods from the Columbia Plateau regional model, average annual recharge from irrigation is estimated to be about 2.2 in/yr for the 13 square miles of irrigated land in the upper Umatilla River Basin.Groundwater discharges to streams throughout the year and is a large component of annual streamflow in the upper Umatilla River Basin. Upward vertical hydraulic gradients near the Umatilla River indicate the potential for groundwater discharge. Groundwater discharge to the Umatilla River generally occurs in the upper part of the basin, upstream from the main stem.Groundwater development in the upper Umatilla River Basin began sometime after 1950 (Davies-Smith and others, 1988; Gonthier and Bolke, 1991). By water year 2010, groundwater use in the upper Umatilla River Basin was approximately 11,214 acre-feet (acre-ft). Total groundwater withdrawals for the study area were estimated at 7,575 acre-ft for irrigation, 3,173 acre-ft for municipal use, and 466 acre-ft for domestic use.Total groundwater flow into or from the study area depends locally on geology and hydraulic head distribution. Estimates of subsurface flow were calculated using the U.S. Geological Survey Columbia Plateau regional groundwater flow model. Net flux values range from 25,000 to 27,700 acre-ft per year and indicate that groundwater is moving out of the upper Umatilla River Basin into the lower Umatilla River Basin.Water level changes depend on storage changes within an aquifer, and storage changes depend on the storage properties of the aquifer, as well as recharge to or discharge from the aquifer. Groundwater level data in the upper Umatilla River Basin are mostly available from wells in Columbia River basalt units, which indicate areas of long-term water level declines in the Grande Ronde basalt unit near Pendleton and Athena, Oregon. Groundwater levels in the Wanapum basalt unit do not show long-term declines in the upper Umatilla River Basin. Because of pumping, some areas in the upper Umatilla River Basin have shown a decrease, or reversal, in the upward vertical head gradient.Key data needs are improvement of the spatial and temporal distribution of water-level data collection and continued monitoring of streamflow gaging sites. Additionally, refinement of recharge estimates would enhance understanding of the processes that provide the groundwater resources in the upper Umatilla River Basin.

Spatiotemporal Assessment of Groundwater Resources in the South Platte Basin, Colorado

NASA Astrophysics Data System (ADS)

Ruybal, C. J.; McCray, J. E.; Hogue, T. S.

2015-12-01

The South Platte Basin is one of the most economically diverse and fastest growing basins in Colorado. Strong competition for water resources in an over-appropriated system brings challenges to meeting future water demands. Balancing the conjunctive use of surface water and groundwater from the South Platte alluvial aquifer and the Denver Basin aquifer system is critical for meeting future demands. Over the past decade, energy development in the basin has added to the competition for water resources, highlighting the need to advance our understanding of the availability and sustainability of groundwater resources. Current work includes evaluating groundwater storage changes and recharge regimes throughout the South Platte Basin under competing uses, e.g. agriculture, oil and gas, urban, recreational, and environmental. The Gravity Recovery and Climate Experiment satellites in conjunction with existing groundwater data is used to evaluate spatiotemporal variability in groundwater storage and identify areas of high water stress. Spatiotemporal data will also be utilized to develop a high resolution groundwater model of the region. Results will ultimately help stakeholders in the South Platte Basin better understand groundwater resource challenges and contribute to Colorado's strategic future water planning.

Effects of stormwater infiltration on quality of groundwater beneath retention and detention basins

USGS Publications Warehouse

Fischer, D.; Charles, E.G.; Baehr, A.L.

2003-01-01

Infiltration of storm water through detention and retention basins may increase the risk of groundwater contamination, especially in areas where the soil is sandy and the water table shallow, and contaminants may not have a chance to degrade or sorb onto soil particles before reaching the saturated zone. Groundwater from 16 monitoring wells installed in basins in southern New Jersey was compared to the quality of shallow groundwater from 30 wells in areas of new-urban land use. Basin groundwater contained much lower levels of dissolved oxygen, which affected concentrations of major ions. Patterns of volatile organic compound and pesticide occurrence in basin groundwater reflected the land use in the drainage areas served by the basins, and differed from patterns in background samples, exhibiting a greater occurrence of petroleum hydrocarbons and certain pesticides. Dilution effects and volatilization likely decrease the concentration and detection frequency of certain compounds commonly found in background groundwater. High recharge rates in storm water basins may cause loading factors to be substantial even when constituent concentrations in infiltrating storm water are relatively low.

Groundwater quality in the Indian Wells Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Indian Wells Valley is one of the study areas being evaluated. The Indian Wells study area is approximately 600 square miles (1,554 square kilometers) and includes the Indian Wells Valley groundwater basin (California Department of Water Resources, 2003). Indian Wells Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lake beds in the lower parts of the valley. Land use in the study area is approximately 97.0 percent (%) natural, 0.4% agricultural, and 2.6% urban. The primary natural land cover is shrubland. The largest urban area is the city of Ridgecrest (2010 population of 28,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from the Sierra Nevada to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and direct infiltration from irrigation and septic systems. The primary sources of discharge are pumping wells and evapotranspiration near the dry lakebeds. The primary aquifers in the Indian Wells study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Indian Wells Valley are completed to depths between 240 and 800 feet (73 to 244 meters), consist of solid casing from the land surface to a depth of 180 to 260 feet (55 to 79 meters), and are screened or perforated below the solid casing.

Groundwater sustainability and groundwater/surface-water interaction in arid Dunhuang Basin, northwest China

NASA Astrophysics Data System (ADS)

Lin, Jingjing; Ma, Rui; Hu, Yalu; Sun, Ziyong; Wang, Yanxin; McCarter, Colin P. R.

2018-03-01

The Dunhuang Basin, a typical inland basin in northwestern China, suffers a net loss of groundwater and the occasional disappearance of the Crescent Lake. Within this region, the groundwater/surface-water interactions are important for the sustainability of the groundwater resources. A three-dimensional transient groundwater flow model was established and calibrated using MODFLOW 2000, which was used to predict changes to these interactions once a water diversion project is completed. The simulated results indicate that introducing water from outside of the basin into the Shule and Danghe rivers could reverse the negative groundwater balance in the Basin. River-water/groundwater interactions control the groundwater hydrology, where river leakage to the groundwater in the Basin will increase from 3,114 × 104 m3/year in 2017 to 11,875 × 104 m3/year in 2021, and to 17,039 × 104 m3/year in 2036. In comparison, groundwater discharge to the rivers will decrease from 3277 × 104 m3/year in 2017 to 1857 × 104 m3/year in 2021, and to 510 × 104 m3/year by 2036; thus, the hydrology will switch from groundwater discharge to groundwater recharge after implementing the water diversion project. The simulation indicates that the increased net river infiltration due to the water diversion project will raise the water table and then effectively increasing the water level of the Crescent Lake, as the lake level is contiguous with the water table. However, the regional phreatic evaporation will be enhanced, which may intensify soil salinization in the Dunhuang Basin. These results can guide the water allocation scheme for the water diversion project to alleviate groundwater depletion and mitigate geo-environmental problem.

Hydrogeologic framework and occurrence, movement, and chemical characterization of groundwater in Dixie Valley, west-central Nevada

USGS Publications Warehouse

Huntington, Jena M.; Garcia, C. Amanda; Rosen, Michael R.

2014-01-01

Dixie Valley, a primarily undeveloped basin in west-central Nevada, is being considered for groundwater exportation. Proposed pumping would occur from the basin-fill aquifer. In response to proposed exportation, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation and Churchill County, conducted a study to improve the understanding of groundwater resources in Dixie Valley. The objective of this report is to characterize the hydrogeologic framework, the occurrence and movement of groundwater, the general water quality of the basin-fill aquifer, and the potential mixing between basin-fill and geothermal aquifers in Dixie Valley. Various types of geologic, hydrologic, and geochemical data were compiled from previous studies and collected in support of this study. Hydrogeologic units in Dixie Valley were defined to characterize rocks and sediments with similar lithologies and hydraulic properties influencing groundwater flow. Hydraulic properties of the basin-fill deposits were characterized by transmissivity estimated from aquifer tests and specific-capacity tests. Groundwater-level measurements and hydrogeologic-unit data were combined to create a potentiometric surface map and to characterize groundwater occurrence and movement. Subsurface inflow from adjacent valleys into Dixie Valley through the basin-fill aquifer was evaluated using hydraulic gradients and Darcy flux computations. The chemical signature and groundwater quality of the Dixie Valley basin-fill aquifer, and potential mixing between basin-fill and geothermal aquifers, were evaluated using chemical data collected from wells and springs during the current study and from previous investigations. Dixie Valley is the terminus of the Dixie Valley flow system, which includes Pleasant, Jersey, Fairview, Stingaree, Cowkick, and Eastgate Valleys. The freshwater aquifer in the study area is composed of unconsolidated basin-fill deposits of Quaternary age. The basin-fill hydrogeologic unit can be several orders of magnitude more transmissive than surrounding and underlying consolidated rocks and Dixie Valley playa deposits. Transmissivity estimates in the basin fill throughout Dixie Valley ranged from 30 to 45,500 feet squared per day; however, a single transmissivity value of 0.1 foot squared per day was estimated for playa deposits. Groundwater generally flows from the mountain range uplands toward the central valley lowlands and eventually discharges near the playa edge. Potentiometric contours east and west of the playa indicate that groundwater is moving eastward from the Stillwater Range and westward from the Clan Alpine Mountains toward the playa. Similarly, groundwater flows from the southern and northern basin boundaries toward the basin center. Subsurface groundwater flow likely enters Dixie Valley from Fairview and Stingaree Valleys in the south and from Jersey and Pleasant Valleys in the north, but groundwater connections through basin-fill deposits were present only across the Fairview and Jersey Valley divides. Annual subsurface inflow from Fairview and Jersey Valleys ranges from 700 to 1,300 acre-feet per year and from 1,800 to 2,300 acre-feet per year, respectively. Groundwater flow between Dixie, Stingaree, and Pleasant Valleys could occur through less transmissive consolidated rocks, but only flow through basin fill was estimated in this study. Groundwater in the playa is distinct from the freshwater, basin-fill aquifer. Groundwater mixing between basin-fill and playa groundwater systems is physically limited by transmissivity contrasts of about four orders of magnitude. Total dissolved solids in playa deposit groundwater are nearly 440 times greater than total dissolved solids in the basin-fill groundwater. These distinctive physical and chemical flow restrictions indicate that groundwater interaction between the basin fill and playa sediments was minimal during this study period (water years 2009–11). Groundwater in Dixie Valley generally can be characterized as a sodium bicarbonate type, with greater proportions of chloride north of the Dixie Valley playa, and greater proportions of sulfate south of the playa. Analysis of major ion water chemistry data sampled during the study period indicates that groundwater north and south of Township 22N differ chemically. Dixie Valley groundwater quality is marginal when compared with national primary and secondary drinking-water standards. Arsenic and fluoride concentrations exceed primary drinking water standards, and total dissolved solids and manganese concentrations exceed secondary drinking water standards in samples collected during this study. High concentrations of boron and tungsten also were observed. Chemical comparisons between basin-fill and geothermal aquifer water indicate that most basin-fill groundwater sampled could contain 10–20 percent geothermal water. Geothermal indicators such as high temperature, lithium, boron, chloride, and silica suggest that mixing occurs in many wells that tap the basin-fill aquifer, particularly on the north, south, and west sides of the basin. Magnesium-lithium geothermometers indicate that some basin-fill aquifer water sampled for the current study likely originates from water that was heated above background mountain-block recharge temperatures (between 3 and 15 degrees Celsius), highlighting the influence of mixing with warm water that was possibly derived from geothermal sources.

An appraisal of the ground-water resources of the lower Susquehanna River basin (An interim report)

USGS Publications Warehouse

Seaber, Paul R.; Hollyday, Este F.

1965-01-01

This report describes the availability, quantity, quality, variability, and cost of development of the ground-water resources in the lower Susquehanna River basin. The report has been prepared for and under specifications established by the Corps of Engineers, U. S. Army, and the Public Health Service, Department of Health, Education, and Welfare.A comprehensive study of the water and related land resources of the Susquehanna River basin was authorized by the Congress of the United States in October 1961, and the task of preparing a report and of coordinating the work being done by others in support of the study was assigned to the Corps of Engineers. The comprehensive study is being conducted by several Federal departments and independent agencies in cooperation with the States of New York, Pennsylvania, and Maryland. The Public Health Service under its authority in the Federal Water Pollution Control Act (P. L. 660) initiated a comprehensive water quality control program for the Chesapeake drainage basin, which includes the Susquehanna River basin.This report is intended to serve the specific needs for ground-water information of both the Corps of Engineers and the Public Health Service, as well as those of the other participating Federal and State agencies.

Regional water table (2000) and ground-water-level changes in the Mojave River and the Morongo ground-water basins, southwestern Mojave Desert, California

USGS Publications Warehouse

Smith, Gregory A.

2003-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems, and consequently, water availability. During 2000, the U. S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 500 wells, providing coverage for most of the basins. Twenty-nine hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 13 short-term (1996 to 2000) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 1998 and 2000 water-levels throughout the basins. In the Mojave River ground-water basins, water-level data showed little change from 1998 to 2000, with the exception of areas along the Mojave River. Water levels along the Mojave River were typically in decline or unchanged, with exceptions near the Hodge and the Lenwood outlet, where water levels rose in response to artificial recharge. The Morongo ground-water basin had virtually no change in water levels from 1998 to 2000, with the exception of Yucca Valley, where artificial recharge and ground-water withdrawal continues.

Fate of human viruses in groundwater recharge systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaughn, J.M.; Landry, E.F.

1980-03-01

The overall objective of this research program was to determine the ability of a well-managed tertiary effluent-recharge system to return virologically acceptable water to the groundwater aquifer. The study assessed the quality of waters renovated by indigenous recharge operations and investigated a number of virus-soil interrelationships. The elucidation of the interactions led to the establishment of basin operating criteria for optimizing virus removal. Raw influents, chlorinated tertiary effluents, and renovated wastewater from the aquifer directly beneath a uniquely designed recharge test basin were assayed on a weekly basis for the presence of human enteroviruses and coliform bacteria. High concentrations ofmore » viruses were routinely isolated from influents but were isolated only on four occasions from tertiary-treated sewage effluents. In spite of the high quality effluent being recharged, viruses were isolated from the groundwater observation well, indicating their ability to penetrate the unsaturated zone. Results of poliovirus seeding experiments carried out in the test basin clearly indicated the need to operate recharge basins at low (e.g. 1 cm/h) infiltration rates in areas having soil types similar to those found at the study site. The method selected for reducing the test basin infiltration rate involved clogging the basin surface with settled organic material from highly turbid effluent. Alternative methods for slowing infiltration rates are discussed in the text.« less

Hydrogeological delineation of groundwater potential zones in the Nabogo basin, Ghana

NASA Astrophysics Data System (ADS)

Nsiah, Emmanuel; Appiah-Adjei, Emmanuel K.; Adjei, Kwaku A.

2018-07-01

This study has delineated groundwater potential zones of the Nabogo basin and categorized the northern and eastern parts, representing about 35% of the total basin, as the most suitable areas for groundwater prospecting. The inhabitants of the basin depend on rainfall and small surface reservoirs for their various water supply needs, which become very scarce and unsustainable in the dry seasons due to the arid to semi-arid conditions of the basin. Thus, groundwater is increasingly being exploited to supplement the water needs of the populace. However, groundwater development in the basin is sometimes hindered by relatively low success rate of boreholes. Therefore, this study was aimed at delineating the groundwater potential zones of the basin to improve on development of the resource for supply to the populace. The methodology used involved acquisition of data on well-distributed boreholes in the basin, computation of transmissivity and specific capacity values from the data, and delineation of potential groundwater zones through integration of borehole yields, regolith thickness, static water level and transmissivity using the weighted overlay technique in a GIS environment. The study results indicate that transmissivity ranges from 0.1 to 535 m2/day with a mean of 19.7 m2/day while the specific capacity ranges from 0.25 to 170.88 m3/day/m with a mean of 13.42 m3/day/m. A groundwater potential map generated categorizes the basin into poor, moderate and high zones covering 652.52 km2, 1250.45 km2 and 1002.23 km2 respectively, which would be very useful for groundwater development.

Groundwater-level trends and implications for sustainable water use in the Kabul Basin, Afghanistan

USGS Publications Warehouse

Mack, Thomas J.; Chornack, Michael P.; Taher, Mohammad R.

2013-01-01

The Kabul Basin, which includes the city of Kabul, Afghanistan, with a population of approximately 4 million, has several Afghan, United States, and international military installations that depend on groundwater resources for a potable water supply. This study examined groundwater levels in the Kabul Basin from 2004 to 2012. Groundwater levels have increased slightly in rural areas of the Kabul Basin as a result of normal precipitation after the drought of the early 2000s. However, groundwater levels have decreased in the city of Kabul due to increasing water use in an area with limited recharge. The rate of groundwater-level decrease in the city is greater for the 2008–2012 period (1.5 meters per year (m/yr) on average) than for the 2004–2008 period (0–0.7 m/yr on average). The analysis, which is corroborated by groundwater-flow modeling and a non-governmental organization decision-support model, identified groundwater-level decreases and associated implications for groundwater sustainability in the city of Kabul. Military installations in the city of Kabul (the Central Kabul subbasin) are likely to face water management challenges resulting from long-term groundwater sustainability concerns, such as the potential drying of shallow water-supply wells. Installations in the northern part of the Kabul Basin may have fewer issues with long-term water sustainability. Groundwater-level monitoring and groundwater-flow simulation can be valuable tools for assessing groundwater management options to improve the sustainability of water resources in the Kabul Basin.

Ground-water geochemistry of the Albuquerque-Belen Basin, central New Mexico

USGS Publications Warehouse

Anderholm, S.K.

1988-01-01

The purpose of this study was to define the areal distribution of different water types, use the distribution to help define the groundwater flow system, and identify processes resulting in differences in groundwater quality in the Albuquerque-Belen Basin in central New Mexico. The chemistry of surface water inflow from adjacent areas, which infiltrates and recharges the aquifer along the basin margin, affects the groundwater quality in the eastern and southeastern areas of the basin. Groundwater in the eastern area generally has a specific conductance less than 400 microsiemens, and calcium and bicarbonate are the dominant ions. Mixing of recharge, groundwater inflow, and surface inflow from adjacent areas, which have different chemical compositions, is the major process affecting groundwater quality in the southwestern, western, and northern areas of the basin. In these areas, there is a large range in specific conductance and distribution of dissolved ions. Groundwater quality in the Rio Grande valley is affected by the infiltration of excess irrigation water. The excess irrigation water generally has a larger specific conductance than other groundwater in the valley, so mixing of these waters results in shallow groundwater generally having larger specific conductance than the deeper groundwater. (USGS)

Calibration parameters used to simulate streamflow from application of the Hydrologic Simulation Program-FORTRAN Model (HSPF) to mountainous basins containing coal mines in West Virginia

USGS Publications Warehouse

Atkins, John T.; Wiley, Jeffrey B.; Paybins, Katherine S.

2005-01-01

This report presents the Hydrologic Simulation Program-FORTRAN Model (HSPF) parameters for eight basins in the coal-mining region of West Virginia. The magnitude and characteristics of model parameters from this study will assist users of HSPF in simulating streamflow at other basins in the coal-mining region of West Virginia. The parameter for nominal capacity of the upper-zone storage, UZSN, increased from south to north. The increase in UZSN with the increase in basin latitude could be due to decreasing slopes, decreasing rockiness of the soils, and increasing soil depths from south to north. A special action was given to the parameter for fraction of ground-water inflow that flows to inactive ground water, DEEPFR. The basis for this special action was related to the seasonal movement of the water table and transpiration from trees. The models were most sensitive to DEEPFR and the parameter for interception storage capacity, CEPSC. The models were also fairly sensitive to the parameter for an index representing the infiltration capacity of the soil, INFILT; the parameter for indicating the behavior of the ground-water recession flow, KVARY; the parameter for the basic ground-water recession rate, AGWRC; the parameter for nominal capacity of the upper zone storage, UZSN; the parameter for the interflow inflow, INTFW; the parameter for the interflow recession constant, IRC; and the parameter for lower zone evapotranspiration, LZETP.

California GAMA Program: Ground-Water Quality Data in the Northern San Joaquin Basin Study Unit, 2005

USGS Publications Warehouse

Bennett, George L.; Belitz, Kenneth; Milby Dawson, Barbara J.

2006-01-01

Growing concern over the closure of public-supply wells because of ground-water contamination has led the State Water Board to establish the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. With the aid of the U.S. Geological Survey (USGS) and Lawrence Livermore National Laboratory, the program goals are to enhance understanding and provide a current assessment of ground-water quality in areas where ground water is an important source of drinking water. The Northern San Joaquin Basin GAMA study unit covers an area of approximately 2,079 square miles (mi2) across four hydrologic study areas in the San Joaquin Valley. The four study areas are the California Department of Water Resources (CADWR) defined Tracy subbasin, the CADWR-defined Eastern San Joaquin subbasin, the CADWR-defined Cosumnes subbasin, and the sedimentologically distinct USGS-defined Uplands study area, which includes portions of both the Cosumnes and Eastern San Joaquin subbasins. Seventy ground-water samples were collected from 64 public-supply, irrigation, domestic, and monitoring wells within the Northern San Joaquin Basin GAMA study unit. Thirty-two of these samples were collected in the Eastern San Joaquin Basin study area, 17 in the Tracy Basin study area, 10 in the Cosumnes Basin study area, and 11 in the Uplands Basin study area. Of the 32 samples collected in the Eastern San Joaquin Basin, 6 were collected using a depth-dependent sampling pump. This pump allows for the collection of samples from discrete depths within the pumping well. Two wells were chosen for depth-dependent sampling and three samples were collected at varying depths within each well. Over 350 water-quality field parameters, chemical constituents, and microbial constituents were analyzed and are reported as concentrations and as detection frequencies, by compound classification as well as for individual constituents, for the Northern San Joaquin Basin study unit as a whole and for each individual study area. Results are presented in a descending order based on detection frequencies (most frequently detected compound listed first), or alphabetically when a detection frequency could not be calculated. Only certain wells were measured for all constituents and water-quality parameters. The results of all of the analyses were compared with U.S. Environmental Protection Agency (USEPA) and California Department of Health Services (CADHS) Maximum Contaminant Levels (MCLs), Secondary Maximum Contaminant Levels (SMCLs), USEPA lifetime health advisories (HA-Ls), the risk-specific dose at a cancer risk level equal to 1 in 100,000 or 10E-5 (RSD5), and CADHS notification levels (NLs). When USEPA and CADHS MCLs are the same, detection levels were compared with the USEPA standard; however, in some cases, the CADHS MCL may be lower. In those cases, the data were compared with the CADHS MCL. Constituents listed by CADHS as 'unregulated chemicals for which monitoring is required' were compared with the CADHS 'detection level for the purposes of reporting' (DLR). DLRs unlike MCLs are not health based standards. Instead, they are levels at which current laboratory detection capabilities allow eighty percent of qualified laboratories to achieve measurements within thirty percent of the true concentration. Twenty-three volatile organic compounds (VOCs) and seven gasoline oxygenates were detected in ground-water samples collected in the Northern San Joaquin Basin GAMA study unit. Additionally, 13 tentatively identified compounds were detected. VOCs were most frequently detected in the Eastern San Joaquin Basin study area and least frequently detected in samples collected in the Cosumnes Basin study area. Dichlorodifluoromethane (CFC-12), a CADHS 'unregulated chemical for which monitoring is required,' was detected in two wells at concentrations greater than the DLR. Trihalomethanes were the most frequently detected class of VOC constituents. Chloroform (trichloromethane) was the m

A synthesis of hydrochemistry with an integrated conceptual model for groundwater in the Hexi Corridor, northwestern China

NASA Astrophysics Data System (ADS)

Wang, Liheng; Dong, Yanhui; Xu, Zhifang

2017-09-01

Although many studies have investigated the recharge and evolution of groundwater in the Hexi Corridor, northwestern (NW) China, they describe individual sites such as Jinchang, Jiuquan, Dunhuang, and others. Considering the similarity of these sites, a systematic review of the entire Hexi Corridor is lacking. This paper compares and summarizes previous studies in the Hexi Corridor to provide a regional perspective of the isotopic characteristics and hydrochemical composition of groundwater. In unconfined aquifers, groundwater is recharged by snow and ice melt water from the Qilian Mountains; local precipitation can be neglected. Therefore, the groundwater belongs to a unique hydrological cycle model in the Hexi Corridor, referred to as snow and ice melt water-groundwater system. The dominant anion species changes from HCO3- in front of the mountains to SO42- in the middle basin and Cl- at the basin boundary along the groundwater flow direction, and TDS increases gradually owing to evaporation. A major hydrogeochemical process is the dissolution of minerals from the aquifer in the recharge area changing to cation exchange reactions in the discharge area. Confined groundwater was recharged mainly in the late Pleistocene and middle Holocene at colder temperatures than those of modern times; thus, it is non-renewable. In addition to dissolution, the hydrochemical composition of confined groundwater is also affected by cation exchange reactions. The hydrogeochemical categories of the confined groundwater are simple and stable. In the present study, a conceptual model is established on the basis of the analyses presented, which has important implications for water resource management in the Hexi Corridor. The inter-basin water allocation program should continue in order to achieve optimal utilization of water resources, but groundwater exploitation should be limited as much as possible. Additionally, on the basis of the review and integration of previous research, the regional groundwater cycle patterns in the Hexi Corridor are illustrated in the present study, and new research questions are identified for future work.

Groundwater-Quality Data in the South Coast Interior Basins Study Unit, 2008: Results from the California GAMA Program

USGS Publications Warehouse

Mathany, Timothy M.; Kulongoski, Justin T.; Ray, Mary C.; Belitz, Kenneth

2009-01-01

Groundwater quality in the approximately 653-square-mile South Coast Interior Basins (SCI) study unit was investigated from August to December 2008, as part of the Priority Basins Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basins Project was developed in response to Legislative mandates (Supplemental Report of the 1999 Budget Act 1999-00 Fiscal Year; and, the Groundwater-Quality Monitoring Act of 2001 [Sections 10780-10782.3 of the California Water Code, Assembly Bill 599]) to assess and monitor the quality of groundwater used as public supply for municipalities in California, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). SCI was the 27th study unit to be sampled as part of the GAMA Priority Basins Project. This study was designed to provide a spatially unbiased assessment of the quality of untreated groundwater used for public water supplies within SCI, and to facilitate statistically consistent comparisons of groundwater quality throughout California. Samples were collected from 54 wells within the three study areas [Livermore, Gilroy, and Cuyama] of SCI in Alameda, Santa Clara, San Benito, Santa Barbara, Ventura, and Kern Counties. Thirty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 19 were selected to aid in evaluation of specific water-quality issues (understanding wells). The groundwater samples were analyzed for organic constituents [volatile organic compounds (VOCs), pesticides and pesticide degradates, polar pesticides and metabolites, and pharmaceutical compounds], constituents of special interest [perchlorate and N-nitrosodimethylamine (NDMA)], naturally occurring inorganic constituents [trace elements, nutrients, major and minor ions, silica, total dissolved solids (TDS), and alkalinity], and radioactive constituents [gross alpha and gross beta radioactivity and radon-222]. Naturally occurring isotopes [stable isotopes of hydrogen, oxygen, and carbon, and activities of tritium and carbon-14] and dissolved noble gases also were measured to help identify the sources and ages of the sampled groundwater. In total, 288 constituents and water-quality indicators (field parameters) were investigated. Three types of quality-control samples (blanks, replicates, and matrix spikes) each were collected at approximately 4-11 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a significant source of bias in the data obtained from the groundwater samples. Differences between replicate samples generally were less than 10 percent relative standard deviation, indicating acceptable analytical reproducibility. Matrix spike recoveries were within the acceptable range (70 to 130 percent) for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, untreated groundwater typically is treated, disinfected, and/or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to untreated groundwater. However, to provide some context for the results, concentrations of constituents measured in the untreated groundwater were compared with regulatory and nonregulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH), and to nonregulatory thresholds established for aesthetic and technical concerns by CDPH. Comparisons between data collected for this study and thresholds for drinking water are for illustrative purposes only, and are not indicative of complia

Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

USGS Publications Warehouse

Stamos, Christina L.; Christensen, Allen H.; Langenheim, Victoria

2017-07-19

The increasing demands on groundwater for water supply in desert areas in California and the western United States have resulted in the need to better understand groundwater sources, availability, and sustainability. This is true for a 650-square-mile area that encompasses the Antelope Valley, El Mirage Valley, and Upper Mojave River Valley groundwater basins, about 50 miles northeast of Los Angeles, California, in the western part of the Mojave Desert. These basins have been adjudicated to ensure that groundwater rights are allocated according to legal judgments. In an effort to assess if the boundary between the Antelope Valley and El Mirage Valley groundwater basins could be better defined, the U.S. Geological Survey began a cooperative study in 2014 with the Mojave Water Agency to better understand the hydrogeology in the area and investigate potential controls on groundwater flow and availability, including basement topography.Recharge is sporadic and primarily from small ephemeral washes and streams that originate in the San Gabriel Mountains to the south; estimates range from about 400 to 1,940 acre-feet per year. Lateral underflow from adjacent basins has been considered minor in previous studies; underflow from the Antelope Valley to the El Mirage Valley groundwater basin has been estimated to be between 100 and 1,900 acre-feet per year. Groundwater discharge is primarily from pumping, mostly by municipal supply wells. Between October 2013 and September 2014, the municipal pumpage in the Antelope Valley and El Mirage Valley groundwater basins was reported to be about 800 and 2,080 acre-feet, respectively.This study was motivated by the results from a previously completed regional gravity study, which suggested a northeast-trending subsurface basement ridge and saddle approximately 3.5 miles west of the boundary between the Antelope Valley and El Mirage Valley groundwater basins that might influence groundwater flow. To better define potential basement structures that could affect groundwater flow between the groundwater basins in the study area, gravity data were collected using more closely spaced measurements in September 2014. Groundwater-level data was gathered and collected from March 2014 through March 2015 to determine depth to water and direction of groundwater flow. The gravity and groundwater-level data showed that the saturated thickness of the alluvium was about 2,000 feet thick to the east and about 130 feet thick above the northward-trending basement ridge near Llano, California. Although it was uncertain whether the basement ridge affects the groundwater system, a potential barrier to groundwater flow could be created if the water table fell below the altitude of the basement ridge, effectively causing the area to the west of the basement ridge to become hydraulically isolated from the area to the east. In addition, the direction of regional-groundwater flow likely will be influenced by future changes in the number and distribution of pumping wells and the thickness of the saturated alluvium from which water is withdrawn. Three-dimensional animations were created to help visualize the relation between the basins’ basement topography and the groundwater system in the area. Further studies that could help to more accurately define the basins and evaluate the groundwater-flow system include exploratory drilling of multi-depth monitoring wells; collection of depth-dependent water-quality samples; and linking together existing, but separate, groundwater-flow models from the Antelope Valley and El Mirage Valley groundwater basins into a single, calibrated groundwater-flow model.

Hydrogeology and ground-water flow in the carbonate rocks of the Little Lehigh Creek basin, Lehigh County, Pennsylvania

USGS Publications Warehouse

Sloto, R.A.; Cecil, L.D.; Senior, L.A.

1991-01-01

The Little Lehigh Creek basin is underlain mainly by a complex assemblage of highly-deformed Cambrian and Ordovician carbonate rocks. The Leithsville Formation, Allentown Dolomite, Beekmantown Group, and Jacksonburg Limestone act as a single hydrologic unit. Ground water moves through fractures and other secondary openings and generally is under water-table conditions. Median annual ground-water discharge (base flow) to Little Lehigh Creek near Allentown (station 01451500) during 1946-86 was 12.97 inches or 82 percent of streamflow. Average annual recharge for 1975-83 was 21.75 inches. Groundwater and surface-water divides do not coincide in the basin. Ground-water underflow from the Little Lehigh Creek basin to the Cedar Creek basin in 1987 was 4 inches per year. A double-mass curve analysis of the relation of cumulative precipitation at Allentown to the flow of Schantz Spring for 1956-84 showed that cessation of quarry pumping and development of ground water for public supply in the Schantz Spring basin did not affect the flow of Schantz Spring. Ground-water flow in the Little Lehigh Creek basin was simulated using a finite-difference, two-dimensional computer model. The geologic units in the modeled area were simulated as a single water-table aquifer. The 134-squaremile area of carbonate rocks between the Lehigh River and Sacony Creek was modeled to include the natural hydrologic boundaries of the ground-water-flow system. The ground-water-flow model was calibrated under steady-state conditions using 1975-83 average recharge, evapotranspiration, and pumping rates. Each geologic unit was assigned a different hydraulic conductivity. Initial aquifer hydraulic conductivity was estimated from specific-capacity data. The average (1975-83) water budget for the Little Lehigh Creek basin was simulated. The simulated base flow from the carbonate rocks of the Little Lehigh Creek basin above gaging station 01451500 is 11.85 inches per year. The simulated ground-water underflow from the Little Lehigh Creek basin to the Cedar Creek basin is 4.04 inches per year. For steady-state calibration, the root-mean-squared difference between observed and simulated heads was 21.19 feet. The effects of increased ground-water development on base flow and underflow out of the Little Lehigh Creek basin for average and drought conditions were simulated by locating a hypothetical well field in different parts of the basin. Steady-state simulations were used to represent equilibrium conditions, which would be the maximum expected long-term effect. Increased ground-water development was simulated as hypothetical well fields pumping at the rate of 15, 25, and 45 million gallons per day in addition to existing ground-water withdrawals. Four hypothetical well fields were located near and away from Little Lehigh Creek in upstream and downstream areas. The effects of pumping a well field in different parts of the Little Lehigh Creek basin were compared. Pumping a well field located near the headwaters of Little Lehigh Creek and away from the stream would have greatest effect on inducing underflow from the Sacony Greek basin and the least effect on reducing base flow and underflow to the Ceda^r Creek basin. Pumping a well field located near the headwaters of Little Leh|igh Creek near the stream would have less impact on inducing underflow from|the Sacony Creek basin and a greater impact on reducing the base flow of Little Lehigh Creek because more of the pumpage would come from diverted base flow. Pumping a well field located in the downstream area of the Little Lehigh Creek basin away from the stream would have the greatest effect on the underflow to the Cedar Creek basin. Pumping a well field located in the downstream area of the Little Lehigh Creek basin near the stream would have the greatest effect on reducing the base flow of Little Lehigh Cteek. Model simulations show that groundwater withdrawals do not cause a proportional reduction in base flow. Under average conditions, ground-water withdrawals are equal to 48 to 70 percent of simulated base-flow reductions; under drought conditions, ground-water withdrawals are equal to 35 to 73 percent of simulated base-flow reductions. The hydraulic effects of pumping largely depend on well location. In the Little Lehigh basin, surface-water and ground-water divides do not coincide, and ground-water development, especially near surface-water divides, can cause ground-water divides to shift and induce ground-water underflow from adjacent basins. Large-scale ground-water pumping in a basin may not produce expected reductions of base flow in that basin because of shifts in the ground-water divide; however, such shifts can reduce base flow in adjacent surface-water basins. 

Groundwater quality in the Owens Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Owens Valley are completed to depths between 210 and 480 feet (64 to 146 meters), consist of solid casing from the land surface to a depth of 50 to 80 feet (15 to 24 meters), and are screened or perforated below the solid casing.

Outlier detection for groundwater data in France

NASA Astrophysics Data System (ADS)

Valmy, Larissa; de Fouquet, Chantal; Bourgine, Bernard

2014-05-01

Quality and quantity water in France are increasingly observed since the 70s. Moreover, in 2000, the EU Water Framework Directive established a framework for community action in the water policy field for the protection of inland surface waters (rivers and lakes), transitional waters (estuaries), coastal waters and groundwater. It will ensure that all aquatic ecosystems and, with regard to their water needs, terrestrial ecosystems and wetlands meet 'good status' by 2015. The Directive requires Member States to establish river basin districts and for each of these a river basin management plan. In France, monitoring programs for the water status were implemented in each basin since 2007. The data collected through these programs feed into an information system which contributes to check the compliance of water environmental legislation implementation, assess the status of water guide management actions (programs of measures) and evaluate their effectiveness, and inform the public. Our work consists in study quality and quantity groundwater data for some basins in France. We propose a specific mathematical approach in order to detect outliers and study trends in time series. In statistic, an outlier is an observation that lies outside the overall pattern of a distribution. Usually, the presence of an outlier indicates some sort of problem, thus, it is important to detect it in order to know the cause. In fact, techniques for temporal data analysis have been developed for several decades in parallel with geostatistical methods. However compared to standard statistical methods, geostatistical analysis allows incomplete or irregular time series analysis. Otherwise, tests carried out by the BRGM showed the potential contribution of geostatistical methods for characterization of environmental data time series. Our approach is to exploit this potential through the development of specific algorithms, tests and validation of methods. We will introduce and explain our method and approach by considering the Loire Bretagne basin case.

Assessing the influence of climate change and inter-basin water diversion on Haihe River basin, eastern China: a coupled model approach

NASA Astrophysics Data System (ADS)

Xia, Jun; Wang, Qiang; Zhang, Xiang; Wang, Rui; She, Dunxian

2018-04-01

The modeling of changes in surface water and groundwater in the areas of inter-basin water diversion projects is quite difficult because surface water and groundwater models are run separately most of the time and the lack of sufficient data limits the application of complex surface-water/groundwater coupling models based on physical laws, especially for developing countries. In this study, a distributed surface-water and groundwater coupling model, named the distributed time variant gain model-groundwater model (DTVGM-GWM), was used to assess the influence of climate change and inter-basin water diversion on a watershed hydrological cycle. The DTVGM-GWM model can reflect the interaction processes of surface water and groundwater at basin scale. The model was applied to the Haihe River Basin (HRB) in eastern China. The possible influences of climate change and the South-to-North Water Diversion Project (SNWDP) on surface water and groundwater in the HRB were analyzed under various scenarios. The results showed that the newly constructed model DTVGM-GWM can reasonably simulate the surface and river runoff, and describe the spatiotemporal distribution characteristics of groundwater level, groundwater storage and phreatic recharge. The prediction results under different scenarios showed a decline in annual groundwater exploitation and also runoff in the HRB, while an increase of groundwater storage and groundwater level after the SNWDP's operation. Additionally, as the project also addresses future scenarios, a slight increase is predicted in the actual evapotranspiration, soil water content and phreatic recharge. This study provides valuable insights for developing sustainable groundwater management options for the HRB.

Surface-water hydrology and runoff simulations for three basins in Pierce County, Washington

USGS Publications Warehouse

Mastin, M.C.

1996-01-01

The surface-water hydrology in Clear, Clarks, and Clover Creek Basins in central Pierce County, Washington, is described with a conceptual model of the runoff processes and then simulated with the Hydrological Simulation Program-FORTRAN (HSPF), a continuous, deterministic hydrologic model. The study area is currently undergoing a rapid conversion of rural, undeveloped land to urban and suburban land that often changes the flow characteristics of the streams that drain these lands. The complex interactions of land cover, climate, soils, topography, channel characteristics, and ground- water flow patterns determine the surface-water hydrology of the study area and require a complex numerical model to assess the impact of urbanization on streamflows. The U.S. Geological Survey completed this investigation in cooperation with the Storm Drainage and Surface Water Management Utility within the Pierce County Department of Public Works to describe the important rainfall-runoff processes within the study area and to develop a simulation model to be used as a tool to predict changes in runoff characteristics resulting from changes in land use. The conceptual model, a qualitative representation of the study basins, links the physical characteristics to the runoff process of the study basins. The model incorporates 11 generalizations identified by the investigation, eight of which describe runoff from hillslopes, and three that account for the effects of channel characteristics and ground-water flow patterns on runoff. Stream discharge was measured at 28 sites and precipitation was measured at six sites for 3 years in two overlapping phases during the period of October 1989 through September 1992 to calibrate and validate the simulation model. Comparison of rainfall data from October 1989 through September 1992 shows the data-collection period beginning with 2 wet water years followed by the relatively dry 1992 water year. Runoff was simulated with two basin models-the Clover Creek Basin model and the Clear-Clarks Basin model-by incorporating the generalizations of the conceptual model into the construction of two HSPF numerical models. Initially, the process-related parameters for runoff from glacial-till hillslopes were calibrated with numerical models for three catchment sites and one headwater basin where streamflows were continuously measured and little or no influence from ground water, channel storage, or channel losses affected runoff. At one of the catchments soil moisture was monitored and compared with simulated soil moisture. The values for these parameters were used in the basin models. Basin models were calibrated to the first year of observed streamflow data by adjusting other parameters in the numerical model that simulated channel losses, simulated channel storage in a few of the reaches in the headwaters and in the floodplain of the main stem of Clover Creek, and simulated volume and outflow of the ground-water reservoir representing the regional ground-water aquifers. The models were run for a second year without any adjustments, and simulated results were compared with observed results as a measure of validation of the models. The investigation showed the importance of defining the ground-water flow boundaries and demonstrated a simple method of simulating the influence of the regional ground-water aquifer on streamflows. In the Clover Creek Basin model, ground-water flow boundaries were used to define subbasins containing mostly glacial outwash soils and not containing any surface drainage channels. In the Clear-Clarks Basin model, ground-water flow boundaries outlined a recharge area outside the surface-water boundaries of the basin that was incorporated into the model in order to provide sufficient water to balance simulated ground-water outflows to the creeks. A simulated ground-water reservoir used to represent regional ground-water flow processes successfully provided the proper water balance of inflows and outfl

Groundwater and surface water interaction in a basin surrounded by steep mountains, central Japan

NASA Astrophysics Data System (ADS)

Ikeda, Koichi; Tsujimura, Maki; Kaeriyama, Toshiaki; Nakano, Takanori

2015-04-01

Mountainous headwaters and lower stream alluvial plains are important as water recharge and discharge areas from the view point of groundwater flow system. Especially, groundwater and surface water interaction is one of the most important processes to understand the total groundwater flow system from the mountain to the alluvial plain. We performed tracer approach and hydrometric investigations in a basin with an area 948 square km surrounded by steep mountains with an altitude from 250m to 2060m, collected 258 groundwater samples and 112 surface water samples along four streams flowing in the basin. Also, Stable isotopes ratios of oxygen-18 (18O) and deuterium (D) and strontium (Sr) were determined on all water samples. The 18O and D show distinctive values for each sub-basin affected by different average recharge altitudes among four sub-basins. Also, Sr isotope ratio shows the same trend as 18O and D affected by different geological covers in the recharge areas among four sub-basins. The 18O, D and Sr isotope values of groundwater along some rivers in the middle stream region of the basin show close values as the rivers, and suggesting that direct recharge from the river to the shallow groundwater is predominant in that region. Also, a decreasing trend of discharge rate of the stream along the flow supports this idea of the groundwater and surface water interaction in the basin.

Geohydrology, water quality, and estimation of ground-water recharge in San Francisco, California, 1987-92

USGS Publications Warehouse

Phillips, S.P.; Hamlin, S.N.; Yates, E.B.

1993-01-01

The city of San Francisco is considering further development of local groundwater resources as a supplemental source of water for potable or nonpotable use. By the year 2010, further water demand is projected to exceed the delivery capacity of the existing supply system, which is fed by surface-water sources; thus supplies are susceptible to drought conditions and damage to conveyance lines by earthquakes. The primary purpose of this study is to describe local geohydrology and water quality and to estimate groundwater recharge in the area of the city of San Francisco. Seven groundwater basins were identified in San Francisco on the basis of geologic and geophysical data. Basins on the east side of the city are relatively thin and contain a greater percentage of fine-grained sediments than those on the west side. The relatively small capacity of the basins and greater potential for contamination from sewer sources may limit the potential for groundwater development on the east side. Basins on the west side of the city have a relatively large capacity and low density sewer network. Water-level data indicate that the southern part of the largest basin on the west side of the city (Westside basin) probably cannot accommodate additional groundwater development without adversely affecting water levels and water quality in Lake Merced; however, the remainder of the basin, which is largely undeveloped, could be developed further. A hydrologic routing model was developed for estimating groundwater recharge throughout San Francisco. The model takes into account climatic factors, land and water use, irrigation, leakage from underground pipes, rainfall runoff, evapotranspiration, and other factors associated with an urban environment. Results indicate that area recharge rates for water years 1987-88 for the 7 groundwater basins ranged from 0.32 to 0.78 feet per year. Recharge for the Westside basin was estimated at 0.51 feet per year. Average annual groundwater recharge represents the maximum annual long-term yield of the basin. Attainable yield may be less than the volume of groundwater recharge because interception of all discharge from the basin may not be feasible without inducing seawater intrusion or causing other undesirable effects.

Evolutionary analysis of groundwater flow: Application of multivariate statistical analysis to hydrochemical data in the Densu Basin, Ghana

NASA Astrophysics Data System (ADS)

Yidana, Sandow Mark; Bawoyobie, Patrick; Sakyi, Patrick; Fynn, Obed Fiifi

2018-02-01

An evolutionary trend has been postulated through the analysis of hydrochemical data of a crystalline rock aquifer system in the Densu Basin, Southern Ghana. Hydrochemcial data from 63 groundwater samples, taken from two main groundwater outlets (Boreholes and hand dug wells) were used to postulate an evolutionary theory for the basin. Sequential factor and hierarchical cluster analysis were used to disintegrate the data into three factors and five clusters (spatial associations). These were used to characterize the controls on groundwater hydrochemistry and its evolution in the terrain. The dissolution of soluble salts and cation exchange processes are the dominant processes controlling groundwater hydrochemistry in the terrain. The trend of evolution of this set of processes follows the pattern of groundwater flow predicted by a calibrated transient groundwater model in the area. The data suggest that anthropogenic activities represent the second most important process in the hydrochemistry. Silicate mineral weathering is the third most important set of processes. Groundwater associations resulting from Q-mode hierarchical cluster analysis indicate an evolutionary pattern consistent with the general groundwater flow pattern in the basin. These key findings are at variance with results of previous investigations and indicate that when carefully done, groundwater hydrochemical data can be very useful for conceptualizing groundwater flow in basins.

Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America

NASA Astrophysics Data System (ADS)

Neff, K.; Meixner, T.; De La Cruz, L.

2014-12-01

Groundwater recharge is the primary source of aquifer replenishment, an important source of freshwater for human consumption and riparian area sustainability in semi-arid regions. It is critical to understand the current groundwater recharge regimes in groundwater basins throughout the Western U.S. and how those regimes might shift in the face of climate change, land use change and management manipulations that impact the availability and composition of groundwater resources. Watersheds in the Basin and Range Province are characterized by a variable precipitation regime of wet winters, and variable summer precipitation. The horst-graben structure of these basins lends itself to orographic and continental precipitation effects that make mountain block and mountain front recharge critical components of annual recharge. The current assumption is that the relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation dominating in the northern parts of the region, and summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon extends its influence. To test this hypothesis, stable water isotope data of groundwater and precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to characterize and compare groundwater recharge regimes throughout the region. Preliminary stable water isotope results from the southernmost Rio San Miguel Basin in Sonora, Mexico indicate that groundwater is composed of 64%±14% summer monsoon precipitation, in contrast to more northern basins where winter precipitation is the source of 79-90% of basin groundwater.

Spatial and temporal constraints on regional-scale groundwater flow in the Pampa del Tamarugal Basin, Atacama Desert, Chile

NASA Astrophysics Data System (ADS)

Jayne, Richard S.; Pollyea, Ryan M.; Dodd, Justin P.; Olson, Elizabeth J.; Swanson, Susan K.

2016-12-01

Aquifers within the Pampa del Tamarugal Basin (Atacama Desert, northern Chile) are the sole source of water for the coastal city of Iquique and the economically important mining industry. Despite this, the regional groundwater system remains poorly understood. Although it is widely accepted that aquifer recharge originates as precipitation in the Altiplano and Andean Cordillera to the east, there remains debate on whether recharge is driven primarily by near-surface groundwater flow in response to periodic flood events or by basal groundwater flux through deep-seated basin fractures. In addressing this debate, the present study quantifies spatial and temporal variability in regional-scale groundwater flow paths at 20.5°S latitude by combining a two-dimensional model of groundwater and heat flow with field observations and δ18O isotope values in surface water and groundwater. Results suggest that both previously proposed aquifer recharge mechanisms are likely influencing aquifers within the Pampa del Tamarugal Basin; however, each mechanism is operating on different spatial and temporal scales. Storm-driven flood events in the Altiplano readily transmit groundwater to the eastern Pampa del Tamarugal Basin through near-surface groundwater flow on short time scales, e.g., 100-101 years, but these effects are likely isolated to aquifers in the eastern third of the basin. In addition, this study illustrates a physical mechanism for groundwater originating in the eastern highlands to recharge aquifers and salars in the western Pampa del Tamarugal Basin over timescales of 104-105 years.

Recharge Net Metering to Incentivize Sustainable Groundwater Management

NASA Astrophysics Data System (ADS)

Fisher, A. T.; Coburn, C.; Kiparsky, M.; Lockwood, B. S.; Bannister, M.; Camara, K.; Lozano, S.

2016-12-01

Stormwater runoff has often been viewed as a nuisance rather than a resource, but with passage of the Sustainable Groundwater Management Act (2014), many basins in California are taking a fresh look at options to enhance groundwater supplies with excess winter flows. In some basins, stormwater can be used for managed aquifer recharge (MAR), routing surface water to enhance groundwater resources. As with many public infrastructure programs, financing for stormwater-MAR projects can be a challenge, and there is a need for incentives that will engage stakeholders and offset operation and maintenance costs. The Pajaro Valley Water Management Agency (PVWMA), in central costal California, recently launched California's first Recharge Net Metering (ReNeM) program. MAR projects that are part of the ReNeM program are intended to generate ≥100 ac-ft/yr of infiltration benefit during a normal water year. A team of university and Resource Conservation District partners will collaborate to identify and assess potential project sites, screening for hydrologic conditions, expected runoff, ease and cost of project construction, and ability to measure benefits to water supply and quality. The team will also collect data and samples to measure the performance of each operating project. Groundwater wells within the PVWMA's service area are metered, and agency customers pay an augmentation fee for each unit of groundwater pumped. ReNeM projects will earn rebates of augmentation fees based on the amount of water infiltrated, with rebates calculated using a formula that accounts for uncertainties in the fate of infiltrated water, and inefficiencies in recovery. The pilot ReNeM program seeks to contribute 1000 ac-ft/yr of infiltration benefit by the end of the initial five-year operating period. ReNeM offers incentives that are distinct from those derived from traditional groundwater banking, and thus offers the potential for an innovative addition to the portfolio of options for sustaining and improving groundwater resources. Technical, economic, and institutional uncertainties remain, and ongoing research is addressing the potential for ReNeM in the Pajaro Valley and elsewhere.

Considerations for use of the RORA program to estimate ground-water recharge from streamflow records

USGS Publications Warehouse

Rutledge, A.T.

2000-01-01

The RORA program can be used to estimate ground-water recharge in a basin from analysis of a streamflow record. The program can be appropriate for use if the ground-water flow system is characterized by diffuse areal recharge to the water table and discharge to a stream. The use of the program requires an estimate of a recession index, which is the time required for ground-water discharge to recede by one log cycle after recession becomes linear or near-linear on the semilog hydrograph. Although considerable uncertainty is inherent in the recession index, the results of the RORA program may not be sensitive to this variable. Testing shows that the program can yield consistent estimates under conditions that include leakage to or from deeper aquifers and ground-water evapotranspiration. These tests indicate that RORA estimates the net recharge, which is recharge to the water table minus leakage to a deeper aquifer, or recharge minus ground-water evapotranspiration. Before the program begins making calculations it designates days that fit a requirement of antecedent recession, and these days are used in calculations. The program user might increase the antecedent-recession requirement above its default value to reduce the influence of errors that are caused by direct-surface runoff, but other errors can result from the reduction in the number of peaks detected. To obtain an understanding of flow systems, results from the RORA program might be used in conjunction with other methods such as analysis of ground-water levels, estimates of ground-water discharge from other forms of hydrograph separation, and low-flow variables. Relations among variables may be complex for a variety of reasons; for example, there may not be a unique relation between ground-water level and ground-water discharge, ground-water recharge and discharge are not synchronous, and low-flow variables can be related to other factors such as the recession index.

Distribution of oil and natural-gas wells in relation to ground-water flow systems in the Great Basin region of Nevada and Utah, and adjacent states

USGS Publications Warehouse

Schaefer, Donald H.

1996-01-01

This map publication is one of several in a series concerning various aspects of the ground-water hydrology of the Great Basin in Nevada, Utah, and adjacent States.  One report in the series describes the hydrogeologic framework of the Great Basin (Plume and Carlton, 1988).  Another shows the ground-water levels for the aquifer systems of the Great Basin (Thomas and others, 1986).  A third report in the series describes the regional ground-water flow patterns in the Great Basin (Harrill and others, 1988).

Nitrate Contamination in the groundwater of the Lake Acıgöl Basin, SW Turkey

NASA Astrophysics Data System (ADS)

Karaman, Muhittin; Budakoǧlu, Murat; Taşdelen, Suat

2017-04-01

The lacustrine Acıgöl basin, formed as an extensional half-graben, hosts various bodies of water, such as cold-hot springs, lakes, streams, and wells. The hydrologically closed basin contains a hypersaline lake (Lake Acıgöl) located in the southern part of the basin. The brackish springs and deep waters discharged along the Acıgöl fault zone in the southern part of the basin feed the hypersaline lake. Groundwater is used as drinking, irrigation, and domestic water in the closed Acıgöl Basin. Groundwater flows into the hypersaline lake from the highland. The Acıgöl basin hosts large plains (Hambat, Başmakçı, and Evciler). Waters in agricultural areas contain high amounts of nitrate; groundwater samples in agricultural areas contain nitrate levels higher than 10 mg/L. Nitrate concentrations in the groundwater samples varied from 0 to 487 mg/L (n=165); 25.4 % of the groundwater samples from the basin had nitrate concentrations above 10 mg/L (the WHO drinking guideline) and 52.2% of the groundwater samples from the basin had nitrate concentrations above 3.0 mg/L, and these high values were regarded as the result of human activity. The highest nitrate values were measured in the Hambat plain (480 and 100 mg/L) and Yirce Pinari spring (447 mg/L), which discharges along the Acıgöl fault zone in the southern part of the basin. The average multi-temporal nitrate concentration of the Yirce Pınarı spring was 3.3 mg/L. Extreme nitrate values were measured in the Yirce Pınarı spring during periods when sheep wool was washed (human activity). The lowest nitrate concentrations were observed in some springs that discharged along the Acıgöl fault zone in the southern part of the basin. Nitrate was not detected in deep groundwater discharged along the Acıgöl fault zone. Nitrate concentrations in deep groundwater and some springs discharged along the Acıgöl fault zone and those feeding the hypersaline lake were significantly affected by redox conditions. Nitrate in these reducing waters was transformed into ammonium. Nitrate concentrations in the Acıgöl Basin were enriched in groundwater beneath agricultural areas and this affected redox conditions. The main source of nitrate contamination was agricultural fertilizers. Elevated nitrate concentrations in groundwater, especially in agricultural areas of the Acigol Basin, can cause public health problems and environmental pollution.

Hydrologic analysis of two headwater lake basins of differing lake pH in the west-central Adirondack Mountains of New York

USGS Publications Warehouse

Murdoch, Peter S.; Peters, N.E.; Newton, R.M.

1987-01-01

Hydrologic analysis of two headwater lake basins in the Adirondack Mountains, New York, during 1980-81 indicates that the degree of neutralization of acid precipitation is controlled by the groundwater contribution to the lake. According to flow-duration analyses, daily mean outflow/unit area from the neutral lake (Panther Lake, pH 5-7) was more sustained and contained a higher percentage of groundwater than that of the acidic lake (Woods Lake, pH 4-5). Outflow recession rates and maximum base-flow rates, derived from individual recession curves, were 3.9 times and 1.5 times greater, respectively, in the neutral-lake basin than in the acidic-lake basin. Groundwater contribution to lake outflow was also calculated from a lake-water budget; the groundwater contribution to the neutral lake was about 10 times greater than that to the acidic lake. Thick sandy till forms the groundwater reservoir and the major recharge area in both basins but covers 8.5 times more area in the neutral-lake basin than in the acidic-lake basin. More groundwater storage within the neutral basin provides longer contact time with neutralizing minerals and more groundwater discharge. As a result, the neutral lake has relatively high pH and alkalinity, and more net cation transport. (USGS)

The origin of groundwater composition in the Pampeano Aquifer underlying the Del Azul Creek basin, Argentina.

PubMed

Zabala, M E; Manzano, M; Vives, L

2015-06-15

The Pampean plain is the most productive region in Argentina. The Pampeano Aquifer beneath the Pampean plain is used mostly for drinking water. The study area is the sector of the Pampeano Aquifer underlying the Del Azul Creek basin, in Buenos Aires province. The main objective is to characterize the chemical and isotopic compositions of groundwater and their origin on a regional scale. The methodology used involved the identification and characterization of potential sources of solutes, the study of rain water and groundwater chemical and isotopic characteristics to deduce processes, the development of a hydrogeochemical conceptual model, and its validation by hydrogeochemical modelling with PHREEQC. Groundwater samples come mostly from a two-depth monitoring network of the "Dr. Eduardo J. Usunoff" Large Plains Hydrology Institute (IHLLA). Groundwater salinity increases from SW to NE, where groundwater is saline. In the upper basin groundwater is of the HCO3-Ca type, in the middle basin it is HCO3-Na, and in the lower basin it is ClSO4-NaCa and Cl-Na. The main processes incorporating solutes to groundwater during recharge in the upper basin are rain water evaporation, dissolution of CO2, calcite, dolomite, silica, and anorthite; cationic exchange with Na release and Ca and Mg uptake, and clay precipitation. The main processes modifying groundwater chemistry along horizontal flow at 30 m depth from the upper to the lower basin are cationic exchange, dissolution of silica and anorthite, and clay precipitation. The origin of salinity in the middle and lower basin is secular evaporation in a naturally endorheic area. In the upper and middle basins there is agricultural pollution. In the lower basin the main pollution source is human liquid and solid wastes. Vertical infiltration through the boreholes annular space during the yearly flooding stages is probably the pollution mechanism of the samples at 30 m depth. Copyright © 2015 Elsevier B.V. All rights reserved.

Annual summary of ground-water conditions in Arizona, spring 1982 to spring 1983

USGS Publications Warehouse

,

1984-01-01

The withdrawal of ground water was slightly less than 4.2 million acre-feet in Arizona in 1982, which is about 1.2 million acre-feet less than the amount withdrawn in 1981. Most of the decrease in 1982 was in the amount of ground water used for irrigation in the Basin and Range lowlands province. Through 1982, slightly more than 193 million acre-feet of ground water had been withdrawn from the ground-water reservoirs in Arizona. The report contains three small-scale maps that show ground-water pumpage by areas, the status of the ground-water inventory and observation-well program, and the ground-water quality sampling program. The main map, which is at a scale of 1:500,000, shows potential well production, depth to water in selected wells in spring 1983, and change in water level in selected wells from 1978 to 1983. A brief text summarizes the current ground-water conditions in the State. (USGS)

The origin of groundwater in Zhangye Basin, northwestern China, using isotopic signature

NASA Astrophysics Data System (ADS)

Chen, Jiansheng; Liu, Xiaoyan; Sun, Xiaoxu; Su, Zhiguo; Yong, Bin

2014-03-01

Zhangye Basin, in arid northwestern China, has recently been repeatedly flooded by rising groundwater. Isotope signatures of sampled waters gained insight into the recharge source of the groundwater. The summer Heihe River water and most of the spring water in Zhangye and Yongchang basins plotted above the global meteoric water line (GMWL) on the δ18O-δD plot. The spring water had R/Ra ratio >1, low TDS and high tritium, which indicates origin from Qilian Mountain glacier meltwater. The groundwater of Qilian Mountains was transported to the Hexi Corridor (in which Zhangye Basin is located) through underground fault zones. Additionally, some of the groundwater in the alluvial plain, and all spring water surrounding Zhangye Basin, plotted below the GMWL on the δ18O-δD plot along an evaporation line, and had R/Ra ratio < 1 and high TDS. It is proposed that the Tibetan rivers or lakes source the Hexi Corridor groundwater through either the NE-trending or NW-trending buried fault zones. The isotopic signatures presented as part of this study rule out the conventional viewpoint that groundwater of the Zhangye Basin was recharged by local precipitation and infiltration of Heihe River water on the alluvial plain.

Hydrogeologic map of the Islamic Republic of Mauritania (phase V, deliverable 56), Synthesis of hydrologic data (phase V, deliverable 57), and chemical hydrologic map of the Islamic Republic of Mauritania (added value): Chapter C in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

USGS Publications Warehouse

Friedel, Michael J.; Finn, Carol A.; Horton, John D.

2015-01-01

A hydrogeologic study was conducted to support mineral-resource assessment activities in Mauritania, Africa. Airborne magnetic depth estimates reveal two primary groundwater basins: the porous coastal Continental Terminal Basin (fill deposits); and the interior, fractured interior Taoudeni Basin. In the Continental Terminal Basin, there is uniform vertical recharge and localized discharge that is coincident with groundwater pumping at Nouakchott. This pumping center induces eastward flow of groundwater from the Atlantic Ocean resulting in a salinity gradient that diminishes quality over 100 km. Groundwater also flows southward into the basin from Western Sahara. By contrast, an interbasin exchange occurs as fresh groundwater flows westward from the Taoudeni Basin. In the Taoudeni Basin, zones of local recharge occur in three areas: northwest at the edge of the Rgueïbat Shield; at the city of Tidjikja; and near the center of the basin. Groundwater also flows across international boundaries: northward into Western Sahara and westward into Mali. At the southern country boundary, the Senegal River serves as both a source and sink of fresh groundwater to the Continental Terminal and Taoudeni basins. Using a geographical information system, thirteen hydrogeologic units are identified based on lateral extent and distinct hydraulic properties for future groundwater model development. Combining this information with drilling productivity, groundwaterquality, and geophysical interpretations (fracturing and absence of subsurface dikes) three potential water-resource development targets were identified: sedimentary rocks of the Jurassic, Cretaceous, and Quaternary Periods; sedimentary rocks of Cambrian and Ordovician Periods; and sedimentary rocks of Neoproterozoic age.

Hydrochemistry of surface water and groundwater in the shale bedrock, Cross River Basin and Niger Delta Region, Nigeria

NASA Astrophysics Data System (ADS)

Nganje, T. N.; Hursthouse, A. S.; Edet, Aniekan; Stirling, D.; Adamu, C. I.

2017-05-01

Water chemistry in the shale bedrock of the Cretaceous-Tertiary of the Cross River and Niger Delta hydrological basins has been investigated using major ions. To carry out a characterization of the water bearing units, 30 and 16 representatives surface and groundwater samples were collected. The evolution of the water is characterized by enhanced content of sodium, calcium and sulphate as a result of leaching of shale rock. The spatial changes in groundwater quality of the area shows an anomalous concentrations of ions in the central parts, while lower values characterize the eastern part of the basin covering Ogoja, Ikom and Odukpani areas. The values of total dissolved solids (TDS) and ions increases down gradient in the direction of groundwater flow. The dissolution of halite and gypsum explains part of the contained Na+, Ca2+, Cl- and SO4 2-, but other processes such as ion exchange, silicate weathering and pyrite oxidation also contribute to water composition. The assessment with contamination indicators such as TDS, hardness, chloride, nitrate and sulphate indicates that the water in area is suitable for human consumption in some locations. Modelling using MINTEQA2 program shows that the water from all the shale water bearing units are under saturated with respect to gypsum.

Hydrogeologic controls on the groundwater interactions with an acidic lake in karst terrain, Lake Barco, Florida

USGS Publications Warehouse

Lee, T.M.

1996-01-01

Transient groundwater interactions and lake stage were simulated for Lake Barco, an acidic seepage lake in the mantled karst of north central Florida. Karst subsidence features affected groundwater flow patterns in the basin and groundwater fluxes to and from the lake. Subsidence features peripheral to the lake intercepted potential groundwater inflow and increased leakage from the shallow perimeter of the lake bed. Simulated groundwater fluxes were checked against net groundwater flow derived from a detailed lake hydrologic budget with short-term lake evaporation computed by the energy budget method. Discrepancies between modeled and budget-derived net groundwater flows indicated that the model underestimated groundwater inflow, possibly contributed to by transient water table mounding near the lake. Recharge from rainfall reduced lake leakage by 10 to 15 times more than it increased groundwater inflow. As a result of the karst setting, the contributing groundwater basin to the lake was 2.4 ha for simulated average rainfall conditions, compared to the topographically derived drainage basin area of 81 ha. Short groundwater inflow path lines and rapid travel times limit the contribution of acid-neutralizing solutes from the basin, making Lake Barco susceptible to increased acidification by acid rain.

Characterization of shallow groundwater quality in the Lower St. Johns River Basin: a case study

Treesearch

Ying Ouyang; Jia-En Zhang; Prem Parajuli

2013-01-01

Characterization of groundwater quality allows the evaluation of groundwater pollution and provides information for better management of groundwater resources. This study characterized the shallow groundwater quality and its spatial and seasonal variations in the Lower St. Johns River Basin, Florida, USA, under agricultural, forest, wastewater, and residential land...

Groundwater-level trends and forecasts, and salinity trends, in the Azraq, Dead Sea, Hammad, Jordan Side Valleys, Yarmouk, and Zarqa groundwater basins, Jordan

USGS Publications Warehouse

Goode, Daniel J.; Senior, Lisa A.; Subah, Ali; Jaber, Ayman

2013-01-01

Changes in groundwater levels and salinity in six groundwater basins in Jordan were characterized by using linear trends fit to well-monitoring data collected from 1960 to early 2011. On the basis of data for 117 wells, groundwater levels in the six basins were declining, on average about -1 meter per year (m/yr), in 2010. The highest average rate of decline, -1.9 m/yr, occurred in the Jordan Side Valleys basin, and on average no decline occurred in the Hammad basin. The highest rate of decline for an individual well was -9 m/yr. Aquifer saturated thickness, a measure of water storage, was forecast for year 2030 by using linear extrapolation of the groundwater-level trend in 2010. From 30 to 40 percent of the saturated thickness, on average, was forecast to be depleted by 2030. Five percent of the wells evaluated were forecast to have zero saturated thickness by 2030. Electrical conductivity was used as a surrogate for salinity (total dissolved solids). Salinity trends in groundwater were much more variable and less linear than groundwater-level trends. The long-term linear salinity trend at most of the 205 wells evaluated was not increasing, although salinity trends are increasing in some areas. The salinity in about 58 percent of the wells in the Amman-Zarqa basin was substantially increasing, and the salinity in Hammad basin showed a long-term increasing trend. Salinity increases were not always observed in areas with groundwater-level declines. The highest rates of salinity increase were observed in regional discharge areas near groundwater pumping centers.

Groundwater simulation and management models for the upper Klamath Basin, Oregon and California

USGS Publications Warehouse

Gannett, Marshall W.; Wagner, Brian J.; Lite, Kenneth E.

2012-01-01

The upper Klamath Basin encompasses about 8,000 square miles, extending from the Cascade Range east to the Basin and Range geologic province in south-central Oregon and northern California. The geography of the basin is dominated by forested volcanic uplands separated by broad interior basins. Most of the interior basins once held broad shallow lakes and extensive wetlands, but most of these areas have been drained or otherwise modified and are now cultivated. Major parts of the interior basins are managed as wildlife refuges, primarily for migratory waterfowl. The permeable volcanic bedrock of the upper Klamath Basin hosts a substantial regional groundwater system that provides much of the flow to major streams and lakes that, in turn, provide water for wildlife habitat and are the principal source of irrigation water for the basin's agricultural economy. Increased allocation of surface water for endangered species in the past decade has resulted in increased groundwater pumping and growing interest in the use of groundwater for irrigation. The potential effects of increased groundwater pumping on groundwater levels and discharge to springs and streams has caused concern among groundwater users, wildlife and Tribal interests, and State and Federal resource managers. To provide information on the potential impacts of increased groundwater development and to aid in the development of a groundwater management strategy, the U.S. Geological Survey, in collaboration with the Oregon Water Resources Department and the Bureau of Reclamation, has developed a groundwater model that can simulate the response of the hydrologic system to these new stresses. The groundwater model was developed using the U.S. Geological Survey MODFLOW finite-difference modeling code and calibrated using inverse methods to transient conditions from 1989 through 2004 with quarterly stress periods. Groundwater recharge and agricultural and municipal pumping are specified for each stress period. All major streams and most major tributaries for which a substantial part of the flow comes from groundwater discharge are included in the model. Groundwater discharge to agricultural drains, evapotranspiration from aquifers in areas of shallow groundwater, and groundwater flow to and from adjacent basins also are simulated in key areas. The model has the capability to calculate the effects of pumping and other external stresses on groundwater levels, discharge to streams, and other boundary fluxes, such as discharge to drains. Historical data indicate that the groundwater system in the upper Klamath Basin fluctuates in response to decadal climate cycles, with groundwater levels and spring flows rising and declining in response to wet and dry periods. Data also show that groundwater levels fluctuate seasonally and interannually in response to groundwater pumping. The most prominent response is to the marked increase in groundwater pumping starting in 2001. The calibrated model is able to simulate observed decadal-scale climate-driven fluctuations in the groundwater system as well as observed shorter-term pumping-related fluctuations. Example model simulations show that the timing and location of the effects of groundwater pumping vary markedly depending on the pumping location. Pumping from wells close (within a few miles) to groundwater discharge features, such as springs, drains, and certain streams, can affect those features within weeks or months of the onset of pumping, and the impacts can be essentially fully manifested in several years. Simulations indicate that seasonal variations in pumping rates are buffered by the groundwater system, and peak impacts are closer to mean annual pumping rates than to instantaneous rates. Thus, pumping effects are, to a large degree, spread out over the entire year. When pumping locations are distant (more than several miles) from discharge features, the effects take many years or decades to fully impact those features, and much of the pumped water comes from groundwater storage over a broad geographic area even after two decades. Moreover, because the effects are spread out over a broad area, the impacts to individual features are much smaller than in the case of nearby pumping. Simulations show that the discharge features most affected by pumping in the area of the Bureau of Reclamation's Klamath Irrigation Project are agricultural drains, and impacts to other surface-water features are small in comparison. A groundwater management model was developed that uses techniques of constrained optimization along with the groundwater flow model to identify the optimal strategy to meet water user needs while not violating defined constraints on impacts to groundwater levels and streamflows. The coupled groundwater simulation-optimization models were formulated to help identify strategies to meet water demand in the upper Klamath Basin. The models maximize groundwater pumping while simultaneously keeping the detrimental impacts of pumping on groundwater levels and groundwater discharge within prescribed limits. Total groundwater withdrawals were calculated under alternative constraints for drawdown, reductions in groundwater discharge to surface water, and water demand to understand the potential benefits and limitations for groundwater development in the upper Klamath Basin. The simulation-optimization model for the upper Klamath Basin provides an improved understanding of how the groundwater and surface-water system responds to sustained groundwater pumping within the Bureau of Reclamation's Klamath Project. Optimization model results demonstrate that a certain amount of supplemental groundwater pumping can occur without exceeding defined limits on drawdown and stream capture. The results of the different applications of the model demonstrate the importance of identifying constraint limits in order to better define the amount and distribution of groundwater withdrawal that is sustainable.

Geospatial data to support analysis of water-quality conditions in basin-fill aquifers in the southwestern United States

USGS Publications Warehouse

McKinney, Tim S.; Anning, David W.

2009-01-01

The Southwest Principal Aquifers study area consists of most of California and Nevada and parts of Utah, Arizona, New Mexico, and Colorado; it is about 409,000 square miles. The Basin-fill aquifers extend through about 201,000 square miles of the study area and are the primary source of water for cities and agricultural communities in basins in the arid and semiarid southwestern United States (Southwest). The demand on limited ground-water resources in areas in the southwestern United States has increased significantly. This increased demand underscores the importance of understanding factors that affect the water quality in basin-fill aquifers in the region, which are being studied through the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program. As a part of this study, spatial datasets of natural and anthropogenic factors that may affect ground-water quality of the basin-fill aquifers in the southwestern United States were developed. These data include physical characteristics of the region, such as geology, elevation, and precipitation, as well as anthropogenic factors, including population, land use, and water use. Spatial statistics for the alluvial basins in the Southwest have been calculated using the datasets. This information provides a foundation for the development of conceptual and statistical models that relate natural and anthropogenic factors to ground-water quality across the Southwest. A geographic information system (GIS) was used to determine and illustrate the spatial distribution of these basin-fill variables across the region. One hundred-meter resolution raster data layers that represent the spatial characteristics of the basins' boundaries, drainage areas, population densities, land use, and water use were developed for the entire Southwest.

Regression method for estimating long-term mean annual ground-water recharge rates from base flow in Pennsylvania

USGS Publications Warehouse

Risser, Dennis W.; Thompson, Ronald E.; Stuckey, Marla H.

2008-01-01

A method was developed for making estimates of long-term, mean annual ground-water recharge from streamflow data at 80 streamflow-gaging stations in Pennsylvania. The method relates mean annual base-flow yield derived from the streamflow data (as a proxy for recharge) to the climatic, geologic, hydrologic, and physiographic characteristics of the basins (basin characteristics) by use of a regression equation. Base-flow yield is the base flow of a stream divided by the drainage area of the basin, expressed in inches of water basinwide. Mean annual base-flow yield was computed for the period of available streamflow record at continuous streamflow-gaging stations by use of the computer program PART, which separates base flow from direct runoff on the streamflow hydrograph. Base flow provides a reasonable estimate of recharge for basins where streamflow is mostly unaffected by upstream regulation, diversion, or mining. Twenty-eight basin characteristics were included in the exploratory regression analysis as possible predictors of base-flow yield. Basin characteristics found to be statistically significant predictors of mean annual base-flow yield during 1971-2000 at the 95-percent confidence level were (1) mean annual precipitation, (2) average maximum daily temperature, (3) percentage of sand in the soil, (4) percentage of carbonate bedrock in the basin, and (5) stream channel slope. The equation for predicting recharge was developed using ordinary least-squares regression. The standard error of prediction for the equation on log-transformed data was 9.7 percent, and the coefficient of determination was 0.80. The equation can be used to predict long-term, mean annual recharge rates for ungaged basins, providing that the explanatory basin characteristics can be determined and that the underlying assumption is accepted that base-flow yield derived from PART is a reasonable estimate of ground-water recharge rates. For example, application of the equation for 370 hydrologic units in Pennsylvania predicted a range of ground-water recharge from about 6.0 to 22 inches per year. A map of the predicted recharge illustrates the general magnitude and variability of recharge throughout Pennsylvania.

Changes in groundwater recharge under projected climate in the upper Colorado River basin

USGS Publications Warehouse

Tillman, Fred; Gangopadhyay, Subhrendu; Pruitt, Tom

2016-01-01

Understanding groundwater-budget components, particularly groundwater recharge, is important to sustainably manage both groundwater and surface water supplies in the Colorado River basin now and in the future. This study quantifies projected changes in upper Colorado River basin (UCRB) groundwater recharge from recent historical (1950–2015) through future (2016–2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 climate projections. Simulated future groundwater recharge in the UCRB is generally expected to be greater than the historical average in most decades. Increases in groundwater recharge in the UCRB are a consequence of projected increases in precipitation, offsetting reductions in recharge that would result from projected increased temperatures.

Test drilling in the upper Sevier River drainage basin, Garfield and Piute Counties, Utah

USGS Publications Warehouse

Feltis, R.D.; Robinson, G.B. Jr.

1963-01-01

A test-drilling program was conducted by the U.S. Geological Survey in the upper Sevier River drainage basin (fig. 1) in the summer of 1962. The program was part of a ground-water investigation made in cooperation with the Utah State Engineer. The drilling was financed cooperatively through the State Engineer by the U.S. Geological Survey, Garfield, Piute, Sevier, Sanpete, and Millard Counties, and various water users within those counties. Drilling began in May and continued through September 1962, and 21 test holes were drilled.

Reconnaissance of hydrology, land use, ground-water chemistry, and effects of land use on ground-water chemistry in the Albuquerque-Belen basin, New Mexico

USGS Publications Warehouse

Anderholm, S.K.

1987-01-01

In 1984, the U.S. Geological Survey began regional assessments of groundwater contamination in 14 areas, one of which was the Albuquerque-Belen basin. Groundwater recharge occurs along the basin margins. Groundwater discharge occurs as evapotranspiration in the Rio Grande valley, pumpage, and groundwater flow to the Socorro basin. Open-space land use, which primarily is used for grazing livestock, occupies the majority of the basin. In the Rio Grande valley, agricultural and residential land uses are predominant; in the area near Albuquerque, the land also is used for commercial, institutional , and industrial purposes. The Albuquerque-Belen basin was divided into seven zones on the basis of water chemistry. These water-chemistry zones indicate that large variations in water chemistry exist in the basin as the result of natural processes. Groundwater in the majority of the Albuquerque-Belen basin has a relatively low susceptibility to contamination because the depth to water is > 100 ft and there is virtually no natural mechanism for recharge to the groundwater system. Groundwater in the Rio Grande valley has a relatively high susceptibility to contamination because the depth to water is generally < 30 ft and there are many types of recharge to the groundwater system. Changes in land use may cause changes in the chemical composition of recharge to the groundwater system. The relatively large concentrations of dissolved iron in the Rio Grande valley near Albuquerque may result from the change from agricultural land use to residential land use. Recharge associated with agricultural land use is relatively oxidized because the water is in equilibrium with the atmosphere, whereas recharge associated with residential land use (onsite waste-disposal effluent) is relatively reduced and has larger concentrations of organic carbon, biological oxygen demand, and chemical oxygen demand. The constituents in the onsite waste-disposal effluent could cause reducing conditions in the aquifer and the subsequent dissolution of iron and manganese oxides. Trace metals adsorbed to these iron and manganese oxides could be remobilized in groundwater after dissolution of the oxides. (Author 's abstract)

Child-education program for the reduction of health risks due to fluoride in water sources in the Chiang Mai Basin, Thailand.

PubMed

Takizawa, S; Takeda, T; Wongrueng, A; Wattanachira, S

2010-01-01

Groundwater is the major source of drinking water in Lamphun Province in the Chiang Mai Basin, Thailand. However, groundwater contains high fluoride up to 16 mg F/L, which has caused dental and skeletal fluorosis. Although Thai Government installed RO membrane plants for the removal of fluoride from groundwater; and delivers RO-filtered bottled water that contains less fluoride than the Thai Standard of 0.7 mg F/L, it was found that the urinary fluoride levels are still high among the residents. To find the major sources of fluoride intake, fluoride contents in various water sources, such as village water supply, shallow and deep groundwaters, rain water and bottled water, were measured, and the local people's behavior on water uses was recorded by interview and questionnaire study. As a result, it was found that the highest risk of fluoride ingestion comes from cooking rice with fluoride-containing water because of a lack of knowledge on fluoride sources and fluoride chemistry. To reduce the health risks arising from fluoride intake, a hands-on educational program on the sources and risks of fluoride in water was developed and implemented in the local schools. The participatory educational program promoted active involvement of schoolchildren, but it was found that the effectiveness of education varied depending on the questions we asked. Therefore, it needs to be improved by an iterative and interactive educational program. In conclusion, it was found that the benefits of providing safe drinking water using such advanced technology as RO membrane can be maximized only when it comes along with a participatory educational program on fluoride sources and health risks.

Geohydrologic framework of the Roswell ground-water basin, Chaves and Eddy Counties, New Mexico

USGS Publications Warehouse

Welder, G.E.

1983-01-01

This report describes the geohydrology of the Roswell ground-water basin and shows the long-term hydrostatic-head changes in the aquifers. The Roswell ground-water basin consists of a carbonate artesian aquifer overlain by a leaky confining bed, which, in turn is overlain by an alluvial water-table aquifer. The water-table aquifer is hydraulically connected to the Pecos River. Ground-water pumpage from about 1,500 wells in the basin was about 378,000 acre-feet in 1978. Irrigation use on about 122,000 acres accounted for 95 percent of that pumpage.

Study of Basin Recession Characteristics and Groundwater Storage Properties

NASA Astrophysics Data System (ADS)

Yen-Bo, Chen; Cheng-Haw, Lee

2017-04-01

Stream flow and groundwater storage are freshwater resources that human live on.In this study, we discuss southern area basin recession characteristics and Kao-Ping River basin groundwater storage, and hope to supply reference to Taiwan water resource management. The first part of this study is about recession characteristics. We apply Brutsaert (2008) low flow analysis model to establish two recession data pieces sifting models, including low flow steady period model and normal condition model. Within individual event analysis, group event analysis and southern area basin recession assessment, stream flow and base flow recession characteristics are parameterized. The second part of this study is about groundwater storage. Among main basin in southern Taiwan, there are sufficient stream flow and precipitation gaging station data about Kao-Ping River basin and extensive drainage data, and data about different hydrological characteristics between upstream and downstream area. Therefore, this study focuses on Kao-Ping River basin and accesses groundwater storage properties. Taking residue of groundwater volume in dry season into consideration, we use base flow hydrograph to access periodical property of groundwater storage, in order to establish hydrological period conceptual model. With groundwater storage and precipitation accumulative linearity quantified by hydrological period conceptual model, their periodical changing and alternation trend properties in each drainage areas of Kao-Ping River basin have been estimated. Results of this study showed that the recession time of stream flow is related to initial flow rate of the recession events. The recession time index is lower when the flow is stream flow, not base flow, and the recession time index is higher in low flow steady flow period than in normal recession condition. By applying hydrological period conceptual model, groundwater storage could explicitly be analyzed and compared with precipitation, by only using stream flow data. Keywords: stream flow, base flow, recession characteristics, groundwater storage

Groundwater model of the Blue River basin, Nebraska-Twenty years later

USGS Publications Warehouse

Alley, W.M.; Emery, P.A.

1986-01-01

Groundwater flow models have become almost a routine tool of the practicing hydrologist. Yet, surprisingly little attention has been given to true verification analysis of studies using these models. This paper examines predictions for 1982 of water-level declines and streamflow depletions that were made in 1965 using an electric analog groundwater model of the Blue River basin in southeastern Nebraska. Analysis of the model's predictions suggests that the analog model used too low an estimate of net groundwater withdrawals, yet overestimated water-level declines. The model predicted that almost all of the net groundwater pumpage would come from storage in the Pleistocene aquifer within the Blue River basin. It appears likely that the model underestimated the contributions of other sources of water to the pumpage, and that the aquifer storage coefficients used in the model were too low. There is some evidence that groundwater pumpage has had a greater than predicted effect on streamflow. Considerable uncertainty about the basic conceptualization of the hydrology of the Blue River basin greatly limits the reliability of groundwater models developed for the basin. The paper concludes with general perspectives on groundwater modeling gained from this post-audit analysis. ?? 1986.

Recharge and Groundwater Flow Within an Intracratonic Basin, Midwestern United States.

PubMed

Panno, Samuel V; Askari, Zohreh; Kelly, Walton R; Parris, Thomas M; Hackley, Keith C

2018-01-01

The conservative nature of chloride (Cl - ) in groundwater and the abundance of geochemical data from various sources (both published and unpublished) provided a means of developing, for the first time, a representation of the hydrogeology of the Illinois Basin on a basin-wide scale. The creation of Cl - isocons superimposed on plan view maps of selected formations and on cross sections across the Illinois Basin yielded a conceptual model on a basin-wide scale of recharge into, groundwater flow within and through the Illinois Basin. The maps and cross sections reveal the infiltration and movement of freshwater into the basin and dilution of brines within various geologic strata occurring at basin margins and along geologic structures. Cross-formational movement of brines is also seen in the northern part of the basin. The maps and cross sections also show barriers to groundwater movement created by aquitards resulting in areas of apparent isolation/stagnation of concentrated brines within the basin. The distribution of Cl - within the Illinois Basin suggests that the current chemical composition of groundwater and distribution of brines within the basin is dependent on five parameters: (1) presence of bedrock exposures along basin margins; (2) permeability of geologic strata and their distribution relative to one another; (3) presence or absence of major geologic structures; (4) intersection of major waterways with geologic structures, basin margins, and permeable bedrock exposures; and (5) isolation of brines within the basin due to aquitards, inhomogeneous permeability, and, in the case of the deepest part of the basin, brine density effects. © 2017, National Ground Water Association.

Using Radar Interferometry (DinSAR) to Evaluate Land Subsidence Caused by Excessive Groundwater Withdrawal in Morocco

NASA Astrophysics Data System (ADS)

Durham, M. C.; Milewski, A.; El Kadiri, R.

2013-12-01

The combination of natural, anthropogenic, and climate change impacts on the water resources of the Middle East and North Africa (MENA) region has devastated its water resources well beyond its current and projected populations. The increased exploitation of groundwater resources in the past half-century coupled with successive droughts has resulted in the acceleration of subsidence rates in the Souss and Massa basins in Morocco. We have completed a preliminary investigation of these impacts on the Souss and Massa basins (~27,000 km2) in the southwestern part of Morocco. This area is characterized by a semi-arid climate (annual precipitation 70-250 mm/year) with agriculture, tourism, and commercial fishing as the primary economic activities, all of which require availability of adequate freshwater resources. Additionally the primary groundwater aquifer (Plio-Quaternary Plain Aquifer), an unconfined aquifer formed mostly of sand and gravel, is being harvested by >20,000 wells at a rate of 650 MCM/yr., exceeding the rate of recharge by 260 MCM/year. Intense development over the past 50 years has exposed the aquifer to a serious risk of groundwater table drawdown (0.5m-2.5m/yr.), land subsidence, loss of artesian pressure, salinization, salt water intrusions along the coast, and deterioration of water quality across the watershed. Differential Interferometry Synthetique Aperture Radar (DInSAR) was utilized to measure ground subsidence induced by groundwater withdrawal. Land subsidence caused by excessive groundwater extraction was determined using a threefold methodology: (1) extraction of subsidence and land deformation patterns using radar interferometry, (2) correlation of the high subsidence areas within the basins to possible natural and anthropogenic factors (e.g. sea level rise, unconsolidated lithological formations distribution, urbanization, excessive groundwater extraction), and (3) forecasting the future of the Souss and Massa basins over the next century if both subsidence and groundwater extraction continue at present rates. Interferometric processing (persistent scatter and small baseline subset) was conducted using ENVI's SARscape program with 168 archived ENVISAT SLC images and 350 ERS1/2 SLC images acquired through the European Space Agency. Radar interferometry results are spatially and temporally consistent with groundwater extraction rates. This analysis has provided insight into the impacts that land subsidence will have on the infrastructure, the population, and the economy of the Souss and Massa basins. Our results could be used to develop management plans for modulating these adverse effects and could be vital to the Moroccan economy and the livelihood of the citizens that inhabit the basins. More broadly, this approach could be applied to other areas within the MENA region facing similar impacts.

Evaluation of the importance of clay confining units on groundwaterflow in alluvial basins using solute and isotope tracers: the case of Middle San Pedro Basin in southeastern Arizona (USA)

USGS Publications Warehouse

Hopkins, Candice B.; McIntosh, Jennifer C.; Eastoe, Chris; Dickinson, Jesse; Meixner, Thomas

2014-01-01

As groundwater becomes an increasingly important water resource worldwide, it is essential to understand how local geology affects groundwater quality, flowpaths and residence times. This study utilized multiple tracers to improve conceptual and numerical models of groundwater flow in the Middle San Pedro Basin in southeastern Arizona (USA) by determining recharge areas, compartmentalization of water sources, flowpaths and residence times. Ninety-five groundwater and surface-water samples were analyzed for major ion chemistry (water type and Ca/Sr ratios) and stable (18O, 2H, 13C) and radiogenic (3H, 14C) isotopes, and resulting data were used in conjunction with hydrogeologic information (e.g. hydraulic head and hydrostratigraphy). Results show that recent recharge (<60 years) has occurred within mountain systems along the basin margins and in shallow floodplain aquifers adjacent to the San Pedro River. Groundwater in the lower basin fill aquifer (semi confined) was recharged at high elevation in the fractured bedrock and has been extensively modified by water-rock reactions (increasing F and Sr, decreasing 14C) over long timescales (up to 35,000 years BP). Distinct solute and isotope geochemistries between the lower and upper basin fill aquifers show the importance of a clay confining unit on groundwater flow in the basin, which minimizes vertical groundwater movement.

Estimation of groundwater use for a groundwater-flow model of the Lake Michigan Basin and adjacent areas, 1864-2005

USGS Publications Warehouse

Buchwald, Cheryl A.; Luukkonen, Carol L.; Rachol, Cynthia M.

2010-01-01

The U.S. Geological Survey, at the request of Congress, is assessing the availability and use of the Nation's water resources to help characterize how much water is available now, how water availability is changing, and how much water can be expected to be available in the future. The Great Lakes Basin Pilot project of the U.S. Geological Survey national assessment of water availability and use focused on the Great Lakes Basin and included detailed studies of the processes governing water availability in the Great Lakes Basin. One of these studies included the development of a groundwater-flow model of the Lake Michigan Basin. This report describes the compilation and estimation of the groundwater withdrawals in those areas in Wisconsin, Michigan, Indiana, and Illinois that were needed for the Lake Michigan Basin study groundwater-flow model. These data were aggregated for 12 model time intervals spanning 1864 to 2005 and were summarized by model area, model subregion, category of water use, aquifer system, aquifer type, and hydrogeologic unit model layer. The types and availability of information on groundwater withdrawals vary considerably among states because water-use programs often differ in the types of data collected and in the methods and frequency of data collection. As a consequence, the methods used to estimate and verify the data also vary. Additionally, because of the different sources of data and different terminologies applied for the purposes of this report, the water-use data published in this report may differ from water-use data presented in other reports. These data represent only a partial estimate of groundwater use in each state because estimates were compiled only for areas in Wisconsin, Michigan, Indiana, and Illinois within the Lake Michigan Basin model area. Groundwater-withdrawal data were compiled for both nearfield and farfield model areas in Wisconsin and Illinois, whereas these data were compiled primarily for the nearfield model area in Michigan and Indiana. Overall water use for the selected areas in Wisconsin, Michigan, Indiana, and Illinois was less during early time intervals than during more recent intervals, with large increases beginning around the 1960s. Total estimated groundwater withdrawals for model input range from 18.01 million gallons per day (Mgal/d) for interval 1 (1864-1900) to 1,280.25 Mgal/d for interval 12 (2001-5). Withdrawals for the public-supply category make up the majority of the withdrawals in each of the four states. In Wisconsin and Michigan, the second largest withdrawals are for the irrigation category; in Indiana and Illinois, industrial withdrawals account for the second largest withdrawal amounts. The smallest withdrawals are for miscellaneous uses in Wisconsin and irrigation uses in Indiana and Illinois. Estimated groundwater withdrawals in the Southern Lower Peninsula of Michigan, Northeastern Illinois, and the farfield model area are generally larger than in the other model subregions. Withdrawals in Michigan and Indiana are predominantly from the Quaternary aquifer system, whereas withdrawals in Illinois are predominantly from the Cambrian-Ordovician aquifer systems. Withdrawals in Wisconsin are about equal from the Quaternary and Cambrian-Ordovician aquifer systems. Estimated groundwater withdrawals in Michigan and Indiana are predominantly from the unconfined unconsolidated aquifer type. Withdrawals in Illinois are largely from the deep confined bedrock aquifer type, although they decreased considerably in more recent time intervals. Wisconsin withdrawals are about equal from unconfined unconsolidated and deep confined bedrock aquifer types. Groundwater-withdrawal estimates in Wisconsin were compiled for the 47 easternmost counties within the boundary of the Lake Michigan Basin model, of which 32 counties, though not entirely contained, are at least partly within the Lake Michigan Basin. Overall, 6,457 withdrawal locations were estima

Ground-water hydrology and water quality of Irwin Basin at Fort Irwin National Training Center, California

USGS Publications Warehouse

Densmore, Jill N.; Londquist, Clark J.

1997-01-01

Geohydrologic data were collected from Irwin Basin at Fort Irwin National Training Center in the Mojave Desert of southern California by the U.S. Geological Survey during 199296 to deter mine the quantity and quality of ground water available in this basin. In addition to data collected from existing wells and test holes, 17 monitoring sites were constructed in Irwin Basin to provide data on subsurface geology, ground-water levels, and ground-water quality. Eleven of these sites were multiple-well monitoring sites that were constructed to provide depth-dependent geohydrologic data in the aquifer system. The aquifer system of Irwin Basin, defined on the basis of hydrologic data collected from wells in Irwin Basin, consists of an upper and a lower aquifer. A 1994 water-table contour map shows that a cone of depression beneath Irwin Basin well field has developed as a result of ground-water development. Water-quality samples collected from Irwin Basin wells to determine potential sources of ground-water degradation indicate that water in three areas in the basin contains high nitrate and dissolved-solids concentrations. The stable isotopes of oxygen and hydrogen indicate that present-day precipitation is not a major source of recharge in this basin. Tritium and carbon-14 data indicate that most of the basin was recharged before 1953 and that this water may be more than 14,000 years old.

U.S. Geological Survey groundwater toolbox, a graphical and mapping interface for analysis of hydrologic data (version 1.0): user guide for estimation of base flow, runoff, and groundwater recharge from streamflow data

USGS Publications Warehouse

Barlow, Paul M.; Cunningham, William L.; Zhai, Tong; Gray, Mark

2015-01-01

This report is a user guide for the streamflow-hydrograph analysis methods provided with version 1.0 of the U.S. Geological Survey (USGS) Groundwater Toolbox computer program. These include six hydrograph-separation methods to determine the groundwater-discharge (base-flow) and surface-runoff components of streamflow—the Base-Flow Index (BFI; Standard and Modified), HYSEP (Fixed Interval, Sliding Interval, and Local Minimum), and PART methods—and the RORA recession-curve displacement method and associated RECESS program to estimate groundwater recharge from streamflow data. The Groundwater Toolbox is a customized interface built on the nonproprietary, open source MapWindow geographic information system software. The program provides graphing, mapping, and analysis capabilities in a Microsoft Windows computing environment. In addition to the four hydrograph-analysis methods, the Groundwater Toolbox allows for the retrieval of hydrologic time-series data (streamflow, groundwater levels, and precipitation) from the USGS National Water Information System, downloading of a suite of preprocessed geographic information system coverages and meteorological data from the National Oceanic and Atmospheric Administration National Climatic Data Center, and analysis of data with several preprocessing and postprocessing utilities. With its data retrieval and analysis tools, the Groundwater Toolbox provides methods to estimate many of the components of the water budget for a hydrologic basin, including precipitation; streamflow; base flow; runoff; groundwater recharge; and total, groundwater, and near-surface evapotranspiration.

Hydrologic monitoring for Chicago’s Sustainable Streetscapes Program

USGS Publications Warehouse

Duncker, James J.; Morrow, William S.

2016-04-05

The Chicago Department of Transportation’s Sustainable Streetscapes Program is an innovative program that strives to convert Chicago’s neighborhood commercial areas, riverwalks, and bicycle facilities into active, attractive places for Chicagoans to live, work, and play. The objective of each project is to create flourishing public places while improving the ability of infrastructure to support dense urban living. The U.S. Geological Survey (USGS), in cooperation with the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC), and the Chicago Department of Transportation (CDOT), is monitoring the pre- and postconstruction hydrologic characteristics of an urban corridor on the south side of Chicago that is being renovated using sustainable streetscapes technology.The CDOT Sustainable Streetscapes Program utilizes urban stormwater best-management practices (BMPs) to reduce the storm runoff to the local combined sewer system. The urban stormwater BMPs include permeable pavement, bioswales, infiltration basins, and planters. The urban stormwater BMPs are designed to capture the first flush of storm runoff through features that enhance the infiltration of stormwater runoff to shallow groundwater.The hydrology of the Sustainable Streetscapes Program area is being monitored to evaluate the impacts and effectiveness of the urban stormwater BMP’s. Continuous monitoring of rainfall, sewer flows, stormwater runoff, soil moisture, and groundwater levels will give engineers and scientists measured data to define baseline pre- and postconstruction conditions for the evaluation of the BMPs.Three tipping-bucket rain gages are located along the project corridor. The data provide information on the intensity and volume of rainfall. Rainfall can be highly variable even over a small area like the project corridor.Continuous recording meters are located at specific locations in the combined sewers to record water level and flow during both dry weather (mostly sanitary flow) and wet weather conditions (stormwater runoff in addition to the sanitary flow). Sanitary flow is the largest source of flow in the combined sewers during dry weather, and stormwater runoff and sanitary flow combine during wet weather. The sewer flow data allow engineers and scientists to calculate total runoff volume for selected storm events.Wells are located within the project corridor to record water levels and help determine the direction of movement of groundwater in response to rainfall and snowmelt. In urban settings with aging sewer systems, groundwater can seep into the sewers or combined sewage can seep from the sewers into the local groundwater system. The groundwater data are also important in evaluating the overall impacts of increased infiltration resulting from BMPs.Data from wells show the relative water levels of shallow groundwater, water levels in the combined sewer system, and nearby surface-water channels within the project corridor. In some aging urban sewer systems, the local combined sewer system lies below the water table and receives substantial amounts of groundwater inflow, which can significantly reduce the amount of additional water the sewer system can accept.The bioswale along the south side of West Cermak Road near South Throop Street functions to infiltrate stormwater runoff from the road. Stormwater on the road surface initially drains to the curb and then flows along the curb until it reaches a curb cut-out. Materials within the bioswale allow stormwater to infiltrate and reduce the load to the combined sewer.A common feature in urban areas are curbside catch basins that collect stormwater runoff from paved streets. Stormwater drains first to the curb and then flows along the curb to the catch basin. Lateral sewer pipe connects the catch basin to the combined sewer beneath the street. The use of permeable pavers along the curbs in the project study reach let stormwater infiltrate before it reaches the curb, thus reducing the amount of stormwater draining to the combined sewers.Water-level data from catch basins in the project study area show the effects of permeable pavers in reducing the stormwater drainage to the combined sewers.

Study on Law of Groundwater Evolution under Natural and Artificial Forcing with Case study of Haihe River Basin

NASA Astrophysics Data System (ADS)

You, Jinjun; Gan, Hong; Wang, Lin; Bi, Xue; Du, Sisi

2010-05-01

The evolution of groundwater is one of the key problems of water cycle study. It is a result of joint effect of natural condition and human activities, but until now the driving forces of groundwater system evolution were not fully understood due to the complexity of groundwater system structures and the uncertainty of affecting factors. Geology, precipitation and human activity are the main factors affecting the groundwater system evolution and interact each other, but the influence of such three factors on groundwater system are not clarified clearly on a macroscopic scale. The precipitation changes the volume of water recharge and the groundwater pumping effect the discharge of groundwater. Another important factor influencing balance of groundwater storage is the underlaying that affects the renewablility of groundwater. The underlaying is decided mainly by geological attributes but also influenced by human activited. The macroscopic environment of groundwater evolves under the natural and anthropic factors. This paper study the general law of groundwater evolution among the factors based on the case study in Haihe River Basin, a typical area with dramatic groundwater change under natural precipitation attenuation and gradually increase of water suuply. Haihe River Basin is located in north-China, covers an area of 320,041 km2 with over 40% plain areas. The plain area of Haihe Basin is densely populated with many large and medium-sized cities, including metropolis of Beijing and Tianjin, and concentrated irrigated areas, playing important roles in China's economy and food production. It is the unique basin where groundwater occupies majority of total water supply in China. Long-term groundwater over-exploitation causes a series of ecological and environmental problems that threats the sustainable development. In this paper, the historical process of groundwater balance in Haihe Basin is divided into three phases by decrease of rainfall and increase of water pumping. The different problems caused by groundwater shrinkage are summarized. The volume of recharge from natural precipitation and artificial water cycle, natural evaporation and groundwater exploitation are analyzed based on water balance. Through the historical data analysis the changing trend of coefficients of groundwater balance discovers the evolution of groundwater. The general law is concluded with deeper analysis displays the contribution of natural and artificial factors causing deterioration of groundwater balance. A general law of groundwater evolution is put forward to describe the affection of both natural and anthropogenic factors with a relation curve. Considering the water demand of future socio-economic development in Haihe River Basin, the prospective of future vision of groundwater cycle is analyzed by the law of groundwater evolution. Iterated scenario analysis based on comparison of ameliorative function on groundwater balance to point out reasonable control on groundwater exploitation and rational water allocation under the condition of completion of South-to-North Water Transfer Project that could bring more than 7 billion m3 into Haihe River Basin from Yantze River. Finally, the advantages and disadvantages are concluded through the case study and the farther research in this field is pointed out.

Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

NASA Astrophysics Data System (ADS)

Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

2016-09-01

Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The previous hypothesis that regional groundwater flow from the piedmont groundwater recharge zone predominantly discharges at the coastline may therefore be false. A more reliable alternative might be to conceptualize deep groundwater below the coastal plains a hydrodynamically stagnant zone, responding gradually to landscape and hydrological change on geologic timescales. This study brings a new and original understanding of the groundwater flow system in an important regional basin, in the context of its geometry and evolution over geological timescales. There are important implications for the sustainability of the ongoing high rates of groundwater extraction in the NCB.

Water use, ground-water recharge and availability, and quality of water in the Greenwich area, Fairfield County, Connecticut and Westchester County, New York, 2000-2002

USGS Publications Warehouse

Mullaney, John R.

2004-01-01

Ground-water budgets were developed for 32 small basin-based zones in the Greenwich area of southwestern Connecticut, where crystalline-bedrock aquifers supply private wells, to determine the status of residential ground-water consumption relative to rates of ground-water recharge and discharge. Estimated residential ground-water withdrawals for small basins (averaging 1.7 square miles (mi2)) ranged from 0 to 0.16 million gallons per day per square mile (Mgal/d/mi2). To develop these budgets, residential ground-water withdrawals were estimated using multiple-linear regression models that relate water use from public water supply to data on residential property characteristics. Average daily water use of households with public water supply ranged from 219 to 1,082 gallons per day (gal/d). A steady-state finite-difference ground-water- flow model was developed to track water budgets, and to estimate optimal values for hydraulic conductivity of the bedrock (0.05 feet per day) and recharge to the overlying till deposits (6.9 inches) using nonlinear regression. Estimated recharge rates to the small basins ranged from 3.6 to 7.5 inches per year (in/yr) and relate to the percentage of the basin underlain by coarse- grained glacial stratified deposits. Recharge was not applied to impervious areas to account for the effects of urbanization. Net residential ground-water consumption was estimated as ground-water withdrawals increased during the growing season, and ranged from 0 to 0.9 in/yr. Long-term average stream base flows simulated by the ground-water-flow model were compared to calculated values of average base flow and low flow to determine if base flow was substantially reduced in any of the basins studied. Three of the 32 basins studied had simulated base flows less than 3 in/yr, as a result of either ground-water withdrawals or reduced recharge due to urbanization. A water-availability criteria of the difference between the 30-day 2-year low flow and the recharge rate for each basin was explored as a method to rate the status of water consumption in each basin. Water consumption ranged from 0 to 14.3 percent of available water based on this criteria for the 32 basins studied. Base-flow water quality was related to the amount of urbanized area in each basin sampled. Concentrations of total nitrogen and phosphorus, chloride, indicator bacteria, and the number of pesticide detections increased with basin urbanization, which ranged from 18 to 63 percent of basin area.

The Slow Moving Threat of Groundwater Salinization: Mechanisms, Costs, and Adaptation Strategies

NASA Astrophysics Data System (ADS)

Pauloo, R.; Guo, Z.; Fogg, G. E.

2016-12-01

Population growth, the Green Revolution, and climate uncertainties have accelerated overdraft in groundwater basins worldwide, which in some regions is converting these basins into closed hydrologic systems, where the dominant exits for water are evapotranspiration and pumping. Irrigated agricultural basins are particularly at risk to groundwater salinization, as naturally occurring (i.e., sodium, potassium, chloride) and anthropogenic (i.e., nitrate fertilizers) salts leach back into the water table through the root zone, while a large portion of pumped groundwater leaves the system as it is evapotranspired by crops. Decreasing water quality associated with increases in Total Dissolved Solids (TDS) has been documented in aquifers across the United States in the past half century. This study suggests that the increase in TDS in aquifers can be partially explained by closed basin hydrogeology and rock-water interactions leading to groundwater salinization. This study will present: (1) a report on historical water quality in the Tulare basin, (2) a forward simulation of salt balance in Tulare Basin based on the Department of Water Resources numerical model C2VSim, and a simple mixing model, (3) an economic analysis forecasting the cost of desalination under varying degrees of managed groundwater recharge where the basin is gradually filled, avoiding hydraulic closure.

Evolving Groundwater Rights and Management in Metropolitan Los Angeles: Implications for Water Supply and Stormwater

NASA Astrophysics Data System (ADS)

Porse, E.; Pincetl, S.; Glickfeld, M.

2015-12-01

Groundwater supports many aspects of human life. In cities, groundwater can provide a cost-effective source of water for drinking and industrial uses, while groundwater basins provide storage. The role of groundwater in a city's water supply tends to change over time. In the Los Angeles metropolitan area, groundwater is critical. Over decades, users in the region's many basins allocated annual pumping rights to groundwater among users through adjudications. These rights were determined through collective processes over decades, which contributed to the complex array of public and private organizations involved in water management. The rights also continue to evolve. We analyzed changes in the distribution of groundwater rights over time for adjudicated basins in Southern Los Angeles County. Results indicate that groundwater rights are increasingly: 1) controlled or regulated by public institutions and municipalities, and 2) consolidated among larger users. Yet, both the percentage of total supplies provided by groundwater, as well as the distribution of groundwater rights, varies widely among cities and communities throughout Los Angeles. As metropolitan Los Angeles faces reduced water imports and emphasizes local water reliance, access to pumping rights and storage capacity in groundwater basins will become even more vital. We discuss implications of our results for future urban water management.

Identifying the Source of High-Nitrate Ground Water Related to Artificial Recharge in a Desert Basin

NASA Astrophysics Data System (ADS)

Densmore, J. N.; Nishikawa, T.; Bohlke, J. K.; Martin, P.

2002-12-01

Ground water has been the sole source of water supply for the community of Yucca Valley in the Mojave Desert, California. Domestic wastewater from the community is treated using septic tanks. An imbalance between ground-water recharge and pumpage caused ground-water levels in the ground-water basin to decline by as much as 300 feet from the late 1940s through 1994. In response to this decline, the local water district, Hi-Desert Water District, began an artificial recharge program in February 1995 to replenish the ground water in the basin using imported surface water. The artificial recharge program resulted in water-level recovery of about 250 feet between February 1995 and December 2001; however, nitrate concentrations in some wells also increased from a background concentration of 10 mg/L as NO3 to more than the U.S. Environmental Protection Agency maximum contaminant level of 45 mg/L as NO3, limiting water use for some wells. The largest increase in nitrate concentrations occurred adjacent to the artificial recharge sites where the largest increase in water levels occurred even though the recharge water had low nitrate concentrations. The source of high nitrate concentrations observed in ground water during aquifer recovery was identified by compiling historical water-quality data; monitoring changes in water quality since artificial recharge began; and analyzing selected samples for major-ion chemistry, stable isotopes of H,O, and N, caffeine, and pharmaceuticals. The major-ions and H and O stable-isotope data indicate that ground-water samples that had the highest nitrate concentrations were mixtures of imported water and native ground water. Nitrate-to-chloride ratios, N isotopes and caffeine and pharmaceutical data indicate septic-tank seepage (septage) is the primary source of increases in nitrate concentration. The rapid rise in water levels entrained the large volume of high-nitrate septage stored in the unsaturated zone, resulting in the rapid increase in nitrate concentrations. Results of this study indicate that the potential for ground-water contamination should be evaluated before beginning an artificial recharge program in an area that uses septic tanks.

Ground Water in the Southern Lihue Basin, Kauai, Hawaii

USGS Publications Warehouse

Izuka, Scot K.; Gingerich, Stephen B.

1998-01-01

A multi-phased study of ground-water resources, including well drilling, aquifer tests, analysis of ground-water discharge, and numerical ground-water modeling, indicates that the rocks of the southern Lihue Basin, Kauai, have permeabilities that are much lower than in most other areas of ground-water development in the Hawaiian islands. The regional hydraulic conductivity of the Koloa Volcanics, which dominates fresh ground-water flow in the basin, is about 0.275 foot per day. The Waimea Canyon Basalt which surrounds the basin and underlies the Koloa Volcanics within the basin is intruded by dikes that reduce the bulk hydraulic conductivity of the rocks to about 1.11 feet per day. The low permeabilities result in steeper head gradients compared with other areas in the Hawaiian islands, and a higher proportion of ground-water discharging to streams than to the ocean. Water levels rise from near sea level at the coast to several hundreds of feet above sea level at the center of the basin a few miles inland. The high inland water levels are part of a completely saturated ground-water system. Because of the low regional hydraulic conductivity and high influx of water from recharge in the southern Lihue Basin, the rocks become saturated nearly to the surface and a variably saturated/unsaturated (perched) condition is not likely to exist. Streams incising the upper part of the aquifer drain ground water and keep the water levels just below the surface in most places. Streams thus play an important role in shaping the water table in the southern Lihue Basin. At least 62 percent of the ground water discharging from the aquifer in the southern Lihue Basin seeps to streams; the remainder seeps directly to the ocean or is withdrawn by wells.

Development and application of a novel method for regional assessment of groundwater contamination risk in the Songhua River Basin.

PubMed

Nixdorf, Erik; Sun, Yuanyuan; Lin, Mao; Kolditz, Olaf

2017-12-15

The main objective of this study is to quantify the groundwater contamination risk of Songhua River Basin by applying a novel approach of integrating public datasets, web services and numerical modelling techniques. To our knowledge, this study is the first to establish groundwater risk maps for the entire Songhua River Basin, one of the largest and most contamination-endangered river basins in China. Index-based groundwater risk maps were created with GIS tools at a spatial resolution of 30arc sec by combining the results of groundwater vulnerability and hazard assessment. Groundwater vulnerability was evaluated using the DRASTIC index method based on public datasets at the highest available resolution in combination with numerical groundwater modelling. As a novel approach to overcome data scarcity at large scales, a web mapping service based data query was applied to obtain an inventory for potential hazardous sites within the basin. The groundwater risk assessment demonstrated that <1% of Songhua River Basin is at high or very high contamination risk. These areas were mainly located in the vast plain areas with hotspots particularly in the Changchun metropolitan area. Moreover, groundwater levels and pollution point sources were found to play a significantly larger impact in assessing these areas than originally assumed by the index scheme. Moderate contamination risk was assigned to 27% of the aquifers, predominantly associated with less densely populated agricultural areas. However, the majority of aquifer area in the sparsely populated mountain ranges displayed low groundwater contamination risk. Sensitivity analysis demonstrated that this novel method is valid for regional assessments of groundwater contamination risk. Despite limitations in resolution and input data consistency, the obtained groundwater contamination risk maps will be beneficial for regional and local decision-making processes with regard to groundwater protection measures, particularly if other data availability is limited. Copyright © 2017 Elsevier B.V. All rights reserved.

Numerical simulation of ground-water flow in lower Satus Creek Basin, Yakima Indian Reservation, Washington

USGS Publications Warehouse

Prych, E.A.

1983-01-01

A multilayer numerical model of steady-state ground-water flow in lower Satus Creek basin was constructed, calibrated using time-averaged data, and used to estimate the long-term effects of proposed irrigation-water management plans on ground-water levels in the area. Model computations showed that irrigation of new lands in the Satus uplands would raise ground-water levels in lower Satus Creek basin and thereby increase the size of the waterlogged areas. The model also demonstrated that pumping water from wells, reducing the amount of irrigation water used in the lowlands, and stopping leakage from Satus No. 2 and 3 Pump Canals were all effective methods to alleviate present waterlogging in some parts of the basin and to counteract some of the anticipated ground-water-level rises that would be caused by irrigating the uplands. The proposed changes in water use affected model-computed ground-water levels most in the eastern part of the basin between Satus No. 2 and No. 3 Pump Canals. The effects on ground-water levels in the western part of the basin between Satus Creek and Satus No. 2 Pump Canal were smaller. (USGS)

Hydrogeology and steady-state numerical simulation of groundwater flow in the Lost Creek Designated Ground Water Basin, Weld, Adams, and Arapahoe Counties, Colorado

USGS Publications Warehouse

Arnold, L.R.

2010-01-01

The Lost Creek Designated Ground Water Basin (Lost Creek basin) is an important alluvial aquifer for irrigation, public supply, and domestic water uses in northeastern Colorado. Beginning in 2005, the U.S. Geological Survey, in cooperation with the Lost Creek Ground Water Management District and the Colorado Water Conservation Board, collected hydrologic data and constructed a steady-state numerical groundwater flow model of the Lost Creek basin. The model builds upon the work of previous investigators to provide an updated tool for simulating the potential effects of various hydrologic stresses on groundwater flow and evaluating possible aquifer-management strategies. As part of model development, the thickness and extent of regolith sediments in the basin were mapped, and data were collected concerning aquifer recharge beneath native grassland, nonirrigated agricultural fields, irrigated agricultural fields, and ephemeral stream channels. The thickness and extent of regolith in the Lost Creek basin indicate the presence of a 2- to 7-mile-wide buried paleovalley that extends along the Lost Creek basin from south to north, where it joins the alluvial valley of the South Platte River valley. Regolith that fills the paleovalley is as much as about 190 ft thick. Average annual recharge from infiltration of precipitation on native grassland and nonirrigated agricultural fields was estimated by using the chloride mass-balance method to range from 0.1 to 0.6 inch, which represents about 1-4 percent of long-term average precipitation. Average annual recharge from infiltration of ephemeral streamflow was estimated by using apparent downward velocities of chloride peaks to range from 5.7 to 8.2 inches. Average annual recharge beneath irrigated agricultural fields was estimated by using passive-wick lysimeters and a water-balance approach to range from 0 to 11.3 inches, depending on irrigation method, soil type, crop type, and the net quantity of irrigation water applied. Estimated average annual recharge beneath irrigated agricultural fields represents about 0-43 percent of net irrigation. The U.S. Geological Survey modular groundwater modeling program, MODFLOW-2000, was used to develop a steady-state groundwater flow model of the Lost Creek basin. Groundwater in the basin is simulated generally to flow from the basin margins toward the center of the basin and northward along the paleovalley. The largest source of inflow to the model occurs from recharge beneath flood- and sprinkler-irrigated agricultural fields (14,510 acre-feet per year [acre-ft/yr]), which represents 39.7 percent of total simulated inflow. Other substantial sources of inflow to the model are recharge from precipitation and stream-channel infiltration in nonirrigated areas (13,810 acre-ft/yr) seepage from Olds Reservoir (4,280 acre-ft/yr), and subsurface inflow from ditches and irrigated fields outside the model domain (2,490 acre-ft/yr), which contribute 37.7, 11.7, and 6.8 percent, respectively, of total inflow. The largest outflow from the model occurs from irrigation well withdrawals (26,760 acre-ft/yr), which represent 73.2 percent of total outflow. Groundwater discharge (6,640 acre-ft/yr) at the downgradient end of the Lost Creek basin represents 18.2 percent of total outflow, and evapotranspiration (3,140 acre-ft/yr) represents about 8.6 percent of total outflow.

Regional water table (2016) in the Mojave River and Morongo groundwater basins, southwestern Mojave Desert, California

USGS Publications Warehouse

Dick, Meghan; Kjos, Adam

2017-12-07

From January to April 2016, the U.S. Geological Survey (USGS), the Mojave Water Agency, and other local water districts made approximately 1,200 water-level measurements in about 645 wells located within 15 separate groundwater basins, collectively referred to as the Mojave River and Morongo groundwater basins. These data document recent conditions and, when compared with older data, changes in groundwater levels. A water-level contour map was drawn using data measured in 2016 that shows the elevation of the water table and general direction of groundwater movement for most of the groundwater basins. Historical water-level data stored in the USGS National Water Information System (https://waterdata.usgs.gov/nwis/) database were used in conjunction with data collected for this study to construct 37 hydrographs to show long-term (1930–2016) and short-term (1990–2016) water-level changes in the study area.

Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

NASA Astrophysics Data System (ADS)

Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

2015-05-01

Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

Impact of stormwater infiltration basins on groundwater quality, Perth metropolitan region, Western Australia

NASA Astrophysics Data System (ADS)

Appleyard, S. J.

1993-08-01

Twelve bores were sunk adjacent to three stormwater infiltration basins in the Perth metropolitan area to examine the impact of runoff from a light industrial area, a medium-density residential area, and a major arterial road on groundwater quality, and to examine the hydrological response of the aquifer to runoff recharge. Automatic and manual water level monitoring between April and November 1990 indicated that groundwater levels responded within minutes to recharge from the infiltration basins. Peak water levels of up to 2.5 m above rest levels occurred 6 24 h after the commencement of ponding in the infiltration basins. There was a marked reduction in salinity and increase in dissolved oxygen concentrations in the upper part of the aquifer downgradient of the infiltration basins. Concentrations of toxic metals, nutrients, pesticides, and phenolic compounds in groundwater near the infiltration basins were low and generally well within Australian drinking water guidelines. However, sediment in the base of an infiltration basin draining a major road contained in excess of 3500 ppm of lead. Phthalates, which are US EPA priority pollutants, were detected in all but one bore near the infiltration basins. Their detection may be a sampling artifact, but they may also be derived from the plastic litter that accumulates in the infiltration basins. The concentration of iron in groundwater near the infiltration basins appears to be controlled by dissolved oxygen concentrations, with high iron concentrations occurring where dissolved oxygen concentrations are low. Pumping bores located near infiltration basins may suffer from iron encrustation problems caused by the mixing of shallow, oxygenated groundwater with water containing higher concentrations of iron from deeper in the aquifer.

Ground-water-quality assessment of the Carson River basin, Nevada and California; analysis of available water-quality data through 1987

USGS Publications Warehouse

Welch, A.H.; Plume, R.W.; Frick, E.A.; Hughes, J.L.

1989-01-01

Data on groundwater quality, hydrogeology, and land and water use for the Carson River basin, Nevada and California were analyzed as part of the U. S. Geological Survey National Water-Quality Assessment program. The basin consists of six hydrographic areas--a mountainous headwaters area and five downstream areas interconnected by the Carson River. Each valley contains one or more basin-fill aquifers. The data on groundwater quality came from several agencies and were screened to verify site location and to avoid analyses of treated water. The screened data are stored in the U. S. Geological Survey National Water Information System data base. Differences in sample-collection and preservation procedures among some of the data-collection agencies restrict use of the data to a descriptive analysis. Drinking water standards were employed as the basis for evaluating reported concentrations. Frequencies with which primary or secondary standards are exceeded increase from upstream parts of the basin to downstream parts. Primary standards commonly exceeded are fluoride in upstream areas and arsenic and fluoride in downstream areas. Secondary standards commonly exceeded are iron and manganese in upstream areas and chloride, dissolved solids, iron, manganese, and sulfate in downstream areas. The poorer-quality groundwater generally is a result of natural geochemical reactions, rather than the introduction of chemicals by man. Limited data indicate, however , that manmade organic compounds are present, mostly at or near urban land. (USGS)

Geohydrology and water chemistry in the Rialto-Colton Basin, San Bernardino County, California

USGS Publications Warehouse

Woolfenden, Linda R.; Kadhim, Dina

1997-01-01

The 40-square-mile Rialto-Colton ground- water basin is in western San Bernardino County, California, about 60 miles east of Los Angeles.This basin was chosen for storage of imported water because of the good quality of native ground water, the known capacity for additional ground-water storage in the basin, and the availability of imported water. Because the movement and mixing of imported water needed to be determined, the San Bernardino Valley Municipal Water District entered into a cooperative program with the U.S.Geological Survey in 1991 to study the geohydrology and water chemistry in the Rialto- Colton basin. Ground-water flow and chemistry were investigated using existing data, borehole- geophysical and lithologic logs from newly drilled test holes, measurement of water levels, and chemical analyses of water samples. The Rialto-Colton basin is bounded on the northwest and southeast by the San Gabriel Mountains and the Badlands, respectively. The San Jacinto Fault and Barrier E form the northeastern boundary, and the Rialto-Colton Fault forms the southwestern boundary. Except in the southeastern part of the basin, the San Jacinto and Rialto-Colton Faults act as groundwater barriers that impede ground- water flow into and out of the basin.Barrier E generally does not impede ground- water flow into the basin. The ground-water system consists primarily of gravel, sand, silt, and clay. The maximum thickness is greater than 1,000 feet. The ground- water system is divided into four water-bearing units: river-channel deposits, and upper, middle, and lower water-bearing units. Relatively impermeable consolidated deposits underlie the lower water- bearing unit and form the lower boundary of the ground- water system. Ground water moves from east to west in the river-channel deposits and upper water-bearing unit in the southeastern part of the basin, and from northwest to southeast in the middle and lower water-bearing units. Two major internal faults, Barrier J and an unnamed fault, affect ground-water movement. Ground water moves across Barrier J in the unfaulted part of the ground-water system. The unnamed fault is a partial barrier to ground-water movement in the middle water- bearing unit and an effective barrier in the lower water-bearing unit.Imported water flows laterally across the unnamed fault above the saturated zone. Major sources of recharge to the ground- water system are underflow; precipitation that collects in small streams that drain the San Gabriel Mountains and the Badlands or runs off the mountain front as sheet flow, and sub-surface inflow; imported water; seepage loss from the Santa Ana River and Warm Creek; infiltration of rainfall; and irrigation return flow. The main component of discharge is pumpage. Long-term water levels in production wells reflect precipitation cycles. During a 194777 dry period, water levels in three wells declined almost continuously?as much as 100 feet in one well.Water levels in a well north of Barrier J are not affected by stresses on the groundwater system south of the barrier, indicating that these two parts of the ground-water system are not well connected. Water levels in cluster wells east of the unnamed fault north and south of the Linden Ponds artificial-recharge site rose as much as 70 feet during 1992-95. The rise in water levels in wells near the recharge ponds was observed within 2 months after the beginning of recharge. Water levels in most wells west of the unnamed fault changed very little during 1992-95. Water-chemistry data indicate that chemical characteristics vary within the groundwater system, and that dissolvedsolids concentrations are generally higher in the river-channel deposits, upper water- bearing unit, and the consolidated deposits than in the middle and lower water-bearing units. The chemical characteristics in water from the middle water-bearing unit were similar for most wells sampled west of the unnamed fault. In water from well

Controls on groundwater flow in the Bengal Basin of India and Bangladesh: Regional modeling analysis

USGS Publications Warehouse

Michael, H.A.; Voss, C.I.

2009-01-01

Groundwater for domestic and irrigation purposes is produced primarily from shallow parts of the Bengal Basin aquifer system (India and Bangladesh), which contains high concentrations of dissolved arsenic (exceeding worldwide drinking water standards), though deeper groundwater is generally low in arsenic. An essential first step for determining sustainable management of the deep groundwater resource is identification of hydrogeologic controls on flow and quantification of basin-scale groundwater flow patterns. Results from groundwater modeling, in which the Bengal Basin aquifer system is represented as a single aquifer with higher horizontal than vertical hydraulic conductivity, indicate that this anisotropy is the primary hydrogeologic control on the natural flowpath lengths. Despite extremely low hydraulic gradients due to minimal topographic relief, anisotropy implies large-scale (tens to hundreds of kilometers) flow at depth. Other hydrogeologic factors, including lateral and vertical changes in hydraulic conductivity, have minor effects on overall flow patterns. However, because natural hydraulic gradients are low, the impact of pumping on groundwater flow is overwhelming; modeling indicates that pumping has substantially changed the shallow groundwater budget and flowpaths from predevelopment conditions. ?? Springer-Verlag 2009.

Controls on groundwater flow in the Bengal Basin of India and Bangladesh: regional modeling analysis

NASA Astrophysics Data System (ADS)

Michael, Holly A.; Voss, Clifford I.

2009-11-01

Groundwater for domestic and irrigation purposes is produced primarily from shallow parts of the Bengal Basin aquifer system (India and Bangladesh), which contains high concentrations of dissolved arsenic (exceeding worldwide drinking water standards), though deeper groundwater is generally low in arsenic. An essential first step for determining sustainable management of the deep groundwater resource is identification of hydrogeologic controls on flow and quantification of basin-scale groundwater flow patterns. Results from groundwater modeling, in which the Bengal Basin aquifer system is represented as a single aquifer with higher horizontal than vertical hydraulic conductivity, indicate that this anisotropy is the primary hydrogeologic control on the natural flowpath lengths. Despite extremely low hydraulic gradients due to minimal topographic relief, anisotropy implies large-scale (tens to hundreds of kilometers) flow at depth. Other hydrogeologic factors, including lateral and vertical changes in hydraulic conductivity, have minor effects on overall flow patterns. However, because natural hydraulic gradients are low, the impact of pumping on groundwater flow is overwhelming; modeling indicates that pumping has substantially changed the shallow groundwater budget and flowpaths from predevelopment conditions.

U.S. Geological Survey middle Rio Grande basin study; proceedings of the third annual workshop, Albuquerque, New Mexico, February 24-25, 1999

USGS Publications Warehouse

Bartolino, James R.

1999-01-01

Approximately 40 percent (about 600,000 people) of the total population of New Mexico lives within the Middle Rio Grande Basin, which includes the City of Albuquerque. Ongoing analyses of the central portion of the Middle Rio Grande Basin by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque and other agencies have shown that ground water in the basin is not as readily accessible as earlier studies indicated. A more complete characterization of the ground-water resources of the entire Middle Rio Grande Basin is hampered by a scarcity of data in the northern and southern areas of the basin. The USGS Middle Rio Grande Basin study is a 5-year effort by the USGS and other agencies to improve the understanding of the hydrology, geology, and land-surface characteristics of the Middle Rio Grande Basin. The primary objective of this study is to improve the understanding of the water resources of the basin. Of particular interest is to determine the extent of hydrologic connection between the Rio Grande and the Santa Fe Group aquifer. Additionally, ground-water quality affects the availability of water supplies in the basin. Improving the existing USGS-constructed ground-water flow model of the Middle Rio Grande Basin will integrate all the various tasks that improve our knowledge of the various components of the Middle Rio Grande water budget. Part of this improvement will be accompanied by extended knowledge of the aquifer system beyond the Albuquerque area into the northern and southern reaches of the basin. Other improvements will be based on understanding gained through process-oriented research and improved geologic characterization of the deposits. The USGS and cooperating agencies will study the hydrology, geology, and land-surface characteristics of the basin to provide the scientific information needed for water-resources management and for managers to plan for water supplies needed for a growing population. To facilitate exchange of information among the scientists working on the Middle Rio Grande Basin study, yearly technical meetings have been held for each of the first 3 years of the anticipated 5-year study. These meetings provide an opportunity to present research results and plan new field efforts. This report documents the results of research presented at the third annual technical workshop held in Albuquerque, New Mexico, February 24-25, 1999. The report is organized into this introduction and five chapters that focus on Middle Rio Grande Basin study investigations in progress in the Middle Rio Grande Basin. The first chapter describes geographic data and analysis efforts in the basin. The second chapter details work being done on the hydrogeologic and geologic framework of the basin. The third chapter describes studies on ground-water recharge in the basin. The fourth chapter provides details on the research on the ground-water flow system in the basin, including modeling efforts. The fifth chapter is devoted to an overview of New Mexico District Cooperative Program studies in the basin. The information in this report presents preliminary results of an evolving study. As the study progresses and individual projects publish their results in more detail, the USGS hopes to expand the scientific basis needed for management decisions regarding the Middle Rio Grande Basin.

Plan of study for the regional aquifer-system analysis of the San Juan structural basin, New Mexico, Colorado, Arizona, and Utah

USGS Publications Warehouse

Welder, G.E.

1986-01-01

The San Juan structural basin is an 18,000 sq mi area that contains several extensive aquifers. The basin includes three surface drainage basins and parts of New Mexico, Colorado, Arizona, and Utah. Surface water in the area is fully appropriated, and the steadily increasing demand for groundwater has resulted in water supply concerns. Competition is great between mining and electric power companies, municipalities, and Indian communities for the limited groundwater supplies. This report outlines a 4-year plan for a study of the regional aquifer system in the San Juan structural basin. The purposes of the study are to define and understand the aquifer system; to assess the effects of groundwater use on the aquifers and streams; and to determine the availability and quality of groundwater in the basin. (Author 's abstract)

Synthesizing diverse stakeholder needs for a drought early warning information system in the Apalachicola-Chattahoochee-Flint River Basin

NASA Astrophysics Data System (ADS)

Darby, L. S.; Mcnutt, C. A.; Ingram, K.; Knox, P.; Martinez, C. J.; Zierden, D.; Pulwarty, R. S.; Verdin, J. P.

2011-12-01

From fall 2009 to fall 2010 the National Integrated Drought Information System (NIDIS) Program Office coordinated several stakeholder meetings in the Apalachicola-Chattahoochee-Flint (ACF) River Basin, which extends from Georgia into Alabama and Florida. The purpose of the meetings was to ascertain which products and services are needed by basin stakeholders for drought early warning. Drought vulnerabilities across the basin are quite diverse - from changes in salinity that harm oyster bed productivity in Apalachicola Bay, to the health of crops in the agricultural fields of the Flint River basin, to municipal water supply issues for the city of Atlanta and smaller communities along the tributaries. These, and many other vulnerabilities, exist against a backdrop of decades-long water allocation litigation among the three states. The benefits of these stakeholder meetings went beyond information gathering by serving as opportunities for communication across state lines among people with differing needs and perspectives regarding water management decisions in the basin. The meetings also provided a good opportunity for stakeholders from all three states to share lessons learned from various management perspectives during the drought that affected the basin from 2006 to 2009. Common issues and needs identified from all regions of the basin include: (1) Education and Communication - People across the basin agree that education and communication regarding drought needs improvement (e.g., definition of drought, sector-specific impacts); (2) Improved interactions with the US Army Corps of Engineers (e.g., increased data sharing and opportunities for communication between the Corps and other stakeholders); (3) Data - easier access to real-time calibrated and quality-controlled data; (4) ACF Basin-wide webinars and climate outlooks; (5) Drought Index - Can a basin-wide drought index be established?; (6) Resolve perceived discrepancies regarding groundwater (How much groundwater is withdrawn, how frequently should withdrawals be recorded, can we improve groundwater modeling?); (7) Presentation of Information - Basin-scale graphics available from one web site with historical context; Updates on current NIDIS activities, along with proposed future plans for the drought early warning information system for the ACF Basin, will be presented.

Potential impact of climate change on groundwater resources in the Central Huai Luang Basin, Northeast Thailand.

PubMed

Pholkern, Kewaree; Saraphirom, Phayom; Srisuk, Kriengsak

2018-08-15

The Central Huai Luang Basin is one of the important rice producing areas of Udon Thani Province in Northeastern Thailand. The basin is underlain by the rock salt layers of the Maha Sarakham Formation and is the source of saline groundwater and soil salinity. The regional and local groundwater flow systems are the major mechanisms responsible for spreading saline groundwater and saline soils in this basin. Climate change may have an impact on groundwater recharge, on water table depth and the consequences of waterlogging, and on the distribution of soil salinity in this basin. Six future climate conditions from the SEACAM and CanESM2 models were downscaled to investigate the potential impact of future climate conditions on groundwater quantity and quality in this basin. The potential impact was investigated by using a set of numerical models, namely HELP3 and SEAWAT, to estimate the groundwater recharge and flow and the salt transport of groundwater simulation, respectively. The results revealed that within next 30years (2045), the future average annual temperature is projected to increase by 3.1°C and 2.2°C under SEACAM and CanESM2 models, respectively, while the future precipitation is projected to decrease by 20.85% under SEACAM and increase by 18.35% under the CanESM2. Groundwater recharge is projected to increase under the CanESM2 model and to slightly decrease under the SEACAM model. Moreover, for all future climate conditions, the depths of the groundwater water table are projected to continuously increase. The results showed the impact of climate change on salinity distribution for both the deep and shallow groundwater systems. The salinity distribution areas are projected to increase by about 8.08% and 56.92% in the deep and shallow groundwater systems, respectively. The waterlogging areas are also projected to expand by about 63.65% from the baseline period. Copyright © 2018 Elsevier B.V. All rights reserved.

2002 Water-Table Contours of the Mojave River and the Morongo Ground-Water Basins, San Bernardino County, California

USGS Publications Warehouse

Smith, G.A.; Stamos, C.L.; Predmore, S.K.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During 2002, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 660 wells, providing coverage for most of the basins. Twenty-eight hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 9 short-term (1997 to 2002) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 2000 and 2002 water levels throughout the basins. In the Mojave River ground-water basin, about 66 percent of the wells had water-level declines of 0.5 ft or more since 2000 and about 27 percent of the wells had water-level declines greater than 5 ft. The only area that had water-level increases greater than 5 ft that were not attributed to fluctuations in nearby pumpage was in the Harper Lake (dry) area where there has been a significant reduction in pumpage during the last decade. In the Morongo ground-water basin, about 36 percent of the wells had water-level declines of 0.5 ft or more and about 10 percent of the wells had water-level declines greater than 5 ft. Water-level increases greater than 5 ft were measured only in the Warren subbasin, where artificial-recharge operations have caused water levels to rise almost 60 ft since 2000.

Regional Water Table (2002) and Water-Level Changes in the Mojave River and Morongo Ground-Water Basins, Southwestern Mojave Desert, California

USGS Publications Warehouse

Smith, Gregory A.; Stamos, Christina L.; Predmore, Steven K.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During 2002, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 600 wells, providing coverage for most of the basins. Twenty-eight hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 9 short-term (1997 to 2002) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 2000 and 2002 water levels throughout the basins. In the Mojave River ground-water basin, about 66 percent of the wells had water-level declines of 0.5 ft or more since 2000 and about 27 percent of the wells had water-level declines greater than 5 ft. The only area that had water-level increases greater than 5 ft that were not attributed to fluctuations in nearby pumpage was in the Harper Lake (dry) area where there has been a significant reduction in pumpage during the last decade. In the Morongo ground-water basin, about 36 percent of the wells had water-level declines of 0.5 ft or more and about 10 percent of the wells had water-level declines greater than 5 ft. Water-level increases greater than 5 ft were measured only in the Warren subbasin, where artificial-recharge operations have caused water levels to rise almost 60 ft since 2000.

Application of a Geographic Information System for regridding a ground-water flow model of the Columbia Plateau Regional Aquifer System, Walla Walla River basin, Oregon-Washington

USGS Publications Warehouse

Darling, M.E.; Hubbard, L.E.

1994-01-01

Computerized Geographic Information Systems (GIS) have become viable and valuable tools for managing,analyzing, creating, and displaying data for three-dimensional finite-difference ground-water flow models. Three GIS applications demonstrated in this study are: (1) regridding of data arrays from an existing large-area, low resolution ground-water model to a smaller, high resolution grid; (2) use of GIS techniques for assembly of data-input arrays for a ground-water model; and (3) use of GIS for rapid display of data for verification, for checking of ground-water model output, and for the cre.ation of customized maps for use in reports. The Walla Walla River Basin was selected as the location for the demonstration because (1) data from a low resolution ground-water model (Columbia Plateau Regional Aquifer System Analysis [RASA]) were available and (2) concern for long-term use of water resources for irrigation in the basin. The principal advantage of regridding is that it may provide the ability to more precisely calibrate a model, assuming chat a more detailed coverage of data is available, and to evaluate the numerical errors associated with a particular grid design.Regridding gave about an 8-fold increase in grid-node density.Several FORTRAN programs were developed to load the regridded ground-water data into a finite-difference modular model as model-compatible input files for use in a steady-state model run.To facilitate the checking and validating of the GIS regridding process, maps and tabular reports were produced for each of eight ground-water parameters by model layer. Also, an automated subroutine that was developed to view the model-calculated water levels in cross-section will aid in the synthesis and interpretation of model results.

Identifying and quantifying geochemical and mixing processes in the Matanza-Riachuelo Aquifer System, Argentina.

PubMed

Armengol, S; Manzano, M; Bea, S A; Martínez, S

2017-12-01

The Matanza-Riachuelo River Basin, in the Northeast of the Buenos Aires Province, is one of the most industrialized and populated region in Argentina and it is worldwide known for its alarming environmental degradation. In order to prevent further damages, the aquifer system, which consists of two overlaid aquifers, is being monitored from 2008 by the river basin authority, Autoridad de la Cuenca Matanza-Riachuelo. The groundwater chemical baseline has been established in a previous paper (Zabala et al., 2016), and this one is devoted to the identification of the main physical and hydrogeochemical processes that control groundwater chemistry and its areal distribution. Thirty five representative groundwater samples from the Upper Aquifer and thirty four from the deep Puelche Aquifer have been studied with a multi-tool approach to understand the origin of their chemical and isotopic values. The resulting conceptual model has been validated though hydrogeochemical modeling. Most of the aquifer system has fresh groundwater, but some areas have brackish and salt groundwater. Water recharging the Upper Aquifer is of the Ca-HCO 3 type as a result of soil CO 2 and carbonate dissolution. Evapotranspiration plays a great role concentrating recharge water. After recharge, groundwater becomes Na-HCO 3 , mostly due to cation exchange with Na release and Ca uptake, which induces calcite dissolution. Saline groundwaters exist in the lower and upper sectors of the basin as a result of Na-HCO 3 water mixing with marine water of different origins. In the upper reaches, besides mixing with connate sea water other sources of SO 4 exist, most probably gypsum and/or sulfides. This work highlights the relevance of performing detailed studies to understand the processes controlling groundwater chemistry at regional scale. Moreover, it is a step forward in the knowledge of the aquifer system, and provides a sound scientific basis to design effective management programs and recovery plans. Copyright © 2017 Elsevier B.V. All rights reserved.

Water-Level and land-subsidence studies in the Mojave River and Morongo groundwater basins

USGS Publications Warehouse

Stamos, Christina L.; Glockhoff, Carolyn S.; McPherson, Kelly R.; Julich, Raymond J.

2007-01-01

What's New! Water-level data, contours, and meta data for spring 2008 are included in Version 2.0 of SIR 2007-5097 (http://ca.water.usgs.gov/mojave/wl_studies/wl2008.html). All the original data are still available on the web site. Introduction Since 1992, the U.S. Geological Survey (USGS), in cooperation with the Mojave Water Agency (MWA), has constructed a series of regional water-table maps for intermittent years in a continuing effort to monitor groundwater conditions in the Mojave River and Morongo groundwater basins. The previously published data, which were used to construct these maps, can be accessed on the interactive map. The associated reports describing the groundwater conditions for the Mojave River groundwater basin for 1992 (Stamos and Predmore, 1995), the Morongo groundwater basin for 1994 (Trayler and Koczot, 1995), and for both groundwater basins for 1996 (Mendez and Christensen, 1997); for 1998 (Smith and Pimentel, 2000), for 2000 (Smith, 2002), for 2002 (Smith and others, 2004), for 2004 (Stamos and others, 2004), and for 2006 (Stamos and others, 2007) can be accessed using this web site. Spatially detailed maps of interferometric synthetic aperture radar (InSAR) methods were used to characterize land subsidence associated with groundwater-level declines during various intervals of time between 1992 and 1999 in the Mojave River and Morongo groundwater basins (Sneed and others, 2003). Concerns related to the potential for new or renewed land subsidence in the basins resulted in a cooperative study between the MWA and the USGS in 2006. InSAR data were developed to determine the location, extent, and magnitude of vertical land-surface changes in the Mojave River and Morongo groundwater basins for time intervals ranging from about 35 days to 14 months between 1999 and 2000 and between 2003 and 2004. (interactive Google map) The results from many future land-subsidence studies, which are scheduled about every 10 years, will be available on this website. Mapping of water-level contours, water-level change and numerous InSAR images were combined in an interactive map. This interactive map may be customized to your needs and viewed at a scale that is appropriate for the data.

Analyses of infrequent (quasi-decadal) large groundwater recharge events in the northern Great Basin: Their importance for groundwater availability, use, and management

USGS Publications Warehouse

Masbruch, Melissa D.; Rumsey, Christine; Gangopadhyay, Subhrendu; Susong, David D.; Pruitt, Tom

2016-01-01

There has been a considerable amount of research linking climatic variability to hydrologic responses in the western United States. Although much effort has been spent to assess and predict changes in surface water resources, little has been done to understand how climatic events and changes affect groundwater resources. This study focuses on characterizing and quantifying the effects of large, multiyear, quasi-decadal groundwater recharge events in the northern Utah portion of the Great Basin for the period 1960–2013. Annual groundwater level data were analyzed with climatic data to characterize climatic conditions and frequency of these large recharge events. Using observed water-level changes and multivariate analysis, five large groundwater recharge events were identified with a frequency of about 11–13 years. These events were generally characterized as having above-average annual precipitation and snow water equivalent and below-average seasonal temperatures, especially during the spring (April through June). Existing groundwater flow models for several basins within the study area were used to quantify changes in groundwater storage from these events. Simulated groundwater storage increases per basin from a single recharge event ranged from about 115 to 205 Mm3. Extrapolating these amounts over the entire northern Great Basin indicates that a single large quasi-decadal recharge event could result in billions of cubic meters of groundwater storage. Understanding the role of these large quasi-decadal recharge events in replenishing aquifers and sustaining water supplies is crucial for long-term groundwater management.

Coupled SWAT-MODFLOW Model Development for Large Basins

NASA Astrophysics Data System (ADS)

Aliyari, F.; Bailey, R. T.; Tasdighi, A.

2017-12-01

Water management in semi-arid river basins requires allocating water resources between urban, industrial, energy, and agricultural sectors, with the latter competing for necessary irrigation water to sustain crop yield. Competition between these sectors will intensify due to changes in climate and population growth. In this study, the recently developed SWAT-MODFLOW coupled hydrologic model is modified for application in a large managed river basin that provides both surface water and groundwater resources for urban and agricultural areas. Specific modifications include the linkage of groundwater pumping and irrigation practices and code changes to allow for the large number of SWAT hydrologic response units (HRU) required for a large river basin. The model is applied to the South Platte River Basin (SPRB), a 56,980 km2 basin in northeastern Colorado dominated by large urban areas along the front range of the Rocky Mountains and agriculture regions to the east. Irregular seasonal and annual precipitation and 150 years of urban and agricultural water management history in the basin provide an ideal test case for the SWAT-MODFLOW model. SWAT handles land surface and soil zone processes whereas MODFLOW handles groundwater flow and all sources and sinks (pumping, injection, bedrock inflow, canal seepage, recharge areas, groundwater/surface water interaction), with recharge and stream stage provided by SWAT. The model is tested against groundwater levels, deep percolation estimates, and stream discharge. The model will be used to quantify spatial groundwater vulnerability in the basin under scenarios of climate change and population growth.

Evaluation of the effects of precipitation on ground-water levels from wells in selected alluvial aquifers in Utah and Arizona, 1936-2005

USGS Publications Warehouse

Gardner, Philip M.; Heilweil, Victor M.

2009-01-01

Increased withdrawals from alluvial aquifers of the southwestern United States during the last half-century have intensified the effects of drought on ground-water levels in valleys where withdrawal for irrigation is greatest. Furthermore, during wet periods, reduced withdrawals coupled with increased natural recharge cause rising ground-water levels. In order to manage water resources more effectively, analysis of ground-water levels under the influence of natural and anthropogenic stresses is useful. This report evaluates the effects of precipitation patterns on ground-water levels in areas of Utah and Arizona that have experienced different amounts of ground-water withdrawal. This includes a comparison of water-level records from basins that are hydrogeologically and climatologically similar but have contrasting levels of ground-water development. Hydrologic data, including records of ground-water levels, basin-wide annual ground-water withdrawals, and precipitation were examined from two basins in Utah (Milford and central Sevier) and three in Arizona (Aravaipa Canyon, Willcox, and Douglas). Most water-level records examined in this study from basins experiencing substantial ground-water development (Milford, Douglas, and Willcox) showed strong trends of declining water levels. Other water-level records, generally from the less-developed basins (central Sevier and Aravaipa Canyon) exhibited trends of increasing water levels. These trends are likely the result of accumulating infiltration of unconsumed irrigation water. Water-level records that had significant trends were detrended by subtraction of a low-order polynomial in an attempt to eliminate the variation in the water-level records that resulted from ground-water withdrawal or the application of water for irrigation. After detrending, water-level residuals were correlated with 2- to 10-year moving averages of annual precipitation from representative stations for the individual basins. The water-level residual time series for each well was matched with the 2- to 10-year moving average of annual precipitation with which it was best correlated and the results were compared across basins and hydrologic settings. Analysis of water-level residuals and moving averages of annual precipitation indicate that ground-water levels in the Utah basins respond more slowly to precipitation patterns than those from the Arizona basins. This is attributed to the dominant mechanism of recharge that most directly influences the respective valley aquifers. Substantial recharge in the Utah basins likely originates as infiltrating snowmelt in the mountain block far from the valley aquifer, whereas mountain-front recharge and streambed infiltration of runoff are the dominant recharge mechanisms operating in the Arizona basins. It was determined that the fraction of water-level variation caused by local precipitation patterns becomes more difficult to resolve with increasing effects of ground-water pumping, especially from incomplete records. As the demand for ground water increases in the southwestern United States, long-term records of ground-water levels have the potential to provide valuable information about the precipitation-driven variation in water levels, which has implications to water management related to water availability.

Assessment of Groundwater Pollution Potential Resulting From Stormwater Infiltration BMPs

DOT National Transportation Integrated Search

1995-08-01

Washington State has begun a program to dispose of highway runoff in which a priority has been given to the use of infiltration type technologies (e.g., infiltration basins, dry wells, etc.). Heavy metals are the most prevalent priority pollutant in ...

Hydrogeologic framework of the uppermost principal aquifer systems in the Williston and Powder River structural basins, United States and Canada

USGS Publications Warehouse

Thamke, Joanna N.; LeCain, Gary D.; Ryter, Derek W.; Sando, Roy; Long, Andrew J.

2014-01-01

Regionally, water in the lower Tertiary and Upper Cretaceous aquifer systems flows in a northerly or northeasterly direction from the Powder River structural basin to the Williston structural basin. Groundwater flow in the Williston structural basin generally is easterly or northeasterly. Flow in the uppermost hydrogeologic units generally is more local and controlled by topography where unglaciated in the Williston structural basin than is flow in the glaciated part and in underlying aquifers. Groundwater flow in the Powder River structural basin generally is northerly with local variations greatest in the uppermost aquifers. Groundwater is confined, and flow is regional in the underlying aquifers.

Hydrogeologic Framework of the Salt Basin, New Mexico and Texas

NASA Astrophysics Data System (ADS)

Ritchie, A. B.; Phillips, F. M.

2010-12-01

The Salt Basin is a closed drainage basin located in southeastern New Mexico (Otero, Chaves, and Eddy Counties), and northwestern Texas (Hudspeth, Culberson, Jeff Davis, and Presidio Counties), which can be divided into a northern and a southern system. Since the 1950s, extensive groundwater withdrawals have been associated with agricultural irrigation in the Dell City, Texas region, just south of the New Mexico-Texas border. Currently, there are three major applications over the appropriations of groundwater in the Salt Basin. Despite these factors, relatively little is known about the recharge rates and storage capacity of the basin, and the estimates that do exist are highly variable. The Salt Basin groundwater system was declared by the New Mexico State Engineer during 2002 in an attempt to regulate and control growing interest in the groundwater resources of the basin. In order to help guide long-term management strategies, a conceptual model of groundwater flow in the Salt Basin was developed by reconstructing the tectonic forcings that have affected the basin during its formation, and identifying the depositional environments that formed and the resultant distribution of facies. The tectonic history of the Salt Basin can be divided into four main periods: a) Pennsylvanian-to-Early Permian, b) Mid-to-Late Permian, c) Late Cretaceous, and d) Tertiary-to-Quaternary. Pennsylvanian-to-Permian structural features affected deposition throughout the Permian, resulting in three distinct hydrogeologic facies: basin, shelf-margin, and shelf. Permian shelf facies rocks form the primary aquifer within the northern Salt Basin, although minor aquifers occur in Cretaceous rocks and Tertiary-to-Quaternary alluvium. Subsequent tectonic activity during the Late Cretaceous resulted in the re-activation of many of the earlier structures. Tertiary-to-Quaternary Basin-and-Range extension produced the current physiographic form of the basin.

Regional Water Table (1998) and Ground-Water-Level Changes in the Mojave River, and the Morongo Ground-Water Basins, San Bernardino County, California

USGS Publications Warehouse

Smith, Gregory A.; Pimentel, M. Isabel

2000-01-01

The Mojave River and the Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The rapid and continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The continuing collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems and, consequently, water availability. During 1998 the U.S. Geological Survey and other agencies made approximately 2,370 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and changes in ground-water levels. A water-level contour map was drawn using data from 450 wells, providing coverage for most of both basins. Twenty-three hydrographs show long-term (as much as 70 years) water-level trends throughout the basins. To help show effects of late seasonal recharge along the Mojave River, 14 short-term (13 years) hydrographs were created. A water-level change map was compiled to enable comparison of 1996 and 1998 water levels. The Mojave River and the Morongo ground-water basins had little change in water levels between 1996 and 1998 - with the exception of the areas of the Yucca Valley affected by artificial recharge. Other water-level changes were localized and reflected pumping or measurements made before seasonal recharge. Three areas of perched ground water were identified: El Mirage Lake (dry), Adelanto, and Lucerne Valley.

Effects of unsaturated zone on ground-water mounding

USGS Publications Warehouse

Sumner, D.M.; Rolston, D.E.; Marino, M.A.

1999-01-01

The design of infiltration basins used to dispose of treated wastewater or for aquifer recharge often requires estimation of ground-water mounding beneath the basin. However, the effect that the unsaturated zone has on water-table response to basin infiltration often has been overlooked in this estimation. A comparison was made between two methods used to estimate ground-water mounding-an analytical approach that is limited to the saturated zone and a numerical approach that incorporates both the saturated and the unsaturated zones. Results indicate that the error that is introduced by a method that ignores the effects of the unsaturated zone on ground-water mounding increases as the basin-loading period is shortened; as the depth to the water table increases, with increasing subsurface anisotropy; and with the inclusion of fine-textured strata. Additionally, such a method cannot accommodate the dynamic nature of basin infiltration, the finite transmission time of the infiltration front to the water table, or the interception of the basin floor by the capillary fringe.The design of infiltration basins used to dispose of treated wastewater or for aquifer recharge often requires estimation of ground-water mounding beneath the basin. However, the effect that the unsaturated zone has on water-table response to basin infiltration often has been overlooked in this estimation. A comparison was made between two methods used to estimate ground-water mounding - an analytical approach that is limited to the saturated zone and a numerical approach that incorporates both the saturated and the unsaturated zones. Results indicate that the error that is introduced by a method that ignores the effects of the unsaturated zone on ground-water mounding increases as the basin-loading period is shortened; as the depth to the water table increases, with increasing subsurface anisotropy; and with the inclusion of fine-textured strata. Additionally, such a method cannot accommodate the dynamic nature of basin infiltration, the finite transmission time of the infiltration front to the water, or the interception of the basin floor by the capillary fringe.

Towards a Better Understanding of the Hydrologic Setting of the Nubian Sandstone Aquifer System: Inferences from Groundwater Flow Models, CL-36 Ages, and GRACE Data

NASA Astrophysics Data System (ADS)

Sultan, M.; Mohamed, A.; Yan, E.; Ahmed, E.; Sturchio, N. C.

2015-12-01

The Nubian Sandstone Aquifer System (NSAS), one of the largest (area: ~2×106 km2) groundwater systems worldwide, is formed of three major sub-basins: Kufra (Libya, NE Chad and NW Sudan), Dakhla (Egypt), and N. Sudan Platform (Sudan). To determine the mean residence time of water in the aquifer, the connectivity of its sub-basins and the groundwater flow across these sub-basins have to be understood. An integrated approach was adopted to address these issues using: (1) a regional calibrated groundwater flow model that simulates early (>10,000 years) steady-state conditions under wet climatic periods, and later (<10,000 years) transient conditions under arid condition; (2) 36Cl ages, and (3) GRACE solutions. Our findings include: (1) the NSAS was recharged (recharge: plains: 2-7 mm/yr; highlands 10-27 mm/yr) in the previous wet climatic periods on a regional scale, yet its outcrops are still receiving in dry periods appreciable precipitation over the highlands and modest (3.04±1.10 km3/yr) local recharge; (2) a progressive increase in 36Cl groundwater ages were observed along groundwater flow directions and along structures that are sub-parallel to the groundwater flow direction; (3) the NE-SW Pelusium shear zone provides a preferred groundwater flow pathway from the Kufra to the Dakhla sub-basin as evidenced by the relatively high hydraulic conductivities and relatively younger ages of groundwater along the shear zone compared to the groundwater ages in areas surrounding the shear zone; (4) the E-W trending Uweinat-Aswan basement uplift impedes groundwater flow from the N-Sudan Platform sub-basin as evidenced by the difference in groundwater isotopic compositions across the uplift, the depletion in GRACE-derived total water storage north but not south, of the uplift, and groundwater ages that are indicative of autochthonous precipitation and recharge over the Dakhla sub-basin. Our findings provide valuable insights into optimum ways for the utilization of the NSAS.Keywords: NSAS, Groundwater flow model, Ages data, isotopic data

Effects of Irrigation, Drought, and Ground-Water Withdrawals on Ground-Water Levels in the Southern Lihue Basin, Kauai, Hawaii

USGS Publications Warehouse

Izuka, Scot K.

2006-01-01

A numerical ground-water-flow model was used to investigate the effects of irrigation on ground-water levels in the southern Lihue Basin, Kauai, Hawaii, and the relation between declining ground-water levels observed in the basin in the 1990s and early 2000s and concurrent drought, irrigation reduction, and changes in ground-water withdrawal. Results of steady-state model simulations indicate that changing from pre-development to 1981 irrigation and ground-water-withdrawal conditions could, given enough time for steady state to be achieved, raise ground-water levels in some areas of the southern Lihue Basin by as much as 200 feet, and that changing from 1981 to 1998 irrigation and ground-water-withdrawal conditions could lower ground-water levels in some areas by as much as 100 feet. Transient simulations combining drought, irrigation reduction, and changes in ground-water withdrawal show trends that correspond with those observed in measured water levels. Results of this study indicate that irrigation reduction was the primary cause of the observed decline in ground-water-levels. In contrast, ground-water withdrawal had a long-duration but small-magnitude effect, and drought had a widespread, high-magnitude but short-duration effect. Inasmuch as irrigation in the future is unlikely to return to the same levels as during the period of peak sugarcane agriculture, the decline in ground-water levels resulting from the reduction and ultimate end of sugarcane irrigation can be considered permanent. Assuming that irrigation does not return to the southern Lihue Basin and that, on average, normal rainfall persists and ground-water withdrawal remains at 1998 rates, model projections indicate that average ground-water levels in the Kilohana-Puhi area will continue to recover from the drought of 1998-2002 and eventually rise to within about 4 feet of the pre-drought conditions. Long-term climate trends, increases in ground-water withdrawal, or other factors not simulated in the model could also affect ground-water levels in the southern Lihue Basin in the future.

Impact of excessive groundwater pumping on rejuvenation processes in the Bandung basin (Indonesia) as determined by hydrogeochemistry and modeling

NASA Astrophysics Data System (ADS)

Taufiq, Ahmad; Hosono, Takahiro; Ide, Kiyoshi; Kagabu, Makoto; Iskandar, Irwan; Effendi, Agus J.; Hutasoit, Lambok M.; Shimada, Jun

2017-12-01

In the Bandung basin, Indonesia, excessive groundwater pumping caused by rapid increases in industrialization and population growth has caused subsurface environmental problems, such as excessive groundwater drawdown and land subsidence. In this study, multiple hydrogeochemical techniques and numerical modeling have been applied to evaluate the recharge processes and groundwater age (rejuvenation). Although all the groundwater in the Bandung basin is recharged at the same elevation at the periphery of the basin, the water type and residence time of the shallow and deep groundwater could be clearly differentiated. However, there was significant groundwater drawdown in all the depression areas and there is evidence of groundwater mixing between the shallow and deep groundwater. The groundwater mixing was traced from the high dichlorodifluoromethane (CFC-12) concentrations in some deep groundwater samples and by estimating the rejuvenation ratio (R) in some representative observation wells. The magnitude of CFC-12 concentration, as an indicator of young groundwater, showed a good correlation with R, determined using 14C activity in samples taken between 2008 and 2012. These correlations were confirmed with the estimation of vertical downward flux from shallower to deeper aquifers using numerical modeling. Furthermore, the change in vertical flux is affected by the change in groundwater pumping. Since the 1970s, the vertical flux increased significantly and reached approximately 15% of the total pumping amount during the 2000s, as it compensated the groundwater pumping. This study clearly revealed the processes of groundwater impact caused by excessive groundwater pumping using a combination of hydrogeochemical methods and modeling.

Impact of excessive groundwater pumping on rejuvenation processes in the Bandung basin (Indonesia) as determined by hydrogeochemistry and modeling

NASA Astrophysics Data System (ADS)

Taufiq, Ahmad; Hosono, Takahiro; Ide, Kiyoshi; Kagabu, Makoto; Iskandar, Irwan; Effendi, Agus J.; Hutasoit, Lambok M.; Shimada, Jun

2018-06-01

In the Bandung basin, Indonesia, excessive groundwater pumping caused by rapid increases in industrialization and population growth has caused subsurface environmental problems, such as excessive groundwater drawdown and land subsidence. In this study, multiple hydrogeochemical techniques and numerical modeling have been applied to evaluate the recharge processes and groundwater age (rejuvenation). Although all the groundwater in the Bandung basin is recharged at the same elevation at the periphery of the basin, the water type and residence time of the shallow and deep groundwater could be clearly differentiated. However, there was significant groundwater drawdown in all the depression areas and there is evidence of groundwater mixing between the shallow and deep groundwater. The groundwater mixing was traced from the high dichlorodifluoromethane (CFC-12) concentrations in some deep groundwater samples and by estimating the rejuvenation ratio ( R) in some representative observation wells. The magnitude of CFC-12 concentration, as an indicator of young groundwater, showed a good correlation with R, determined using 14C activity in samples taken between 2008 and 2012. These correlations were confirmed with the estimation of vertical downward flux from shallower to deeper aquifers using numerical modeling. Furthermore, the change in vertical flux is affected by the change in groundwater pumping. Since the 1970s, the vertical flux increased significantly and reached approximately 15% of the total pumping amount during the 2000s, as it compensated the groundwater pumping. This study clearly revealed the processes of groundwater impact caused by excessive groundwater pumping using a combination of hydrogeochemical methods and modeling.

Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin

USGS Publications Warehouse

Bartos, Timothy T.; Hallberg, Laura L.; Eddy-Miller, Cheryl

2015-07-14

The groundwater-level measurements were used to construct a generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system. Groundwater-level altitudes measured in nonflowing and flowing wells used to construct the potentiometric-surface map ranged from 6,451 to 7,307 feet (excluding four unmeasured flowing wells used for contour construction purposes). The potentiometric-surface map indicates that groundwater in the study area generally moves from north to south, but this pattern of flow is altered locally by groundwater divides, groundwater discharge to the Green River, and possibly to a tributary river (Big Sandy River) and two reservoirs (Fontenelle and Big Sandy Reservoirs).

Mapping groundwater availability and adequacy in the Lower Zambezi River basin

NASA Astrophysics Data System (ADS)

Pérez-Lapeña, Blanca; Saimone, Francisco; Juizo, Dinis

2018-05-01

Groundwater plays an important role as a source of water for various socio-economic uses and environmental requirements in the lower Zambezi basin in Mozambique. Hence it is important to know its availability and adequacy in space to inform decision making for sustainable water management practices. For a derivation of a Groundwater Availability map and a Groundwater Adequacy map we adapted the DRASTIC methodology in a GIS environment to determine how different parameters, such as precipitation, topography, soil drainage, land use and vegetation cover, aquifer characteristics and groundwater quality affect (i) groundwater recharge on a long-term sustainable basis, (ii) the short-term abstraction potential and (iii) the long-term adequacy of groundwater utilization for domestic use. Results showed that groundwater availability in the Zambezi basin varies mostly from medium to low, with highest potential along the perennial rivers and in the delta where it plays a crucial role in environmental preservation. The southern margin of the Zambezi River shows low groundwater availability and also presents low adequacy for domestic use due to poor groundwater quality. The results from this study will be used in determining the most promising future development pathways and select the most attractive strategic development plans of the Mozambican government for the Lower Zambezi basin.

Identification of hydrogeochemical processes and pollution sources of groundwater nitrate in Leiming Basin of Hainan island, Southern China

NASA Astrophysics Data System (ADS)

Shaowen, Y.; Zhan, Y., , Dr; Li, Q.

2017-12-01

Identifying the evolution of groundwater quality is important for the control and management of groundwater resources. The main aims of the present study are to identify the major factors affecting hydrogeochemistry of groundwater resources and to evaluate the potential sources of groundwater nitrate in Leiming basin using chemical and isotopic methods. The majority of samples belong to Na-Cl water type and are followed by Ca-HCO3 and mixed Ca-Na-HCO3. The δ18O and δ2H values in groundwater indicate that the shallow fissure groundwater is mainly recharged by rainfall. The evaporated surface water is another significant origin of groundwater. The weathering and dissolution of different rocks and minerals, input of precipitation, evaporation, ion exchange and anthropogenic activities, especially agricultural activities, influence the hydrogeochemistry of the study area. NO- 3 concentration in the groundwater varies from 0.7 to 51.7 mg/L and high values are mainly occurred in the densely populated area. The combined use of isotopic values and hydrochemical data suggests that the NO- 3 load in Leiming basin is not only derived from agricultural activities but also from other sources such as waste water and atmospheric deposition. Fertilizer is considered as the major source of NO- 3 in the groundwater in Leiming basin.

A groundwater convection model for Rio Grande rift geothermal resources

NASA Technical Reports Server (NTRS)

Morgan, P.; Harder, V.; Daggett, P. H.; Swanberg, C. A.

1981-01-01

It has been proposed that forced convection, driven by normal groundwater flow through the interconnected basins of the Rio Grande rift is the primary source mechanism for the numerous geothermal anomalies along the rift. A test of this concept using an analytical model indicates that significant forced convection must occur in the basins even if permeabilities are as low as 50-200 millidarcies at a depth of 2 km. Where groundwater flow is constricted at the discharge areas of the basins forced convection can locally increase the gradient to a level where free convection also occurs, generating surface heat flow anomalies 5-15 times background. A compilation of groundwater data for the rift basins shows a strong correlation between constrictions in groundwater flow and hot springs and geothermal anomalies, giving strong circumstantial support to the convection model.

Installation of a groundwater monitoring-well network on the east side of the Uncompahgre River in the Lower Gunnison River Basin, Colorado, 2012

USGS Publications Warehouse

Thomas, Judith C.; Arnold, Larry R. Rick

2015-07-06

The east side of the Uncompahgre River Basin has been a known contributor of dissolved selenium to recipient streams. Discharge of groundwater containing dissolved selenium contributes to surface-water selenium concentrations and loads; however, the groundwater system on the east side of the Uncompahgre River Basin is not well characterized. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board and the Bureau of Reclamation, has established a groundwater-monitoring network on the east side of the Uncompahgre River Basin. Ten monitoring wells were installed during October and November 2012. This report presents location data, lithologic logs, well-construction diagrams, and well-development information. Understanding the groundwater system will provide managers with an additional metric for evaluating the effectiveness of salinity and selenium control projects.

Seismic investigation of the buried horst between the Jornada del Muerto and Mesilla ground-water basins near Las Cruces, Dona Ana County, New Mexico

USGS Publications Warehouse

Woodward, D.G.; Myers, R.G.

1997-01-01

Six seismic reflection profiles were collected in the vicinity of the Jornada Horst between Goat Mountain and Tortugas Mountain (northeast and east of Las Cruces, New Mexico) to delineate more precisely the geometry of the horst and to determine whether large, buried channels have been incised into the top of the horst. The Jornada fault zone separates the southern Jornada del Muerto ground-water basin from the Mesilla ground-water basin in the Mesilla drainage basin. The upper part of the Jornada Horst is composed of Tertiary volcanic and volcaniclastic rocks; these rocks overlie Permian sedimentary rocks. The horst, in turn, is overlain by unconsolidated sediments of the upper Santa Fe Group. Some test holes indicate that little or no ground water flows from the Jornada del Muerto ground-water basin to the Mesilla ground-water basin over some portions of the horst. However, some ground water flows through the upper Santa Fe Group deposits above some portions of the horst. Ground-water flow immediately east of the horst near U.S. Highway 70 is deflected northward in the southern Jornada del Muerto ground-water basin presumably because of the change from higher hydraulic-conductivity values of aquifer materials in the southern basin to lower hydraulic-conductivity values of materials in the horst. Incised, buried channels, if present on the horst, could be filled with alluvial material with higher hydraulic- conductivity values than those of the material in the horst. Incised, buried channels would allow ground water to readily move from the Jornada del Muerto ground-water basin to the Mesilla ground-water basin. The gross geometry of the horst--eastern extent, constraints on the western extent, and general altitude of the top--was discerned by interpretations of the seismic profiles. The presence or absence of large channels incised into the top of the horst could not be confirmed by these interpretations. However, the seismic interpretations suggest that the water table is above the top of the horst for most of its extent between U.S. Highway 70 and Tortugas Mountain and that the top of the horst is above the water table and acts as a subsurface flow barrier north of U.S. Highway 70.

Chloride control and monitoring program in the Wichita River Basin, Texas, 1996-2009

USGS Publications Warehouse

Haynie, M.M.; Burke, G.F.; Baldys, Stanley

2011-01-01

Water resources of the Wichita River Basin in north-central Texas are vital to the water users in Wichita Falls, Tex., and surrounding areas. The Wichita River Basin includes three major forks of the Wichita River upstream from Lake Kemp, approximately 50 miles southwest of Wichita Falls, Tex. The main stem of the Wichita River is formed by the confluence of the North Wichita River and Middle Fork Wichita River upstream from Truscott Brine Lake. The confluence of the South Wichita River with the Wichita River is northwest of Seymour, Tex. (fig. 1). Waters from the Wichita River Basin, which is part of the Red River Basin, are characterized by high concentrations of chloride and other salinity-related constituents from salt springs and seeps (hereinafter salt springs) in the upper reaches of the basin. These salt springs have their origins in the Permian Period when the Texas Panhandle and western Oklahoma areas were covered by a broad shallow sea. Over geologic time, evaporation of the shallow seas resulted in the formation of salt deposits, which today are part of the geologic formations underlying the area. Groundwater in these formations is characterized by high chloride concentrations from these salt deposits, and some of this groundwater is discharged by the salt springs into the Wichita River.

Factors affecting ground-water exchange and catchment size for Florida lakes in mantled karst terrain

USGS Publications Warehouse

Lee, Terrie Mackin

2002-01-01

In the mantled karst terrain of Florida, the size of the catchment delivering ground-water inflow to lakes is often considerably smaller than the topographically defined drainage basin. The size is determined by a balance of factors that act individually to enhance or diminish the hydraulic connection between the lake and the adjacent surficial aquifer, as well as the hydraulic connection between the surficial aquifer and the deeper limestone aquifer. Factors affecting ground-water exchange and the size of the ground-water catchment for lakes in mantled karst terrain were examined by: (1) reviewing the physical and hydrogeological characteristics of 14 Florida lake basins with available ground-water inflow estimates, and (2) simulating ground-water flow in hypothetical lake basins. Variably-saturated flow modeling was used to simulate a range of physical and hydrogeologic factors observed at the 14 lake basins. These factors included: recharge rate to the surficial aquifer, thickness of the unsaturated zone, size of the topographically defined basin, depth of the lake, thickness of the surficial aquifer, hydraulic conductivity of the geologic units, the location and size of karst subsidence features beneath and onshore of the lake, and the head in the Upper Floridan aquifer. Catchment size and the magnitude of ground-water inflow increased with increases in recharge rate to the surficial aquifer, the size of the topographically defined basin, hydraulic conductivity in the surficial aquifer, the degree of confinement of the deeper Upper Floridan aquifer, and the head in the Upper Floridan aquifer. The catchment size and magnitude of ground-water inflow increased with decreases in the number and size of karst subsidence features in the basin, and the thickness of the unsaturated zone near the lake. Model results, although qualitative, provided insights into: (1) the types of lake basins in mantled karst terrain that have the potential to generate small and large amounts of ground-water inflow, and (2) the location of ground-water catchments that could be managed to safeguard lake water quality. Knowledge of how ground-water catchments are related to lakes could be used by water-resource managers to recommend setback distances for septic tank drain fields, agricultural land uses, and other land-use practices that contribute nutrients and major ions to lakes.

Using hydrogeologic data to evaluate geothermal potential in the eastern Great Basin

USGS Publications Warehouse

Masbruch, Melissa D.; Heilweil, Victor M.; Brooks, Lynette E.

2012-01-01

In support of a larger study to evaluate geothermal resource development of high-permeability stratigraphic units in sedimentary basins, this paper integrates groundwater and thermal data to evaluate heat and fluid flow within the eastern Great Basin. Previously published information from a hydrogeologic framework, a potentiometric-surface map, and groundwater budgets was compared to a surficial heat-flow map. Comparisons between regional groundwater flow patterns and surficial heat flow indicate a strong spatial relation between regional groundwater movement and surficial heat distribution. Combining aquifer geometry and heat-flow maps, a selected group of subareas within the eastern Great Basin are identified that have high surficial heat flow and are underlain by a sequence of thick basin-fill deposits and permeable carbonate aquifers. These regions may have potential for future geothermal resources development.

Comparison of evaporation at two central Florida lakes, April 2005–November 2007

USGS Publications Warehouse

Swancar, Amy

2015-09-25

Both lakes are seepage lakes (no surface-water inflow or outflows) that are dependent on groundwater inflow from their basins to offset an atmospheric deficit, because long-term rainfall in this area is less than evaporation. The Lake Starr basin, where sandy, well-drained ridges surround the lake, has a greater capacity to store infiltrating rain than the Lake Calm basin, which is flat and has poorly drained soils. The storage capacities of the basins affect groundwater exchange with the lakes. Rainfall and net groundwater exchange, which is related to basin characteristics, varied more between these two lakes than did evaporation during this study.

Changes in projected spatial and seasonal groundwater recharge in the upper Colorado River Basin

USGS Publications Warehouse

Tillman, Fred; Gangopadhyay, Subhrendu; Pruitt, Tom

2017-01-01

The Colorado River is an important source of water in the western United States, supplying the needs of more than 38 million people in the United States and Mexico. Groundwater discharge to streams has been shown to be a critical component of streamflow in the Upper Colorado River Basin (UCRB), particularly during low-flow periods. Understanding impacts on groundwater in the basin from projected climate change will assist water managers in the region in planning for potential changes in the river and groundwater system. A previous study on changes in basin-wide groundwater recharge in the UCRB under projected climate change found substantial increases in temperature, moderate increases in precipitation, and mostly periods of stable or slight increases in simulated groundwater recharge through 2099. This study quantifies projected spatial and seasonal changes in groundwater recharge within the UCRB from recent historical (1950 to 2015) through future (2016 to 2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections. Simulation results indicate that projected increases in basin-wide recharge of up to 15% are not distributed uniformly within the basin or throughout the year. Northernmost subregions within the UCRB are projected an increase in groundwater recharge, while recharge in other mainly southern subregions will decline. Seasonal changes in recharge also are projected within the UCRB, with decreases of 50% or more in summer months and increases of 50% or more in winter months for all subregions, and increases of 10% or more in spring months for many subregions.

Changes in Projected Spatial and Seasonal Groundwater Recharge in the Upper Colorado River Basin.

PubMed

Tillman, Fred D; Gangopadhyay, Subhrendu; Pruitt, Tom

2017-07-01

The Colorado River is an important source of water in the western United States, supplying the needs of more than 38 million people in the United States and Mexico. Groundwater discharge to streams has been shown to be a critical component of streamflow in the Upper Colorado River Basin (UCRB), particularly during low-flow periods. Understanding impacts on groundwater in the basin from projected climate change will assist water managers in the region in planning for potential changes in the river and groundwater system. A previous study on changes in basin-wide groundwater recharge in the UCRB under projected climate change found substantial increases in temperature, moderate increases in precipitation, and mostly periods of stable or slight increases in simulated groundwater recharge through 2099. This study quantifies projected spatial and seasonal changes in groundwater recharge within the UCRB from recent historical (1950 to 2015) through future (2016 to 2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections. Simulation results indicate that projected increases in basin-wide recharge of up to 15% are not distributed uniformly within the basin or throughout the year. Northernmost subregions within the UCRB are projected an increase in groundwater recharge, while recharge in other mainly southern subregions will decline. Seasonal changes in recharge also are projected within the UCRB, with decreases of 50% or more in summer months and increases of 50% or more in winter months for all subregions, and increases of 10% or more in spring months for many subregions. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Regional water table (2004) and water-level changes in the Mojave River and Morongo ground-water basins, Southwestern Mojave Desert, California

USGS Publications Warehouse

Stamos, Christina L.; Huff, Julia A.; Predmore, Steven K.; Clark, Dennis A.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During March and April 2004, the U.S. Geological Survey and other agencies made almost 900 water-level measurements in about 740 wells in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with historical data, changes in ground-water levels. A water-level contour map was drawn using data from 500 wells, providing coverage for most of the basins. In addition, 26 long-term (as much as 74 years) hydrographs were constructed which show water-level conditions throughout the basins, 9 short-term (1992 to 2004) hydrographs were constructed which show the effects of recharge and discharge along the Mojave River, and a water-level-change map was compiled to compare 2002 and 2004 water levels throughout the basins. The water-level change data show that in the Mojave River ground-water basin, more than one half (102) of the wells had water-level declines of 0.5 ft or more and almost one fifth (32) of the wells had declines greater than 5 ft. between 2002 and 2004. The water-level change data also show that about one tenth (17) of the wells compared in the Mojave River ground-water basin had water level increases of 0.5 ft or more. Most of the water-level increases were the result of stormflow in the Mojave River during March 2004, which resulted in recharge to wells in the floodplain aquifer mainly along the river in the Alto subarea and the Transition zone, and along the river east of Barstow. In the Morongo ground-water basin, nearly one half (55) of the wells had water-level declines of 0.5 ft or more, and about one tenth (13) of the wells had declines greater than 5 ft. The Warren subbasin, where artificial-recharge operations in Yucca Valley (pl. 1) have caused water levels to rise, had water-level increases of as much as about 97 ft since 2002.

Hybrid-optimization algorithm for the management of a conjunctive-use project and well field design

USGS Publications Warehouse

Chiu, Yung-Chia; Nishikawa, Tracy; Martin, Peter

2012-01-01

Hi‐Desert Water District (HDWD), the primary water‐management agency in the Warren Groundwater Basin, California, plans to construct a waste water treatment plant to reduce future septic‐tank effluent from reaching the groundwater system. The treated waste water will be reclaimed by recharging the groundwater basin via recharge ponds as part of a larger conjunctive‐use strategy. HDWD wishes to identify the least‐cost conjunctive‐use strategies for managing imported surface water, reclaimed water, and local groundwater. As formulated, the mixed‐integer nonlinear programming (MINLP) groundwater‐management problem seeks to minimize water‐delivery costs subject to constraints including potential locations of the new pumping wells, California State regulations, groundwater‐level constraints, water‐supply demand, available imported water, and pump/recharge capacities. In this study, a hybrid‐optimization algorithm, which couples a genetic algorithm and successive‐linear programming, is developed to solve the MINLP problem. The algorithm was tested by comparing results to the enumerative solution for a simplified version of the HDWD groundwater‐management problem. The results indicate that the hybrid‐optimization algorithm can identify the global optimum. The hybrid‐optimization algorithm is then applied to solve a complex groundwater‐management problem. Sensitivity analyses were also performed to assess the impact of varying the new recharge pond orientation, varying the mixing ratio of reclaimed water and pumped water, and varying the amount of imported water available. The developed conjunctive management model can provide HDWD water managers with information that will improve their ability to manage their surface water, reclaimed water, and groundwater resources.

A multi-tracer approach to delineate groundwater dynamics in the Rio Actopan Basin, Veracruz State, Mexico

NASA Astrophysics Data System (ADS)

Pérez Quezadas, Juan; Heilweil, Victor M.; Cortés Silva, Alejandra; Araguas, Luis; Salas Ortega, María del Rocío

2016-12-01

Geochemistry and environmental tracers were used to understand groundwater resources, recharge processes, and potential sources of contamination in the Rio Actopan Basin, Veracruz State, Mexico. Total dissolved solids are lower in wells and springs located in the basin uplands compared with those closer to the coast, likely associated with rock/water interaction. Geochemical results also indicate some saltwater intrusion near the coast and increased nitrate near urban centers. Stable isotopes show that precipitation is the source of recharge to the groundwater system. Interestingly, some high-elevation springs are more isotopically enriched than average annual precipitation at higher elevations, indicating preferential recharge during the drier but cooler winter months when evapotranspiration is reduced. In contrast, groundwater below 1,200 m elevation is more isotopically depleted than average precipitation, indicating recharge occurring at much higher elevation than the sampling site. Relatively cool recharge temperatures, derived from noble gas measurements at four sites (11-20 °C), also suggest higher elevation recharge. Environmental tracers indicate that groundwater residence time in the basin ranges from 12,000 years to modern. While this large range shows varying groundwater flowpaths and travel times, ages using different tracer methods (14C, 3H/3He, CFCs) were generally consistent. Comparing multiple tracers such as CFC-12 with CFC-113 indicates piston-flow to some discharge points, yet binary mixing of young and older groundwater at other points. In summary, groundwater within the Rio Actopan Basin watershed is relatively young (Holocene) and the majority of recharge occurs in the basin uplands and moves towards the coast.

Interaction of surface water and groundwater in the Nile River basin: isotopic and piezometric evidence

NASA Astrophysics Data System (ADS)

Kebede, Seifu; Abdalla, Osman; Sefelnasr, Ahmed; Tindimugaya, Callist; Mustafa, Osman

2017-05-01

Past discussions around water-resources management and development in the River Nile basin disregard groundwater resources from the equation. There is an increasing interest around factoring the groundwater resources as an integral part of the Nile Basin water resources. This is hampered by knowledge gap regarding the groundwater resources dynamics (recharge, storage, flow, quality, surface-water/groundwater interaction) at basin scale. This report provides a comprehensive analysis of the state of surface-water/groundwater interaction from the headwater to the Nile Delta region. Piezometric and isotopic (δ18O, δ2H) evidence reveal that the Nile changes from a gaining stream in the headwater regions to mostly a loosing stream in the arid lowlands of Sudan and Egypt. Specific zones of Nile water leakage to the adjacent aquifers is mapped using the two sources of evidence. Up to 50% of the surface-water flow in the equatorial region of the Nile comes from groundwater as base flow. The evidence also shows that the natural direction and rate of surface-water/groundwater interaction is largely perturbed by human activities (diversion, dam construction) particularly downstream of the Aswan High Dam in Egypt. The decrease in discharge of the Nile River along its course is attributed to leakage to the aquifers as well as to evaporative water loss from the river channel. The surface-water/groundwater interaction occurring along the Nile River and its sensitivity to infrastructure development calls for management strategies that account groundwater as an integral part of the Nile Basin resources.

Groundwater Levels for Selected Wells in the Chehalis River Basin, Washington

USGS Publications Warehouse

Fasser, E.T.; Julich, R.J.

2010-01-01

Groundwater levels for selected wells in the Chehalis River basin, Washington, are presented on an interactive web-based map to document the spatial distribution of groundwater levels in the study area during late summer 2009. Groundwater level data and well information were collected by the U.S. Geological Survey using standard techniques. The data are stored in the USGS National Water Information System (NWIS), Ground-Water Site-Inventory (GWSI) System.

Computer programs for describing the recession of ground-water discharge and for estimating mean ground-water recharge and discharge from streamflow records-update

USGS Publications Warehouse

Rutledge, A.T.

1998-01-01

The computer programs included in this report can be used to develop a mathematical expression for recession of ground-water discharge and estimate mean ground-water recharge and discharge. The programs are intended for analysis of the daily streamflow record of a basin where one can reasonably assume that all, or nearly all, ground water discharges to the stream except for that which is lost to riparian evapotranspiration, and where regulation and diversion of flow can be considered to be negligible. The program RECESS determines the master reces-sion curve of streamflow recession during times when all flow can be considered to be ground-water discharge and when the profile of the ground-water-head distribution is nearly stable. The method uses a repetitive interactive procedure for selecting several periods of continuous recession, and it allows for nonlinearity in the relation between time and the logarithm of flow. The program RORA uses the recession-curve displacement method to estimate the recharge for each peak in the streamflow record. The method is based on the change in the total potential ground-water discharge that is caused by an event. Program RORA is applied to a long period of record to obtain an estimate of the mean rate of ground-water recharge. The program PART uses streamflow partitioning to estimate a daily record of base flow under the streamflow record. The method designates base flow to be equal to streamflow on days that fit a requirement of antecedent recession, linearly interpolates base flow for other days, and is applied to a long period of record to obtain an estimate of the mean rate of ground-water discharge. The results of programs RORA and PART correlate well with each other and compare reasonably with results of the corresponding manual method.

Regional groundwater flow modeling of the Geba basin, northern Ethiopia

NASA Astrophysics Data System (ADS)

Gebreyohannes, Tesfamichael; De Smedt, Florimond; Walraevens, Kristine; Gebresilassie, Solomon; Hussien, Abdelwassie; Hagos, Miruts; Amare, Kassa; Deckers, Jozef; Gebrehiwot, Kindeya

2017-05-01

The Geba basin is one of the most food-insecure areas of the Tigray regional state in northern Ethiopia due to recurrent drought resulting from erratic distribution of rainfall. Since the beginning of the 1990s, rain-fed agriculture has been supported through small-scale irrigation schemes mainly by surface-water harvesting, but success has been limited. Hence, use of groundwater for irrigation purposes has gained considerable attention. The main purpose of this study is to assess groundwater resources in the Geba basin by means of a MODFLOW modeling approach. The model is calibrated using observed groundwater levels, yielding a clear insight into the groundwater flow systems and reserves. Results show that none of the hydrogeological formations can be considered as aquifers that can be exploited for large-scale groundwater exploitation. However, aquitards can be identified that can support small-scale groundwater abstraction for irrigation needs in regions that are either designated as groundwater discharge areas or where groundwater levels are shallow and can be tapped by hand-dug wells or shallow boreholes.

Hydrology and simulation of ground-water flow in the Tooele Valley ground-water basin, Tooele County, Utah

USGS Publications Warehouse

Stolp, Bernard J.; Brooks, Lynette E.

2009-01-01

Ground water is the sole source of drinking water within Tooele Valley. Transition from agriculture to residential land and water use necessitates additional understanding of water resources. The ground-water basin is conceptualized as a single interconnected hydrologic system consisting of the consolidated-rock mountains and adjoining unconsolidated basin-fill valleys. Within the basin fill, unconfined conditions exist along the valley margins and confined conditions exist in the central areas of the valleys. Transmissivity of the unconsolidated basin-fill aquifer ranges from 1,000 to 270,000 square feet per day. Within the consolidated rock of the mountains, ground-water flow largely is unconfined, though variability in geologic structure, stratigraphy, and lithology has created some areas where ground-water flow is confined. Hydraulic conductivity of the consolidated rock ranges from 0.003 to 100 feet per day. Ground water within the basin generally moves from the mountains toward the central and northern areas of Tooele Valley. Steep hydraulic gradients exist at Tooele Army Depot and near Erda. The estimated average annual ground-water recharge within the basin is 82,000 acre-feet per year. The primary source of recharge is precipitation in the mountains; other sources of recharge are irrigation water and streams. Recharge from precipitation was determined using the Basin Characterization Model. Estimated average annual ground-water discharge within the basin is 84,000 acre-feet per year. Discharge is to wells, springs, and drains, and by evapotranspiration. Water levels at wells within the basin indicate periods of increased recharge during 1983-84 and 1996-2000. During these periods annual precipitation at Tooele City exceeded the 1971-2000 annual average for consecutive years. The water with the lowest dissolved-solids concentrations exists in the mountain areas where most of the ground-water recharge occurs. The principal dissolved constituents are calcium and bicarbonate. Dissolved-solids concentration increases in the central and northern parts of Tooele Valley, at the distal ends of the ground-water flow paths. Increased concentration is due mainly to greater amounts of sodium and chloride. Deuterium and oxygen-18 values indicate water recharged primarily from precipitation occurs throughout the ground-water basin. Ground water with the highest percentage of recharge from irrigation exists along the eastern margin of Tooele Valley, indicating negligible recharge from the adjacent consolidated rock. Tritium and tritiogenic helium-3 concentrations indicate modern water exists along the flow paths originating in the Oquirrh Mountains between Settlement and Pass Canyons and extending between the steep hydraulic gradient areas at Tooele Army Depot and Erda. Pre-modern water exists in areas east of Erda and near Stansbury Park. Using the change in tritium along the flow paths originating in the Oquirrh Mountains, a first-order estimate of average linear ground-water velocity for the general area is roughly 2 to 5 feet per day. A numerical ground-water flow model was developed to simulate ground-water flow in the Tooele Valley ground-water basin and to test the conceptual understanding of the ground-water system. Simulating flow in consolidated rock allows recharge and withdrawal from wells in or near consolidated rock to be simulated more accurately. In general, the model accurately simulates water levels and water-level fluctuations and can be considered an adequate tool to help determine the valley-wide effects on water levels of additional ground-water withdrawal and changes in water use. The simulated increase in storage during a projection simulation using 2003 withdrawal rates and average recharge indicates that repeated years of average precipitation and recharge conditions do not completely restore the system after multiple years of below-normal precipitation. In the similar case where precipitation is 90

Hydrogeology of the Socorro and La Jencia basins, Socorro County, New Mexico

USGS Publications Warehouse

Anderholm, Scott K.

1987-01-01

The Socorro and La Jencia Basins are located in central Socorro County, New Mexico. The principal aquifer system in the Socorro and La Jencia Basins consists of, in descending order, the shallow aquifer, the Popotosa confining bed, and the Popotosa aquifer. The minor aquifer systems, which are dominant along the basin margins, are the Socorro volcanics aquifer system and the Mesozoic-Paleozoic aquifer system. On the east side of the Socorro Basin, water enters the principal aquifer system from the Mesozoic-Paleozoic aquifer system. On the west side of the Socorro Basin, groundwater flows from the principal aquifer system in La Jencia Basin eastward to the principal aquifer system in the Socorro Basin. The volume of this flow is limited by the permeability of the minor aquifer systems and the Popotosa confining bed. A water budget indicates that if no change in groundwater storage occurs in the Socorro Basin, groundwater inflow to the basin is about 53,000 acre-feet per year greater than groundwater outflow. Dissolution of gypsum, calcite, and dolomite seems to control water quality in the Mesozoic-Paleozoic aquifer. Water with a chloride concentration of as much as 1,000 milligrams per liter and a specific conductance of as much as 6,700 microsiemens per centimeter at 25 C is present in the northern and southern parts of the Socorro Basin. These large chloride concentrations may indicate upward movement of water from deeper in the basin in these areas. The water with the large chloride concentration in the southern part of the basin also may be caused by leakage of geothermal waters along the Capitan Lineament. In the central part of the Socorro Basin, infiltration of excess irrigation water and inflow of groundwater from the basin margins control water quality. In this area, specific conductance generally is less than 1,000 microsiemens per centimeter. Water in La Jencia Basin generally is of the calcium sodium bicarbonate type with specific conductance less than 500 microsiemens per centimeter. (USGS)

Gravity survey of groundwater characterization at Labuan Basin

NASA Astrophysics Data System (ADS)

Handayani, L.; Wardhana, D. D.; Hartanto, P.; Delinom, R.; Sudaryanto; Bakti, H.; Lubis, RF

2018-02-01

Labuan groundwater basin currently has an abundance of water. As a deltaic area of Lada Bay, groundwater supply comes from local precipitation and also from recharge region in mountain ranges surrounding. However, Labuan has been experiencing a fast economic development with high population and tourism industry growth. Such progress would lead to the increase of water consumption. A comprehensive groundwater management should be prepared for possible future problems. Therefore, a groundwater investigation is a necessary step towards that purpose. Gravity method was applied to identify the regional condition of the basement. The assessment of deep buried basin and basement relationship using gravity data is a challenge in groundwater investigation, but previous studies had indicated the efficiency of the method to obtain basic information and can be used as a foundation for more advanced studies.

Sustainability of water-supply at military installations, Kabul Basin, Afghanistan

USGS Publications Warehouse

Mack, Thomas J.; Chornack, Michael P.; Verstraeten, Ingrid M.; Linkov, Igor

2014-01-01

The Kabul Basin, including the city of Kabul, Afghanistan, is host to several military installations of Afghanistan, the United States, and other nations that depend on groundwater resources for water supply. These installations are within or close to the city of Kabul. Groundwater also is the potable supply for the approximately four million residents of Kabul. The sustainability of water resources in the Kabul Basin is a concern to military operations, and Afghan water-resource managers, owing to increased water demands from a growing population and potential mining activities. This study illustrates the use of chemical and isotopic analysis, groundwater flow modeling, and hydrogeologic investigations to assess the sustainability of groundwater resources in the Kabul Basin.Water supplies for military installations in the southern Kabul Basin were found to be subject to sustainability concerns, such as the potential drying of shallow-water supply wells as a result of declining water levels. Model simulations indicate that new withdrawals from deep aquifers may have less of an impact on surrounding community water supply wells than increased withdrawals from near- surface aquifers. Higher rates of recharge in the northern Kabul Basin indicate that military installations in that part of the basin may have fewer issues with long-term water sustainability. Simulations of groundwater withdrawals may be used to evaluate different withdrawal scenarios in an effort to manage water resources in a sustainable manner in the Kabul Basin.

Ground-Water Quality Data in the Coastal Los Angeles Basin Study Unit, 2006: Results from the California GAMA Program

USGS Publications Warehouse

Mathany, Timothy M.; Land, Michael; Belitz, Kenneth

2008-01-01

Ground-water quality in the approximately 860 square-mile Coastal Los Angeles Basin study unit (CLAB) was investigated from June to November of 2006 as part of the Statewide Basin Assessment Project of the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment was developed in response to the Ground-Water Quality Monitoring Act of 2001, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The Coastal Los Angeles Basin study was designed to provide a spatially unbiased assessment of raw ground-water quality within CLAB, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 69 wells in Los Angeles and Orange Counties. Fifty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (?grid wells?). Fourteen additional wells were selected to evaluate changes in ground-water chemistry or to gain a greater understanding of the ground-water quality within a specific portion of the Coastal Los Angeles Basin study unit ('understanding wells'). Ground-water samples were analyzed for: a large number of synthetic organic constituents [volatile organic compounds (VOCs), gasoline oxygenates and their degradates, pesticides, polar pesticides, and pesticide degradates, pharmaceutical compounds, and potential wastewater-indicators]; constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), 1,4-dioxane, and 1,2,3-trichloropropane (1,2,3-TCP)]; inorganic constituents that can occur naturally [nutrients, major and minor ions, and trace elements]; radioactive constituents [gross-alpha and gross-beta radiation, radium isotopes, and radon-222]; and microbial indicators. Naturally occurring isotopes [stable isotopic ratios of hydrogen and oxygen, and activities of tritium and carbon-14] and dissolved noble gases also were measured to help identify the sources and ages of the sampled ground water. Quality-control samples (blanks, replicates, and samples for matrix spikes) were collected at approximately one-fourth of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a significant source of bias. Differences between replicate samples were within acceptable ranges, indicating acceptably low variability. Matrix spike recoveries were within acceptable ranges for most compounds. Assessment of the quality-control information resulted in applying ?V? codes to approximately 0.1 percent of the data collected for ground-water samples (meaning a constituent was detected in blanks as well as the corresponding environmental data). This study did not attempt to evaluate the quality of drinking water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain acceptable drinking-water quality. Regulatory thresholds are applied to the treated drinking water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with regulatory and non-regulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA), California Department of Public Health (CDPH, formerly California Department of Health Services [CADHS]) and thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only, and are not indicative of compliance or non-compliance with those thresholds. VOCs were detected in alm

A multi-method study of regional groundwater circulation in the Ordos Plateau, NW China

NASA Astrophysics Data System (ADS)

Jiang, Xiao-Wei; Wan, Li; Wang, Xu-Sheng; Wang, Dan; Wang, Heng; Wang, Jun-Zhi; Zhang, Hong; Zhang, Zhi-Yuan; Zhao, Ke-Yu

2018-01-01

The Ordos Basin is one of the most intensively studied groundwater basins in China. The Ordos Plateau, located in the north part of the Ordos Basin, is ideal to study the pattern of regional groundwater circulation induced by water-table undulations due to the wavy topography and the relatively simple aquifer systems with macroscopically homogeneous sandstone. In catchments located near the first-order divide, the water table is found to be a subdued replica of the topography, and the nonclosed water-table contours in topographic highs of a catchment are indicative of regional groundwater outflow to other catchments. In topographic lows, groundwater-fed lakes/rivers, topography-driven flowing wells, water-loving and/or salt-tolerant vegetation, and soap holes are all indicative of discharge areas. In discharge areas, although groundwater inflow from recharge areas is relatively stable, seasonal variations in groundwater recharge and evapotranspiration lead to significant seasonal fluctuations in the water table, which can be used to estimate groundwater inflow and evapotranspiration rates based on water balance at different stages of water-table change. In the lowest reaches of a complex basin, superposition of local flow systems on regional flow systems has been identified based on groundwater samples collected from wells with different depths and geophysical measurements of apparent resistivity, both of which can be used for characterizing groundwater flow systems. This study enhances understanding of the pattern of regional groundwater circulation in the Ordos Plateau, and also tests the effectiveness of methods for groundwater flow-system characterization.

California GAMA program: ground-water quality data in the San Diego drainages hydrogeologic province, California, 2004

USGS Publications Warehouse

Wright, Michael T.; Belitz, Kenneth; Burton, Carmen A.

2005-01-01

Because of concerns over ground-water quality, the California State Water Resources Control Board (SWRCB), in collaboration with the U.S. Geological Survey and Lawrence Livermore National Laboratory, has implemented the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. A primary objective of the program is to provide a current assessment of ground-water quality in areas where public supply wells are an important source of drinking water. The San Diego GAMA study unit was the first region of the state where an assessment of ground-water quality was implemented under the GAMA program. The San Diego GAMA study unit covers the entire San Diego Drainages hydrogeologic province, and is broken down into four distinct hydrogeologic study areas: the Temecula Valley study area, the Warner Valley study area, the Alluvial Basins study area, and the Hard Rock study area. A total of 58 ground-water samples were collected from public supply wells in the San Diego GAMA study unit: 19 wells were sampled in the Temecula Valley study area, 9 in the Warner Valley study area, 17 in the Alluvial Basins study area, and 13 in the Hard Rock study area. Over 350 chemical and microbial constituents and water-quality indicators were analyzed for in this study. However, only select wells were measured for all constituents and water-quality indicators. Results of analyses were calculated as detection frequencies by constituent classification and by individual constituents for the entire San Diego GAMA study unit and for the individual study areas. Additionally, concentrations of constituents that are routinely monitored were compared to maximum contaminant levels (MCL) and secondary maximum contaminant levels (SMCL). Concentrations of constituents classified as 'unregulated chemicals for which monitoring is required' (UCMR) were compared to the 'detection level for the purposes of reporting' (DLR). Eighteen of the 88 volatile organic compounds (VOCs) and gasoline oxygenates analyzed for were detected in ground-water samples. Twenty-eight wells sampled in the San Diego GAMA study had at least a single detection of VOCs or gasoline oxygenates. These constituents were most frequently detected in the Alluvial Basin study area (11 of 17 wells), and least frequently detected in the Warner Valley study area (one of nine wells). Trihalomethanes (THMs) were the most frequently detected class of VOCs (18 of 58 wells). The most frequently detected VOCs were chloroform (18 of 58 wells), bromodichloromethane (8 of 58 wells), and methyl tert-butyl ether (MTBE) (7 of 58 wells). Three VOCs were detected at concentrations greater than their MCLs. Tetrachloroethylene (PCE) and trichloroethylene (TCE) were detected in one well in the Hard Rock study area at concentrations of 9.75 and 7.27 micrograms per liter (?g/L), respectively; the MCL for these compounds is 5 ?g/L. MTBE was detected in one well in the Alluvial Basins study area at a concentration of 28.3 ?g/L; the MCL for MTBE is 13 ?g/L. Twenty-one of the 122 pesticides and pesticide degradates analyzed for were detected in ground-water samples. Pesticide or pesticide degradates were detected in 33 of 58 wells sampled, and were most frequently detected in the Temecula Valley study area wells (9 of 14 wells), and least frequently in the Warner Valley study area wells (3 of 9 wells). Herbicides were the most frequently detected class of pesticides (31 of 58 wells), and simazine was the most frequently detected compound (27 of 58 wells), followed by deethylatrazine (14 of 58 wells), prometon (10 of 58 wells), and atrazine (9 of 58 wells). None of the pesticides detected in ground-water samples had concentrations that exceeded MCLs. Eight waste-water indicator compounds were detected in ground-water samples. Twenty-one of 47 wells sampled for waste-water indicator compounds had at least a single detection. Waste-water indicator compounds were detected most frequently in the Allu

The quality of our Nation's waters: water quality in the Denver Basin aquifer system, Colorado, 2003-05

USGS Publications Warehouse

Bauch, Nancy J.; Musgrove, MaryLynn; Mahler, Barbara J.; Paschke, Suzanne

2015-01-01

Availability and sustainability of groundwater in the Denver Basin aquifer system depend on water quantity and water quality. The Denver Basin aquifer system underlies about 7,000 square miles of the Great Plains in eastern Colorado and is the primary or sole source of water for domestic and public supply in many areas of the basin. Use of groundwater from the Denver Basin sandstone aquifers has been instrumental for development of the south Denver metropolitan area and other areas, but has resulted in a decline in water levels in some parts of the system. Human activities in many areas have adversely affected the quality of water in the aquifer system, especially the shallow parts. Groundwater in deeper parts of the system used for drinking water, once considered isolated from the effects of overlying land use, is increasingly vulnerable to contamination from human activities and geologic materials. Availability and sustainability of high-quality groundwater are vital to the economic health of the Denver Basin area.

Conceptual model of the uppermost principal aquifer systems in the Williston and Powder River structural basins, United States and Canada

USGS Publications Warehouse

Long, Andrew J.; Aurand, Katherine R.; Bednar, Jennifer M.; Davis, Kyle W.; McKaskey, Jonathan D.R.G.; Thamke, Joanna N.

2014-01-01

The three uppermost principal aquifer systems of the Northern Great Plains—the glacial, lower Tertiary, and Upper Cretaceous aquifer systems—are described in this report and provide water for irrigation, mining, public and domestic supply, livestock, and industrial uses. These aquifer systems primarily are present in two nationally important fossil-fuelproducing areas: the Williston and Powder River structural basins in the United States and Canada. The glacial aquifer system is contained within glacial deposits that overlie the lower Tertiary and Upper Cretaceous aquifer systems in the northeastern part of the Williston structural basin. Productive sand and gravel aquifers exist within this aquifer system. The Upper Cretaceous aquifer system is contained within bedrock lithostratigraphic units as deep as 2,850 and 8,500 feet below land surface in the Williston and Powder River structural basins, respectively. Petroleum extraction from much deeper formations, such as the Bakken Formation, is rapidly increasing because of recently improved hydraulic fracturing methods that require large volumes of relatively freshwater from shallow aquifers or surface water. Extraction of coalbed natural gas from within the lower Tertiary aquifer system requires removal of large volumes of groundwater to allow degasification. Recognizing the importance of understanding water resources in these energy-rich basins, the U.S. Geological Survey (USGS) Groundwater Resources Program (http://water.usgs.gov/ogw/gwrp/) began a groundwater study of the Williston and Powder River structural basins in 2011 to quantify this groundwater resource, the results of which are described in this report. The overall objective of this study was to characterize, quantify, and provide an improved conceptual understanding of the three uppermost and principal aquifer systems in energy-resource areas of the Northern Great Plains to assist in groundwater-resource management for multiple uses. The study area includes parts of Montana, North Dakota, South Dakota, and Wyoming in the United States and Manitoba and Saskatchewan in Canada. The glacial aquifer system is contained within glacial drift consisting primarily of till, with smaller amounts of glacial outwash sand and gravel deposits. The lower Tertiary and Upper Cretaceous aquifer systems are contained within several formations of the Tertiary and Cretaceous geologic systems, which are hydraulically separated from underlying aquifers by a basal confining unit. The lower Tertiary and Upper Cretaceous aquifer systems each were divided into three hydrogeologic units that correspond to one or more lithostratigraphic units. The period prior to 1960 is defined as the predevelopment period when little groundwater was extracted. From 1960 through 1990, numerous flowing wells were installed near the Yellowstone, Little Missouri and Knife Rivers, resulting in local groundwater declines. Recently developed technologies for the extraction of petroleum resources, which largely have been applied in the study area since about 2005, require millions of gallons of water for construction of each well, with additional water needed for long-term operation; therefore, the potential for an increase in groundwater extraction is high. In this study, groundwater recharge and discharge components were estimated for the period 1981–2005. Groundwater recharge primarily occurs from infiltration of rainfall and snowmelt (precipitation recharge) and infiltration of streams into the ground (stream infiltration). Total estimated recharge to the Williston and Powder River control volumes is 4,560 and 1,500 cubic feet per second, respectively. Estimated precipitation recharge is 26 and 15 percent of total recharge for the Williston and Powder River control volumes, respectively. Estimated stream infiltration is 71 and 80 percent of total recharge for the Williston and Powder River control volumes, respectively. Groundwater discharge primarily is to streams and springs and is estimated to be about 97 and 92 percent of total discharge for the Williston and Powder River control volumes, respectively. Most of the remaining discharge results from pumped and flowing wells. Groundwater flow in the Williston structural basin generally is from the west and southwest toward the east, where discharge to streams occurs. Locally, in the uppermost hydrogeologic units, groundwater generally is unconfined and flows from topographically high to low areas, where discharge to streams occurs. Groundwater flow in the Powder River structural basin generally is toward the north, with local variations, particularly in the upper Fort Union aquifer, where flow is toward streams.

A thick lens of fresh groundwater in the southern Lihue Basin, Kauai, Hawaii, USA

USGS Publications Warehouse

Izuka, S.K.; Gingerich, S.B.

2003-01-01

A thick lens of fresh groundwater exists in a large region of low permeability in the southern Lihue Basin, Kauai, Hawaii, USA. The conventional conceptual model for groundwater occurence in Hawaii and other shield-volcano islands does not account for such a thick freshwater lens. In the conventional conceptual model, the lava-flow accumulations of which most shield volcanoes are built form large regions of relatively high permeability and thin freshwater lenses. In the southern Lihue Basin, basin-filling lavas and sediments form a large region of low regional hydraulic conductivity, which, in the moist climate of the basin, is saturated nearly to the land surface and water tables are hundreds of meters above sea level within a few kilometers from the coast. Such high water levels in shield-volcano islands were previously thought to exist only under perched or dike-impounded conditions, but in the southern Lihue Basin, high water levels exist in an apparently dike-free, fully saturated aquifer. A new conceptual model of groundwater occurrence in shield-volcano islands is needed to explain conditions in the southern Lihue Basin.

Groundwater quality assessment/corrective action feasibility plan: New TNX Seepage Basin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichols, R.L.

1989-12-05

The New TNX Seepage Basin is located across River Road east of the TNX Area at the Savannah River Site. Currently the basin is out of service and is awaiting closure in accordance with the Consent Decree settled under Civil Act No. 1:85-2583. Groundwater monitoring data from the detection monitoring network around the New TNX Seepage Basin was recently analyzed using South Carolina Hazardous Waste Management Regulations R.61-79.264.92 methods to determine if groundwater downgradient of the New TNX Seepage Basin had been impacted. Results from the data analysis indicate that the groundwater has been impacted by inorganic constituents with nomore » associated health risks. The impacts resulting from elevated levels of inorganic constituents, such as Mn, Na, and Total PO{sub 4} in the water table, do not pose a threat to human health and the environment.« less

Water quality, discharge, and groundwater levels in the Palomas, Mesilla, and Hueco Basins in New Mexico and Texas from below Caballo Reservoir, New Mexico, to Fort Quitman, Texas, 1889-2013

USGS Publications Warehouse

McKean, Sarah E.; Matherne, Anne Marie; Thomas, Nicole

2014-01-01

The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, compiled data from various sources to develop a dataset that can be used to conduct an assessment of the total dissolved solids in surface water and groundwater of the Palomas, Mesilla, and Hueco Basins in New Mexico and Texas, from below Caballo Reservoir, N. Mex., to Fort Quitman, Tex. Data include continuous surface-water discharge records at various locations on the Rio Grande; surface-water-quality data for the Rio Grande collected at selected locations in the Palomas, Mesilla, and Hueco Basins; groundwater levels and groundwater-quality data collected from selected wells in the Palomas and Mesilla Basins; and data from several seepage investigations conducted on the Rio Grande and selected drains in the Mesilla Basin.

Groundwater availability of the Denver Basin aquifer system, Colorado

USGS Publications Warehouse

Paschke, Suzanne

2011-01-01

The Denver Basin aquifer system is a critical water resource for growing municipal, industrial, and domestic uses along the semiarid Front Range urban corridor of Colorado. The confined bedrock aquifer system is located along the eastern edge of the Rocky Mountain Front Range where the mountains meet the Great Plains physiographic province. Continued population growth and the resulting need for additional water supplies in the Denver Basin and throughout the western United States emphasize the need to continually monitor and reassess the availability of groundwater resources. In 2004, the U.S. Geological Survey initiated large-scale regional studies to provide updated groundwater-availability assessments of important principal aquifers across the United States, including the Denver Basin. This study of the Denver Basin aquifer system evaluates the hydrologic effects of continued pumping and documents an updated groundwater flow model useful for appraisal of hydrologic conditions.

Effects of recharge and discharge on delta2H and delta18O composition and chloride concentration of high arsenic/fluoride groundwater from the Datong Basin, northern China.

PubMed

Xie, Xianjun; Wang, Yanxin; Su, Chunli; Duan, Mengyu

2013-02-01

To better understand the effects of recharge and discharge on the hydrogeochemistry of high levels of arsenic (As) and fluoride (F) in groundwater, environmental isotopic composition (delta2H and delta18O) and chloride (Cl) concentrations were analyzed in 29 groundwater samples collected from the Datong Basin. High arsenic groundwater samples (As > 50 micog/L) were found to be enriched in lighter isotopic composition that ranged from -92 to -78 per thousand for deuterium (delta2H) and from -12.5 to -9.9 per thousand for oxygen-18 (delta18O). High F-containing groundwater (F > 1 mg/L) was relatively enriched in heavier isotopic composition and varied from -90 to -57 per thousand and from -12.2 to -6.7 per thousand for delta2H and delta18O, respectively. High chloride concentrations and delta18O values were primarily measured in groundwater samples from the northern and southwestern portions of the study area, indicating the effect of evaporation on groundwater. The observation of relatively homogenized and low delta18O values and chloride concentrations in groundwater samples from central part of the Datong Basin might be a result of fast recharge by irrigation returns, which suggests that irrigation using arsenic-contaminated groundwater affected the occurrence of high arsenic-containing groundwater in the basin.

IDENTIFYING DISCHARGE ZONES OF ARSENIC IN THE GOOSE RIVER BASIN, MAINE

EPA Science Inventory

Groundwater discharge areas are simulated from water balance modeling and kriging of oxygen isotopes in groundwater within the Goose River basin. Groundwater fluxes of discharge range from -10 cm yr-1 to < -25 cm yr-1 and are associated with areas of elevated arsenic in wells. De...

Forecasting the effects of EU policy measures on the nitrate pollution of groundwater and surface waters

NASA Astrophysics Data System (ADS)

Kunkel, R.; Kreins, P.; Tetzlaff, B.; Wendland, F.

2009-04-01

The fundamental objectives of the European Union-Water Framework Directive and the EU Groundwater Directive are to attain a good status of water and groundwater resources in the member states of the EU by 2015. Following the implementation time table, the EU member States carried out a review about the qualitative and quantitative status for all river basins in the EU. For river basins, whose good status cannot be guaranteed by 2015, catchment wide operational plans and measurement programs are to be drafted and implemented until 2009. In the river basin district Weser, Germany, which comprises a catchment area of ca. 49.000 km2, the achievement of the good status is unclear, or rather unlikely for 63% of the groundwater bodies. Inputs from diffuse sources and most of all nitrogen losses from agriculturally used land have been identified as the main reasons for exceeding the groundwater threshold value for nitrate (50 mg/l) and for failing the „good qualitative status" of groundwater in 2015. For this reason the drafting and implementation of measurement programs in the Weser basin are primarily focused on nitrate. The achievement of good qualitative status of groundwater bodies entails a particular challenge especially for large river basins as the complex ecological, hydrological, hydrogeological and agro-economic relationships have to be considered simultaneously. Integrated large scale agroeconomic- hydrologic models are powerful tools to analyze the actual pollution loads and "hot spot" areas and to predict the temporal and spatial effects of reduction measures. We used the interdisciplinary model network REGFLUD to predict the nitrogen intakes into groundwater and the nitrogen losses to surface waters by different pathways at the regional scale using an area differentiated approach. The model system combines the agro-economic model RAUMIS for estimating nitrogen surpluses from agriculture and the hydrological models GROWA/DENUZ/WEKU for describing the reactive nitrate transport in the soil-groundwater system. Nitrogen transport by groundwater runoff, surface runoff, drainage runoff and natural interflow is considered. In a first step the model is used to analyze the present situation using N surpluses from agriculture for the year 2003. In many region of the Weser basin, particularly in the northwestern part which is characterized by high livestock densities, predicted nitrate concentrations in percolation water exceed the EU groundwater quality standard of 50 mg/L by far. In parallel, high nitrogen outputs to surface waters via the different pathways are predicted for these areas. The regional importance of a specific outtake pathway for nitrogen, however, may vary significantly depending on the individual site characteristics. Based on the results of the analysis of the present situation regionally adapted and hence effective agri-environmental reduction measures need to be derived and implemented to improve groundwater and surface water quality by 2015. These measures include both single measures and combination of measures, which will be analyzed with regard to their impact on the regional quality of percolation water and on their impacts on the regional agricultural income. In this context it is very important to distinguish between the effects of measures, which have already been implemented by current agricultural policy and measures which have to be additionally implemented to meet the environmental targets of the EU Water Framework Directive. For this purpose a baseline scenario is developed, which projects the effects of modified general conditions of the agricultural sector on the nitrogen surpluses to the year 2015. In this baseline scenario the effects of the common agricultural policy (CAP) of the EU, already implemented agri-environmental measures of the Federal States and the expected developments of agriculture are considered. According to this scenario the nitrogen surpluses for agricultural areas can be expected to be reduced only by about 10 kg N ha-1 a-1 on average for the whole Weser basin. However, for the agriculturally intensive used regions the expected N surpluses reduction may be much higher and can amount 40 kg N ha-1 a-1 or more. The REGLUD model system is used to quantify the potential effects of these projected N surpluses on the intakes into the groundwater the nitrogen pollution of surface waters. A comparison to the present situation shows that the potential nitrate concentration in the leachate will decrease in almost all regions of the Weser basin, mostly by about 10 mg NO3/L. In the agriculturally intensive used regions much higher reductions in the order of 40 mg NO3/L may be expected. Consequently, reduced nitrogen outflows to surface waters via the different pathways are obtained. Using environmental target values for groundwater and surface waters, e.g. a concentration of 50 mg NO3/L in the leachate as a target for groundwater protection, the model results can be used directly to identify those regions where additional agri-environmental reduction measures are required. Additionally, a backward calculation by the REGFLUD allows the quantification of maximal permissible nitrogen surplus levels, which can be used as a reference for the derivation of additional regionally adapted and hence effective nitrogen reduction measures. The research work presented here is carried out in the framework of the still ongoing AGRUM Weser project which is funded on behalf of the German Federal Ministry of Food, Agriculture and Consumer protection (BMELV) and the River Basin Commission Weser (FGG).

Use of environmental isotope tracer and GIS techniques to estimate basin recharge

NASA Astrophysics Data System (ADS)

Odunmbaku, Abdulganiu A. A.

The extensive use of ground water only began with the advances in pumping technology at the early portion of 20th Century. Groundwater provides the majority of fresh water supply for municipal, agricultural and industrial uses, primarily because of little to no treatment it requires. Estimating the volume of groundwater available in a basin is a daunting task, and no accurate measurements can be made. Usually water budgets and simulation models are primarily used to estimate the volume of water in a basin. Precipitation, land surface cover and subsurface geology are factors that affect recharge; these factors affect percolation which invariably affects groundwater recharge. Depending on precipitation, soil chemistry, groundwater chemical composition, gradient and depth, the age and rate of recharge can be estimated. This present research proposes to estimate the recharge in Mimbres, Tularosa and Diablo Basin using the chloride environmental isotope; chloride mass-balance approach and GIS. It also proposes to determine the effect of elevation on recharge rate. Mimbres and Tularosa Basin are located in southern New Mexico State, and extend southward into Mexico. Diablo Basin is located in Texas in extends southward. This research utilizes the chloride mass balance approach to estimate the recharge rate through collection of groundwater data from wells, and precipitation. The data were analysed statistically to eliminate duplication, outliers, and incomplete data. Cluster analysis, piper diagram and statistical significance were performed on the parameters of the groundwater; the infiltration rate was determined using chloride mass balance technique. The data was then analysed spatially using ArcGIS10. Regions of active recharge were identified in Mimbres and Diablo Basin, but this could not be clearly identified in Tularosa Basin. CMB recharge for Tularosa Basin yields 0.04037mm/yr (0.0016in/yr), Diablo Basin was 0.047mm/yr (0.0016 in/yr), and 0.2153mm/yr (0.00848in/yr) for Mimbres Basin. The elevation where active recharge occurs was determined to be 1,500m for Mimbres and Tularosa Basin and 1,200m for Diablo Basin. The results obtained in this study were consistent with result obtained by other researchers working in basins with similar semiarid mountainous conditions, thereby validating the applicability of CMB in the three basins. Keywords: Recharge, chloride mass balance, elevation, Mimbres, Tularosa, Diablo, Basin, GIS, chloride, elevation.

Research to More Effectively Manage Critical Ground-Water Basins

USGS Publications Warehouse

Nickles, James

2008-01-01

As the regional management agency for two of the most heavily used ground-water basins in California, the Water Replenishment District of Southern California (WRD) plays a vital role in sheparding the water resources of southern Los Angeles County. WRD is using the results of the U.S. Geological Survey (USGS) studies to help more effectively manage the Central and West Coast basins in the most efficient, cost-effective way. In partnership with WRD, the USGS is using the latest research tools to study the geohydrology and geochemistry of the two basins. USGS scientists are: *Drilling and collecting detailed data from over 40 multiple-well monitoring sites, *Conducting regional geohydrologic and geochemical analyses, *Developing and applying a computer simulation model of regional ground-water flow. USGS science is providing a more detailed understanding of ground-water flow and quality. This research has enabled WRD to more effectively manage the basins. It has helped the District improve the efficiency of its spreading ponds and barrier injection wells, which replenish the aquifers and control seawater intrusion into the ground-water system.

Human Health Impact of Fluoride in Groundwater in the Chiang Mai Basin

NASA Astrophysics Data System (ADS)

Matsui, Y.; Takizawa, S.; Wattanachira, S.; Wongrueng, A.; Ibaraki, M.

2005-12-01

Chiang Mai Basin, in Northern Thailand, is known as a fluorotic area. Groundwater of the Chiang Mai Basin has been gradually replaced by contaminated surface water since the 1980's. People have been exposed to fluoride contaminated groundwater since that time. As a result, harmful health effects on dental and skeletal growth were observed in the 90's. These include dental and skeletal fluorosis. Dental fluorosis is characterized by yellow or white spots on teeth and pitting or mottled enamel, consequently causing the teeth to look unsightly. Skeletal fluorosis leads to changes in bone structure, making them extremely weak and brittle. The most severe form of this is known as ``crippling skeletal fluorosis,'' a condition that can cause immobility, muscle wasting, and neurological problems related to spinal cord compression. This study focuses on the problematic issue of the Chiang Mai Basin's groundwater from the viewpoint of fluoride occurrence and current health impacts. Chiang Mai and Lamphun Provinces comprise the Chiang Mai Basin. Fluoride rich granites or fluorite deposits are scattered across the mountainside of the Lamphun Province. Tropical savanna climate conditions with seasonal monsoons bring more than 1,000 mm of annual precipitation, which can prompt weathering of minerals containing fluoride. The Ping River dominates the Basin, and the main eastern tributary of the Ping River runs through the Lamphun Province. The Basin has geological units composed of lower semi-consolidated Tertiary fluvial and upper unconsolidated Quaternary alluvium deposits. The main aquifers are in the upper unconsolidated unit. High fluoride concentrations tend to be observed in the aquifer located in lower part of this unconsolidated unit. We have been investigating two areas in the Basin. These two locations are similar with respect to geological and hydrological settings. However, one area in which groundwater is Ca-bicarbonate dominant has a low fluoride occurrence. Groundwater of the other area contains a high fluoride concentration and is Na-bicarbonate dominant. We will present how naturally-occurring fluoride found in this groundwater has impacted the health of a large portion of residents in the Chiang Mai Basin, and we will explain the mechanism that differentiates Ca concentration, which controls fluoride concentration in groundwater, between different areas in the Basin.

Estimation of Groundwater Storage Change via GRACE over a Small Watershed - A Case Study over Konya Closed Basin

NASA Astrophysics Data System (ADS)

Karasu, İ. G.; Yilmaz, K. K.; Yilmaz, M. T.

2017-12-01

Estimation of the groundwater storage change and its interannual variability is critical over Konya Closed Basin which has excessive agricultural production. The annual total precipitation falling over the region is not sufficient to compensate the agricultural irrigation needs of the region. This leds many to use groundwater as the primary water resource, which resulted in significant drop in the groundwater levels. Accordingly, monitoring of the groundwater change is critical for sustainable water resources management. Gravity Recovery and Climate Experiment (GRACE) observations and Global Land Data Assimilation System (GLDAS) have been succesfully used over many locations to monitor the change in the groundwater storages. In this study, GRACE-derived terrestrial water storage estimates and GLDAS model soil moisture, canopy water, snow water equivalent and surface runoff simulations are used to retrieve the change in the groundwater storage over Konya Closed Basin streching over 50,000 km2 area. Initial comparisons show the declining trend in GRACE and GLDAS combined groundwater storage change estimates between 2002 and 2016 are consistent with the actual groundwater level change observed at ground stations. Even though many studies recommend GRACE observations to be used over regions larger than 100,000 km2 - 200,000 km2 area, results show GRACE remote sensing and GLDAS modeled groundwater change information are skillful to monitor the large mass changes occured as a result of the excessive groundwater exploitation over Konya Closed Basin with 50,000 km2 area.

Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia

NASA Astrophysics Data System (ADS)

Cui, Tao; Raiber, Matthias; Pagendam, Dan; Gilfedder, Mat; Rassam, David

2018-03-01

Understanding the response of groundwater levels in alluvial and sedimentary basin aquifers to climatic variability and human water-resource developments is a key step in many hydrogeological investigations. This study presents an analysis of groundwater response to climate variability from 2000 to 2012 in the Queensland part of the sedimentary Clarence-Moreton Basin, Australia. It contributes to the baseline hydrogeological understanding by identifying the primary groundwater flow pattern, water-level response to climate extremes, and the resulting dynamics of surface-water/groundwater interaction. Groundwater-level measurements from thousands of bores over several decades were analysed using Kriging and nonparametric trend analysis, together with a newly developed three-dimensional geological model. Groundwater-level contours suggest that groundwater flow in the shallow aquifers shows local variations in the close vicinity of streams, notwithstanding general conformance with topographic relief. The trend analysis reveals that climate variability can be quickly reflected in the shallow aquifers of the Clarence-Moreton Basin although the alluvial aquifers have a quicker rainfall response than the sedimentary bedrock formations. The Lockyer Valley alluvium represents the most sensitively responding alluvium in the area, with the highest declining (-0.7 m/year) and ascending (2.1 m/year) Sen's slope rates during and after the drought period, respectively. Different surface-water/groundwater interaction characteristics were observed in different catchments by studying groundwater-level fluctuations along hydrogeologic cross-sections. The findings of this study lay a foundation for future water-resource management in the study area.

The role of baseflow in dissolved solids delivery to streams in the Upper Colorado River Basin

NASA Astrophysics Data System (ADS)

Rumsey, C.; Miller, M. P.; Schwarz, G. E.; Susong, D.

2017-12-01

Salinity has a major effect on water users in the Colorado River Basin, estimated to cause almost $300 million per year in economic damages. The Colorado River Basin Salinity Control Program implements and manages projects to reduce salinity (dissolved solids) loads, investing millions of dollars per year in irrigation upgrades, canal projects, and other mitigation strategies. To inform and improve mitigation efforts, there is a need to better understand sources of salinity to streams and how salinity has changed over time. This study explores salinity in baseflow, or groundwater discharge to streams, to assess whether groundwater is a significant contributor of dissolved solids to streams in the Upper Colorado River Basin (UCRB). Chemical hydrograph separation was used to estimate long-term mean annual baseflow discharge and baseflow dissolved solids loads at stream gages (n=69) across the UCRB. On average, it is estimated that 89% of dissolved solids loads originate from the baseflow fraction of streamflow. Additionally, a statistical trend analysis using weighted regressions on time, discharge, and season was used to evaluate changes in baseflow dissolved solids loads in streams with data from 1987 to 2011 (n=29). About two-thirds (62%) of these streams showed statistically significant decreasing trends in baseflow dissolved solids loads. At the two most downstream sites, Green River at Green River, UT and Colorado River at Cisco, UT, baseflow dissolved solids loads decreased by a combined 780,000 metric tons, which is approximately 65% of the estimated basin-scale decrease in total dissolved solids loads in the UCRB attributed to salinity control efforts. Results indicate that groundwater discharged to streams, and therefore subsurface transport processes, play a large role in delivering dissolved solids to streams in the UCRB. Decreasing trends in baseflow dissolved solids loads suggest that salinity mitigation projects, changes in land use, and/or climate are decreasing salinity in groundwater transported to streams.

Application of nonlinear-regression methods to a ground-water flow model of the Albuquerque Basin, New Mexico

USGS Publications Warehouse

Tiedeman, C.R.; Kernodle, J.M.; McAda, D.P.

1998-01-01

This report documents the application of nonlinear-regression methods to a numerical model of ground-water flow in the Albuquerque Basin, New Mexico. In the Albuquerque Basin, ground water is the primary source for most water uses. Ground-water withdrawal has steadily increased since the 1940's, resulting in large declines in water levels in the Albuquerque area. A ground-water flow model was developed in 1994 and revised and updated in 1995 for the purpose of managing basin ground- water resources. In the work presented here, nonlinear-regression methods were applied to a modified version of the previous flow model. Goals of this work were to use regression methods to calibrate the model with each of six different configurations of the basin subsurface and to assess and compare optimal parameter estimates, model fit, and model error among the resulting calibrations. The Albuquerque Basin is one in a series of north trending structural basins within the Rio Grande Rift, a region of Cenozoic crustal extension. Mountains, uplifts, and fault zones bound the basin, and rock units within the basin include pre-Santa Fe Group deposits, Tertiary Santa Fe Group basin fill, and post-Santa Fe Group volcanics and sediments. The Santa Fe Group is greater than 14,000 feet (ft) thick in the central part of the basin. During deposition of the Santa Fe Group, crustal extension resulted in development of north trending normal faults with vertical displacements of as much as 30,000 ft. Ground-water flow in the Albuquerque Basin occurs primarily in the Santa Fe Group and post-Santa Fe Group deposits. Water flows between the ground-water system and surface-water bodies in the inner valley of the basin, where the Rio Grande, a network of interconnected canals and drains, and Cochiti Reservoir are located. Recharge to the ground-water flow system occurs as infiltration of precipitation along mountain fronts and infiltration of stream water along tributaries to the Rio Grande; subsurface flow from adjacent regions; irrigation and septic field seepage; and leakage through the Rio Grande, canal, and Cochiti Reservoir beds. Ground water is discharged from the basin by withdrawal; evapotranspiration; subsurface flow; and flow to the Rio Grande, canals, and drains. The transient, three-dimensional numerical model of ground-water flow to which nonlinear-regression methods were applied simulates flow in the Albuquerque Basin from 1900 to March 1995. Six different basin subsurface configurations are considered in the model. These configurations are designed to test the effects of (1) varying the simulated basin thickness, (2) including a hypothesized hydrogeologic unit with large hydraulic conductivity in the western part of the basin (the west basin high-K zone), and (3) substantially lowering the simulated hydraulic conductivity of a fault in the western part of the basin (the low-K fault zone). The model with each of the subsurface configurations was calibrated using a nonlinear least- squares regression technique. The calibration data set includes 802 hydraulic-head measurements that provide broad spatial and temporal coverage of basin conditions, and one measurement of net flow from the Rio Grande and drains to the ground-water system in the Albuquerque area. Data are weighted on the basis of estimates of the standard deviations of measurement errors. The 10 to 12 parameters to which the calibration data as a whole are generally most sensitive were estimated by nonlinear regression, whereas the remaining model parameter values were specified. Results of model calibration indicate that the optimal parameter estimates as a whole are most reasonable in calibrations of the model with with configurations 3 (which contains 1,600-ft-thick basin deposits and the west basin high-K zone), 4 (which contains 5,000-ft-thick basin de

NAWQA, National Water-Quality Assessment Program; Allegheny-Monongahela River Basin

USGS Publications Warehouse

McAuley, Steven D.; Brown, Juliane B.; Sams, James I.

1997-01-01

Surface-water and ground-water quality and aquatic life can be significantly affected by the following principal issues identified in the Allegheny-Monongahela River Basin:Contaminants common to surface and under-ground coal mine discharge such as acidity, iron, aluminum, manganese, and sulfate.Volatile organic compounds (VOC’s), pesti-cides, and nutrients from increased urbanization.Runoff and loading of nutrients and pesticides to streams from nonpoint and point sources such as agricultural land uses.Radon in ground water.

The integrated project AquaTerra of the EU sixth framework lays foundations for better understanding of river-sediment-soil-groundwater systems.

PubMed

Gerzabek, M H; Barceló, D; Bellin, A; Rijnaarts, H H M; Slob, A; Darmendrail, D; Fowler, H J; Négrel, Ph; Frank, E; Grathwohl, P; Kuntz, D; Barth, J A C

2007-07-01

The integrated project "AquaTerra" with the full title "integrated modeling of the river-sediment-soil-groundwater system; advanced tools for the management of catchment areas and river basins in the context of global change" is among the first environmental projects within the sixth Framework Program of the European Union. Commencing in June 2004, it brought together a multidisciplinary team of 45 partner organizations from 12 EU countries, Romania, Switzerland, Serbia and Montenegro. AquaTerra is an ambitious project with the primary objective of laying the foundations for a better understanding of the behavior of environmental pollutants and their fluxes in the soil-sediment-water system with respect to climate and land use changes. The project performs research as well as modeling on river-sediment-soil-groundwater systems through quantification of deposition, sorption and turnover rates and the development of numerical models to reveal fluxes and trends in soil and sediment functioning. Scales ranging from the laboratory to river basins are addressed with the potential to provide improved river basin management, enhanced soil and groundwater monitoring as well as the early identification and forecasting of impacts on water quantity and quality. Study areas are the catchments of the Ebro, Meuse, Elbe and Danube Rivers and the Brévilles Spring. Here we outline the general structure of the project and the activities conducted within eleven existing sub-projects of AquaTerra.

Effects of Stormwater Infiltration on Quality of Groundwater Beneath Retention and Detention Basins

EPA Science Inventory

Use of stormwater retention and detention basins has become a popular method for managing urban and suburban stormwater runoff. Infiltration of stormwater through these basins may increase the risk to ground-water quality, especially in areas where the soil is sandy and the wate...

Forecasting the effects of EU policy measures on the nitrate pollution of groundwater based on a coupled agroeconomic - hydro(geo)logic model (Invited)

NASA Astrophysics Data System (ADS)

Wendland, F.

2010-12-01

The fundamental objectives of the European Union-Water Framework Directive and the EU Groundwater Directive are to attain a good status of water and groundwater resources in the member states of the EU by 2015. For river basins, whose good status cannot be guaranteed by 2015, catchment wide operational plans and measurement programs have to be drafted and implemented until 2009. In the river basin district Weser, Germany, which comprises a catchment area of ca. 49.000 km2, the achievement of the good status is unclear, or rather unlikely for 63% of the groundwater bodies. Inputs from diffuse sources and most of all nitrate losses from agriculturally used land have been identified as the main reasons for exceeding the groundwater threshold value for nitrate (50 mg/l) and for failing the good qualitative status of groundwater. The achievement of good qualitative status of groundwater bodies entails a particular challenge as the complex ecological, hydrological, hydrogeological and agro-economic relationships have to be considered simultaneously. We used an interdisciplinary model network to predict the nitrogen intakes into groundwater at the regional scale using an area differentiated approach. The model system combines the agro-economic model RAUMIS for estimating nitrogen surpluses from agriculture and the hydrological models GROWA/DENUZ/WEKU for describing the reactive nitrate transport in the soil-groundwater system. In a first step the model is used to analyze the present situation using N surpluses from agriculture for the year 2003. In many region of the Weser basin, particularly in the northwestern part which is characterized by high livestock densities, predicted nitrate concentrations in percolation water exceed the EU groundwater quality standard of 50 mg/L by far. In a second step the temporal and spatial impacts of the common agricultural policy (CAP) of the EU, already implemented agri-environmental measures of the Federal States and the expected developments of agriculture were assessed with regard to both, groundwater quality in 2015 and the regional agricultural income. On average for the whole Weser basin, the reduction of nitrogen surpluses for agricultural areas leads to a decrease of nitrate concentrations in the leachate by about 10 mg NO3/L. In the agricultural intensive used regions much higher reductions in the order of 40 mg NO3/L may be expected. Using the environmental target value for groundwater, i.e. a concentration of 50 mg NO3/L in the leachate as a target for groundwater protection, the model results were used directly to identify those regions where additional agro-environmental reduction measures are required. There, a backward calculation allows the quantification of maximal permissible nitrogen surplus levels, which was used as a reference for the derivation of additional nitrogen reduction measures. It could be shown that a further reduction by ca. 20.000 t N/a (19%) is necessary to reach a nitrate concentration in groundwater of 50 mg/l. The related costs sum up to ca. 75 Mio €/a. The research work was carried out in the framework of the AGRUM Weser project which was funded on behalf of the German Federal Ministry of Food, Agriculture and Consumer protection (BMELV) and the River Basin Commission Weser (FGG).

Preliminary three-dimensional geohydrologic framework of the San Antonio Creek Groundwater Basin, Santa Barbara County, California

NASA Astrophysics Data System (ADS)

Cromwell, G.; Sweetkind, D. S.; O'leary, D. R.

2017-12-01

The San Antonio Creek Groundwater Basin is a rural agricultural area that is heavily dependent on groundwater to meet local water demands. The U.S. Geological Survey (USGS) is working cooperatively with Santa Barbara County and Vandenberg Air Force Base to assess the quantity and quality of the groundwater resources within the basin. As part of this assessment, an integrated hydrologic model that will help stakeholders to effectively manage the water resources in the basin is being developed. The integrated hydrologic model includes a conceptual model of the subsurface geology consisting of stratigraphy and variations in lithology throughout the basin. The San Antonio Creek Groundwater Basin is a relatively narrow, east-west oriented valley that is structurally controlled by an eastward-plunging syncline. Basin-fill material beneath the valley floor consists of relatively coarse-grained, permeable, marine and non-marine sedimentary deposits, which are underlain by fine-grained, low-permeability, marine sedimentary rocks. To characterize the system, surficial and subsurface geohydrologic data were compiled from geologic maps, existing regional geologic models, and lithology and geophysical logs from boreholes, including two USGS multiple-well sites drilled as part of this study. Geohydrologic unit picks and lithologic variations are incorporated into a three-dimensional framework model of the basin. This basin (model) includes six geohydrologic units that follow the structure and stratigraphy of the area: 1) Bedrock - low-permeability marine sedimentary rocks; 2) Careaga Formation - fine to coarse grained near-shore sandstone; 3) Paso Robles Formation, lower portion - sandy-gravely deposits with clay and limestone; 4) Paso Robles Formation, middle portion - clayey-silty deposits; 5) Paso Robles Formation, upper portion - sandy-gravely deposits; and 6) recent Quaternary deposits. Hydrologic data show that the upper and lower portions of the Paso Robles Formation are the primary grou­ndwater-bearing units within the basin, and that the fine-grained layer within this Formation locally restricts vertical groundwater flow.

Records of wells, ground-water levels, and ground-water withdrawals in the lower Goose Creek Basin, Cassia County, Idaho

USGS Publications Warehouse

Mower, R.W.

1954-01-01

Investigations by the United States Geological Survey of Ground Water in the Southern border area of the Snake Rive Plain, south of the Snake River, a re concerned at the present time with delineation of the principal ground-water districts, the extent and location of existing ground-water developments, the possibilities for additional development, and the effects of ground-water development on the regimen of streams and reservoirs whose waters are appropriate for beneficial use. The lower part of the Goose Creek Basin is one of the important ground-water districts of the southern plains area and there are substantial but spotty developments of ground water for irrigation in the basin. Several thousand irrigable acres that are now dry could be put under irrigation if a dependable supply of ground water could be developed. The relations of the ground-water reservoirs to the regime of the Snake River and Goose Cree, and to the large body of ground water in the Snake River Plain north of the Snake, are poorly known. A large amount of geologic and hydrologic study remains to be done before those relations can be accurately determined. Investigations will be continued in the future but file work and preparation of a comprehensive report inevitably will be delayed. Therefore the available records are presented herein in order to make them accessible to farmers, well drillers, government agencies, and the general public. Interpretation of the records is not attempted in this report and is deferred pending the accumulation of additional and quantitative information. The data summarized herein include records of the locations and physical characteristics of wells, the depth to water in wells, fluctuations of water levels in observation wells, and estimated rates and volumes of seasonal ans yearly ground-water pumpage for irrigation, municipal, and other uses. This information is complete for work done as of December 31, 1952. The investigations upon which this report is based were undertaken in cooperation with the U.S. Bureau of Reclamation, Region I, at the request of the Planning Division, Central Snake River District. The report was complied in the first instance for the use of the Bureau of Reclamation but is now released to the public. The observation-well program in the area has been maintained in cooperation with the Idaho State Department of Reclamation as part of the regular cooperative program of the Geological Survey.

A high-resolution global-scale groundwater model

NASA Astrophysics Data System (ADS)

de Graaf, I. E. M.; Sutanudjaja, E. H.; van Beek, L. P. H.; Bierkens, M. F. P.

2015-02-01

Groundwater is the world's largest accessible source of fresh water. It plays a vital role in satisfying basic needs for drinking water, agriculture and industrial activities. During times of drought groundwater sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global-scale hydrological models (GHMs) do not include a groundwater flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and groundwater head dynamics, a realistic physical representation of the groundwater system is needed, especially for GHMs that run at finer resolutions. In this study we present a global-scale groundwater model (run at 6' resolution) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The used aquifer schematization and properties are based on available global data sets of lithology and transmissivities combined with the estimated thickness of an upper, unconfined aquifer. This model is forced with outputs from the land-surface PCRaster Global Water Balance (PCR-GLOBWB) model, specifically net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed that variation in saturated conductivity has the largest impact on the groundwater levels simulated. Validation with observed groundwater heads showed that groundwater heads are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional-scale groundwater patterns and flow paths demonstrate the relevance of lateral groundwater flow in GHMs. Inter-basin groundwater flows can be a significant part of a basin's water budget and help to sustain river baseflows, especially during droughts. Also, water availability of larger aquifer systems can be positively affected by additional recharge from inter-basin groundwater flows.

Groundwater-Quality Data in the South Coast Range-Coastal Study Unit, 2008: Results from the California GAMA Program

USGS Publications Warehouse

Mathany, Timothy M.; Burton, Carmen A.; Land, Michael; Belitz, Kenneth

2010-01-01

Groundwater quality in the approximately 766-square-mile South Coast Range-Coastal (SCRC) study unit was investigated from May to December 2008, as part of the Priority Basins Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basins Project was developed in response to legislative mandates (Supplemental Report of the 1999 Budget Act 1999-00 Fiscal Year; and, the Groundwater Quality Monitoring Act of 2001 [Sections 10780-10782.3 of the California Water Code, Assembly Bill 599]) to assess and monitor the quality of groundwater in California, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The SCRC study unit was the 25th study unit to be sampled as part of the GAMA Priority Basins Project. The SCRC study unit was designed to provide a spatially unbiased assessment of untreated groundwater quality in the primary aquifer systems and to facilitate statistically consistent comparisons of untreated groundwater quality throughout California. The primary aquifer systems (hereinafter referred to as primary aquifers) were defined as that part of the aquifer corresponding to the perforation interval of wells listed in the California Department of Public Health (CDPH) database for the SCRC study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from the quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to surficial contamination. In the SCRC study unit, groundwater samples were collected from 70 wells in two study areas (Basins and Uplands) in Santa Barbara and San Luis Obispo Counties. Fifty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 15 wells were selected to aid in evaluation of specific water-quality issues (understanding wells). In addition to the 70 wells sampled, 3 surface-water samples were collected in streams near 2 of the sampled wells in order to better comprehend the interaction between groundwater and surface water in the area. The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOC], pesticides and pesticide degradates, polar pesticides and metabolites, and pharmaceutical compounds), constituents of special interest (perchlorate, N-nitrosodimethylamine [NDMA], and 1,2,3-TCP), naturally occurring inorganic constituents (trace elements, nutrients, dissolved organic carbon [DOC], major and minor ions, silica, total dissolved solids [TDS], and alkalinity), and radioactive constituents (gross alpha and gross beta radioactivity). Naturally occurring isotopes (stable isotopes of hydrogen and oxygen in water, stable isotopes of nitrogen and oxygen in dissolved nitrate, stable isotopes of sulfur in dissolved sulfate, stable isotopes of carbon in dissolved inorganic carbon, activities of tritium, and carbon-14 abundance), and dissolved gases (including noble gases) also were measured to help identify the sources and ages of the sampled groundwater. In total, 298 constituents and field water-quality indicators were investigated. Three types of quality-control samples (blanks, replicates, and matrix-spikes) were collected at approximately 3 to 12 percent of the wells in the SCRC study unit, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination from sample collection procedures was not a significant source of bias in the data for the groundwater samples. Differences between replicate samples generally were less than 10 percent relative and/or standard deviation, indicating acceptable analytical reproducibility. Matrix-spike recoveries were within the acceptable range (70 to 130 percent) for approximately 84

Hydrogeological bedrock inferred from electrical resistivity model in Taichung Basin, Taiwan

NASA Astrophysics Data System (ADS)

Chiang, C. W.; Chang, P. Y.; Chang, L. C.

2015-12-01

The four-year project of the study of groundwater hydrogeology and recharge model was indicated by Central Geological Survey, MOEA, Taiwan (R.O.C.) to evaluate recharge groundwater areas in Taiwan where included Taipei, Taichung Basins, Lanyang and Chianan Plains. The groundwater recharge models of Lanyang Plain and Taipei Basin have successfully been estimated in two years ago (2013-2014). The third year of the project integrates with geophysical, geochemistry, and hydrogeology models to estimate the groundwater recharge model in Taichung Basin region. Taichung Basin is mainly covered by Pre-Pleistocene of thick gravel, sandy and muddy sediment rocks within a joint alluvial fan, whereas the depth of the hydrological bedrock remains uncertain. Two electrical resistivity geophysical tools were carried out utilizing direct current resistivity and audio-magnetotelluric (AMT) explorations, which could ideally provide the depth resolutions from shallow to depth for evaluating the groundwater resources. The study has carried out 21 AMT stations in the southern Taichung Basin in order to delineate hydrological bedrock in the region. All the AMT stations were deployed about 24 hours and processed with remote reference technique to reduce culture noises. The quality of most stations shows acceptable in the area which two stations were excluded due to near-field source effect in the southwestern basin. The best depth resolution is identified in 500 meters for the model. The preliminary result shows that the depths of the bedrock gradually changes from southern ~20 m toward to ~400 m in central, and eastern ~20 m to 180 m in the western basin inferred from the AMT model. The investigation shows that AMT method could be a useful geophysical tool to enhance the groundwater recharge model estimation without dense loggings in the region.

Ground-water quality in the Santa Rita, Buellton, and Los Olivos hydrologic subareas of the Santa Ynez River basin, Santa Barbara County, California

USGS Publications Warehouse

Hamlin, S.N.

1985-01-01

Groundwater quality in the upper Santa Ynez River Valley in Santa Barbara County has degraded due to both natural and anthropogenic causes. The semiarid climate and uneven distribution of rainfall has limited freshwater recharge and caused salt buildup in water supplies. Tertiary rocks supply mineralized water. Agricultural activities (irrigation return flow containing fertilizers and pesticides, cultivation, feedlot waste disposal) are a primary cause of water quality degradation. Urban development, which also causes water quality degradation (introduced contaminants, wastewater disposal, septic system discharge, and land fill disposal of waste), has imposed stricter requirements on water supply quality. A well network was designed to monitor changes in groundwater quality related to anthropogenic activities. Information from this network may aid in efficient management of the groundwater basins as public water supplies, centered around three basic goals. First is to increase freshwater recharge to the basins by conjunctive surface/groundwater use and surface-spreading techniques. Second is to optimize groundwater discharge by efficient timing and spacing of pumping. Third is to control and reduce sources of groundwater contamination by regulating wastewater quality and distribution and, preferably, by exporting wastewaters from the basin. (USGS)

Basin characteristics, history of stream gaging, and statistical summary of selected streamflow records for the Rapid Creek basin, western South Dakota

USGS Publications Warehouse

Driscoll, Daniel G.; Zogorski, John S.

1990-01-01

The report presents a summary of basin characteristics affecting streamflow, a history of the U.S. Geological Survey 's stream-gaging program, and a compilation of discharge records and statistical summaries for selected sites within the Rapid Creek basin. It is the first in a series which will investigate surface-water/groundwater relations along Rapid Creek. The summary of basin characteristics includes descriptions of the geology and hydrogeology, physiography and climate, land use and vegetation, reservoirs, and water use within the basin. A recounting of the U.S. Geological Survey 's stream-gaging program and a tabulation of historic stream-gaging stations within the basin are furnished. A compilation of monthly and annual mean discharge values for nine currently operated, long-term, continuous-record, streamflow-gaging stations on Rapid Creek is presented. The statistical summary for each site includes summary statistics on monthly and annual mean values, correlation matrix for monthly values, serial correlation for 1 year lag for monthly values, percentile rankings for monthly and annual mean values, low and high value tables, duration curves, and peak-discharge tables. Records of monthend contents for two reservoirs within the basin also are presented. (USGS)

Physicochemical quality evaluation of groundwater and development of drinking water quality index for Araniar River Basin, Tamil Nadu, India.

PubMed

Jasmin, I; Mallikarjuna, P

2014-02-01

Groundwater is the most important natural resource which cannot be optimally used and sustained unless its quality is properly assessed. In the present study, the spatial and temporal variations in physicochemical quality parameters of groundwater of Araniar River Basin, India were analyzed to determine its suitability for drinking purpose through development of drinking water quality index (DWQI) maps of the post- and pre-monsoon periods. The suitability for drinking purpose was evaluated by comparing the physicochemical parameters of groundwater in the study area with drinking water standards prescribed by the World Health Organization (WHO) and Bureau of Indian Standards (BIS). Interpretation of physicochemical data revealed that groundwater in the basin was slightly alkaline. The cations such as sodium (Na(+)) and potassium (K(+)) and anions such as bicarbonate (HCO3 (-)) and chloride (Cl(-)) exceeded the permissible limits of drinking water standards (WHO and BIS) in certain pockets in the northeastern part of the basin during the pre-monsoon period. The higher total dissolved solids (TDS) concentration was observed in the northeastern part of the basin, and the parameters such as calcium (Ca(2+)), magnesium (Mg(2+)), sulfate (SO4 (2-)), nitrate (NO3 (-)), and fluoride (F(-)) were within the limits in both the seasons. The hydrogeochemical evaluation of groundwater of the basin demonstrated with the Piper trilinear diagram indicated that the groundwater samples of the area were of Ca(2+)-Mg(2+)-Cl(-)-SO4 (2-), Ca(2+)-Mg(2+)-HCO3 (-) and Na(+)-K(+)-Cl(-)-SO4 (2-) types during the post-monsoon period and Ca(2+)-Mg(2+)-Cl(-)-SO4 (2-), Na(+)-K(+)-Cl(-)-SO4 (2-) and Ca(2+)-Mg(2+)-HCO3 (-) types during the pre-monsoon period. The DWQI maps for the basin revealed that 90.24 and 73.46% of the basin area possess good quality drinking water during the post- and pre-monsoon seasons, respectively.

Geologic and climatic controls on streamflow generation processes in a complex eogenetic karst basin

NASA Astrophysics Data System (ADS)

Vibhava, F.; Graham, W. D.; Maxwell, R. M.

2012-12-01

Streamflow at any given location and time is representative of surface and subsurface contributions from various sources. The ability to fully identify the factors controlling these contributions is key to successfully understanding the transport of contaminants through the system. In this study we developed a fully integrated 3D surface water-groundwater-land surface model, PARFLOW, to evaluate geologic and climatic controls on streamflow generation processes in a complex eogenetic karst basin in North Central Florida. In addition to traditional model evaluation criterion, such as comparing field observations to model simulated streamflow and groundwater elevations, we quantitatively evaluated the model's predictions of surface-groundwater interactions over space and time using a suite of binary end-member mixing models that were developed using observed specific conductivity differences among surface and groundwater sources throughout the domain. Analysis of model predictions showed that geologic heterogeneity exerts a strong control on both streamflow generation processes and land atmospheric fluxes in this watershed. In the upper basin, where the karst aquifer is overlain by a thick confining layer, approximately 92% of streamflow is "young" event flow, produced by near stream rainfall. Throughout the upper basin the confining layer produces a persistent high surficial water table which results in high evapotranspiration, low groundwater recharge and thus negligible "inter-event" streamflow. In the lower basin, where the karst aquifer is unconfined, deeper water tables result in less evapotranspiration. Thus, over 80% of the streamflow is "old" subsurface flow produced by diffuse infiltration through the epikarst throughout the lower basin, and all surface contributions to streamflow originate in the upper confined basin. Climatic variability provides a secondary control on surface-subsurface and land-atmosphere fluxes, producing significant seasonal and interannual variability in these processes. Spatial and temporal patterns of evapotranspiration, groundwater recharge and streamflow generation processes reveal potential hot spots and hot moments for surface and groundwater contamination in this basin.

Hydroeconomic modeling of sustainable groundwater management

NASA Astrophysics Data System (ADS)

MacEwan, Duncan; Cayar, Mesut; Taghavi, Ali; Mitchell, David; Hatchett, Steve; Howitt, Richard

2017-03-01

In 2014, California passed legislation requiring the sustainable management of critically overdrafted groundwater basins, located primarily in the Central Valley agricultural region. Hydroeconomic modeling of the agricultural economy, groundwater, and surface water systems is critically important to simulate potential transition paths to sustainable management of the basins. The requirement for sustainable groundwater use by 2040 is mandated for many overdrafted groundwater basins that are decoupled from environmental and river flow effects. We argue that, for such cases, a modeling approach that integrates a biophysical response function from a hydrologic model into an economic model of groundwater use is preferable to embedding an economic response function in a complex hydrologic model as is more commonly done. Using this preferred approach, we develop a dynamic hydroeconomic model for the Kings and Tulare Lake subbasins of California and evaluate three groundwater management institutions—open access, perfect foresight, and managed pumping. We quantify the costs and benefits of sustainable groundwater management, including energy pumping savings, drought reserve values, and avoided capital costs. Our analysis finds that, for basins that are severely depleted, losses in crop net revenue are offset by the benefits of energy savings, drought reserve value, and avoided capital costs. This finding provides an empirical counterexample to the Gisser and Sanchez Effect.

Groundwater-surfacewater relationships in the Bonaparte Creek basin, Okanogan County, Washington, 1979-1980

USGS Publications Warehouse

Packard, F.A.; Sumioka, S.S.; Whiteman, K.J.

1983-01-01

Ground water-surface-water relationships were studied in five morphological segments in the Bonaparte Creek basin, Washington during 1979 and 1980. In one segment, kettle lakes were found to be closely associated with the ground-water system. In the other four segments, a close relationship was found between streamflow and ground water. It was concluded that additional ground-water development would adversely affect lake levels and streamflow, thereby reducing surface-water resources already closed to further appropriation. The ground-water divide between the Bonaparte and Sanpoil basins was 6 miles southeast of where it was estimated to be. (USGS)

Geologic sources and concentrations of selenium in the West-Central Denver Basin, including the Toll Gate Creek watershed, Aurora, Colorado, 2003-2007

USGS Publications Warehouse

Paschke, Suzanne S.; Walton-Day, Katherine; Beck, Jennifer A.; Webbers, Ank; Dupree, Jean A.

2014-01-01

Toll Gate Creek, in the west-central part of the Denver Basin, is a perennial stream in which concentrations of dissolved selenium have consistently exceeded the Colorado aquatic-life standard of 4.6 micrograms per liter. Recent studies of selenium in Toll Gate Creek identified the Denver lignite zone of the non-marine Cretaceous to Tertiary-aged (Paleocene) Denver Formation underlying the watershed as the geologic source of dissolved selenium to shallow ground-water and surface water. Previous work led to this study by the U.S. Geological Survey, in cooperation with the City of Aurora Utilities Department, which investigated geologic sources of selenium and selenium concentrations in the watershed. This report documents the occurrence of selenium-bearing rocks and groundwater within the Cretaceous- to Tertiary-aged Denver Formation in the west-central part of the Denver Basin, including the Toll Gate Creek watershed. The report presents background information on geochemical processes controlling selenium concentrations in the aquatic environment and possible geologic sources of selenium; the hydrogeologic setting of the watershed; selenium results from groundwater-sampling programs; and chemical analyses of solids samples as evidence that weathering of the Denver Formation is a geologic source of selenium to groundwater and surface water in the west-central part of the Denver Basin, including Toll Gate Creek. Analyses of water samples collected from 61 water-table wells in 2003 and from 19 water-table wells in 2007 indicate dissolved selenium concentrations in groundwater in the west-central Denver Basin frequently exceeded the Colorado aquatic-life standard and in some locations exceeded the primary drinking-water standard of 50 micrograms per liter. The greatest selenium concentrations were associated with oxidized groundwater samples from wells completed in bedrock materials. Selenium analysis of geologic core samples indicates that total selenium concentrations were greatest in samples containing indications of reducing conditions and organic matter (dark gray to black claystones and lignite horizons). The Toll Gate Creek watershed is situated in a unique hydrogeologic setting in the west-central part of the Denver Basin such that weathering of Cretaceous- to Tertiary-aged, non-marine, selenium-bearing rocks releases selenium to groundwater and surface water under present-day semi-arid environmental conditions. The Denver Formation contains several known and suspected geologic sources of selenium including: (1) lignite deposits; (2) tonstein partings; (3) organic-rich bentonite claystones; (4) salts formed as secondary weathering products; and possibly (5) the Cretaceous-Tertiary boundary. Organically complexed selenium and/or selenium-bearing pyrite in the enclosing claystones are likely the primary mineral sources of selenium in the Denver Formation, and correlations between concentration of dissolved selenium and dissolved organic carbon in groundwater indicate weathering and dissolution of organically complexed selenium from organic-rich claystone is a primary process mobilizing selenium. Secondary salts accumulated along fractures and bedding planes in the weathered zone are another potential geologic source of selenium, although their composition was not specifically addressed by the solids analyses. Results from this and previous work indicate that shallow groundwater and streams similarly positioned over Denver Formation claystone units at other locations in the Denver Basin also may contain concentrations of dissolved selenium greater than the Colorado aquatic-life standard or the drinking- water standard.

Ground-Water Occurrence and Movement, 2006, and Water-Level Changes in the Detrital, Hualapai, and Sacramento Valley Basins, Mohave County, Arizona

USGS Publications Warehouse

Anning, David W.; Truini, Margot; Flynn, Marilyn E.; Remick, William H.

2007-01-01

Ground-water levels for water year 2006 and their change over time in Detrital, Hualapai, and Sacramento Valley Basins of northwestern Arizona were investigated to improve the understanding of current and past ground-water conditions in these basins. The potentiometric surface for ground water in the Basin-Fill aquifer of each basin is generally parallel to topography. Consequently, ground-water movement is generally from the mountain front toward the basin center and then along the basin axis toward the Colorado River or Lake Mead. Observed water levels in Detrital, Hualapai, and Sacramento Valley Basins have fluctuated during the period of historic water-level records (1943 through 2006). In Detrital Valley Basin, water levels in monitored areas have either remained the same, or have steadily increased as much as 3.5 feet since the 1980s. Similar steady conditions or water-level rises were observed for much of the northern and central parts of Hualapai Valley Basin. During the period of historic record, steady water-level declines as large as 60 feet were found in wells penetrating the Basin-Fill aquifer in areas near Kingman, northwest of Hackberry, and northeast of Dolan Springs within the Hualapai Valley Basin. Within the Sacramento Valley Basin, during the period of historic record, water-level declines as large as 55 feet were observed in wells penetrating the Basin-Fill aquifer in the Kingman and Golden Valley areas; whereas small, steady rises were observed in Yucca and in the Dutch Flat area.

A quantitative study on accumulation of age mass around stagnation points in nested flow systems

NASA Astrophysics Data System (ADS)

Jiang, Xiao-Wei; Wan, Li; Ge, Shemin; Cao, Guo-Liang; Hou, Guang-Cai; Hu, Fu-Sheng; Wang, Xu-Sheng; Li, Hailong; Liang, Si-Hai

2012-12-01

The stagnant zones in nested flow systems have been assumed to be critical to accumulation of transported matter, such as metallic ions and hydrocarbons in drainage basins. However, little quantitative research has been devoted to prove this assumption. In this paper, the transport of age mass is used as an example to demonstrate that transported matter could accumulate around stagnation points. The spatial distribution of model age is analyzed in a series of drainage basins of different depths. We found that groundwater age has a local or regional maximum value around each stagnation point, which proves the accumulation of age mass. In basins where local, intermediate and regional flow systems are all well developed, the regional maximum groundwater age occurs at the regional stagnation point below the basin valley. This can be attributed to the long travel distances of regional flow systems as well as stagnancy of the water. However, when local flow systems dominate, the maximum groundwater age in the basin can be located around the local stagnation points due to stagnancy, which are far away from the basin valley. A case study is presented to illustrate groundwater flow and age in the Ordos Plateau, northwestern China. The accumulation of age mass around stagnation points is confirmed by tracer age determined by 14C dating in two boreholes and simulated age near local stagnation points under different dispersivities. The results will help shed light on the relationship between groundwater flow and distributions of groundwater age, hydrochemistry, mineral resources, and hydrocarbons in drainage basins.

Groundwater quality and depletion in the Indo-Gangetic Basin mapped from in situ observations

NASA Astrophysics Data System (ADS)

MacDonald, A. M.; Bonsor, H. C.; Ahmed, K. M.; Burgess, W. G.; Basharat, M.; Calow, R. C.; Dixit, A.; Foster, S. S. D.; Gopal, K.; Lapworth, D. J.; Lark, R. M.; Moench, M.; Mukherjee, A.; Rao, M. S.; Shamsudduha, M.; Smith, L.; Taylor, R. G.; Tucker, J.; van Steenbergen, F.; Yadav, S. K.

2016-10-01

Groundwater abstraction from the transboundary Indo-Gangetic Basin comprises 25% of global groundwater withdrawals, sustaining agricultural productivity in Pakistan, India, Nepal and Bangladesh. Recent interpretations of satellite gravity data indicate that current abstraction is unsustainable, yet these large-scale interpretations lack the spatio-temporal resolution required to govern groundwater effectively. Here we report new evidence from high-resolution in situ records of groundwater levels, abstraction and groundwater quality, which reveal that sustainable groundwater supplies are constrained more by extensive contamination than depletion. We estimate the volume of groundwater to 200 m depth to be >20 times the combined annual flow of the Indus, Brahmaputra and Ganges, and show the water table has been stable or rising across 70% of the aquifer between 2000 and 2012. Groundwater levels are falling in the remaining 30%, amounting to a net annual depletion of 8.0 +/- 3.0 km3. Within 60% of the aquifer, access to potable groundwater is restricted by excessive salinity or arsenic. Recent groundwater depletion in northern India and Pakistan has occurred within a longer history of groundwater accumulation from extensive canal leakage. This basin-wide synthesis of in situ groundwater observations provides the spatial detail essential for policy development, and the historical context to help evaluate recent satellite gravity data.

Computer-program documentation of an interactive-accounting model to simulate streamflow, water quality, and water-supply operations in a river basin

USGS Publications Warehouse

Burns, A.W.

1988-01-01

This report describes an interactive-accounting model used to simulate streamflow, chemical-constituent concentrations and loads, and water-supply operations in a river basin. The model uses regression equations to compute flow from incremental (internode) drainage areas. Conservative chemical constituents (typically dissolved solids) also are computed from regression equations. Both flow and water quality loads are accumulated downstream. Optionally, the model simulates the water use and the simplified groundwater systems of a basin. Water users include agricultural, municipal, industrial, and in-stream users , and reservoir operators. Water users list their potential water sources, including direct diversions, groundwater pumpage, interbasin imports, or reservoir releases, in the order in which they will be used. Direct diversions conform to basinwide water law priorities. The model is interactive, and although the input data exist in files, the user can modify them interactively. A major feature of the model is its color-graphic-output options. This report includes a description of the model, organizational charts of subroutines, and examples of the graphics. Detailed format instructions for the input data, example files of input data, definitions of program variables, and listing of the FORTRAN source code are Attachments to the report. (USGS)

Geohydrology, Geochemistry, and Ground-Water Simulation-Optimization of the Central and West Coast Basins, Los Angeles County, California

USGS Publications Warehouse

Reichard, Eric G.; Land, Michael; Crawford, Steven M.; Johnson, Tyler D.; Everett, Rhett; Kulshan, Trayle V.; Ponti, Daniel J.; Halford, Keith L.; Johnson, Theodore A.; Paybins, Katherine S.; Nishikawa, Tracy

2003-01-01

Historical ground-water development of the Central and West Coast Basins in Los Angeles County, California through the first half of the 20th century caused large water-level declines and induced seawater intrusion. Because of this, the basins were adjudicated and numerous ground-water management activities were implemented, including increased water spreading, construction of injection barriers, increased delivery of imported water, and increased use of reclaimed water. In order to improve the scientific basis for these water management activities, an extensive data collection program was undertaken, geohydrological and geochemical analyses were conducted, and ground-water flow simulation and optimization models were developed. In this project, extensive hydraulic, geologic, and chemical data were collected from new multiple-well monitoring sites. On the basis of these data and data compiled and collected from existing wells, the regional geohydrologic framework was characterized. For the purposes of modeling, the three-dimensional aquifer system was divided into four aquifer systems?the Recent, Lakewood, Upper San Pedro, and Lower San Pedro aquifer systems. Most pumpage in the two basins is from the Upper San Pedro aquifer system. Assessment of the three-dimensional geochemical data provides insight into the sources of recharge and the movement and age of ground water in the study area. Major-ion data indicate the chemical character of water containing less than 500 mg/L dissolved solids generally grades from calcium-bicarbonate/sulfate to sodium bicarbonate. Sodium-chloride water, high in dissolved solids, is present in wells near the coast. Stable isotopes of oxygen and hydrogen provide information on sources of recharge to the basin, including imported water and water originating in the San Fernando Valley, San Gabriel Valley, and the coastal plain and surrounding hills. Tritium and carbon-14 data provide information on relative ground-water ages. Water with abundant tritium (greater than 8 tritium units) is found in and downgradient from the Montebello Forebay and near the seawater barrier projects, indicating recent recharge. Water with less than measurable tritium is present in, and downgradient from, the Los Angeles Forebay and in most wells in the West Coast Basin. Water from several deep wells was analyzed for carbon-14. Uncorrected estimates of age for these samples range from 600 to more than 20,000 years before present. Chemical and isotopic data are combined to evaluate changes in chemical character along flow paths emanating from the Montebello and Los Angeles Forebays. A four-layer ground-water flow model was developed to simulate steady-state ground-water conditions representative of those in 1971 and transient conditions for the period 1971?2000. Model results indicate increases in ground-water storage in all parts of the study area over the simulated thirty-year period. The model was used to develop a three-dimensional ground-water budget and to assess impacts of two alternative future (2001?25) ground-water development scenarios?one that assumes continued pumping at average current rates and a second that assumes increasing pumping from most wells in the Central Basin. The model simulates stable or slightly increasing water levels for the first scenario and declining water levels (25 to 50 ft in the Central Basin) in the second scenario. Model sensitivity to parameter values and to the assumed Orange County boundary condition was evaluated. Particle tracking was applied to simulate advective transport of water from the spreading ponds, the coastline, and the seawater injection barriers. Particle tracking results indicate that most flow within the Upper San Pedro aquifer system occurs within about 20 percent of the total aquifer system thickness and that virtually all water injected into the seawater barrier projects has flowed inland. The simulation model was linked with optimizatio

Hydrology of the Sevier-Sigurd ground-water basin and other ground-water basins, central Sevier Valley, Utah.

USGS Publications Warehouse

Lambert, P.M.; Mason, J.L.; Puchta, R.W

1995-01-01

The hydrologic system in the central Sevier Valley, and more specifically the Sevier-Sigurd basin, is a complex system in which surface- and ground-water systems are interrelated. Seepage from an extensive irrigation system is the primary source of recharge to the basin-fill aquifer in the Sevier-Sigurd basin.Water-quality data indicate that inflow from streams and subsurface inflow that intersect evaporite deposits in the Arapien Shale does not adversely affect ground-water quality in the Sevier-Sigurd basin. Stable-isotope data indicate that large sulfate concentrations in water from wells are from the dissolution of gypsum within the basin fill rather than inflow from the Arapien Shale.A ground-water-flow model of the basin-fill aquifer in the Sevier-Sigurd basin was calibrated to steady-state conditions and transient conditions using yearly water-level changes from 1957-88 and monthly water-level changes from 1958-59. Predictive simulations were made to test the effects of reduced recharge from irrigation and increased well discharge. To simulate the effects of conversion from flood to sprinkler irrigation, recharge from irrigated fields was reduced by 50 percent. After twenty years, this reduction resulted in water-level declines of 1 to 8 feet in most of the basin, and a reduction in ground-water discharge to the Sevier River of 4,800 acre-ft/yr. Water-level declines of as much as 12 feet and a reduction in recharge to the Sevier River of 4,800 acre-ft/yr were the result of increasing well discharge near Richfield and Monroe by 25,000 acre-ft/yr. 

Simulations of hydrologic response in the Apalachicola-Chattahoochee-Flint River Basin, Southeastern United States

USGS Publications Warehouse

LaFontaine, Jacob H.; Jones, L. Elliott; Painter, Jaime A.

2017-12-29

A suite of hydrologic models has been developed for the Apalachicola-Chattahoochee-Flint River Basin (ACFB) as part of the National Water Census, a U.S. Geological Survey research program that focuses on developing new water accounting tools and assessing water availability and use at the regional and national scales. Seven hydrologic models were developed using the Precipitation-Runoff Modeling System (PRMS), a deterministic, distributed-parameter, process-based system that simulates the effects of precipitation, temperature, land cover, and water use on basin hydrology. A coarse-resolution PRMS model was developed for the entire ACFB, and six fine-resolution PRMS models were developed for six subbasins of the ACFB. The coarse-resolution model was loosely coupled with a groundwater model to better assess the effects of water use on streamflow in the lower ACFB, a complex geologic setting with karst features. The PRMS coarse-resolution model was used to provide inputs of recharge to the groundwater model, which in turn provide simulations of groundwater flow that were aggregated with PRMS-based simulations of surface runoff and shallow-subsurface flow. Simulations without the effects of water use were developed for each model for at least the calendar years 1982–2012 with longer periods for the Potato Creek subbasin (1942–2012) and the Spring Creek subbasin (1952–2012). Water-use-affected flows were simulated for 2008–12. Water budget simulations showed heterogeneous distributions of precipitation, actual evapotranspiration, recharge, runoff, and storage change across the ACFB. Streamflow volume differences between no-water-use and water-use simulations were largest along the main stem of the Apalachicola and Chattahoochee River Basins, with streamflow percentage differences largest in the upper Chattahoochee and Flint River Basins and Spring Creek in the lower Flint River Basin. Water-use information at a shorter time step and a fully coupled simulation in the lower ACFB may further improve water availability estimates and hydrologic simulations in the basin.

Status and understanding of groundwater quality in the Northern Coast Ranges study unit, 2009: California GAMA Priority Basin Project

USGS Publications Warehouse

Mathany, Timothy M.; Belitz, Kenneth

2015-01-01

Chloroform, simazine, and perchlorate were observed in the Interior Basins and Coastal Basins study areas, predominantly at shallow sites with top-of-perforation depths ≤70 feet below land surface, with modern water (post-1950s), and with oxic groundwater conditions.

Groundwater Depletion During Drought Threatens Future Water Security of the Colorado River Basin

NASA Technical Reports Server (NTRS)

Castle, Stephanie L.; Thomas, Brian F.; Reager, John T.; Rodell, Matthew; Swenson, Sean C.; Famiglietti, James S.

2014-01-01

Streamflow of the Colorado River Basin is the most overallocated in the world. Recent assessment indicates that demand for this renewable resource will soon outstrip supply, suggesting that limited groundwater reserves will play an increasingly important role in meeting future water needs. Here we analyze 9 years (December 2004 to November 2013) of observations from the NASA Gravity Recovery and Climate Experiment mission and find that during this period of sustained drought, groundwater accounted for 50.1 cu km of the total 64.8 cu km of freshwater loss. The rapid rate of depletion of groundwater storage (5.6 +/- 0.4 cu km/yr) far exceeded the rate of depletion of Lake Powell and Lake Mead. Results indicate that groundwater may comprise a far greater fraction of Basin water use than previously recognized, in particular during drought, and that its disappearance may threaten the long-term ability to meet future allocations to the seven Basin states.

Groundwater depletion during drought threatens future water security of the Colorado River Basin

NASA Astrophysics Data System (ADS)

Castle, Stephanie L.; Thomas, Brian F.; Reager, John T.; Rodell, Matthew; Swenson, Sean C.; Famiglietti, James S.

2014-08-01

Streamflow of the Colorado River Basin is the most overallocated in the world. Recent assessment indicates that demand for this renewable resource will soon outstrip supply, suggesting that limited groundwater reserves will play an increasingly important role in meeting future water needs. Here we analyze 9 years (December 2004 to November 2013) of observations from the NASA Gravity Recovery and Climate Experiment mission and find that during this period of sustained drought, groundwater accounted for 50.1 km3 of the total 64.8 km3 of freshwater loss. The rapid rate of depletion of groundwater storage (-5.6 ± 0.4 km3 yr-1) far exceeded the rate of depletion of Lake Powell and Lake Mead. Results indicate that groundwater may comprise a far greater fraction of Basin water use than previously recognized, in particular during drought, and that its disappearance may threaten the long-term ability to meet future allocations to the seven Basin states.

Installation of a groundwater monitoring-well network on the east side of the Uncompahgre River in the Lower Gunnison River Basin, Colorado, 2014

USGS Publications Warehouse

Thomas, Judith C.

2015-10-07

The east side of the Uncompahgre River Basin has been a known contributor of dissolved selenium to recipient streams. Discharge of groundwater containing dissolved selenium contributes to surface-water selenium concentrations and loads; however, the groundwater system on the east side of the Uncompahgre River Basin is not well characterized. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board and the Bureau of Reclamation, has established a groundwater-monitoring network on the east side of the Uncompahgre River Basin. Thirty wells total were installed for this project: 10 in 2012 (DS 923, http://dx.doi.org/10.3133/ds923), and 20 monitoring wells were installed during April and June 2014 which are presented in this report. This report presents location data, lithologic logs, well-construction diagrams, and well-development information. Understanding the groundwater system can provide managers with an additional metric for evaluating the effectiveness of salinity and selenium control projects.

Quantitative assessment of the impact of an inter-basin surface-water transfer project on the groundwater flow and groundwater-dependent eco-environment in an oasis in arid northwestern China

NASA Astrophysics Data System (ADS)

Zhu, Xiaobin; Wu, Jichun; Nie, Huijun; Guo, Fei; Wu, Jianfeng; Chen, Kouping; Liao, Penghui; Xu, Hongxia; Zeng, Xiankui

2018-06-01

Inter-basin water transfer projects (IBWTPs) can involve basins as water donors and water receivers. In contrast to most studies on IBWTPs, which mainly impact the surface-water eco-environment, this study focuses on the impacts of an IBWTP on groundwater and its eco-environment in a water donor basin in an arid area, where surface water and groundwater are exchanged. Surface water is assumed to recharge groundwater and a groundwater numerical simulation model was constructed using MODFLOW. The model was used to quantitatively evaluate the impact of an IBWTP located in the upstream portion of Nalenggele River (the biggest river in the Qaidam basin, Northwest China). The impact involved decrease in spring flow, drawdown of groundwater, reduction in oasis area, and an increase in species replacement of oasis vegetation in the midstream and downstream of the river. Results show that the emergence sites of springs at the front of the oasis will move 2-5 km downstream, and the outflow of springs will decrease by 42 million m3/a. The maximum drawdown of groundwater level at the front of the oasis will be 3.6 m and the area across which groundwater drawdown exceeds 2.0 m will be about 59.02 km2, accounting for 2.71% of the total area of the oasis. Under such conditions, reeds will gradually be replaced by Tamarix, shrubs, and other alternative plant species. These findings have important implications for the optimization of water resource allocation and protection of the eco-environment in arid regions.

Simulation of ground-water flow and land subsidence in the Antelope Valley ground-water basin, California

USGS Publications Warehouse

Leighton, David A.; Phillips, Steven P.

2003-01-01

Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley ground-water basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, ground water provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most ground-water pumping in the valley occurs in the Antelope Valley ground-water basin, which includes the rapidly growing cities of Lancaster and Palmdale. Ground-water-level declines of more than 200 feet in some parts of the ground-water basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may continue to increase reliance on ground water. To better understand the ground-water flow system and to develop a tool to aid in effectively managing the water resources, a numerical model of ground-water flow and land subsidence in the Antelope Valley ground-water basin was developed using old and new geohydrologic information. The ground-water flow system consists of three aquifers: the upper, middle, and lower aquifers. The aquifers, which were identified on the basis of the hydrologic properties, age, and depth of the unconsolidated deposits, consist of gravel, sand, silt, and clay alluvial deposits and clay and silty clay lacustrine deposits. Prior to ground-water development in the valley, recharge was primarily the infiltration of runoff from the surrounding mountains. Ground water flowed from the recharge areas to discharge areas around the playas where it discharged either from the aquifer system as evapotranspiration or from springs. Partial barriers to horizontal ground-water flow, such as faults, have been identified in the ground-water basin. Water-level declines owing to ground-water development have eliminated the natural sources of discharge, and pumping for agricultural and urban uses have become the primary source of discharge from the ground-water system. Infiltration of return flows from agricultural irrigation has become an important source of recharge to the aquifer system. The ground-water flow model of the basin was discretized horizontally into a grid of 43 rows and 60 columns of square cells 1 mile on a side, and vertically into three layers representing the upper, middle, and lower aquifers. Faults that were thought to act as horizontal-flow barriers were simulated in the model. The model was calibrated to simulate steady-state conditions, represented by 1915 water levels and transient-state conditions during 1915-95 using water-level and subsidence data. Initial estimates of the aquifer-system properties and stresses were obtained from a previously published numerical model of the Antelope Valley ground-water basin; estimates also were obtained from recently collected hydrologic data and from results of simulations of ground-water flow and land subsidence models of the Edwards Air Force Base area. Some of these initial estimates were modified during model calibration. Ground-water pumpage for agriculture was estimated on the basis of irrigated crop acreage and crop consumptive-use data. Pumpage for public supply, which is metered, was compiled and entered into a database used for this study. Estimated annual pumpage peaked at 395,000 acre-feet (acre-ft) in 1952 and then declined because of declining agricultural production. Recharge from irrigation-return flows was estimated to be 30 percent of agricultural pumpage; the irrigation-return flows were simulated as recharge to the regional water table 10 years following application at land surface. The annual quantity of natural recharge initially was based on estimates from previous studies. During model calibration, natural recharge was reduced from the initial

Computation of groundwater resources and recharge in Chithar River Basin, South India.

PubMed

Subramani, T; Babu, Savithri; Elango, L

2013-01-01

Groundwater recharge and available groundwater resources in Chithar River basin, Tamil Nadu, India spread over an area of 1,722 km(2) have been estimated by considering various hydrological, geological, and hydrogeological parameters, such as rainfall infiltration, drainage, geomorphic units, land use, rock types, depth of weathered and fractured zones, nature of soil, water level fluctuation, saturated thickness of aquifer, and groundwater abstraction. The digital ground elevation models indicate that the regional slope of the basin is towards east. The Proterozoic (Post-Archaean) basement of the study area consists of quartzite, calc-granulite, crystalline limestone, charnockite, and biotite gneiss with or without garnet. Three major soil types were identified namely, black cotton, deep red, and red sandy soils. The rainfall intensity gradually decreases from west to east. Groundwater occurs under water table conditions in the weathered zone and fluctuates between 0 and 25 m. The water table gains maximum during January after northeast monsoon and attains low during October. Groundwater abstraction for domestic/stock and irrigational needs in Chithar River basin has been estimated as 148.84 MCM (million m(3)). Groundwater recharge due to monsoon rainfall infiltration has been estimated as 170.05 MCM based on the water level rise during monsoon period. It is also estimated as 173.9 MCM using rainfall infiltration factor. An amount of 53.8 MCM of water is contributed to groundwater from surface water bodies. Recharge of groundwater due to return flow from irrigation has been computed as 147.6 MCM. The static groundwater reserve in Chithar River basin is estimated as 466.66 MCM and the dynamic reserve is about 187.7 MCM. In the present scenario, the aquifer is under safe condition for extraction of groundwater for domestic and irrigation purposes. If the existing water bodies are maintained properly, the extraction rate can be increased in future about 10% to 15%.

A basin-scale approach for assessing water resources in a semiarid environment: San Diego region, California and Mexico

USGS Publications Warehouse

Flint, L.E.; Flint, A.L.; Stolp, B.J.; Danskin, W.R.

2012-01-01

Many basins throughout the world have sparse hydrologic and geologic data, but have increasing demands for water and a commensurate need for integrated understanding of surface and groundwater resources. This paper demonstrates a methodology for using a distributed parameter water-balance model, gaged surface-water flow, and a reconnaissance-level groundwater flow model to develop a first-order water balance. Flow amounts are rounded to the nearest 5 million cubic meters per year. The San Diego River basin is 1 of 5 major drainage basins that drain to the San Diego coastal plain, the source of public water supply for the San Diego area. The distributed parameter water-balance model (Basin Characterization Model) was run at a monthly timestep for 1940–2009 to determine a median annual total water inflow of 120 million cubic meters per year for the San Diego region. The model was also run specifically for the San Diego River basin for 1982–2009 to provide constraints to model calibration and to evaluate the proportion of inflow that becomes groundwater discharge, resulting in a median annual total water inflow of 50 million cubic meters per year. On the basis of flow records for the San Diego River at Fashion Valley (US Geological Survey gaging station 11023000), when corrected for upper basin reservoir storage and imported water, the total is 30 million cubic meters per year. The difference between these two flow quantities defines the annual groundwater outflow from the San Diego River basin at 20 million cubic meters per year. These three flow components constitute a first-order water budget estimate for the San Diego River basin. The ratio of surface-water outflow and groundwater outflow to total water inflow are 0.6 and 0.4, respectively. Using total water inflow determined using the Basin Characterization Model for the entire San Diego region and the 0.4 partitioning factor, groundwater outflow from the San Diego region, through the coastal plain aquifer to the Pacific Ocean, is calculated to be approximately 50 million cubic meters per year. The area-scale assessment of water resources highlights several hydrologic features of the San Diego region. Groundwater recharge is episodic; the Basin Characterization Model output shows that 90 percent of simulated recharge occurred during 3 percent of the 1982–2009 period. The groundwater aquifer may also be quite permeable. A reconnaissance-level groundwater flow model for the San Diego River basin was used to check the water budget estimates, and the basic interaction of the surface-water and groundwater system, and the flow values, were found to be reasonable. Horizontal hydraulic conductivity values of the volcanic and metavolcanic bedrock in San Diego region range from 1 to 10 m per day. Overall, results establish an initial hydrologic assessment formulated on the basis of sparse hydrologic data. The described flow variability, extrapolation, and unique characteristics represent a realistic view of current (2012) hydrologic understanding for the San Diego region.

Arsenic migration to deep groundwater in Bangladesh influenced by adsorption and water demand.

PubMed

Radloff, K A; Zheng, Y; Michael, H A; Stute, M; Bostick, B C; Mihajlov, I; Bounds, M; Huq, M R; Choudhury, I; Rahman, M W; Schlosser, P; Ahmed, K M; van Geen, A

2011-10-01

Drinking shallow groundwater with naturally elevated concentrations of arsenic is causing widespread disease in many parts of South and Southeast Asia. In the Bengal Basin, growing reliance on deep (>150 m) groundwater has lowered exposure. In the most affected districts of Bangladesh, shallow groundwater concentrations average 100 to 370 μg L(-1), while deep groundwater is typically < 10 μg L(-1). Groundwater flow simulations have suggested that, even when deep pumping is restricted to domestic use, deep groundwater in some areas of the Bengal Basin is at risk of contamination. However, these simulations have neglected the impedance of As migration by adsorption to aquifer sediments. Here we quantify for the first time As sorption on deeper sediments in situ by replicating the intrusion of shallow groundwater through injection of 1,000 L of deep groundwater modified with 200 μg L(-1) of As into a deeper aquifer. Arsenic concentrations in the injected water were reduced by 70% due to adsorption within a single day. Basin-scale modelling indicates that while As adsorption extends the sustainable use of deep groundwater, some areas remain vulnerable; these areas can be prioritized for management and monitoring.

Documentation of input datasets for the soil-water balance groundwater recharge model of the Upper Colorado River Basin

USGS Publications Warehouse

Tillman, Fred D.

2015-01-01

The Colorado River and its tributaries supply water to more than 35 million people in the United States and 3 million people in Mexico, irrigating more than 4.5 million acres of farmland, and generating about 12 billion kilowatt hours of hydroelectric power annually. The Upper Colorado River Basin, encompassing more than 110,000 square miles (mi2), contains the headwaters of the Colorado River (also known as the River) and is an important source of snowmelt runoff to the River. Groundwater discharge also is an important source of water in the River and its tributaries, with estimates ranging from 21 to 58 percent of streamflow in the upper basin. Planning for the sustainable management of the Colorado River in future climates requires an understanding of the Upper Colorado River Basin groundwater system. This report documents input datasets for a Soil-Water Balance groundwater recharge model that was developed for the Upper Colorado River Basin.

Distribution and mobility of selenium and other trace elements in shallow groundwater of the western San Joaquin Valley, California

USGS Publications Warehouse

Deverel, S.J.; Milliard, S.P.

1988-01-01

Samples of shallow groundwater that underlies much of the irrigated area in the western San Joaquin Valley, CA, were analyzed for various major ions and trace elements, including selenium. Concentrations of the major ions generally were similar for groundwater collected in the two primary geologic zones - the alluvial fan and basin trough. Selenium concentrations are significantly (α = 0.05) higher in the groundwater of the alluvial-fan zone than in that of the basin-trough zone. The concentrations of oxyanion trace elements were significantly correlated (α = 0.05) with groundwater salinity, but the correlations between selenium and salinity and between molybdenum and salinity were significantly different (α = 0.05) in the alluvial-fan geologic zone compared with those in the basin-trough geologic zone. The evidence suggests that the main factors affecting selenium concentrations in the shallow groundwater are the degree of groundwater salinity and the geologic source of the alluvial soil material.

DETECTION OF GROUNDWATER AGES WITH 85 KR IN ARSENIC-BEARING, FRACTURED CRYSTALLINE BEDROCK OF THE GOOSE RIVER BASIN, MAINE

EPA Science Inventory

Young groundwater from various depths in crystalline bedrock of the Goose River basin, mid-coastal Maine, is documented from 85Kr isotope age analyses (1963 ? 1987) but not from 3H isotope age analyses. Elevated geogenic arsenic in drinking water from groundwater wells and sprin...

DETECTION OF 3 H AND 85KR IN GROUNDWATER FROM ARSENIC-BEARING CRYSTALLINE BEDROCK OF THE GOOSE RIVER BASIN, MAINE

EPA Science Inventory

Young groundwater from various depths in crystalline bedrock of the Goose River basin, mid-coastal Maine, is documented from 85Kr isotope age analyses (1963 ? 1987) but not from 3H isotope age analyses. Elevated geogenic arsenic in drinking water from groundwater wells and sprin...

Ground Water Recharge Estimation Using Water Table Fluctuation Method And By GIS Applications

NASA Astrophysics Data System (ADS)

Vajja, V.; Bekkam, V.; Nune, R.; M. v. S, R.

2007-05-01

Quite often it has become a debating point that how much recharge is occurring to the groundwater table through rainfall on one hand and through recharge structures such as percolation ponds and checkdams on the other. In the present investigations Musi basin of Andhra Pradesh, India is selected for study during the period 2005-06. Pre-monsoon and Post-monsoon groundwater levels are collected through out the Musi basin at 89 locations covering an area11, 291.69 km2. Geology of the study area and rainfall data during the study period has been collected. The contour maps of rainfall and the change in groundwater level between Pre-monsoon and Post- monsoon have been prepared. First the change in groundwater storage is estimated for each successive strips of areas enclosed between two contours of groundwater level fluctuations. In this calculation Specific yield (Sy) values are adopted based on the local Geology. Areas between the contours are estimated through Arc GIS software package. All such storages are added to compute the total storage for the entire basin. In order to find out the percent of rainfall converted into groundwater storage as well as to find out the ground water recharge due to storageponds, a contour map of rainfall for the study area is prepared and areas between successive contours have been calculated. Based on the Geology map, Infiltration values are adopted for each successive strip of the contour area. Then the amount of water infiltrated into the ground is calculated by adjusting the infiltration values for each strip, so that the total infiltrated water for the entire basin is matched with change in Ground water storage, which is 1314.37 MCM for the upper Musi basin while it is 2827.29 MCM for entire Musi basin. With this procedure on an average 29.68 and 30.66 percent of Rainfall is converted into Groundwater recharge for Upper Musi and for entire Musi basin respectively. In the total recharge, the contribution of rainfall directly to Groundwater recharge is 8.53 and 8.81 percent and the remaining 21.15 and 21.85 percent is due to groundwater recharge from water conservation structures such as check dams, contour bunds, tanks, etc. for Upper Musi and for entire Musi basin respectively. The difference is attributable to the canal recharge in the case of Lower Musi. Therefore the Upper Musi values may be taken as a percent of Rainfall that is converted into Groundwater recharge.

Effects of groundwater levels and headwater wetlands on streamflow in the Charlie Creek basin, Peace River watershed, west-central Florida

USGS Publications Warehouse

Lee, T.M.; Sacks, L.A.; Hughes, J.D.

2010-01-01

The Charlie Creek basin was studied from April 2004 to December 2005 to better understand how groundwater levels in the underlying aquifers and storage and overflow of water from headwater wetlands preserve the streamflows exiting this least-developed tributary basin of the Peace River watershed. The hydrogeologic framework, physical characteristics, and streamflow were described and quantified for five subbasins of the 330-square mile Charlie Creek basin, allowing the contribution of its headwaters area and tributary subbasins to be separately quantified. A MIKE SHE model simulation of the integrated surface-water and groundwater flow processes in the basin was used to simulate daily streamflow observed over 21 months in 2004 and 2005 at five streamflow stations, and to quantify the monthly and annual water budgets for the five subbasins including the changing amount of water stored in wetlands. Groundwater heads were mapped in Zone 2 of the intermediate aquifer system and in the Upper Floridan aquifer, and were used to interpret the location of artesian head conditions in the Charlie Creek basin and its relation to streamflow. Artesian conditions in the intermediate aquifer system induce upward groundwater flow into the surficial aquifer and help sustain base flow which supplies about two-thirds of the streamflow from the Charlie Creek basin. Seepage measurements confirmed seepage inflow to Charlie Creek during the study period. The upper half of the basin, comprised largely of the Upper Charlie Creek subbasin, has lower runoff potential than the lower basin, more storage of runoff in wetlands, and periodically generates no streamflow. Artesian head conditions in the intermediate aquifer system were widespread in the upper half of the Charlie Creek basin, preventing downward leakage from expansive areas of wetlands and enabling them to act as headwaters to Charlie Creek once their storage requirements were met. Currently, the dynamic balance between wetland storage, rainfall-runoff processes, and groundwater-level differences in the upper basin allow it to generate approximately half of the streamflow from the Charlie Creek basin. Therefore, future development in the upper basin that would alter the hydraulic connectivity of wetlands during high flow conditions or expand recharging groundwater conditions could substantially affect streamflow in Charlie Creek. LIDAR (Light detection and ranging) based topographic maps and integrated modeling results were used to quantify the water stored in wetlands and other topographic depressions, and to describe the network of shallow stream channels connecting wetlands to Charlie Creek and its tributaries over distances of several thousand feet. Peak flows at all but one streamflow station were underpredicted in MIKE SHE simulations, possibly because the hydraulics of surface channels connecting wetlands to stream channels were not explicitly simulated in the model. Explicitly simulating the smaller channels connecting wetlands and stream channels should improve the ability of future watershed models to simulate peak flows in streams with headwater wetlands. The runoff potential was greater in the lower half of the Charlie Creek basin than in the upper half, and the streambed of Charlie Creek had greater potential to both directly gain streamflow from groundwater and lose streamflow to groundwater. Charlie Creek is more incised into the surficial aquifer in the lower basin than in the upper basin, and the streambed intersects the top of the intermediate aquifer system at two known locations. Groundwater levels in the intermediate aquifer system varied widely in the lower half of the basin from artesian conditions inducing upward flow toward the surficial aquifer and streams, to recharging conditions allowing downward flow and stream leakage. Recharge areas were greatest in May 2004 when rainfall was at a seasonal low and irrigation pumping was at a seasonal high. Recharge conditions

Hydrogeology and effects of tailings basins on the hydrology of Sands Plain, Marquette County, Michigan

USGS Publications Warehouse

Grannemann, N.G.

1984-01-01

Sands Plain, a 225-square mile area, is near the Marquette iron-mining district in Michigan's Upper Peninsula. Gribben Basin, a settling basin for disposal of waste rock particles from iron-ore concentration, is in the western part. Because Sands Plain is near iron-ore deposits, but not underlain by them, parts of the area are being considered as sites for additional tailings basins. Glacial deposits, as much as 500 feet thick, comprise the principal aquifer. Most ground water flows through the glacial deposits and discharges in a series of nearly parallel tributaries to the Chocolay River which flows into Lake Superior. Ninety-five percent of the discharge of these streams is ground-water runoff. The aquifer is recharged by precipitation at an average rate of 15 inches per year and by streamflow losses from the upper reaches of Goose Lake Outlet at an average rate of 2 inches per year. Precipitation collected at two sites had mean pH values of 4.0; rates of deposition of sulfate and total dissolved nitrogen were estimated to be 17.4 and 5.8 pounds per acre per year, respectively. Dissolved-solids concentrations in water from streams ranged from 82 to 143 milligrams per liter; sulfate ranged from 4.2 to 10 milligrams per liter. Calcium and bicarbonate were the principal dissolved substances. Highest dissolved-solids concentrations in water from wells in glacial deposits were found in a major buried valley east of Goose Lake Outlet. These concentrations ranged from 14 to 246 milligrams per liter; sulfate concentrations ranged from 0.9 to 53 milligrams per liter. Because of the high ground-water component of streamflow, mean concentrations of total nitrogen and trace metals in surface water do not differ significantly from mean concentrations in ground water. A two-dimensional digital model of ground-water flow was used to simulate water levels and ground-water runoff under steady-state and transient conditions Predictive simulations with the steady-state model were made to determine the effects of continued operation of Gribben tailings basin and construction and operation of four hypothetical tailings basins. Operation of Gribben Basin has decreased the average rate of ground-water flow to Goose Lake Outlet by 0.9 to 1.6 cubic feet per second but has increased the average rate of groundwater flow to Warner Creek by about 0.2 cubic foot per second. Continued filling of the tailings basin to its design capacity is expected to cause a slight increase in leakage from the basin to Goose Lake Outlet.Four hypothetical tailings basins, comprising a total of 11 square miles, were simulated by successively adding one more basin to the previous basin configuration. Net ground-water flow to streams was reduced by the simulated basins. The magnitude of these reductions depends on engineering decisions about the method of basin construction and a better understanding of the hydraulic properties of the materials used to seal the basin perimeters. The maximum total reduction in ground-water runoff due to construction and operation of 11 square miles of tailings basins is about 18 cubic feet per second compared to flow simulated by a steady-state simulation without tailings basins. If bottom sealing, rather than slurry wall construction, is used for one of the hypothetical basins, the total maximum reduction is 7.5 cubic feet per second. Under some assumed conditions, leakage from the tailings basins may slightly increase ground-water flow to Goose Lake Outlet and Warner Creek. The maximum probable leakage from all tailings basins is about 7 cubic feet per second; the minimum probable leakage is about 0.7 cubic foot per second.

Groundwater quality in the Lake Champlain and Susquehanna River basins, New York, 2014

USGS Publications Warehouse

Scott, Tia-Marie; Nystrom, Elizabeth A.; Reddy, James E.

2016-11-04

In a study conducted by the U.S. Geological Survey in cooperation with the New York State Department of Environmental Conservation, groundwater samples were collected from 6 production wells and 7 domestic wells in the Lake Champlain Basin and from 11 production wells and 9 domestic wells in the Susquehanna River Basin in New York. All samples were collected from June through December 2014 to characterize groundwater quality in these basins. The samples were collected and processed using standard procedures of the U.S. Geological Survey and were analyzed for 148 physiochemical properties and constituents, including dissolved gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds, radionuclides, and indicator bacteria.The Lake Champlain Basin study area covers the 3,050 square miles of the basin in northeastern New York; the remaining part of the basin is in Vermont and Canada. Of the 13 wells sampled in the Lake Champlain Basin, 6 are completed in sand and gravel, and 7 are completed in bedrock. Groundwater in the Lake Champlain Basin was generally of good quality, although properties and concentrations of some constituents— fluoride, iron, manganese, dissolved solids, sodium, radon-222, total coliform bacteria, fecal coliform bacteria, and Escherichia coli bacteria—sometimes equaled or exceeded primary, secondary, or proposed drinking-water standards. The constituent most frequently detected in concentrations exceeding drinking-water standards (5 of 13 samples) was radon-222.The Susquehanna River Basin study area covers the entire 4,522 square miles of the basin in south-central New York; the remaining part of the basin is in Pennsylvania. Of the 20 wells sampled in the Susquehanna River Basin, 11 are completed in sand and gravel, and 9 are completed in bedrock. Groundwater in the Susquehanna River Basin was generally of good quality, although properties and concentrations of some constituents—pH, chloride, sodium, dissolved solids, iron, manganese, aluminum, arsenic, barium, gross-alpha radioactivity, radon-222, methane, total coliform bacteria, and fecal coliform bacteria—sometimes equaled or exceeded primary, secondary, or proposed drinking-water standards. As in the Lake Champlain Basin, the constituent most frequently detected in concentrations exceeding drinking-water standards (13 of 20 samples) was radon-222.

Improving groundwater predictions utilizing seasonal precipitation forecasts from general circulation models forced with sea surface temperature forecasts

USGS Publications Warehouse

Almanaseer, Naser; Sankarasubramanian, A.; Bales, Jerad

2014-01-01

Recent studies have found a significant association between climatic variability and basin hydroclimatology, particularly groundwater levels, over the southeast United States. The research reported in this paper evaluates the potential in developing 6-month-ahead groundwater-level forecasts based on the precipitation forecasts from ECHAM 4.5 General Circulation Model Forced with Sea Surface Temperature forecasts. Ten groundwater wells and nine streamgauges from the USGS Groundwater Climate Response Network and Hydro-Climatic Data Network were selected to represent groundwater and surface water flows, respectively, having minimal anthropogenic influences within the Flint River Basin in Georgia, United States. The writers employ two low-dimensional models [principle component regression (PCR) and canonical correlation analysis (CCA)] for predicting groundwater and streamflow at both seasonal and monthly timescales. Three modeling schemes are considered at the beginning of January to predict winter (January, February, and March) and spring (April, May, and June) streamflow and groundwater for the selected sites within the Flint River Basin. The first scheme (model 1) is a null model and is developed using PCR for every streamflow and groundwater site using previous 3-month observations (October, November, and December) available at that particular site as predictors. Modeling schemes 2 and 3 are developed using PCR and CCA, respectively, to evaluate the role of precipitation forecasts in improving monthly and seasonal groundwater predictions. Modeling scheme 3, which employs a CCA approach, is developed for each site by considering observed groundwater levels from nearby sites as predictands. The performance of these three schemes is evaluated using two metrics (correlation coefficient and relative RMS error) by developing groundwater-level forecasts based on leave-five-out cross-validation. Results from the research reported in this paper show that using precipitation forecasts in climate models improves the ability to predict the interannual variability of winter and spring streamflow and groundwater levels over the basin. However, significant conditional bias exists in all the three modeling schemes, which indicates the need to consider improved modeling schemes as well as the availability of longer time-series of observed hydroclimatic information over the basin.

Assessing groundwater accessibility in the Kharga Basin, Egypt: A remote sensing approach

NASA Astrophysics Data System (ADS)

Parks, Shawna; Byrnes, Jeffrey; Abdelsalam, Mohamed G.; Laó Dávila, Daniel A.; Atekwana, Estella A.; Atya, Magdy A.

2017-12-01

We used multi-map analysis of remote sensing and ancillary data to identify potentially accessible sites for groundwater resources in the Kharga Basin in the Western Desert of Egypt. This basin is dominated by Cretaceous sandstone formations and extends within the Nubian Sandstone Aquifer. It is dissected by N-S and E-W trending faults, possibly acting as conduits for upward migration of groundwater. Analysis of paleo-drainage using Digital Elevation Model (DEM) generated from the Shuttle Radar Topography Mission (SRTM) data shows that the Kharga was a closed basin that might have been the site of a paleo-lake. Lake water recharged the Nubian Sandstone Aquifer during the wetter Holocene time. We generated the following layers for the multi-map analysis: (1) Fracture density map from the interpretation of Landsat Operational Land Imager (OLI), SRTM DEM, and RADARSAT data. (2) Thermal Inertia (TI) map (for moisture content imaging) from the Moderate Resolution Imaging Spectroradiometer (MODIS) data. (3) Hydraulic conductivity map from mapping lithological units using the Landsat OLI and previously published data. (4) Aquifer thickness map from previously published data. We quantitatively ranked the Kharga Basin by considering that regions of high fracture density, high TI, thicker aquifer, and high hydraulic conductivity have higher potential for groundwater accessibility. Our analysis shows that part of the southern Kharga Basin is suitable for groundwater extraction. This region is where N-S and E-W trending faults intersect, has relatively high TI and it is underlain by thick aquifer. However, the suitability of this region for groundwater use will be reduced significantly when considering the changes in land suitability and economic depth to groundwater extraction in the next 50 years.

Groundwater mining of bedrock aquifers in the Denver Basin - Past, present, and future

USGS Publications Warehouse

Moore, J.E.; Raynolds, R.G.; Barkmann, P.E.

2004-01-01

The Denver Basin bedrock aquifer system is an important source of water for municipal and agricultural uses in the Denver and Colorado Springs metropolitan areas. The Denver area is one of the fastest growing areas in the United States with a population of 1.2 million in 1960 that has increased to over 2.4 million by 2000. This rapid population growth has produced a corresponding increase in demand for potable water. Historically, the Denver area has relied on surface water, however, in the past 10 years new housing and recreation developments have begun to rely on groundwater from the bedrock aquifers as the surface water is fully appropriated and in short supply. The Denver Basin bedrock aquifer system consists of Tertiary and Cretaceous age sedimentary rocks known as the Dawson, Denver, Arapahoe and Laramie-Fox Hills Aquifers. The number of bedrock wells has increased from 12,000 in 1985 to 33,700 in 2001 and the withdrawal of groundwater has caused water level declines of 76 m. Water level declines for the past 10 years have ranged from 3 to 12 m per year. The groundwater supplies were once thought to last 100 years but there is concern that the groundwater supplies may be essentially depleted in 10 to 15 years in areas on the west side of the basin. Extensive development of the aquifer system has occurred in the last 25 years especially near the center of the basin in Douglas and El Paso Counties where rapid urban growth continues and surface water is lacking. Groundwater is being mined from the aquifer system because the discharge by wells exceeds the rate of recharge. Concern is mounting that increased groundwater withdrawal will cause water level declines, increased costs to withdraw groundwater, reduced well yield, and reduced groundwater storage. As the long-term sustainability of the groundwater resource is in doubt, water managers believe that the life of the Denver Basin aquifers can be extended with artificial recharge, water reuse, restrictions on lawn watering, well permit restrictions and conservation measures.

Regional transport modelling for nitrate trend assessment and forecasting in a chalk aquifer.

PubMed

Orban, Philippe; Brouyère, Serge; Batlle-Aguilar, Jordi; Couturier, Julie; Goderniaux, Pascal; Leroy, Mathieu; Maloszewski, Piotr; Dassargues, Alain

2010-10-21

Regional degradation of groundwater resources by nitrate has become one of the main challenges for water managers worldwide. Regulations have been defined to reverse observed nitrate trends in groundwater bodies, such as the Water Framework Directive and the Groundwater Daughter Directive in the European Union. In such a context, one of the main challenges remains to develop efficient approaches for groundwater quality assessment at regional scale, including quantitative numerical modelling, as a decision support for groundwater management. A new approach combining the use of environmental tracers and the innovative 'Hybrid Finite Element Mixing Cell' (HFEMC) modelling technique is developed to study and forecast the groundwater quality at the regional scale, with an application to a regional chalk aquifer in the Geer basin in Belgium. Tritium data and nitrate time series are used to produce a conceptual model for regional groundwater flow and contaminant transport in the combined unsaturated and saturated zones of the chalk aquifer. This shows that the spatial distribution of the contamination in the Geer basin is essentially linked to the hydrodynamic conditions prevailing in the basin, more precisely to groundwater age and mixing and not to the spatial patterns of land use or local hydrodispersive processes. A three-dimensional regional scale groundwater flow and solute transport model is developed. It is able to reproduce the spatial patterns of tritium and nitrate and the observed nitrate trends in the chalk aquifer and it is used to predict the evolution of nitrate concentrations in the basin. The modelling application shows that the global inertia of groundwater quality is strong in the basin and trend reversal is not expected to occur before the 2015 deadline fixed by the European Water Framework Directive. The expected time required for trend reversal ranges between 5 and more than 50 years, depending on the location in the basin and the expected reduction in nitrate application. To reach a good chemical status, nitrate concentrations in the infiltrating water should be reduced as soon as possible below 50mg/l; however, even in that case, more than 50 years is needed to fully reverse upward trends. Copyright © 2010 Elsevier B.V. All rights reserved.

Hydrogeochemistry of high-fluoride groundwater at Yuncheng Basin, northern China.

PubMed

Li, Chengcheng; Gao, Xubo; Wang, Yanxin

2015-03-01

Hydrogeochemical and environmental isotope methods were integrated to delineate the spatial distribution and enrichment of fluoride in groundwater at Yuncheng Basin in northern China. One hundred groundwater samples and 10 Quaternary sediment samples were collected from the Basin. Over 69% of the shallow groundwater (with a F(-) concentration of up to 14.1mg/L), 44% of groundwater samples from the intermediate and 31% from the deep aquifers had F(-) concentrations above the WHO provisional drinking water guideline of 1.5mg/L. Groundwater with high F(-) concentrations displayed a distinctive major ion chemistry: Na-rich and Ca-poor with a high pH value and high HCO3(-) content. Hydrochemical diagrams and profiles and hydrogen and oxygen isotope compositions indicate that variations in the major ion chemistry and pH are controlled by mineral dissolution, cation exchange and evaporation in the aquifer systems, which are important for F(-) mobilization as well. Leakage of shallow groundwater and/or evaporite (gypsum and mirabilite) dissolution may be the major sources for F(-) in groundwater of the intermediate and deep aquifers. Copyright © 2014 Elsevier B.V. All rights reserved.

Simulation of groundwater and surface-water flow in the upper Deschutes Basin, Oregon

USGS Publications Warehouse

Gannett, Marshall W.; Lite, Kenneth E.; Risley, John C.; Pischel, Esther M.; La Marche, Jonathan L.

2017-10-20

This report describes a hydrologic model for the upper Deschutes Basin in central Oregon developed using the U.S. Geological Survey (USGS) integrated Groundwater and Surface-Water Flow model (GSFLOW). The upper Deschutes Basin, which drains much of the eastern side of the Cascade Range in Oregon, is underlain by large areas of permeable volcanic rock. That permeability, in combination with the large annual precipitation at high elevations, results in a substantial regional aquifer system and a stream system that is heavily groundwater dominated.The upper Deschutes Basin is also an area of expanding population and increasing water demand for public supply and agriculture. Surface water was largely developed for agricultural use by the mid-20th century, and is closed to additional appropriations. Consequently, water users look to groundwater to satisfy the growing demand. The well‑documented connection between groundwater and the stream system, and the institutional and legal restrictions on streamflow depletion by wells, resulted in the Oregon Water Resources Department (OWRD) instituting a process whereby additional groundwater pumping can be permitted only if the effects to streams are mitigated, for example, by reducing permitted surface-water diversions. Implementing such a program requires understanding of the spatial and temporal distribution of effects to streams from groundwater pumping. A groundwater model developed in the early 2000s by the USGS and OWRD has been used to provide insights into the distribution of streamflow depletion by wells, but lacks spatial resolution in sensitive headwaters and spring areas.The integrated model developed for this project, based largely on the earlier model, has a much finer grid spacing allowing resolution of sensitive headwater streams and important spring areas, and simulates a more complete set of surface processes as well as runoff and groundwater flow. In addition, the integrated model includes improved representation of subsurface geology and explicitly simulates the effects of hydrologically important fault zones not included in the previous model.The upper Deschutes Basin GSFLOW model was calibrated using an iterative trial and error approach using measured water-level elevations (water levels) from 800 wells, 144 of which have time series of 10 or more measurements. Streamflow was calibrated using data from 21 gage locations. At 14 locations where measured flows are heavily influenced by reservoir operations and irrigation diversions, so called “naturalized” flows, with the effects of reservoirs and diversion removed, developed by the Bureau of Reclamation, were used for calibration. Surface energy and moisture processes such as solar radiation, snow accumulation and melting, and evapotranspiration were calibrated using national datasets as well as data from long-term measurement sites in the basin. The calibrated Deschutes GSFLOW model requires daily precipitation, minimum and maximum air temperature data, and monthly data describing groundwater pumping and artificial recharge from leaking irrigation canals (which are a significant source of groundwater recharge).The calibrated model simulates the geographic distribution of hydraulic head over the 5,000 ft range measured in the basin, with a median absolute residual of about 53 ft. Temporal variations in head resulting from climate cycles, pumping, and canal leakage are well simulated over the model area. Simulated daily streamflow matches gaged flows or calculated naturalized flows for streams including the Crooked and Metolius Rivers, and lower parts of the mainstem Deschutes River. Seasonal patterns of runoff are less well fit in some upper basin streams. Annual water balances of streamflow are good over most of the model domain. Model fit and overall capabilities are appropriate for the objectives of the project.The integrated model results confirm findings from other studies and models indicating that most streamflow in the upper Deschutes Basin comes directly from groundwater discharge. The integrated model provides additional insights about the components of streamflow including direct groundwater discharge to streams, interflow, groundwater discharge to the land surface (Dunnian flow), and direct runoff (Hortonian flow). The new model provides improved capability for exploring the timing and distribution of streamflow capture by wells, and the hydrologic response to changes in other external stresses such as canal operation, irrigation, and drought. Because the model uses basic meteorological data as the primary input; and simulates surface energy and moisture balances, groundwater recharge and flow, and all components of streamflow; it is well suited for exploring the hydrologic response to climate change, although no such simulations are included in this report.The model was developed as a tool for future application; however, example simulations are provided in this report. In the example simulations, the model is used to explore the influence of well location and geologic structure on stream capture by pumping wells. Wells were simulated at three locations within a 12-mi area close to known groundwater discharge areas and crossed by a regional fault zone. Simulations indicate that the magnitude and timing of stream capture from pumping is largely controlled by the geographic location of the wells, but that faults can have a large influence on the propagation of pumping stresses.

Groundwater Management Innovations in the High Plains Aquifer, USA: A possible path towards sustainability? (Invited)

NASA Astrophysics Data System (ADS)

Sophocleous, M. A.

2009-12-01

The U.S. High Plains aquifer, one of the largest freshwater aquifer systems in the world covering parts of eight US states, continues to decline, threatening the long-term viability of the region’s irrigation-based economy. The theory of the commons has meaningful messages for High-Plains jurisdictions as no private incentive exists to save for tomorrow, and agricultural prosperity depends on mining water from large portions of the aquifer. The eight High Plains states take different approaches to the development and management of the aquifer based on each state’s body of water laws that abide by different legal doctrines, on which Federal laws are superposed, thus creating difficulties in integrated regional water management efforts. Although accumulating hydrologic stresses and competing demands on groundwater resources are making groundwater management increasingly complex, they are also leading to innovative approaches to the management of groundwater supplies, and those are highlighted in this presentation as good examples for emulation in managing groundwater resources. The highlighted innovations include (1) the Texas Groundwater Availability Modeling program, (2) Colorado’s water-augmentation program, (3) Kansas’ Intensive Groundwater Use Control Area policy, (4) the Kansas Groundwater Management Districts’ “safe yield” policies, (5) the water-use reporting program in Kansas, (6) the Aquifer Storage and Recovery program of the City of Wichita, Kansas, and (7) Nebraska’s Natural Resources Districts. It is concluded that the fragmented and piecemeal institutional arrangements for managing the supplies and quality of water are unlikely to be sufficient to meet the water challenges of the future. A number of recommendations for enhancing the sustainability of the aquifer are presented, including the formation of an interstate groundwater commission for the High Plains aquifer along the lines of the Delaware and Susquehanna River Basins Commissions in the US. Finally, some lessons on groundwater management that other countries can learn from the US experience are outlined.

Hybrid Multi-Objective Optimization of Folsom Reservoir Operation to Maximize Storage in Whole Watershed

NASA Astrophysics Data System (ADS)

Goharian, E.; Gailey, R.; Maples, S.; Azizipour, M.; Sandoval Solis, S.; Fogg, G. E.

2017-12-01

The drought incidents and growing water scarcity in California have a profound effect on human, agricultural, and environmental water needs. California experienced multi-year droughts, which have caused groundwater overdraft and dropping groundwater levels, and dwindling of major reservoirs. These concerns call for a stringent evaluation of future water resources sustainability and security in the state. To answer to this call, Sustainable Groundwater Management Act (SGMA) was passed in 2014 to promise a sustainable groundwater management in California by 2042. SGMA refers to managed aquifer recharge (MAR) as a key management option, especially in areas with high variation in water availability intra- and inter-annually, to secure the refill of underground water storage and return of groundwater quality to a desirable condition. The hybrid optimization of an integrated water resources system provides an opportunity to adapt surface reservoir operations for enhancement in groundwater recharge. Here, to re-operate Folsom Reservoir, objectives are maximizing the storage in the whole American-Cosumnes watershed and maximizing hydropower generation from Folsom Reservoir. While a linear programing (LP) module tends to maximize the total groundwater recharge by distributing and spreading water over suitable lands in basin, a genetic based algorithm, Non-dominated Sorting Genetic Algorithm II (NSGA-II), layer above it controls releases from the reservoir to secure the hydropower generation, carry-over storage in reservoir, available water for replenishment, and downstream water requirements. The preliminary results show additional releases from the reservoir for groundwater recharge during high flow seasons. Moreover, tradeoffs between the objectives describe that new operation performs satisfactorily to increase the storage in the basin, with nonsignificant effects on other objectives.

Hydrographs Showing Ground-Water Level Changes for Selected Wells in the Lower Skagit River Basin, Washington

USGS Publications Warehouse

Fasser, E.T.; Julich, R.J.

2009-01-01

Hydrographs for selected wells in the Lower Skagit River basin, Washington, are presented in an interactive web-based map to illustrate monthly and seasonal changes in ground-water levels in the study area. Ground-water level data and well information were collected by the U.S. Geological Survey using standard techniques and were stored in the USGS National Water Information System (NWIS), Ground-Water Site-Inventory (GWSI) System.

Modeling Groundwater Flow System of a Drainage Basin in the Basement Complex Environment of Southwestern Nigera

NASA Astrophysics Data System (ADS)

Akinwumiju, Akinola S.; Olorunfemi, Martins O.

2018-05-01

This study attempted to model the groundwater flow system of a drainage basin within the Basement Complex environment of Southwestern Nigeria. Four groundwater models were derived from Vertical Electrical Sounding (VES) Data, remotely sensed data, geological information (hydrolineaments and lithology) and borehole data. Subsequently, two sub-surface (local and regional) flow systems were delineated in the study area. While the local flow system is controlled by surface topography, the regional flow system is controlled by the networks of intermediate and deep seated faults/fractures. The local flow system is characterized by convergence, divergence, inflow and outflow in places, while the regional flow system is dominated by NNE-SSW and W-E flow directions. Minor flow directions include NNW-SSE and E-W with possible linkages to the main flow-paths. The NNE-SSW regional flow system is a double open ended flow system with possible linkage to the Niger Trough. The W-E regional flow system is a single open ended system that originates within the study area (with possible linkage to the NNE-SSW regional flow system) and extends to Ikogosi in the adjoining drainage basin. Thus, the groundwater drainage basin of the study area is much larger and extensive than its surface drainage basin. The all year round flowing (perennial) rivers are linked to groundwater outcrops from faults/fractures and contact zones. Consequently, larger percentage of annual rainwater usually leaves the basin in form of runoff and base flow. Therefore, the basin is categorized as a donor basin but with suspected subsurface water input at its northeastern axis.

Parameter Identification and Uncertainty Analysis for Visual MODFLOW based Groundwater Flow Model in a Small River Basin, Eastern India

NASA Astrophysics Data System (ADS)

Jena, S.

2015-12-01

The overexploitation of groundwater resulted in abandoning many shallow tube wells in the river Basin in Eastern India. For the sustainability of groundwater resources, basin-scale modelling of groundwater flow is essential for the efficient planning and management of the water resources. The main intent of this study is to develope a 3-D groundwater flow model of the study basin using the Visual MODFLOW package and successfully calibrate and validate it using 17 years of observed data. The sensitivity analysis was carried out to quantify the susceptibility of aquifer system to the river bank seepage, recharge from rainfall and agriculture practices, horizontal and vertical hydraulic conductivities, and specific yield. To quantify the impact of parameter uncertainties, Sequential Uncertainty Fitting Algorithm (SUFI-2) and Markov chain Monte Carlo (MCMC) techniques were implemented. Results from the two techniques were compared and the advantages and disadvantages were analysed. Nash-Sutcliffe coefficient (NSE) and coefficient of determination (R2) were adopted as two criteria during calibration and validation of the developed model. NSE and R2 values of groundwater flow model for calibration and validation periods were in acceptable range. Also, the MCMC technique was able to provide more reasonable results than SUFI-2. The calibrated and validated model will be useful to identify the aquifer properties, analyse the groundwater flow dynamics and the change in groundwater levels in future forecasts.

Hydrogeologic and geochemical characterization of groundwater resources in Rush Valley, Tooele County, Utah

USGS Publications Warehouse

Gardner, Philip M.; Kirby, Stefan

2011-01-01

The water resources of Rush Valley were assessed during 2008–2010 with an emphasis on refining the understanding of the groundwater-flow system and updating the groundwater budget. Surface-water resources within Rush Valley are limited and are generally used for agriculture. Groundwater is the principal water source for most other uses including supplementing irrigation. Most groundwater withdrawal in Rush Valley is from the unconsolidated basin-fill aquifer where conditions are generally unconfined near the mountain front and confined at lower altitudes near the valley center. Productive aquifers also occur in fractured bedrock along the valley margins and beneath the basin-fill deposits in some areas.Drillers’ logs and geophysical gravity data were compiled and used to delineate seven hydrogeologic units important to basin-wide groundwater movement. The principal basin-fill aquifer includes the unconsolidated Quaternary-age alluvial and lacustrine deposits of (1) the upper basin-fill aquifer unit (UBFAU) and the consolidated and semiconsolidated Tertiary-age lacustrine and alluvial deposits of (2) the lower basin-fill aquifer unit (LBFAU). Bedrock hydrogeologic units include (3) the Tertiary-age volcanic unit (VU), (4) the Pennsylvanian- to Permian-age upper carbonate aquifer unit (UCAU), (5) the upper Mississippian- to lower Pennsylvanian-age upper siliciclastic confining unit (USCU), (6) the Middle Cambrian- to Mississippian-age lower carbonate aquifer unit (LCAU), and (7) the Precambrian- to Lower Cambrian-age noncarbonate confining unit (NCCU). Most productive bedrock wells in the Rush Valley groundwater basin are in the UCAU.Average annual recharge to the Rush Valley groundwater basin is estimated to be about 39,000 acre-feet. Nearly all recharge occurs as direct infiltration of snowmelt and rainfall within the mountains with smaller amounts occurring as infiltration of streamflow and unconsumed irrigation water at or near the mountain front. Groundwater generally flows from the higher altitude recharge areas toward two distinct valley-bottom discharge areas: one in the vicinity of Rush Lake in northern Rush Valley and the other located west and north of Vernon. Average annual discharge from the Rush Valley groundwater basin is estimated to be about 43,000 acre-feet. Most discharge occurs as evapotranspiration in the valley lowlands, as discharge to springs and streams, and as withdrawal from wells. Subsurface discharge outflow to Tooele and Cedar Valleys makes up only a small fraction of natural discharge.Groundwater samples were collected from 25 sites (24 wells and one spring) for geochemical analysis. Dissolved-solids concentrations in water from these sites ranged from 181 to 1,590 milligrams per liter. Samples from seven wells contained arsenic concentrations that exceed the Environmental Protection Agency Maximum Contaminant Level of 10 micrograms per liter. The highest arsenic levels are found north of Vernon and in southeastern Rush Valley. Stable-isotope ratios of oxygen and deuterium, along with dissolved-gas recharge temperatures, indicate that nearly all modern groundwater is meteoric and derived from the infiltration of high altitude precipitation in the mountains. These data are consistent with recharge estimates made using a Basin Characterization Model of net infiltration that shows nearly all recharge occurring as infiltration of precipitation and snowmelt within the mountains surrounding Rush Valley. Tritium concentrations between 0.4 and 10 tritium units indicate the presence of modern (less than 60 years old) groundwater at 7 of the 25 sample sites. Apparent 3H/3He ages, calculated for six of these sites, range from 3 to 35 years. Adjusted minimum radiocarbon ages of premodern water samples range from about 1,600 to 42,000 years with samples from 11 of 13 sites being more than 11,000 years. These data help to identify areas where modern groundwater is circulating through the hydrologic system on time scales of decades or less and indicate that large parts of the principal basin-fill and the bedrock aquifers are much less active and receive little to no modern recharge.

Oxygen, hydrogen, and helium isotopes for investigating groundwater systems of the Cape Verde Islands, West Africa

USGS Publications Warehouse

Heilweil, V.M.; Solomon, K.D.; Gingerich, S.B.; Verstraeten, Ingrid M.

2009-01-01

Stable isotopes (??18O, ??2H), tritium (3H), and helium isotopes (3He, 4He) were used for evaluating groundwater recharge sources, flow paths, and residence times of three watersheds in the Cape Verde Islands (West Africa). Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. In contrast to other active oceanic hotspots, environmental tracers show that deep geothermal circulation does not strongly affect groundwater. Low tritium concentrations at seven groundwater sites indicate groundwater residence times of more than 50 years. Higher tritium values at other sites suggest some recent recharge. High 4He and 3He/4He ratios precluded 3H/3He dating at six sites. These high 3He/4He ratios (R/Ra values of up to 8.3) are consistent with reported mantle derived helium of oceanic island basalts in Cape Verde and provided end-member constraints for improved dating at seven other locations. Tritium and 3H/3He dating shows that S??o Nicolau Island's Ribeira Faj?? Basin has groundwater residence times of more than 50 years, whereas Fogo Island's Mosteiros Basin and Santo Ant??o Island's Ribeira Paul Basin contain a mixture of young and old groundwater. Young ages at selected sites within these two basins indicate local recharge and potential groundwater susceptibility to surface contamination and/or salt-water intrusion. ?? Springer-Verlag 2009.

Hydrogeologic framework and groundwater/surface-water interactions of the upper Yakima River Basin, Kittitas County, central Washington

USGS Publications Warehouse

Gendaszek, Andrew S.; Ely, D. Matthew; Hinkle, Stephen R.; Kahle, Sue C.; Welch, Wendy B.

2014-01-01

The hydrogeology, hydrology, and geochemistry of groundwater and surface water in the upper (western) 860 square miles of the Yakima River Basin in Kittitas County, Washington, were studied to evaluate the groundwater-flow system, occurrence and availability of groundwater, and the extent of groundwater/surface-water interactions. The study area ranged in altitude from 7,960 feet in its headwaters in the Cascade Range to 1,730 feet at the confluence of the Yakima River with Swauk Creek. A west-to-east precipitation gradient exists in the basin with the western, high-altitude headwaters of the basin receiving more than 100 inches of precipitation per year and the eastern, low-altitude part of the basin receiving about 20 inches of precipitation per year. From the early 20th century onward, reservoirs in the upper part of the basin (for example, Keechelus, Kachess, and Cle Elum Lakes) have been managed to store snowmelt for irrigation in the greater Yakima River Basin. Canals transport water from these reservoirs for irrigation in the study area; additional water use is met through groundwater withdrawals from wells and surface-water withdrawals from streams and rivers. Estimated groundwater use for domestic, commercial, and irrigation purposes is reported for the study area. A complex assemblage of sedimentary, metamorphic, and igneous bedrock underlies the study area. In a structural basin in the southeastern part of the study area, the bedrock is overlain by unconsolidated sediments of glacial and alluvial origin. Rocks and sediments were grouped into six hydrogeologic units based on their lithologic and hydraulic characteristics. A map of their extent was developed from previous geologic mapping and lithostratigraphic information from drillers’ logs. Water flows through interstitial space in unconsolidated sediments, but largely flows through fractures and other sources of secondary porosity in bedrock. Generalized groundwater-flow directions within the unconfined part of the aquifers in unconsolidated sediments indicate generalized groundwater movement toward the Yakima River and its tributaries and the outlet of the study area. Groundwater movement through fractures within the bedrock aquifers is complex and varies over spatial scales depending on the architecture of the fracture-flow system and its hydraulic properties. The complexity of the fracturedbedrock groundwater-flow system is supported by a wide range of groundwater ages determined from geochemical analyses of carbon-14, sulfur hexafluoride, and tritium in groundwater. These geochemical data also indicate that the shallow groundwater system is actively flushing with young, isotopically heavy groundwater, but isotopicallylight, Pleistocene-age groundwater with a geochemicallyevolved composition occurs at depth within the fracturedbedrock aquifers of upper Kittitas County. An eastward depletion of stable isotopes in groundwater is consistent with hydrologically separate subbasins. This suggests that groundwater that recharges in one subbasin is not generally available for withdrawal or discharge into surface-water features within other subbasins. Water budget components were calculated for 11 subbasins using a watershed model and varied based on the climate, land uses, and geology of the subbasin. Synoptic streamflow measurements made in August 2011 indicate that groundwater discharges into several tributaries of the Yakima River with several losses of streamflow measured where the streams exit bedrock uplands and flow over unconsolidated sediments. Profiles of stream temperature during late summer suggest cool groundwater inflow over discrete sections of streams. This groundwater/surfacewater connection is further supported by the stable-isotope composition of stream water, which reflects the local stableisotope composition of groundwater measured at some wells and springs. Collectively, these hydrogeologic, hydrologic, and geochemical data support a framework for evaluating the potential effects of future groundwater appropriations on senior surface-water and groundwater rights and streamflows. Although total pumping rates in upper Kittitas County of about 3.5 cubic feet per second are small relative to other components of the water budget, the magnitude, timing, and location of withdrawals may have important effects on the hydrologic system. The heterogeneous and variably fractured bedrock in the study area precluded a detailed evaluation of localized effects of pumping, but several generalizations about the groundwater and surface-water systems can be made. These generalizations include evidence for the continuity between the groundwater and surface-water system apparent from synoptic streamflow measurements, stream-temperature profiles, and stable-isotope data of groundwater and surface waters.

Geochemical evolution of groundwater salinity at basin scale: a case study from Datong basin, Northern China.

PubMed

Wu, Ya; Wang, Yanxin

2014-05-01

A hydrogeochemical investigation using integrated methods of stable isotopes ((18)O, (2)H), (87)Sr/(86)Sr ratios, Cl/Br ratios, chloride-mass balance, mass balance and hydrogeochemical modeling was conducted to interpret the geochemical evolution of groundwater salinity in Datong basin, northern China. The δ(2)H, δ(18)O ratios in precipitation exhibited a local meteoric water line of δ(2)H = 6.4 δ(18)O -5 (R(2) = 0.94), while those in groundwater suggested their meteoric origin in a historically colder climatic regime with a speculated recharge rate of less than 20.5 mm overall per year, in addition to recharge from a component of deep residual ancient lake water enriched with Br. According to the Sr isotope binary mixing model, the mixing of recharges from the Shentou karst springs (24%), the western margins (11%) and the eastern margins (65%) accounts for the groundwater from the deep aquifers of the down-gradient parts in the central basin is a possible mixing mechanism. In Datong, hydrolysis of silicate minerals is the most important hydrogeochemical process responsible for groundwater chemistry, in addition to dissolution of carbonate and evaporites. In the recharge areas, silicate chemical weathering is typically at the bisiallitization stage, while that in the central basin is mostly at the monosiallitization stage with limited evidence of being in equilibrium with gibbsite. Na exchange with bound Ca, Mg prevails at basin scale, and intensifies with groundwater salinity, while Ca, Mg exchange with bound Na locally occurs in the east pluvial and alluvial plains. Although groundwater salinity increases with the progress of water-rock/sediment interactions along the flow path, as a result of carbonate solubility control and continuous evapotranspiration, Na-HCO3 and Na-Cl-SO4 types of water are usually characterized respectively in the deep and the shallow aquifers of an inland basin with a silicate terrain in an arid climatic regime.

Water Quality

Treesearch

Terry L. Maluk; Thomas A. Abrahamsen; Richard H. Day

2000-01-01

The U.S. Geological Survey (USGS) began the National Water-Quality Assessment Program (NAWQA) in 1991 to describe the status of and long-term trends in the quality of the Nation's surface- and ground-water resources. The study of the Santee River Basin and Coastal Drainages began in 1994 and included about 60800 km2 in North Carolina and...

Hydrogeologic setting, water budget, and preliminary analysis of ground-water exchange at Lake Starr, a seepage lake in Polk County, Florida

USGS Publications Warehouse

Swancar, Amy; Lee, T.M.; O'Hare, T. M.

2000-01-01

Lake Starr, a 134-acre seepage lake of multiple-sinkhole origin on the Lake Wales Ridge of central Florida, was the subject of a detailed water-budget study from August 1996 through July 1998. The study monitored the effects of hydrogeologic setting, climate, and ground-water pumping on the water budget and lake stage. The hydrogeologic setting of the Lake Starr basin differs markedly on the two sides of the lake. Ground water from the surficial aquifer system flows into the lake from the northwest side of the basin, and lake water leaks out to the surficial aquifer system on the southeast side of the basin. Lake Starr and the surrounding surficial aquifer system recharge the underlying Upper Floridan aquifer. The rate of recharge to the Upper Floridan aquifer is determined by the integrity of the intermediate confining unit and by the downward head gradient between the two aquifers. On the inflow side of the lake, the intermediate confining unit is more continuous, allowing ground water from the surficial aquifer system to flow laterally into the lake. Beneath the lake and on the southeast side of the basin, breaches in the intermediate confining unit enhance downward flow to the Upper Floridan aquifer, so that water flows both downward and laterally away from the lake through the ground-water flow system in these areas. An accurate water budget, including evaporation measured by the energy-budget method, was used to calculate net ground-water flow to the lake, and to do a preliminary analysis of the relation of net ground-water fluxes to other variables. Water budgets constructed over different timeframes provided insight on processes that affect ground-water interactions with Lake Starr. Weekly estimates of net ground-water flow provided evidence for the occurrence of transient inflows from the nearshore basin, as well as the short-term effects of head in the Upper Floridan aquifer on ground-water exchange with the lake. Monthly water budgets showed the effects of wet and dry seasons, and provided evidence for ground-water inflow generated from the upper basin. Annual water budgets showed how differences in timing of rainfall and pumping stresses affected lake stage and lake ground-water interactions. Lake evaporation measurements made during the study suggest that, on average, annual lake evaporation exceeds annual precipitation in the basin. Rainfall was close to the long-term average of 51.99 inches per year for the 2 years of the study (50.68 and 54.04 inches, respectively). Lake evaporation was 57.08 and 55.88 inches per year for the same 2 years, making net precipitation (rainfall minus evaporation) negative during both years. If net precipitation to seepage lakes in this area is negative over the long-term, then the ability to generate net ground-water inflow from the surrounding basin plays an important role in sustaining lake levels. Evaporation exceeded rainfall by a similar amount for both years of the study, but net ground-water flow differed substantially between the 2 years. The basin contributed net ground-water inflow to the lake in both years, however, net ground-water inflow was not sufficient to make up for the negative net precipitation during the first year, and the lake fell 4.9 inches. During the second year, net ground-water inflow exceeded the difference between evaporation and rainfall and the lake rose by 12.7 inches. The additional net ground-water inflow in the second year was due to both an increase in the amount of gross ground-water inflow and a decrease in lake leakage (ground-water outflow). Ground-water inflow was greater during the second year because more rain fell during the winter, when evaporative losses were low, resulting in greater ground-water recharge. However, decreased lake leakage during this year was probably at least as important as increased ground-water inflow in explaining the difference in net ground-water flow to the lake between the 2 years. Estimates of lake leakage

Summary of Hydrologic Data for the Tuscarawas River Basin, Ohio, with an Annotated Bibliography

USGS Publications Warehouse

Haefner, Ralph J.; Simonson, Laura A.

2010-01-01

The Tuscarawas River Basin drains approximately 2,600 square miles in eastern Ohio and is home to 600,000 residents that rely on the water resources of the basin. This report summarizes the hydrologic conditions in the basin, describes over 400 publications related to the many factors that affect the groundwater and surface-water resources, and presents new water-quality information and a new water-level map designed to provide decisionmakers with information to assist in future data-collection efforts and land-use decisions. The Tuscarawas River is 130 miles long, and the drainage basin includes four major tributary basins and seven man-made reservoirs designed primarily for flood control. The basin lies within two physiographic provinces-the Glaciated Appalachian Plateaus to the north and the unglaciated Allegheny Plateaus to the south. Topography, soil types, surficial geology, and the overall hydrology of the basin were strongly affected by glaciation, which covered the northern one-third of the basin over 10,000 years ago. Within the glaciated region, unconsolidated glacial deposits, which are predominantly clay-rich till, overlie gently sloping Pennsylvanian-age sandstone, limestone, coal, and shale bedrock. Stream valleys throughout the basin are filled with sands and gravels derived from glacial outwash and alluvial processes. The southern two-thirds of the basin is characterized by similar bedrock units; however, till is absent and topographic relief is greater. The primary aquifers are sand- and gravel-filled valleys and sandstone bedrock. These sands and gravels are part of a complex system of aquifers that may exceed 400 feet in thickness and fill glacially incised valleys. Sand and gravel aquifers in this basin are capable of supporting sustained well yields exceeding 1,000 gallons per minute. Underlying sandstones within 300 feet of the surface also provide substantial quantities of water, with typical well yields of up to 100 gallons per minute. Although hydraulic connection between the sandstone bedrock and the sands and gravels in valleys is likely, it has not been assessed in the Tuscarawas River Basin. In 2001, the major land uses in the basin were approximately 40 percent forested, 39 percent agricultural, and 17 percent urban/residential. Between 1992 and 2001, forested land use decreased by 2 percent with correspondingly small increases in agricultural and urban land uses, but from 1980 to 2005, the 13-county area that encompasses the basin experienced a 7.1-percent increase in population. Higher population density and percentages of urban land use were typical of the northern, headwaters parts of the basin in and around the cities of Akron, Canton, and New Philadelphia; the southern area was rural. The basin receives approximately 38 inches of precipitation per year that exits the basin through evapotranspiration, streamflow, and groundwater withdrawals. Recharge to groundwater is estimated to range from 6 to 10 inches per year across the basin. In 2000, approximately 89 percent of the 116 million gallons per day of water used in the basin came from groundwater sources, whereas 11 percent came from surface-water sources. To examine directions of groundwater flow in the basin, a new dataset of water-level contours was developed by the Ohio Department of Natural Resources. The contours were compiled on a map that shows that groundwater flows from the uplands towards the valleys and that the water-level surface mimics surface topography; however, there are areas where data were too sparse to adequately map the water-level surface. Additionally, little is known about deep groundwater that may be flowing into the basin from outside the basin and groundwater interactions with surface-water bodies. Many previous reports as well as new data collected as part of this study show that water quality in the streams and aquifers in the Tuscarawas River Basin has been degraded by urban, suburban, and rural

Simulation of rainfall-runoff response in mined and unmined watersheds in coal areas of West Virginia

USGS Publications Warehouse

Puente, Celso; Atkins, John T.

1989-01-01

Meteorologic and hydrologic data from five small watersheds in the coal areas of West Virginia were used to calibrate and test the U.S. Geological Survey Precipitation-Runoff Modeling System for simulating streamflow under various climatic and land-use conditions. Three of the basins--Horsecamp Run, Gilmer Run, and Collison Creek--are primarily forested and relatively undisturbed. The remaining basins--Drawdy Creek and Brier Creek-are extensively mined, both surface and underground above stream drainage level. Low-flow measurements at numerous synoptic sites in the mined basins indicate that coal mining has substantially altered the hydrologic system of each basin. The effects of mining on streamflow that were identified are (1) reduced base flow in stream segments underlain by underground mines, (2) increased base flow in streams that are downdip and stratigraphically below the elevation of the mined coal beds, and (3) interbasin transfer of ground water through underground mines. These changes probably reflect increased permeability of surface rocks caused by subsidence fractures associated with collapsed underground mines in the basin. Such fractures would increase downward percolation of precipitation, surface and subsurface flow, and ground-water flow to deeper rocks or to underground mine workings. Model simulations of the water budgets for the unmined basins during the 1972-73 water years indicate that total annual runoff averaged 60 percent of average annual precipitation; annual evapotranspiration losses averaged 40 percent of average annual precipitation. Of the total annual runoff, approximately 91 percent was surface and subsurface runoff and 9 percent was groundwater discharge. Changes in storage in the soil zone and in the subsurface and ground-water reservoirs in the basins were negligible. In contrast, water-budget simulations for the mined basins indicate significant differences in annual recharge and in total annual runoff. Model simulations of the water budget for Drawdy Creek basin indicate that total annual runoff during 1972-73 averaged only 43 percent of average annual precipitation--the lowest of all study basins; annual evapotranspiration losses averaged 49 percent, and interbasin transfer of ground-water losses averaged about 8 percent. Of the total annual runoff, approximately 74 percent was surface and subsurface flow and 26 percent was ground-water discharge. The low total annual runoff at Drawdy Creek probably reflects increased recharge of precipitation and surface and subsurface flow losses to ground water. Most of the increase in ground-water storage is, in turn, lost to a ground-water sink--namely, interbasin transfer of ground water by gravity drainage and (or) mine pumpage from underground mines that extend to adjacent basins. Hypothetical mining situations were posed for model analysis to determine the effects of increased mining on streamflow in the mined basins. Results of model simulations indicate that streamflow characteristics, the water budget, and the seasonal distribution of streamflow would be significantly modified in response to an increase in mining in the basins. Simulations indicate that (1) total annual runoff in the basins would decrease because of increased surface- and subsurface-flow losses and increased recharge of precipitation to ground water (these losses would tend to reduce medium to high flows mainly during winter and spring when losses would be greatest), (2) extreme high flows in response to intense rainstorms would be negligibly affected, regardless of the magnitude of mining in the basins, (3) ground-water discharge also would decrease during winter and spring, but the amount and duration of low flows during summer and fall would substantially increase in response to increased ground-water storage in rocks and in underground mines, and (4) the increase in ground-water storage in the basins would be depleted, mostly by increased losses to a grou

Characterizing the Sensitivity of Groundwater Storage to Climate variation in the Indus Basin

NASA Astrophysics Data System (ADS)

Huang, L.; Sabo, J. L.

2017-12-01

Indus Basin represents an extensive groundwater aquifer facing the challenge of effective management of limited water resources. Groundwater storage is one of the most important variables of water balance, yet its sensitivity to climate change has rarely been explored. To better estimate present and future groundwater storage and its sensitivity to climate change in the Indus Basin, we analyzed groundwater recharge/discharge and their historical evolution in this basin. Several methods are applied to specify the aquifer system including: water level change and storativity estimates, gravity estimates (GRACE), flow model (MODFLOW), water budget analysis and extrapolation. In addition, all of the socioeconomic and engineering aspects are represented in the hydrological system through the change of temporal and spatial distributions of recharge and discharge (e.g., land use, crop structure, water allocation, etc.). Our results demonstrate that the direct impacts of climate change will result in unevenly distributed but increasing groundwater storage in the short term through groundwater recharge. In contrast, long term groundwater storage will decrease as a result of combined indirect and direct impacts of climate change (e.g. recharge/discharge and human activities). The sensitivity of groundwater storage to climate variation is characterized by topography, aquifer specifics and land use. Furthermore, by comparing possible outcomes of different human interventions scenarios, our study reveals human activities play an important role in affecting the sensitivity of groundwater storage to climate variation. Over all, this study presents the feasibility and value of using integrated hydrological methods to support sustainable water resource management under climate change.

A multitracer approach for characterizing interactions between shallow groundwater and the hydrothermal system in the Norris Geyser Basin area, Yellowstone National Park

USGS Publications Warehouse

Gardner, W.P.; Susong, D.D.; Solomon, D.K.; Heasler, H.P.

2011-01-01

Multiple environmental tracers are used to investigate age distribution, evolution, and mixing in local- to regional-scale groundwater circulation around the Norris Geyser Basin area in Yellowstone National Park. Springs ranging in temperature from 3??C to 90??C in the Norris Geyser Basin area were sampled for stable isotopes of hydrogen and oxygen, major and minor element chemistry, dissolved chlorofluorocarbons, and tritium. Groundwater near Norris Geyser Basin is comprised of two distinct systems: a shallow, cool water system and a deep, high-temperature hydrothermal system. These two end-member systems mix to create springs with intermediate temperature and composition. Using multiple tracers from a large number of springs, it is possible constrain the distribution of possible flow paths and refine conceptual models of groundwater circulation in and around a large, complex hydrothermal system. Copyright 2011 by the American Geophysical Union.

Stable isotope compositions of waters in the Great Basin, United States 3. Comparison of groundwaters with modern precipitation

USGS Publications Warehouse

Smith, G.I.; Friedman, I.; Veronda, G.; Johnson, C.A.

2002-01-01

Groundwater samples from wells and springs, scattered over most of the Great Basin province, were collected and analyzed for their isotopic makeup. They were augmented by previously published isotopic data on groundwaters from southeast California and by several hundred unpublished isotopic analyses. The ratio of 2H (deuterium, D) to 1H, in water samples from valleys in parts of California, Idaho, Nevada, Oregon, and Utah, are here compared with the winter, summer, and annual isotopic compositions of precipitation falling in or near the sampled areas. The main goal of this study was to identify basins where the groundwaters have isotopic compositions that are "lighter" (depleted in the heavier isotope, D) relative to modern winter precipitation. Where these basins do not adjoin substantially higher terrain, we consider those light groundwaters to be of Pleistocene age and thus more than 10,000 years old. Where the groundwater is 10 to 19??? lighter than local winter precipitation, we consider it to be possibly an indication of Pleistocene water; where the ??D makeup is >20??? lighter, we consider it to be probably Pleistocene water. More than 80 sites underlain by waters of possible or probable Pleistocene age were identified.

Integrated groundwater resource management in Indus Basin using satellite gravimetry and physical modeling tools.

PubMed

Iqbal, Naveed; Hossain, Faisal; Lee, Hyongki; Akhter, Gulraiz

2017-03-01

Reliable and frequent information on groundwater behavior and dynamics is very important for effective groundwater resource management at appropriate spatial scales. This information is rarely available in developing countries and thus poses a challenge for groundwater managers. The in situ data and groundwater modeling tools are limited in their ability to cover large domains. Remote sensing technology can now be used to continuously collect information on hydrological cycle in a cost-effective way. This study evaluates the effectiveness of a remote sensing integrated physical modeling approach for groundwater management in Indus Basin. The Gravity Recovery and Climate Experiment Satellite (GRACE)-based gravity anomalies from 2003 to 2010 were processed to generate monthly groundwater storage changes using the Variable Infiltration Capacity (VIC) hydrologic model. The groundwater storage is the key parameter of interest for groundwater resource management. The spatial and temporal patterns in groundwater storage (GWS) are useful for devising the appropriate groundwater management strategies. GRACE-estimated GWS information with large-scale coverage is valuable for basin-scale monitoring and decision making. This frequently available information is found useful for the identification of groundwater recharge areas, groundwater storage depletion, and pinpointing of the areas where groundwater sustainability is at risk. The GWS anomalies were found to favorably agree with groundwater model simulations from Visual MODFLOW and in situ data. Mostly, a moderate to severe GWS depletion is observed causing a vulnerable situation to the sustainability of this groundwater resource. For the sustainable groundwater management, the region needs to implement groundwater policies and adopt water conservation techniques.

Ground-water hydrology and simulated effects of development in the Milford area, an arid basin in southwestern Utah

USGS Publications Warehouse

Mason, James L.

1998-01-01

A three-dimensional, finite-difference model was constructed to simulate ground-water flow in the Milford area. The purpose of the study was to evaluate present knowledge and concepts of the groundwater system, to analyze the ability of the model to represent past and current (1984) conditions, and to estimate the effects of various groundwater development alternatives. The alternative patterns of groundwater development might prove effective in capturing natural discharge from the basin-fill aquifer while limiting water-level declines. Water levels measured during this study indicate that ground water in the Milford area flows in a northwesterly direction through consolidated rocks in the northern San Francisco Mountains toward Sevier Lake. The revised potentiometric surface shows a large area for probable basin outflow, indicating that more water leaves the Milford area than the 8 acre-feet per year estimated previously.Simulations made to calibrate the model were able to approximate steady-state conditions for 1927, before ground-water development began, and transient conditions for 1950-82, during which groundwater withdrawal increased. Basin recharge from the consolidated rocks and basin outflow were calculated during the calibration process. Transient simulations using constant and variable recharge from surface water were made to test effects of large flows in the Beaver River.Simulations were made to project water-level declines over a 37- year period (1983-2020) using the present pumping distribution. Ground-water withdrawals were simulated at 1, 1.5, and 2 times the 1979-82 average rate.The concepts of "sustained" yield, ground-water mining, and the capture of natural discharge were tested using several hypothetical pumping distributions over a 600-year simulation period. Simulations using concentrated pumping centers were the least efficient at capturing natural discharge and produced the largest water-level declines. Simulations using strategically placed ground-water withdrawals in the discharge area were the most efficient at eliminating natural discharge with small water-level declines.

Groundwater chemistry near an impoundment for produced water, Powder River Basin, Wyoming, USA

USGS Publications Warehouse

Healy, R.W.; Bartos, T.T.; Rice, C.A.; McKinley, M.P.; Smith, B.D.

2011-01-01

The Powder River Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of the large amounts of groundwater extracted during CBNG production. Most of this produced water is disposed of in unlined surface impoundments. A 6-year study of groundwater flow and water chemistry at one impoundment, Skewed Reservoir, has produced the most detailed data set for any impoundment in the Basin. Data were collected from a network of 21 observation wells and three suction lysimeters. A groundwater mound formed atop bedrock within initially unsaturated, unconsolidated deposits underlying the reservoir. Heterogeneity in physical and chemical properties of sediments resulted in complex groundwater flow paths and highly variable groundwater chemistry. Sulfate, bicarbonate, sodium, and magnesium were the dominant ions in all areas, but substantial variability existed in relative concentrations; pH varied from less than 3 to more than 9, and total dissolved solids concentrations ranged from less than 5000 to greater than 100,000 mg/L. Selenium was a useful tracer of reservoir water; selenium concentrations exceeded 300 μg/L in samples obtained from 18 of the 24 sampling points. Groundwater travel time from the reservoir to a nearby alluvial aquifer (a linear distance of 177 m) was calculated at 474 days on the basis of selenium concentrations. The produced water is not the primary source of solutes in the groundwater. Naturally occurring salts and minerals within the unsaturated zone, dissolved and mobilized by infiltrating impoundment water, account for most of the solute mass in groundwater. Gypsum dissolution, cation-exchange, and pyrite oxidation appear to be important reactions. The complex geochemistry and groundwater flow paths at the study site underscore the difficulty in assessing effects of surface impoundments on water resources within the Powder River Basin.

A simple method for estimating basin-scale groundwater discharge by vegetation in the basin and range province of Arizona using remote sensing information and geographic information systems

USGS Publications Warehouse

Tillman, F.D.; Callegary, J.B.; Nagler, P.L.; Glenn, E.P.

2012-01-01

Groundwater is a vital water resource in the arid to semi-arid southwestern United States. Accurate accounting of inflows to and outflows from the groundwater system is necessary to effectively manage this shared resource, including the important outflow component of groundwater discharge by vegetation. A simple method for estimating basin-scale groundwater discharge by vegetation is presented that uses remote sensing data from satellites, geographic information systems (GIS) land cover and stream location information, and a regression equation developed within the Southern Arizona study area relating the Enhanced Vegetation Index from the MODIS sensors on the Terra satellite to measured evapotranspiration. Results computed for 16-day composited satellite passes over the study area during the 2000 through 2007 time period demonstrate a sinusoidal pattern of annual groundwater discharge by vegetation with median values ranging from around 0.3 mm per day in the cooler winter months to around 1.5 mm per day during summer. Maximum estimated annual volume of groundwater discharge by vegetation was between 1.4 and 1.9 billion m3 per year with an annual average of 1.6 billion m3. A simplified accounting of the contribution of precipitation to vegetation greenness was developed whereby monthly precipitation data were subtracted from computed vegetation discharge values, resulting in estimates of minimum groundwater discharge by vegetation. Basin-scale estimates of minimum and maximum groundwater discharge by vegetation produced by this simple method are useful bounding values for groundwater budgets and groundwater flow models, and the method may be applicable to other areas with similar vegetation types.

Prediction of monthly regional groundwater levels through hybrid soft-computing techniques

NASA Astrophysics Data System (ADS)

Chang, Fi-John; Chang, Li-Chiu; Huang, Chien-Wei; Kao, I.-Feng

2016-10-01

Groundwater systems are intrinsically heterogeneous with dynamic temporal-spatial patterns, which cause great difficulty in quantifying their complex processes, while reliable predictions of regional groundwater levels are commonly needed for managing water resources to ensure proper service of water demands within a region. In this study, we proposed a novel and flexible soft-computing technique that could effectively extract the complex high-dimensional input-output patterns of basin-wide groundwater-aquifer systems in an adaptive manner. The soft-computing models combined the Self Organized Map (SOM) and the Nonlinear Autoregressive with Exogenous Inputs (NARX) network for predicting monthly regional groundwater levels based on hydrologic forcing data. The SOM could effectively classify the temporal-spatial patterns of regional groundwater levels, the NARX could accurately predict the mean of regional groundwater levels for adjusting the selected SOM, the Kriging was used to interpolate the predictions of the adjusted SOM into finer grids of locations, and consequently the prediction of a monthly regional groundwater level map could be obtained. The Zhuoshui River basin in Taiwan was the study case, and its monthly data sets collected from 203 groundwater stations, 32 rainfall stations and 6 flow stations during 2000 and 2013 were used for modelling purpose. The results demonstrated that the hybrid SOM-NARX model could reliably and suitably predict monthly basin-wide groundwater levels with high correlations (R2 > 0.9 in both training and testing cases). The proposed methodology presents a milestone in modelling regional environmental issues and offers an insightful and promising way to predict monthly basin-wide groundwater levels, which is beneficial to authorities for sustainable water resources management.

Groundwater Discharge to Upper Barataria Basin Driven by Mississippi River Stage

NASA Astrophysics Data System (ADS)

Cable, J. E.; Kim, J.; Johannesson, K. H.; Kolker, A.; Telfeyan, K.; Breaux, A.

2017-12-01

Groundwater flow into deltaic wetlands occurs despite the heterogeneous and anisotropic depositional environment of deltas. Along the Mississippi River this groundwater flow is augmented by the vast alluvial aquifer and the levees which confine the river to a zone much more narrow than the historical floodplain. The effect of the levees has been to force the river stage to as much as 10 m above the adjacent back-levee wetlands. Consequently, the head difference created by higher river stages can drive groundwater flow into these wetlands, especially during flood seasons. We measured Rn-222 in the surface waters of a bayou draining a bottomland hardwood swamp in the lower Mississippi River valley over a 14-month period. With a half-life of 3.83 days and its conservative geochemical behavior, Rn-222 is a well-known tracer for groundwater inputs in both fresh and marine environments. Transects from the mouth to the headwaters of the bayou were monitored for Rn-222 in real-time using Rad-7s on a semi-monthly basis. We found that Rn-222 decreased exponentially from the swamp at the headwaters to the mouth of the bayou. Using a mass balance approach, we calculated groundwater inputs to the bayou headwaters and compared these discharge estimates to variations in Mississippi River stage. Groundwater inputs to the Barataria Basin, Louisiana, represent a significant fraction of the freshwater budget of the basin. The flow appears to occur through the sandy Point Bar Aquifer that lies adjacent to the river and underlies many of the freshwater swamps of the Basin. Tracer measurements throughout the Basin in these swamp areas appear to confirm our hypothesis about the outlet for groundwater in this deltaic environment.

Construction of 3-D geologic framework and textural models for Cuyama Valley groundwater basin, California

USGS Publications Warehouse

Sweetkind, Donald S.; Faunt, Claudia C.; Hanson, Randall T.

2013-01-01

Groundwater is the sole source of water supply in Cuyama Valley, a rural agricultural area in Santa Barbara County, California, in the southeasternmost part of the Coast Ranges of California. Continued groundwater withdrawals and associated water-resource management concerns have prompted an evaluation of the hydrogeology and water availability for the Cuyama Valley groundwater basin by the U.S. Geological Survey, in cooperation with the Water Agency Division of the Santa Barbara County Department of Public Works. As a part of the overall groundwater evaluation, this report documents the construction of a digital three-dimensional geologic framework model of the groundwater basin suitable for use within a numerical hydrologic-flow model. The report also includes an analysis of the spatial variability of lithology and grain size, which forms the geologic basis for estimating aquifer hydraulic properties. The geologic framework was constructed as a digital representation of the interpreted geometry and thickness of the principal stratigraphic units within the Cuyama Valley groundwater basin, which include younger alluvium, older alluvium, and the Morales Formation, and underlying consolidated bedrock. The framework model was constructed by creating gridded surfaces representing the altitude of the top of each stratigraphic unit from various input data, including lithologic and electric logs from oil and gas wells and water wells, cross sections, and geologic maps. Sediment grain-size data were analyzed in both two and three dimensions to help define textural variations in the Cuyama Valley groundwater basin and identify areas with similar geologic materials that potentially have fairly uniform hydraulic properties. Sediment grain size was used to construct three-dimensional textural models that employed simple interpolation between drill holes and two-dimensional textural models for each stratigraphic unit that incorporated spatial structure of the textural data.

Opportunities and Barriers to Address Seawater Intrusion Along California's Coast

NASA Astrophysics Data System (ADS)

Langridge, R.

2016-12-01

In many California coastal areas reliant on groundwater seawater intrusion is a serious problem. This presentation will discuss how particular groundwater management institutions in the state are addressing seawater intrusion issues, how stakeholders are participating in this process, and how scientific information can contribute to policies that support reducing or halting ongoing intrusion. In 2014, the California Legislature passed the Sustainable Groundwater Management Act (SGMA). The Act established requirements for 127 high and medium priority groundwater basins to form groundwater sustainability agencies (GSAs) and develop plans to sustainably manage their basin. Sustainable is defined in SGMA as avoiding specific unacceptable impacts, including significant and unreasonable seawater intrusion. Special Act Districts, created by an act of the legislature, have the option to be the sole GSA in their service area, and they can provide a window into current and potentially future strategies to address seawater intrusion. Additionally, adjudicated basins are often considered one of the best approaches to achieve efficient groundwater management, and these basins are exempt from SGMA and managed pursuant to a court judgment. The strategies utilized to manage seawater intrusion by three special act districts and five adjudicated basins will be discussed. These basins cover significant areas of central and southern California and all have experienced seawater intrusion. Our research team just completed reports for the State Water Resources Control Board on all the adjudicated and special act districts in the state, and this presentation will draw on our findings to better understand the barriers and opportunities to alleviate seawater intrusion and the information required to develop solutions.

Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwestern United States

USGS Publications Warehouse

Anning, David W.; Paul, Angela P.; McKinney, Tim S.; Huntington, Jena M.; Bexfield, Laura M.; Thiros, Susan A.

2012-01-01

The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) is conducting a regional analysis of water quality in the principal aquifer systems across the United States. The Southwest Principal Aquifers (SWPA) study is building a better understanding of the susceptibility and vulnerability of basin-fill aquifers in the region to groundwater contamination by synthesizing baseline knowledge of groundwater-quality conditions in 16 basins previously studied by the NAWQA Program. The improved understanding of aquifer susceptibility and vulnerability to contamination is assisting in the development of tools that water managers can use to assess and protect the quality of groundwater resources.Human-health concerns and economic considerations associated with meeting drinking-water standards motivated a study of the vulnerability of basin-fill aquifers to nitrate con­tamination and arsenic enrichment in the southwestern United States. Statistical models were developed by using the random forest classifier algorithm to predict concentrations of nitrate and arsenic across a model grid that represents about 190,600 square miles of basin-fill aquifers in parts of Arizona, California, Colorado, Nevada, New Mexico, and Utah. The statistical models, referred to as classifiers, reflect natural and human-related factors that affect aquifer vulnerability to contamina­tion and relate nitrate and arsenic concentrations to explana­tory variables representing local- and basin-scale measures of source, aquifer susceptibility, and geochemical conditions. The classifiers were unbiased and fit the observed data well, and misclassifications were primarily due to statistical sampling error in the training datasets.The classifiers were designed to predict concentrations to be in one of six classes for nitrate, and one of seven classes for arsenic. Each classification scheme allowed for identification of areas with concentrations that were equal to or exceeding the U.S. Environmental Protection Agency drinking-water standard. Whereas 2.4 percent of the area underlain by basin-fill aquifers in the study area was predicted to equal or exceed this standard for nitrate (10 milligrams per liter as N; mg/L), 42.7 percent was predicted to equal or exceed the standard for arsenic (10 micrograms per liter; μg/L). Areas predicted to equal or exceed the drinking-water standard for nitrate include basins in central Arizona near Phoenix; the San Joaquin, Inland, and San Jacinto basins of California; and the San Luis Valley of Colorado. Much of the area predicted to equal or exceed the drinking-water standard for arsenic is within a belt of basins along the western portion of the Basin and Range Physiographic Province in Nevada, California, and Arizona. Predicted nitrate and arsenic concentrations are substantially lower than the drinking-water standards in much of the study area—about 93.0 percent of the area underlain by basin-fill aquifers was less than one-half the standard for nitrate (5.0 mg/L), and 50.2 percent was less than one-half the standard for arsenic (5.0 μg/L).

The occurrence and geochemistry of arsenic in groundwaters of Taiwan

NASA Astrophysics Data System (ADS)

Chen, W.; Lu, H.; Liu, T.

2008-12-01

Blackfoot disease caused by digesting water with high concentration (>0.3 mg/L) of arsenic from deep wells affected thousands of people in Chianan of Taiwan during 1930 to 1960. Drinking water with arsenic, even in a lower concentration (0.1-0.01 mg/L) increase risk of cancer that had been demonstrated by a number of studies on Taiwan. By concerning the effects of long-term chronic exposure to arsenic, the EPA of United States had revised the regulatory limit of arsenic for drinking water from 0.05 to 0.01 mg/L in 2006. Many researches have investigated on the occurrence and chemistry of the arsenic-contained groundwater and its health effects in Chianan of Taiwan. However, there are only a few studies on the other groundwater basins of Taiwan that providing about one third of water supplies for a population of 21 million. In this study, we investigate the occurrence and redox geochemistry of arsenic in nine major groundwater basins of Taiwan. The values and concentrations of pH, Eh, dissolved oxygen, nitrate, sulfate, iron, methane, sulfide, bicarbonate and ammonium in groundwaters were determined with a total of 610 monitoring wells in 2006. More than 60% of wells in the GW6 basin with a concentration of arsenic exceed 0.05 mg/L. The groundwaters in GW6 basin also have the highest average arsenic concentration. The exceeding percent (>0.05 mg/L) of wells for GW7, GW5, GW9 and GW8 basins are 30%, 20%, 18% and 8%, respectively. All of arsenic concentrations in groundwaters of GW1 to GW4 basins are lower than 0.05 mg/L, but some samples are higher than 0.01 mg/L. The exceeding percent of samples for arsenic 0.01 mg/L in GW3, GW1, GW2 and GW4 basins are 28%, 24%, 23% and 6%, respectively. Our results suggest that the concentrations of arsenic as well as iron in groundwaters of Taiwan were elevated by the iron-reducing process in aquifers. Samples, especially those with higher concentration of bicarbonate (> 400 mg/L) and oversaturated methane, mostly in the GW6 basin, show a trend of higher arsenic concentrations.

Using Heat as a Tracer to Estimate Saline Groundwater Fluxes from the Deep Aquifer System to the Shallow Aquifers and the Rio Grande in the Mesilla Basin, New Mexico, USA

NASA Astrophysics Data System (ADS)

Pepin, J. D.; Robertson, A.; Ferguson, C.; Burns, E. R.

2017-12-01

Heat is used as a tracer to estimate vertical groundwater flow and associated saline fluxes from deep (greater than 1 km) parts of the Mesilla Basin regional aquifer to the Rio Grande. Profiles of temperature with depth below ground surface are used to locate groundwater upflow zones and to estimate associated salinity fluxes. The results of this study will inform understanding of the impact of deep saline groundwater on regional water supplies. The Mesilla Basin in southern New Mexico, Texas, and Chihuahua, Mexico was designated by the U.S. as a priority transboundary aquifer in part because of the presence of the Rio Grande within the basin. Declining water levels, deteriorating water quality in both the aquifer and the river, and increasing use of water resources on both sides of the international border raise concerns about the sustainability of regional water supplies. The Rio Grande chloride concentration increases by about 130% (120 ppm to 280 ppm) as the river traverses the Mesilla Basin. Previous research attributed this reduction in water quality to the upwelling of deep sedimentary brines and geothermal waters within the basin. However, the spatial distribution of these upflow zones and their groundwater flow rates are poorly understood. Temperature profiles from 374 existing boreholes within the Mesilla Basin indicate that temperature-profile shape is affected by heat advection in the basin. Three distinct geothermal upflow zones were identified along regional fault zones in the study area based on the temperature profiles. Groundwater in these zones is considered thermal, having temperatures greater than 50°C at depths of less than 200 m. Identification of upflow-zone profiles combines analysis of temperature profiles, lithologic records, well-completion data, and profile derivatives. The Bredehoeft and Papadopulos (1965) one-dimensional heat-transport analytical solution will be applied to upflow-zone profiles to estimate the corresponding vertical groundwater flow rates. Temperature, heat flow, and salinity maps will be constructed to approximate the areal extents of identified upflow zones. These areal estimates will then be combined with the 1D vertical groundwater flow calculations and salinity data to quantify volumetric salinity fluxes to the shallow aquifer system and Rio Grande.

Annual and average estimates of water-budget components based on hydrograph separation and PRISM precipitation for gaged basins in the Appalachian Plateaus Region, 1900-2011

USGS Publications Warehouse

Nelms, David L.; Messinger, Terence; McCoy, Kurt J.

2015-07-14

As part of the U.S. Geological Survey’s Groundwater Resources Program study of the Appalachian Plateaus aquifers, annual and average estimates of water-budget components based on hydrograph separation and precipitation data from parameter-elevation regressions on independent slopes model (PRISM) were determined at 849 continuous-record streamflow-gaging stations from Mississippi to New York and covered the period of 1900 to 2011. Only complete calendar years (January to December) of streamflow record at each gage were used to determine estimates of base flow, which is that part of streamflow attributed to groundwater discharge; such estimates can serve as a proxy for annual recharge. For each year, estimates of annual base flow, runoff, and base-flow index were determined using computer programs—PART, HYSEP, and BFI—that have automated the separation procedures. These streamflow-hydrograph analysis methods are provided with version 1.0 of the U.S. Geological Survey Groundwater Toolbox, which is a new program that provides graphing, mapping, and analysis capabilities in a Windows environment. Annual values of precipitation were estimated by calculating the average of cell values intercepted by basin boundaries where previously defined in the GAGES–II dataset. Estimates of annual evapotranspiration were then calculated from the difference between precipitation and streamflow.

Groundwater monitoring of hydraulic fracturing in California: Recommendations for permit-required monitoring

NASA Astrophysics Data System (ADS)

Esser, B. K.; Beller, H. R.; Carroll, S.; Cherry, J. A.; Jackson, R. B.; Jordan, P. D.; Madrid, V.; Morris, J.; Parker, B. L.; Stringfellow, W. T.; Varadharajan, C.; Vengosh, A.

2015-12-01

California recently passed legislation mandating dedicated groundwater quality monitoring for new well stimulation operations. The authors provided the State with expert advice on the design of such monitoring networks. Factors that must be considered in designing a new and unique groundwater monitoring program include: Program design: The design of a monitoring program is contingent on its purpose, which can range from detection of individual well leakage to demonstration of regional impact. The regulatory goals for permit-required monitoring conducted by operators on a well-by-well basis will differ from the scientific goals of a regional monitoring program conducted by the State. Vulnerability assessment: Identifying factors that increase the probability of transport of fluids from the hydrocarbon target zone to a protected groundwater zone enables the intensity of permit-required monitoring to be tiered by risk and also enables prioritization of regional monitoring of groundwater basins based on vulnerability. Risk factors include well integrity; proximity to existing wellbores and geologic features; wastewater disposal; vertical separation between the hydrocarbon and groundwater zones; and site-specific hydrogeology. Analyte choice: The choice of chemical analytes in a regulatory monitoring program is guided by the goals of detecting impact, assuring public safety, preventing resource degradation, and minimizing cost. Balancing these goals may be best served by tiered approach in which targeted analysis of specific chemical additives is triggered by significant changes in relevant but more easily analyzed constituents. Such an approach requires characterization of baseline conditions, especially in areas with long histories of oil and gas development. Monitoring technology: Monitoring a deep subsurface process or a long wellbore is more challenging than monitoring a surface industrial source. The requirement for monitoring multiple groundwater aquifers across a range of depths and of monitoring at deeper depths than is typical for regulatory monitoring programs requires consideration of monitoring technology, which can range from clusters of wells to multiple wells in a single wellbore to multi-level systems in a single cased wellbore.

Quantification of the Dedolomitization Rate for Correction of Groundwater 14C Ages in Aquifers of the Sacramento Mountains, New Mexico

NASA Astrophysics Data System (ADS)

Morse, J. T.; Phillips, F. M.; Land, L. A.

2009-12-01

Ion chemistry of groundwater from the western part of the Roswell Basin, New Mexico, are consistent with groundwater quality evolution driven by dedolomitization. Measured, uncorrected, 14C values in groundwater yield an apparent residence time of 4700 years for the western part of the Roswell Basin. We have employed a simple model incorporating the changes in bicarbonate, magnesium and 14C along the flow-path to quantify the in-situ rate of dedolomitization and thereby to correct the 14C values for inorganic carbon dilution. The model yielded a corrected residence time of 1300 years at the distal end of the flowpath and a regional hydraulic conductivity of 5×10-4cm/s. Prior studies have inferred that underflow from the Sacramento Mountains constitutes an important component of recharge to the Artesian Aquifer of the Roswell Basin but it has not been possible to quantify this contribution. The information from the corrected 14C dating will allow an improved assessment of the groundwater resources available in this overstressed basin.

Evaluating GCM land surface hydrology parameterizations by computing river discharges using a runoff routing model: Application to the Mississippi basin

NASA Technical Reports Server (NTRS)

Liston, G. E.; Sud, Y. C.; Wood, E. F.

1994-01-01

To relate general circulation model (GCM) hydrologic output to readily available river hydrographic data, a runoff routing scheme that routes gridded runoffs through regional- or continental-scale river drainage basins is developed. By following the basin overland flow paths, the routing model generates river discharge hydrographs that can be compared to observed river discharges, thus allowing an analysis of the GCM representation of monthly, seasonal, and annual water balances over large regions. The runoff routing model consists of two linear reservoirs, a surface reservoir and a groundwater reservoir, which store and transport water. The water transport mechanisms operating within these two reservoirs are differentiated by their time scales; the groundwater reservoir transports water much more slowly than the surface reservior. The groundwater reservior feeds the corresponding surface store, and the surface stores are connected via the river network. The routing model is implemented over the Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project Mississippi River basin on a rectangular grid of 2 deg X 2.5 deg. Two land surface hydrology parameterizations provide the gridded runoff data required to run the runoff routing scheme: the variable infiltration capacity model, and the soil moisture component of the simple biosphere model. These parameterizations are driven with 4 deg X 5 deg gridded climatological potential evapotranspiration and 1979 First Global Atmospheric Research Program (GARP) Global Experiment precipitation. These investigations have quantified the importance of physically realistic soil moisture holding capacities, evaporation parameters, and runoff mechanisms in land surface hydrology formulations.

The Effect of modeled recharge distribution on simulated groundwater availability and capture

USGS Publications Warehouse

Tillman, Fred D.; Pool, Donald R.; Leake, Stanley A.

2015-01-01

Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins along mountain fronts, by flowing overland to infiltrate along ephemeral channels that often traverse basins in the area, or by some combination of these processes. The importance of accurately simulating recharge distributions is a current topic of discussion among hydrologists and water managers in the region, but no comparative study has been performed to analyze the effects of different recharge distributions on groundwater simulations. This study investigates the importance of the distribution of aquifer recharge in simulating regional groundwater flow in basin-fill aquifers by calibrating a groundwater-flow model to four different recharge distributions, all with the same total amount of recharge. Similarities are seen in results from steady-state models for optimized hydraulic conductivity values, fit of simulated to observed hydraulic heads, and composite scaled sensitivities of conductivity parameter zones. Transient simulations with hypothetical storage properties and pumping rates produce similar capture rates and storage change results, but differences are noted in the rate of drawdown at some well locations owing to the differences in optimized hydraulic conductivity. Depending on whether the purpose of the groundwater model is to simulate changes in groundwater levels or changes in storage and capture, the distribution of aquifer recharge may or may not be of primary importance.

Simulated effects of groundwater pumping and artificial recharge on surface-water resources and riparian vegetation in the Verde Valley sub-basin, Central Arizona

USGS Publications Warehouse

Leake, Stanley A.; Pool, Donald R.

2010-01-01

In the Verde Valley sub-basin, groundwater use has increased in recent decades. Residents and stakeholders in the area have established several groups to help in planning for sustainability of water and other resources of the area. One of the issues of concern is the effect of groundwater pumping in the sub-basin on surface water and on groundwater-dependent riparian vegetation. The Northern Arizona Regional Groundwater-Flow Model by Pool and others (in press) is the most comprehensive and up-to-date tool available to understand the effects of groundwater pumping in the sub-basin. Using a procedure by Leake and others (2008), this model was modified and used to calculate effects of groundwater pumping on surface-water flow and evapotranspiration for areas in the sub-basin. This report presents results for the upper two model layers for pumping durations of 10 and 50 years. Results are in the form of maps that indicate the fraction of the well pumping rate that can be accounted for as the combined effect of reduced surface-water flow and evapotranspiration. In general, the highest and most rapid responses to pumping were computed to occur near surface-water features simulated in the modified model, but results are not uniform along these features. The results are intended to indicate general patterns of model-computed response over large areas. For site-specific projects, improved results may require detailed studies of the local hydrologic conditions and a refinement of the modified model in the area of interest.

Simulation of groundwater flow and the interaction of groundwater and surface water in the Willamette Basin and Central Willamette subbasin, Oregon

USGS Publications Warehouse

Herrera, Nora B.; Burns, Erick R.; Conlon, Terrence D.

2014-01-01

Full appropriation of tributary streamflow during summer, a growing population, and agricultural needs are increasing the demand for groundwater in the Willamette Basin. Greater groundwater use could diminish streamflow and create seasonal and long-term declines in groundwater levels. The U.S. Geological Survey (USGS) and the Oregon Water Resources Department (OWRD) cooperated in a study to develop a conceptual and quantitative understanding of the groundwater-flow system of the Willamette Basin with an emphasis on the Central Willamette subbasin. This final report from the cooperative study describes numerical models of the regional and local groundwater-flow systems and evaluates the effects of pumping on groundwater and surface‑water resources. The models described in this report can be used to evaluate spatial and temporal effects of pumping on groundwater, base flow, and stream capture. The regional model covers about 6,700 square miles of the 12,000-square mile Willamette and Sandy River drainage basins in northwestern Oregon—referred to as the Willamette Basin in this report. The Willamette Basin is a topographic and structural trough that lies between the Coast Range and the Cascade Range and is divided into five sedimentary subbasins underlain and separated by basalts of the Columbia River Basalt Group (Columbia River basalt) that crop out as local uplands. From north to south, these five subbasins are the Portland subbasin, the Tualatin subbasin, the Central Willamette subbasin, the Stayton subbasin, and the Southern Willamette subbasin. Recharge in the Willamette Basin is primarily from precipitation in the uplands of the Cascade Range, Coast Range, and western Cascades areas. Groundwater moves downward and laterally through sedimentary or basalt units until it discharges locally to wells, evapotranspiration, or streams. Mean annual groundwater withdrawal for water years 1995 and 1996 was about 400 cubic feet per second; irrigation withdrawals accounted for about 80 percent of that total. The upper 180 feet of productive aquifers in the Central Willamette and Southern Willamette subbasins produced about 70 percent of the total pumped volume. In this study, the USGS constructed a three-dimensional numerical finite-difference groundwater-flow model of the Willamette Basin representing the six hydrogeologic units, defined in previous investigations, as six model layers. From youngest to oldest, and [generally] uppermost to lowermost they are the: upper sedimentary unit, Willamette silt unit, middle sedimentary unit, lower sedimentary unit, Columbia River basalt unit, and basement confining unit. The high Cascade unit is not included in the groundwater-flow model because it is not present within the model boundaries. Geographic boundaries are simulated as no-flow (no water flowing in or out of the model), except where the Columbia River is simulated as a constant hydraulic head boundary. Streams are designated as head-dependent-flux boundaries, in which the flux depends on the elevation of the stream surface. Groundwater recharge from precipitation was estimated using the Precipitation-Runoff Modeling System (PRMS), a watershed model that accounts for evapotranspiration from the unsaturated zone. Evapotranspiration from the saturated zone was not considered an important component of groundwater discharge. Well pumping was simulated as specified flux and included public supply, irrigation, and industrial pumping. Hydraulic conductivity values were estimated from previous studies through aquifer slug and permeameter tests, specific capacity data, core analysis, and modeling. Upper, middle and lower sedimentary unit horizontal hydraulic conductivity values were differentiated between the Portland subbasin and the Tualatin, Central Willamette, and Southern Willamette subbasins based on preliminary model results.

Increased groundwater to stream discharge from permafrost thawing in the Yukon River basin: Potential impacts on lateral export of carbon and nitrogen

USGS Publications Warehouse

Walvoord, Michelle Ann; Striegl, Robert G.

2007-01-01

Arctic and subarctic watersheds are undergoing climate warming, permafrost thawing, and thermokarst formation resulting in quantitative shifts in surface water - groundwater interaction at the basin scale. Groundwater currently comprises almost one fourth of Yukon River water discharged to the Bering Sea and contributes 5-10% of the dissolved organic carbon (DOC) and nitrogen (DON) and 35-45% of the dissolved inorganic carbon (DIC) and nitrogen (DIN) loads. Long-term strearnflow records (>30 yrs) of the Yukon River basin indicate a general upward trend in groundwater contribution to streamflow of 0.7-0.9%/yr and no pervasive change in annual flow. We propose that the increases in groundwater contributions were caused predominately by climate warming and permafrost thawing that enhances infiltration and supports deeper flowpaths. The increased groundwater fraction may result in decreased DOC and DON and increased DIC and DIN export when annual flow remains unchanged.

Numerical studies on groundwater-grassland relations in an inland arid region in China

NASA Astrophysics Data System (ADS)

Wang, J. R.; Hu, L. T.; Sun, K. N.; Liu, X. M.

2017-08-01

In this study, a 2-D numerical model was developed to assess the impacts of groundwater on grassland ecology in the Hulun Lake Basin. An extreme dry climate scenario and water resource management scenario and their interactions in the Hulun Lake Basin were designed, and their influence on groundwater was evaluated. The results show that the grassland ecology is heavily dependent on groundwater, and a distribution of groundwater with a depth of 8 m correlates well with the distribution of grassland. Under the water resource management scenario, the groundwater level will increase to a maximum value of 2.5 m after 15 years around Hulun Lake. The groundwater level will decrease dramatically under the extreme dry climate scenario, thus affecting the environment.

Hydrogeologic framework and groundwater/surface-water interactions of the Chehalis River basin, Washington

USGS Publications Warehouse

Gendaszek, Andrew S.

2011-01-01

The Chehalis River has the largest drainage basin of any river entirely contained within the State of Washington with a watershed of approximately 2,700 mi2 and has correspondingly diverse geology and land use. Demands for water resources have prompted the local citizens and governments of the Chehalis River basin to coordinate with Federal, State and Tribal agencies through the Chehalis Basin Partnership to develop a long-term watershed management plan. The recognition of the interdependence of groundwater and surface-water resources of the Chehalis River basin became the impetus for this study, the purpose of which is to describe the hydrogeologic framework and groundwater/surface-water interactions of the Chehalis River basin. Surficial geologic maps and 372 drillers' lithostratigraphic logs were used to generalize the basin-wide hydrogeologic framework. Five hydrogeologic units that include aquifers within unconsolidated glacial and alluvial sediments separated by discontinuous confining units were identified. These five units are bounded by a low permeability unit comprised of Tertiary bedrock. A water table map, and generalized groundwater-flow directions in the surficial aquifers, were delineated from water levels measured in wells between July and September 2009. Groundwater generally follows landsurface-topography from the uplands to the alluvial valley of the Chehalis River. Groundwater gradients are highest in tributary valleys such as the Newaukum River valley (approximately 23 cubic feet per mile), relatively flat in the central Chehalis River valley (approximately 6 cubic feet per mile), and become tidally influenced near the outlet of the Chehalis River to Grays Harbor. The dynamic interaction between groundwater and surface-water was observed through the synoptic streamflow measurements, termed a seepage run, made during August 2010, and monitoring of water levels in wells during the 2010 Water Year. The seepage run revealed an overall gain of 56.8 ± 23.7 cubic feet per second over 32.8 river miles (1.7 cubic feet per second per mile), and alternating gains and losses of streamflow ranging from -48.3 to 30.9 cubic feet per second per mile, which became more pronounced on the Chehalis River downstream of Grand Mound. However, most gains and losses were within measurement error. Groundwater levels measured in wells in unconsolidated sediments fluctuated with changes in stream stage, often within several hours. These fluctuations were set by precipitation events in the upper Chehalis River basin and tides of the Pacific Ocean in the lower Chehalis River basin.±

Hydrologic Setting and Conceptual Hydrologic Model of the Walker River Basin, West-Central Nevada

USGS Publications Warehouse

Lopes, Thomas J.; Allander, Kip K.

2009-01-01

The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. Between 1882 and 2008, agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-ft. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes the hydrologic setting of the Walker River basin and a conceptual hydrologic model of the relations among streams, groundwater, and Walker Lake with emphasis on the lower Walker River basin from Wabuska to Hawthorne, Nevada. The Walker River basin is about 3,950 square miles and straddles the California-Nevada border. Most streamflow originates as snowmelt in the Sierra Nevada. Spring runoff from the Sierra Nevada typically reaches its peak during late May to early June with as much as 2,800 cubic feet per second in the Walker River near Wabuska. Typically, 3 to 4 consecutive years of below average streamflow are followed by 1 or 2 years of average or above average streamflow. Mountain ranges are comprised of consolidated rocks with low hydraulic conductivities, but consolidated rocks transmit water where fractured. Unconsolidated sediments include fluvial deposits along the active channel of the Walker River, valley floors, alluvial slopes, and a playa. Sand and gravel deposited by the Walker River likely are discontinuous strata throughout the valley floor. Thick clay strata likely were deposited in Pleistocene Lake Lahontan and are horizontally continuous, except where strata have been eroded by the Walker River. At Walker Lake, sediments mostly are clay interbedded with alluvial slope, fluvial, and deltaic deposits along the lake margins. Coarse sediments form a multilayered, confined-aquifer system that could extend several miles from the shoreline. Depth to bedrock in the lower Walker River basin ranges from about 900 to 2,000 feet. The average hydraulic conductivity of the alluvial aquifer in the lower Walker River basin is 10-30 feet per day, except where comprised of fluvial sediments. Fluvial sediments along the Walker River have an average hydraulic conductivity of 70 feet per day. Subsurface flow was estimated to be 2,700 acre-feet per year through Double Spring. Subsurface discharge to Walker Lake was estimated to be 4,400 acre-feet per year from the south and 10,400 acre-feet per year from the north. Groundwater levels and groundwater storage have declined steadily in most of Smith and Mason Valleys since 1960. Groundwater levels around Schurz, Nevada, have changed little during the past 50 years. In the Whisky Flat area south of Hawthorne, Nevada, agricultural and municipal pumpage has lowered groundwater levels since 1956. The water-level decline in Walker Lake since 1882 has caused the surrounding alluvial aquifer to drain and groundwater levels to decline. The Wabuska streamflow-gaging station in northern Mason Valley demarcates the upper and lower Walker River basin. The hydrology of the lower Walker River basin is considerably different than the upper basin. The upper basin consists of valleys separated by consolidated-rock mountains. The alluvial aquifer in each valley thins or pinches out at the downstream end, forcing most groundwater to discharge along the river near where the river is gaged. The lower Walker River basin is one surface-water/groundwater system of losing and gaining reaches from Wabuska to Walker Lake, which makes determining stream losses and the direction and amount of subsurface flow difficult. Isotopic data indicate surface water and groundwater in the lower Walker River basin are from two sources of precipitation that have evaporated. The Walker River, groundwater along the Wassuk Range, and Walker Lake plot along one evaporation line. Groundwater along th

Regional analysis of ground-water recharge: Chapter B in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Flint, Lorraine E.; Flint, Alan L.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

A modeling analysis of runoff and ground-water recharge for the arid and semiarid southwestern United States was performed to investigate the interactions of climate and other controlling factors and to place the eight study-site investigations into a regional context. A distributed-parameter water-balance model (the Basin Characterization Model, or BCM) was used in the analysis. Data requirements of the BCM included digital representations of topography, soils, geology, and vegetation, together with monthly time-series of precipitation and air-temperature data. Time-series of potential evapotranspiration were generated by using a submodel for solar radiation, taking into account topographic shading, cloudiness, and vegetation density. Snowpack accumulation and melting were modeled using precipitation and air-temperature data. Amounts of water available for runoff and ground-water recharge were calculated on the basis of water-budget considerations by using measured- and generated-meteorologic time series together with estimates of soil-water storage and saturated hydraulic conductivity of subsoil geologic units. Calculations were made on a computational grid with a horizontal resolution of about 270 meters for the entire 1,033,840 square-kilometer study area. The modeling analysis was composed of 194 basins, including the eight basins containing ground-water recharge-site investigations. For each grid cell, the BCM computed monthly values of potential evapotranspiration, soil-water storage, in-place ground-water recharge, and runoff (potential stream flow). A fixed percentage of runoff was assumed to become recharge beneath channels operating at a finer resolution than the computational grid of the BCM. Monthly precipitation and temperature data from 1941 to 2004 were used to explore climatic variability in runoff and ground-water recharge.The selected approach provided a framework for classifying study-site basins with respect to climate and dominant recharge processes. The average climate for all 194 basins ranged from hyperarid to humid, with arid and semiarid basins predominating (fig. 6, chapter A, this volume). Four of the 194 basins had an aridity index of dry subhumid; two of the basins were humid. Of the eight recharge-study sites, six were in semiarid basins, and two were in arid basins. Average-annual potential evapotranspiration showed a regional gradient from less than 1 m/yr in the northeastern part of the study area to more than 2 m/yr in the southwestern part of the study area. Average-annual precipitation was lowest in the two arid-site basins and highest in the two study-site basins in southern Arizona. The relative amount of runoff to in-place recharge varied throughout the study area, reflecting differences primarily in soil water-holding capacity, saturated hydraulic conductivity of subsoil materials, and snowpack dynamics. Climatic forcing expressed in El Niño and Pacific Decadal Oscillation indices strongly influenced the generation of precipitation throughout the study area. Positive values of both indices correlated with the highest amounts of runoff and ground-water recharge.

Water resources during drought conditions and postfire water quality in the upper Rio Hondo Basin, Lincoln County, New Mexico, 2010-13

USGS Publications Warehouse

Sherson, Lauren R.; Rice, Steven E.

2015-07-16

Changes in climate and increased groundwater and surface-water use are likely to affect the availability of water in the upper Rio Hondo Basin. Increased drought probably will increase the potential for wildfires, which can affect downstream water quality and increase flood potential. Climate-research predicted decreases in winter precipitation may have an adverse effect on the amount of groundwater recharge that occurs in the upper Rio Hondo Basin, given the predominance of winter precipitation recharge as indicated by the stable isotope results. Decreases in surface-water supplies because of persistent drought conditions and reductions in the quality of water because of the effects of wildfire may lead to a larger reliance on groundwater reserves in the upper Rio Hondo Basin. Decreasing water levels because of increasing groundwater withdrawal could reduce base flows in the Rio Bonito and Rio Ruidoso. Well organized and scientifically supported regional water-resources management will be necessary for dealing with the likely scenario of increases in demand coupled with decreases in supply in the upper Rio Hondo Basin.

Estimates of Monthly Ground-Water Recharge to the Yakima River Basin Aquifer System, Washington, 1960-2001, for Current Land-Use and Land-Cover Conditions

USGS Publications Warehouse

Vaccaro, J.J.; Olsen, T.D.

2007-01-01

Unique ID grid with a unique value per Hydrologic Response Unit (HRU) per basin in reference to the estimated ground-water recharge for current conditions in the Yakima Basin Aquifer System, (USGS report SIR 2007-5007). Total 78,144 unique values. This grid made it easy to provide estimates of monthly ground-water recharge for water years 1960-2001in an electronic format for water managers, planners, and hydrologists, that could be related back to a spatially referenced grid by the unique ID.

Arsenic in ground-water under oxidizing conditions, south-west United States

USGS Publications Warehouse

Robertson, F.N.

1989-01-01

Concentrations of dissolved arsenic in ground-water in alluvial basins of Arizona commonly exceed 50 ??g L-1 and reach values as large as 1,300 ??g L-1. Arsenic speciation analyses show that arsenic occurs in the fully oxidized state of plus 5 (As+5), most likely in the form of HAsO4???2, under existing oxidizing and pH conditions. Arsenic in source areas presumably is oxidized to soluble As before transport into the basin or, if after transport, before burial. Probable sources of arsenic are the sulphide and arsenide deposits in the mineralized areas of the mountains surrounding the basins. Arsenic content of alluvial material ranged from 2 to 88 ppm. Occurrence and removal of arsenic in ground-water are related to the pH and the redox condition of the ground-water, the oxidation state of arsenic, and sorption or exchange. Within basins, dissolved arsenic correlates (P<0.01) with dissolved molybdenum, selenium, vanadium, and fluoride and with pH, suggesting sorption of negative ions. The sorption hypothesis is further supported by enrichment of teachable arsenic in the basin-fill sediments by about tenfold relative to the crustal abundance and by as much as a thousandfold relative to concentrations found in ground-water. Silicate hydrolysis reactions, as defined within the alluvial basins, under closed conditions cause increases in pH basinward and would promote desorption. Within the region, large concentrations of arsenic are commonly associated with the central parts of basins whose chemistries evolve under closed conditions. Arsenic does not correlate with dissolved iron (r = 0.09) but may be partly controlled by iron in the solid phase. High solid-phase arsenic contents were found in red clay beds. Large concentrations of arsenic also were found in water associated with red clay beds. Basins that contain the larger concentrations are bounded primarily by basalt and andesite, suggesting that the iron content as well as the arsenic content of the basin fill may play a role in the occurrence of arsenic in ground-water. Under oxidizing conditions in Arizona, arsenic in ground-water appears to be controlled in part by sorption or desorption of HAsO4???2 on active ferric oxyhydroxide surfaces. ?? 1989 Sciences and Technology Letters.

Groundwater quality in the Basin and Range Basin-Fill Aquifers, southwestern United States

USGS Publications Warehouse

Musgrove, MaryLynn; Belitz, Kenneth

2017-01-19

Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water. The Basin and Range basin-fill aquifers constitute one of the important areas being evaluated. One or more inorganic constituents with human-health benchmarks were detected at high concentrations in about 20 percent of the study area and at moderate concentrations in about 49 percent. Organic constituents were not detected at high concentrations in the study area. One or more organic constituents with human-health benchmarks were detected at moderate concentrations in about 3 percent of the study area.

Ground-water monitoring at Santa Barbara, California; Phase 2, Effects of pumping on water levels and on water quality in the Santa Barbara ground-water basin

USGS Publications Warehouse

Martin, Peter

1984-01-01

From July 1978 to January 1980, water levels in the southern part of the Santa Barbara ground-water basin declined more than 100 feet. These water-level declines resulted from increases in municipal pumping since July 1978. The increase in municipal pumping was part of a basin-testing program designed to determine the usable quantity of ground water in storage. The pumping, centered in the city less than 1 mile from the coast, has caused water-level declines to altitudes below sea level in the main water-bearing zones. As a result, the ground-water basin would be subject to saltwater intrusion if the study-period pumpage were maintained or increased. Data indicate that saltwater intrusion has degraded the quality of the water yielded from six coastal wells. During the study period, the six coastal wells all yielded water with chloride concentrations in excess of 250 milligrams per liter, and four of the wells yielded water with chloride concentrations in excess of 1,000 milligrams per liter. Previous investigators believed that saltwater intrusion was limited to the shallow part of the aquifer, directly adjacent to the coast. The possibility of saltwater intrusion into the deeper water-bearing deposits in the aquifer was thought to be remote because an offshore fault truncates these deeper deposits so that they lie against consolidated rocks on the seaward side of the fault. Results of this study indicate, however, that ocean water has intruded the deeper water-bearing deposits, and to a much greater extent than in the shallow part of the aquifer. Apparently the offshore fault is not an effective barrier to saltwater intrusion. No physical barriers are known to exist between the coast and the municipal well field. Therefore, if the pumping rate maintained during the basin-testing program were continued, the degraded water along the coast could move inland and contaminate the municipal supply wells. The time required for the degraded water to move from the coast to the nearest supply well is estimated, using Darcy's equation, to be about 20 years. Management alternatives for controlling saltwater intrusion in the Santa Barbara area include (1) decreasing municipal pumping, (2) increasing the quantity of water available for recharge by releasing surplus water from surface reservoirs to Mission Creek, (3) artificially recharging the basin using injection wells, and (4) locating municipal supply wells farther from the coast and spacing them farther apart in order to minimize drawdown. Continued monitoring of water levels and water quality would enable assessment of the effectiveness of the control measures employed.

Radionuclide inventories for the F- and H-area seepage basin groundwater plumes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiergesell, Robert A; Kubilius, Walter P.

2016-05-01

Within the General Separations Areas (GSA) at the Savannah River Site (SRS), significant inventories of radionuclides exist within two major groundwater contamination plumes that are emanating from the F- and H-Area seepage basins. These radionuclides are moving slowly with groundwater migration, albeit more slowly due to interaction with the soil and aquifer matrix material. The purpose of this investigation is to quantify the activity of radionuclides associated with the pore water component of the groundwater plumes. The scope of this effort included evaluation of all groundwater sample analyses obtained from the wells that have been established by the Environmental Compliancemore » & Area Completion Projects (EC&ACP) Department at SRS to monitor groundwater contamination emanating from the F- and H-Area Seepage Basins. Using this data, generalized groundwater plume maps for the radionuclides that occur in elevated concentrations (Am-241, Cm-243/244, Cs-137, I-129, Ni-63, Ra-226/228, Sr-90, Tc-99, U-233/234, U-235 and U-238) were generated and utilized to calculate both the volume of contaminated groundwater and the representative concentration of each radionuclide associated with different plume concentration zones.« less

Utilizing potential field data to support delineation of groundwater aquifers in the southern Red Sea coast, Saudi Arabia

NASA Astrophysics Data System (ADS)

Elawadi, Eslam; Mogren, Saad; Ibrahim, Elkhedr; Batayneh, Awni; Al-Bassam, Abdulaziz

2012-06-01

In this paper potential field data are interpreted to map the undulation of the basement surface, which represents the bottom of the water bearing zones, and to delineate the tectonic framework that controls the groundwater flow and accumulation in the southern Red Sea coastal area of Saudi Arabia. The interpretation reveals that the dominant structural trend is a NW (Red Sea) trend that resulted in a series of faulted tilted blocks. These tilted blocks are dissected by another cross-cut NE trend which shapes and forms a series of fault-bounded small basins. These basins and the bounded structural trends control and shape the flow direction of the groundwater in the study area, i.e. they act as groundwater conduits. Furthermore, the present results indicate that volcanic intrusions are present as subsurface flows, which hinder the groundwater exploration and drilling activities in most of the area; in some localities these volcanic flows crop out at the surface and cover the groundwater bearing formations. Furthermore, the gravity and magnetic data interpretation indicates the possible existence of a large structural basin occupying the southeastern side of the study area. This basin is bounded with NW and NE trending faults and is expected to be a good host for groundwater aquifers; thus it is a promising site for hydrogeological investigation.

Evaluation of the sustainability of deep groundwater as an arsenic-safe resource in the Bengal Basin

USGS Publications Warehouse

Michaela, Holly A.; Voss, Clifford I.

2008-01-01

Tens of millions of people in the Bengal Basin region of Bangladesh and India drink groundwater containing unsafe concentrations of arsenic. This high-arsenic groundwater is produced from shallow (<100 m) depths by domestic and irrigation wells in the Bengal Basin aquifer system. The government of Bangladesh has begun to install wells to depths of >150 m where groundwater arsenic concentrations are nearly uniformly low, and many more wells are needed, however, the sustainability of deep, arsenic-safe groundwater has not been previously assessed. Deeper pumping could induce downward migration of dissolved arsenic, permanently destroying the deep resource. Here, it is shown, through quantitative, large-scale hydrogeologic analysis and simulation of the entire basin, that the deeper part of the aquifer system may provide a sustainable source of arsenic-safe water if its utilization is limited to domestic supply. Simulations provide two explanations for this result: deep domestic pumping only slightly perturbs the deep groundwater flow system, and substantial shallow pumping for irrigation forms a hydraulic barrier that protects deeper resources from shallow arsenic sources. Additional analysis indicates that this simple management approach could provide arsenic-safe drinking water to >90% of the arsenic-impacted region over a 1,000-year timescale. This insight may assist water-resources managers in alleviating one of the world's largest groundwater contamination problems.

Declining groundwater level caused by irrigation to row crops in the Lower Mississippi River Basin, Current Situation and Trends

NASA Astrophysics Data System (ADS)

Feng, G.; Gao, F.; Ouyang, Y.

2017-12-01

The Mississippi River is North America's largest river and the second largest watershed in the world. It flows over 3,700 km through America's heartland to the Gulf of Mexico. Over 3 million hectares in the Lower Mississippi River Basin represent irrigated cropland and 90 percent of those lands currently rely on the groundwater supply. The primary crops grown in this region are soybean, corn, cotton, and rice. Increased water withdrawals for irrigating those crops and stagnant recharging jeopardize the long-term availability of the aquifer and place irrigation agriculture in the region on an unsustainable path. The objectives of this study were to: 1) analyze the current groundwater level in the Lower Mississippi River Basin based on the water table depth observed by Yazoo Mississippi Delta Joint Water Management District from 2000 and 2016; 2) determine trends of change in groundwater level under conventional and groundwater saving irrigation management practices (ET or soil moisture based full irrigation scheduling using all groundwater or different percentages of ground and surface water). The coupled SWAT and MODFLOW model was applied to investigate the trends. Observed results showed that the groundwater level has declined from 33 to 26 m at an annual decrease rate of 0.4 m in the past 17 years. Simulated results revealed that the groundwater storage was decreased by 26 cm/month due to irrigation in crop season. It is promising that the groundwater storage was increased by 23 cm/month, sometimes even 60 cm/month in crop off-growing season because of recharge from rainfall. Our results suggest that alternative ET or soil moisture based groundwater saving irrigation scheduling with conjunctive use of surface water is a sustainable practice for irrigated agriculture in in the Lower Mississippi River Basin.

Analysis of Infrequent (Quasi-Decadal) Large Groundwater Recharge Events: A Case Study for Northern Utah, United States

NASA Astrophysics Data System (ADS)

Masbruch, M.; Rumsey, C.; Gangopadhyay, S.; Susong, D.; Pruitt, T.

2015-12-01

There has been a considerable amount of research linking climatic variability to hydrologic responses in arid and semi-arid regions such as the western United States. Although much effort has been spent to assess and predict changes in surface-water resources, little has been done to understand how climatic events and changes affect groundwater resources. This study focuses on quantifying the effects of large quasi-decadal groundwater recharge events on groundwater in the northern Utah portion of the Great Basin for the period 1960 to 2013. Groundwater-level monitoring data were analyzed with climatic data to characterize climatic conditions and frequency of these large recharge events. Using observed water-level changes and multivariate analysis, five large groundwater recharge events were identified within the study area and period, with a frequency of about 11 to 13 years. These events were generally characterized as having above-average annual precipitation and snow water equivalent and below-average seasonal temperatures, especially during the spring (April through June). Existing groundwater flow models for several basins within the study area were used to quantify changes in groundwater storage from these events. Simulated groundwater storage increases per basin from a single event ranged from about 115 Mm3 (93,000 acre-feet) to 205 Mm3 (166,000 acre-ft). Extrapolating these amounts over the entire northern Great Basin indicates that even a single large quasi-decadal recharge event could result in billions of cubic meters (millions of acre-feet) of groundwater recharge. Understanding the role of these large quasi-decadal recharge events in replenishing aquifers and sustaining water supplies is crucial for making informed water management decisions.

Biogeochemistry of Arsenic in Groundwater Flow Systems: The Case of Southern Louisiana

NASA Astrophysics Data System (ADS)

Johannesson, K. H.; Yang, N.; Datta, S.

2017-12-01

Arsenic (As) is a highly toxic and carcinogenic metalloid that can cause serious health effects, including increased risk of cancers, infant mortality, and reduced intellectual and motor function in children to populations chronically exposed to As. Recent estimates suggest that more than 140 million people worldwide are drinking As-contaminated groundwater (i.e., As ≥ 10 µg kg-1), and the most severely affected region is the Ganges-Brahmaputra-Meghna delta in Bangladesh and India (i.e., Bengal Basin). Arsenic appears to be mobilized to Bengal Basin groundwaters by reductive dissolution of Fe oxides in aquifer sediments with the source of the labile organic matter occurring in the aquifer sediments. Studies within the lower Mississippi River delta of southern Louisiana (USA) also reveal high As concentrations (up to 640 µg kg-1) in shallow groundwaters. It is not known what affects, if any, the elevated groundwater As has had on local communities. The regional extent of high As shallow groundwaters is controlled, in part, by the distribution of Holocene sediments, deltaic deposits, and organic-rich sediments, similar to the Bengal Basin. Field and laboratory studies suggest that As is largely of geogenic origin, and further that microbial reduction of Fe(III)/Mn(IV) oxides/oxyhydroxides within the sediments contributes the bulk of the As to the groundwaters. Incubation studies are supported by biogeochemical reactive transport modeling, which also indicates reductive dissolution of metal oxides/oxyhydroxides as the likely source of As to these groundwaters. Finally, reactive transport modeling of As in shallow groundwaters suggests that sorption to aquifer mineral surfaces limits the transport of As after mobilization, which may explain, in part, the heterogeneous distribution of As in groundwaters of southern Louisiana and, perhaps, the Bengal Basin.

Calendar year 1996 annual groundwater monitoring report for the Chestnut Ridge Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-02-01

This annual monitoring report contains groundwater and surface water monitoring data obtained in the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime) during calendar year (CY) 1996. The Chestnut Ridge Regime encompasses a section of Chestnut Ridge west of Scarboro Road and east of an unnamed drainage feature southwest of the US Department of Energy (DOE) Oak Ridge Y-12 Plant (unless otherwise noted, directions are in reference to the Y-12 Plant administrative grid). The Chestnut Ridge Regime contains several sites used for management of hazardous and nonhazardous wastes associated with plant operations. Groundwater and surface water quality monitoring associated with thesemore » waste management sites is performed under the auspices of the Y-12 Plant Groundwater Protection Program (GWPP). Included in this annual monitoring report are the groundwater monitoring data obtained in compliance with the Resource Conservation and Recovery Act (RCRA) Post-Closure Permit for the Chestnut Ridge Regime (post-closure permit) issued by the Tennessee Department of Environment and Conservation (TDEC) in June 1996. Besides the signed certification statement and the RCRA facility information summarized below, condition II.C.6 of the post-closure permit requires annual reporting of groundwater monitoring activities, inclusive of the analytical data and results of applicable data evaluations, performed at three RCRA hazardous waste treatment, storage, or disposal (TSD) units: the Chestnut Ridge Sediment Disposal Basin (Sediment Disposal Basin), the Chestnut Ridge Security Pits (Security Pits), and Kerr Hollow Quarry.« less

Estimation of shallow ground-water recharge in the Great Lakes basin

USGS Publications Warehouse

Neff, B.P.; Piggott, A.R.; Sheets, R.A.

2006-01-01

This report presents the results of the first known integrated study of long-term average ground-water recharge to shallow aquifers (generally less than 100 feet deep) in the United States and Canada for the Great Lakes, upper St. Lawrence, and Ottawa River Basins. The approach used was consistent throughout the study area and allows direct comparison of recharge rates in disparate parts of the study area. Estimates of recharge are based on base-flow estimates for streams throughout the Great Lakes Basin and the assumption that base flow in a given stream is equal to the amount of shallow ground-water recharge to the surrounding watershed, minus losses to evapotranspiration. Base-flow estimates were developed throughout the study area using a single model based on an empirical relation between measured base-flow characteristics at streamflow-gaging stations and the surficial-geologic materials, which consist of bedrock, coarse-textured deposits, fine-textured deposits, till, and organic matter, in the surrounding surface-water watershed. Model calibration was performed using base-flow index (BFI) estimates for 959 stations in the U.S. and Canada using a combined 28,784 years of daily streamflow record determined using the hydrograph-separation software program PART. Results are presented for watersheds represented by 8-digit hydrologic unit code (HUC, U.S.) and tertiary (Canada) watersheds. Recharge values were lowest (1.6-4.0 inches/year) in the eastern Lower Peninsula of Michigan; southwest of Green Bay, Wisconsin; in northwestern Ohio; and immediately south of the St. Lawrence River northeast of Lake Ontario. Recharge values were highest (12-16.8 inches/year) in snow shadow areas east and southeast of each Great Lake. Further studies of deep aquifer recharge and the temporal variability of recharge would be needed to gain a more complete understanding of ground-water recharge in the Great Lakes Basin.

Status and understanding of groundwater quality in the South Coast Interior groundwater basins, 2008: California GAMA Priority Basin Project

USGS Publications Warehouse

Parsons, Mary C.; Kulongoski, Justin T.; Belitz, Kenneth

2014-01-01

Groundwater quality in the approximately 653-square-mile (1,691-square-kilometer) South Coast Interior Basins (SCI) study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The South Coast Interior Basins study unit contains eight priority groundwater basins grouped into three study areas, Livermore, Gilroy, and Cuyama, in the Southern Coast Ranges hydrogeologic province. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA South Coast Interior Basins study was designed to provide a spatially unbiased assessment of untreated (raw) groundwater quality within the primary aquifer system, as well as a statistically consistent basis for comparing water quality between basins. The assessment was based on water-quality and ancillary data collected by the USGS from 50 wells in 2008 and on water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer system was defined by the depth intervals of the wells listed in the CDPH database for the SCI study unit. The quality of groundwater in the primary aquifer system may be different from that in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. The first component of this study, the status of the current quality of the groundwater resource, was assessed by using data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally occurring inorganic constituents, such as trace elements and minor ions. This status assessment is intended to characterize the quality of groundwater resources within the primary aquifer system of the SCI study unit, not the treated drinking water delivered to consumers by water purveyors. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used for evaluating groundwater quality for those constituents that have Federal or California regulatory or non-regulatory benchmarks for drinking-water quality. A relative-concentration greater than 1.0 indicates a concentration greater than a benchmark, and a relative-concentration less than or equal to 1.0 indicates a concentration equal to or less than a benchmark. Relative-concentrations of organic constituents and special-interest constituents were classified as “high” (relative-concentration greater than 1.0), “moderate” (relative-concentration greater than 0.1 and less than or equal to 1.0), or “low” (relative-concentration less than or equal to 0.1). Relative-concentrations of inorganic constituents were classified as “high” (relative-concentration greater than 1.0), “moderate” (relative-concentration greater than 0.5 and less than or equal to 1.0), or “low” (relative-concentration less than or equal to 0.5). Aquifer-scale proportion was used as the primary metric in the status assessment for evaluating regional-scale groundwater quality. High aquifer-scale proportion is defined as the percentage of the area of the primary aquifer system with a relative-concentration greater than 1.0 for a particular constituent or class of constituents; percentage is based on an areal rather than a volumetric basis. Moderate and low aquifer-scale proportions were defined as the areal percentage of the primary aquifer system with moderate and low relative-concentrations, respectively. Two statistical approaches—grid-based and spatially weighted—were used to evaluate aquifer-scale proportions for individual constituents and classes of constituents. Grid-based and spatially weighted estimates were comparable in the SCI study unit (within 90-percent confidence intervals). Inorganic constituents (one or more) with health-based benchmarks were detected at high relative-concentrations in 29 percent of the primary aquifer system, at moderate relative-concentrations in 37 percent, and at low relative-concentrations in 34 percent. High aquifer-scale proportions of inorganic constituents primarily reflected high aquifer-scale proportions of nitrate (14 percent), boron (8.6 percent), molybdenum (8.6 percent), and arsenic (5.7 percent). In contrast, the relative-concentrations of organic constituents (one or more) were high in 1.6 percent, moderate in 2.0 percent, and low or not detected in 96 percent of the primary aquifer system. Of the 207 organic and special-interest constituents analyzed for, 15 constituents were detected. Perchlorate was found at moderate relative-concentrations in 34 percent of the aquifer. Two organic constituents were frequently detected (in greater than 10 percent of samples): the trihalomethane chloroform and the herbicide simazine. The second component of this study, the understanding assessment, identified natural and human factors that may have affected groundwater quality by evaluating land use, physical characteristics of the wells, and geochemical conditions of the aquifer. This evaluation was done by using statistical tests of correlations between these potential explanatory factors and water-quality data. Concentrations of arsenic, molybdenum, and manganese were generally greater in anoxic and pre-modern groundwater than other groundwater. In contrast, concentrations of nitrate and perchlorate were significantly higher in oxic and modern groundwater. Concentrations of simazine were greater in modern than pre-modern groundwater. Chloroform detections were positively correlated with greater urban land use. Boron concentrations and chloroform detections were higher in the Livermore study area than in the other study areas of the SCI; total dissolved solids and sulfate concentrations were greater in the Cuyama study area.

Hydrogeology and Simulated Effects of Ground-Water Withdrawals in the Big River Area, Rhode Island

USGS Publications Warehouse

Granato, Gregory E.; Barlow, Paul M.; Dickerman, David C.

2003-01-01

The Rhode Island Water Resources Board is considering expanded use of ground-water resources from the Big River area because increasing water demands in Rhode Island may exceed the capacity of current sources. This report describes the hydrology of the area and numerical simulation models that were used to examine effects of ground-water withdrawals during 1964?98 and to describe potential effects of different withdrawal scenarios in the area. The Big River study area covers 35.7 square miles (mi2) and includes three primary surface-water drainage basins?the Mishnock River Basin above Route 3, the Big River Basin, and the Carr River Basin, which is a tributary to the Big River. The principal aquifer (referred to as the surficial aquifer) in the study area, which is defined as the area of stratified deposits with a saturated thickness estimated to be 10 feet or greater, covers an area of 10.9 mi2. On average, an estimated 75 cubic feet per second (ft3/s) of water flows through the study area and about 70 ft3/s flows out of the area as streamflow in either the Big River (about 63 ft3/s) or the Mishnock River (about 7 ft3/s). Numerical simulation models are used to describe the hydrology of the area under simulated predevelopment conditions, conditions during 1964?98, and conditions that might occur in 14 hypothetical ground-water withdrawal scenarios with total ground-water withdrawal rates in the area that range from 2 to 11 million gallons per day. Streamflow depletion caused by these hypothetical ground-water withdrawals is calculated by comparison with simulated flows for the predevelopment conditions, which are identical to simulated conditions during the 1964?98 period but without withdrawals at public-supply wells and wastewater recharge. Interpretation of numerical simulation results indicates that the three basins in the study area are in fact a single ground-water resource. For example, the Carr River Basin above Capwell Mill Pond is naturally losing water to the Mishnock River Basin. Withdrawals in the Carr River Basin can deplete streamflows in the Mishnock River Basin. Withdrawals in the Mishnock River Basin deplete streamflows in the Big River Basin and can intercept water flowing to the Flat River Reservoir North of Hill Farm Road in Coventry, Rhode Island. Withdrawals in the Big River Basin can deplete streamflows in the western unnamed tributary to the Carr River, but do not deplete streamflows in the Mishnock River Basin or in the Carr River upstream of Capwell Mill Pond. Because withdrawals deplete streamflows in the study area, the total amount of ground water that may be withdrawn for public supply depends on the minimum allowable streamflow criterion that is applied for each basin.

Numerical Simulation of Ground-Water Flow and Assessment of the Effects of Artificial Recharge in the Rialto-Colton Basin, San Bernardino County, California

USGS Publications Warehouse

Woolfenden, Linda R.; Koczot, Kathryn M.

2001-01-01

The Rialto?Colton Basin, in western San Bernardino County, California, was chosen for storage of imported water because of the good quality of native ground water, the known storage capacity for additional ground-water storage in the basin, and the availability of imported water. To supplement native ground-water resources and offset overdraft conditions in the basin during dry periods, artificial-recharge operations during wet periods in the Rialto?Colton Basin were begun in 1982 to store surplus imported water. Local water purveyors recognized that determining the movement and ultimate disposition of the artificially recharged imported water would require a better understanding of the ground-water flow system. In this study, a finite-difference model was used to simulate ground-water flow in the Rialto?Colton Basin to gain a better understanding of the ground-water flow system and to evaluate the hydraulic effects of artificial recharge of imported water. The ground-water basin was simulated as four horizontal layers representing the river- channel deposits and the upper, middle, and lower water-bearing units. Several flow barriers bordering and internal to the Rialto?Colton Basin influence the direction of ground-water flow. Ground water may flow relatively unrestricted in the shallow parts of the flow system; however, the faults generally become more restrictive at depth. A particle-tracking model was used to simulate advective transport of imported water within the ground-water flow system and to evaluate three artificial-recharge alternatives. The ground-water flow model was calibrated to transient conditions for 1945?96. Initial conditions for the transient-state simulation were established by using 1945 recharge and discharge rates, and assuming no change in storage in the basin. Average hydrologic conditions for 1945?96 were used for the predictive simulations (1997?2027). Ground-water-level measurements made during 1945 were used for comparison with the initial-conditions simulation to determine if there was a reasonable match, and thus reasonable starting heads, for the transient simulation. The comparison between simulated head and measured water levels indicates that, overall, the simulated heads match measured water levels well; the goodness-of-fit value is 0.99. The largest differences between simulated head and measured water level occurred between Barrier H and the Rialto?Colton Fault. Simulated heads near the Santa Ana River and Warm Creek, and simulated heads northwest of Barrier J, generally are within 30 feet of measured water levels and five are within 20 feet. Model-simulated heads were compared with measured long-term changes in hydrographs of composite water levels in selected wells, and with measured short-term changes in hydrographs of water levels in multiple-depth observation wells installed for this project. Simulated hydraulic heads generally matched measured water levels in wells northwest of Barrier J (in the northwestern part of the basin) and in the central part of the basin during 1945?96. In addition, the model adequately simulated water levels in the southeastern part of the basin near the Santa Ana River and Warm Creek and east of an unnamed fault that subparallels the San Jacinto Fault. Simulated heads and measured water levels in the central part of the basin generally are within 10 feet until about 1982?85 when differences become greater. In the northwestern part of the basin southeast of Barrier J, simulated heads were as much as 50 feet higher than measured water levels during 1945?82 but matched measured water levels well after 1982. In the compartment between Barrier H and the Rialto?Colton Fault, simulated heads match well during 1945?82 but are comparatively low during 1982?96. Near the Santa Ana River and Warm Creek, simulated heads generally rose above measured water levels except during 1965?72 when simulated heads compared well with measured water levels. Average

Eolian transport, saline lake basins, and groundwater solutes

USGS Publications Warehouse

Wood, Warren W.; Sanford, Ward E.

1995-01-01

Eolian processes associated with saline lakes are shown to be important in determining solute concentration in groundwater in arid and semiarid areas. Steady state mass balance analyses of chloride in the groundwater at Double Lakes, a saline lake basin in the southern High Plains of Texas, United States, suggest that approximately 4.5 × 105 kg of chloride is removed from the relatively small (4.7 km2) basin floor each year by deflation. This mass enters the groundwater down the wind gradient from the lake, degrading the water quality. The estimates of mass transport were independently determined by evaluation of solutes in the unsaturated zone and by solute mass balance calculations of groundwater flux. Transport of salts from the lake was confirmed over a short term (2 years) by strategically placed dust collectors. Results consistent with those at Double Lake were obtained from dune surfaces collected upwind and downwind from a sabkha near the city of Abu Dhabi in the United Arab Emirates. The eolian transport process provides an explanation of the degraded groundwater quality associated with the 30–40 saline lake basins on the southern half of the southern High Plains of Texas and New Mexico and in many other arid and semiarid areas.

Monitoring and Assessing Groundwater Impacts on Vegetation Health in Groundwater Dependent Ecosystems

NASA Astrophysics Data System (ADS)

Rohde, M. M.; Ulrich, C.; Howard, J.; Sweet, S.

2017-12-01

Sustainable groundwater management is important for preserving our economy, society, and environment. Groundwater supports important habitat throughout California, by providing a reliable source of water for these Groundwater Dependent Ecosystems (GDEs). Groundwater is particularly important in California since it supplies an additional source of water during the dry summer months and periods of drought. The drought and unsustainable pumping practices have, in some areas, lowered groundwater levels causing undesirable results to ecosystems. The Sustainable Groundwater Management Act requires local agencies to avoid undesirable results in the future, but the location and vulnerabilities of the ecosystems that depend on groundwater and interconnected surface water is often poorly understood. This presentation will feature results from a research study conducted by The Nature Conservancy and Lawrence Berkeley National Laboratory that investigated how changes in groundwater availability along an interconnected surface water body can impact the overall health of GDEs. This study was conducted in California's Central Valley along the Cosumnes River, and situated at the boundary of a high and a medium groundwater basin: South American Basin (Sacramento Hydrologic Region) and Cosumnes Basin (San Joaquin Hydrologic Region). By employing geophysical methodology (electrical resistivity tomography) in this study, spatial changes in groundwater availability were determined under groundwater-dependent vegetation. Vegetation survey data were also applied to this study to develop ecosystem health indicators for groundwater-dependent vegetation. Health indicators for groundwater-dependent vegetation were found to directly correlate with groundwater availability, such that greater availability to groundwater resulted in healthier vegetation. This study provides a case study example on how to use hydrological and biological data for setting appropriate minimum thresholds and measurable objectives that can help avoid undesirable results to GDEs.

Hydrogeology and quality of ground water in the upper Arkansas River basin from Buena Vista to Salida, Colorado, 2000-2003

USGS Publications Warehouse

Watts, Kenneth R.

2005-01-01

The upper Arkansas River Basin between Buena Vista and Salida, Colorado, is a downfaulted basin, the Buena Vista-Salida structural basin, located between the Sawatch and Mosquito Ranges. The primary aquifers in the Buena Vista-Salida structural basin consist of poorly consolidated to unconsolidated Quaternary-age alluvial and glacial deposits and Tertiary-age basin-fill deposits. Maximum thickness of the alluvial, glacial, and basin-fill deposits is about 5,000 feet, but 95 percent of the water-supply wells in Chaffee County are no more than 300 feet deep. Hydrologic conditions in the 149-square mile study area are described on the basis of hydrologic and geologic data compiled and collected during September 2000 through September 2003. The principal aquifers described in this report are the alluvial-outwash and basin-fill aquifers. An estimated 3,443 wells pumped about 690 to 1,240 acre-feet for domestic and household use in Chaffee County during 2003. By 2030, projected increases in the population of Chaffee County, Colorado, may require use of an additional 4,000 to 5,000 wells to supply an additional 800 to 1,800 acre-feet per year of ground water for domestic and household supply. The estimated specific yield of the upper 300 feet of the alluvial-outwash and basin-fill aquifers ranged from about 0.02 to 0.2. Current (2003) and projected (2030) ground-water withdrawals by domestic and household wells are less than 1 percent of the estimated 472,000 acre-feet of drainable ground water in the upper 300 feet of the subsurface. Locally, little water is available in the upper 300 feet. In densely populated areas, well interference could result in decreased water levels and well yields, which may require deepening or replacement of wells. Infiltration of surface water diverted for irrigation and from losing streams is the primary source of ground-water recharge in the semiarid basin. Ground-water levels in the alluvial-outwash and basin-fill aquifers vary seasonally with maximum water levels occurring in the early summer after snowmelt runoff peaks. Because of the drought during 2002, relatively large declines in ground-water levels occurred in about one-half of the monitored wells. Differences in water-level altitudes in shallow and deep wells indicate the potential for downward flow in upland areas and support results of preliminary cross-sectional models of ground-water flow. The apparent mean age of ground-water recharge ranged from about 1 to more than 48 years before 2001. The older (pre-1953) water was from wells that were located in ground-water discharge areas. Ground-water flow in the Buena Vista-Salida structural basin drains eastward toward the Arkansas River and, locally, toward the South Arkansas River. Ground water in the alluvial-outwash and basin-fill aquifers generally is calcium-bicarbonate water type with less than 250 milligrams per liter dissolved solids. Nitrate concentrations generally were less than 1 to 2 milligrams per liter and do not indicate widespread contamination of ground water from surface sources.

Hydrogeologic Framework of Bedrock Units and Initial Salinity Distribution for a Simulation of Groundwater Flow for the Lake Michigan Basin

USGS Publications Warehouse

Lampe, David C.

2009-01-01

The U.S. Geological Survey is assessing groundwater availability in the Lake Michigan Basin. As part of the assessment, a variable-density groundwater-flow model is being developed to simulate the effects of groundwater use on water availability throughout the basin. The hydrogeologic framework for the Lake Michigan Basin model was developed by grouping the bedrock geology of the study area into hydrogeologic units on the basis of the functioning of each unit as an aquifer or confining layer within the basin. Available data were evaluated based on the areal extent of coverage within the study area, and procedures were established to characterize areas with sparse data coverage. Top and bottom altitudes for each hydrogeologic unit were interpolated in a geographic information system for input to the model and compared with existing maps of subsurface formations. Fourteen bedrock hydrogeologic units, making up 17 bedrock model layers, were defined, and they range in age from the Jurassic Period red beds of central Michigan to the Cambrian Period Mount Simon Sandstone. Information on groundwater salinity in the Lake Michigan Basin was compiled to create an input dataset for the variable-density groundwater-flow simulation. Data presented in this report are referred to as 'salinity data' and are reported in terms of total dissolved solids. Salinity data were not available for each hydrogeologic unit. Available datasets were assigned to a hydrogeologic unit, entered into a spatial database, and data quality was visually evaluated. A geographic information system was used to interpolate salinity distributions for each hydrogeologic unit with available data. Hydrogeologic units with no available data either were set equal to neighboring units or were vertically interpolated by use of values from units above and below.

Insights into the Groundwater Salinization Processes in Manas River Basin, Northwest China

NASA Astrophysics Data System (ADS)

Jin, M.; Liu, Y.; Liang, X.

2017-12-01

Manas River Basin (MRB) is a typical mountains-oasis-desert inland basin in northwest China, where groundwater salinization is threatening the local water use and the environment, but the groundwater salinization process is not clear. Based on groundwater flow system analysis by integrating flow fields, hydrochemical and isotopic characteristics, a deuterium excess analytical method was used to quantitatively assess salinization mechanism and calculate the contribution ratios of evapoconcentration effect to the salinities. 73 groundwater samples and 11 surface water samples were collected from the basin. Hydrochemical diagrams and δD and δ18O compositions indicated that evapoconcentration, mineral dissolution and transpiration, increased the groundwater salinities (i.e. total dissolved solids). The results showed that the average contribution ratios of evapoconcentration effect to the increased salinities were 5.8% and 32.7% in groundwater and surface water, respectively. From the piedmont plain to the desert plain, the evapoconcentration effect increased the average groundwater loss from 7% to 29%. However, it only increased slight salinity (0 - 0.27 g/L), as determined from the deuterium excess signals. Minerals dissolution and anthropogenic activities are the major cause of groundwater salinization problem. The results revealed that fresh water in the rivers directly and quickly infiltrated the aquifers in the piedmont area with evapoconcentration affected weakly, and the fresh water interacted with the sediments and dissolved soluble minerals, subsequently increasing the salinities. Combined with the groundwater stable isotopic compositions and hydrochemical evolution, the relationships between δ18O and Cl and salinities reveal the soil evaporites leaching by the vertical recharge (irrigation return flow and channels leakage) mainly affect the groundwater salinization processes in the middle alluvial-diluvial plain and the desert land. The saline water released from aquitards by continuous decline of water level due to over exploitation is an additional factor for groundwater salinization.

Geohydrology of the Aucilla-Suwannee-Ochlockonee River Basin, south-central Georgia and adjacent parts of Florida

USGS Publications Warehouse

Torak, Lynn J.; Painter, Jaime A.; Peck, Michael F.

2010-01-01

Major streams and tributaries located in the Aucilla-Suwannee-Ochlockonee (ASO) River Basin of south-central Georgia and adjacent parts of Florida drain about 8,000 square miles of a layered sequence of clastic and carbonate sediments and carbonate Coastal Plain sediments consisting of the surficial aquifer system, upper semiconfining unit, Upper Floridan aquifer, and lower confining unit. Streams either flow directly on late-middle Eocene to Oligocene karst limestone or carve a dendritic drainage pattern into overlying Miocene to Holocene sand, silt, and clay, facilitating water exchange and hydraulic connection with geohydrologic units. Geologic structures operating in the ASO River Basin through time control sedimentation and influence geohydrology and water exchange between geohydrologic units and surface water. More than 300 feet (ft) of clastic sediments overlie the Upper Floridan aquifer in the Gulf Trough-Apalachicola Embayment, a broad area extending from the southwest to the northeast through the center of the basin. These clastic sediments limit hydraulic connection and water exchange between the Upper Floridan aquifer, the surficial aquifer system, and surface water. Accumulation of more than 350 ft of low-permeability sediments in the Southeast Georgia Embayment and Suwannee Strait hydraulically isolates the Upper Floridan aquifer from land-surface hydrologic processes in the Okefenokee Basin physiographic district. Burial of limestone beneath thick clastic overburden in these areas virtually eliminates karst processes, resulting in low aquifer hydraulic conductivity and storage coefficient despite an aquifer thickness of more than 900 ft. Conversely, uplift and faulting associated with regional tectonics and the northern extension of the Peninsular Arch caused thinning and erosion of clastic sediments overlying the Upper Floridan aquifer southeast of the Gulf Trough-Apalachicola Embayment near the Florida-Georgia State line. Limestone dissolution in Brooks and Lowndes Counties, Ga., create karst features that enhance water-transmitting and storage properties of the Upper Floridan aquifer, promoting groundwater recharge and water exchange between the aquifer, land surface, and surface water. Structural control of groundwater flow and hydraulic properties combine with climatic effects and increased hydrologic stress from agricultural pumpage to yield unprecedented groundwater-level decline in the northwestern and central parts of the ASO River Basin. Hydrographs from continuous-record observation wells in these regions document declining groundwater levels, indicating diminished water-resource potential of the Upper Floridan aquifer through time. More than 24 ft of groundwater-level decline occurred along the basin's northwestern boundary with the lower Apalachicola-Chattahoochee-Flint River Basin, lowering hydraulic gradients that provide the potential for groundwater flow into the ASO River Basin and southeastward across the Gulf Trough-Apalachicola Embayment region. Slow-moving groundwater across the trough-embayment region coupled with downward-vertical flow from upper to lower limestone units composing the Upper Floridan aquifer resulted in 40-50 ft of groundwater-level decline since 1969 in southeastern Colquitt County. Multi-year episodes of dry climatic conditions during the 1980s through the early 2000s contributed to seasonal and long-term groundwater-level decline by reducing recharge to the Upper Floridan aquifer and increasing hydrologic stress by agricultural pumpage. Unprecedented and continued groundwater-level decline since 1969 caused 40-50 ft of aquifer dewatering in southeastern Colquitt County that reduced aquifer transmissivity and the ability to supply groundwater to wells, resulting in depletion of the groundwater resource.

Relations of Water Quality to Agricultural Chemical Use and Environmental Setting at Various Scales - Results from Selected Studies of the National Water-Quality Assessment Program

USGS Publications Warehouse

,

2008-01-01

In 1991, the U.S. Geological Survey (USGS) began studies of 51 major river basins and aquifers across the United States as part of the National Water-Quality Assessment (NAWQA) Program to provide scientifically sound information for managing the Nation's water resources. The major goals of the NAWQA Program are to assess the status and long-term trends of the Nation's surface- and ground-water quality and to understand the natural and human factors that affect it (Gilliom and others, 1995). In 2001, the NAWQA Program began a second decade of intensive water-quality assessments. The 42 study units for this second decade were selected to represent a wide range of important hydrologic environments and potential contaminant sources. These NAWQA studies continue to address the goals of the first decade of the assessments to determine how water-quality conditions are changing over time. In addition to local- and regional-scale studies, NAWQA began to analyze and synthesize water-quality status and trends at the principal aquifer and major river-basin scales. This fact sheet summarizes results from four NAWQA studies that relate water quality to agricultural chemical use and environmental setting at these various scales: * Comparison of ground-water quality in northern and southern High Plains agricultural settings (principal aquifer scale); * Distribution patterns of pesticides and degradates in rain (local scale); * Occurrence of pesticides in shallow ground water underlying four agricultural areas (local and regional scales); and * Trends in nutrients and sediment over time in the Missouri River and its tributaries (major river-basin scale).

Hydrogeochemical analysis and evaluation of groundwater in the reclaimed small basin of Abu Mina, Egypt

NASA Astrophysics Data System (ADS)

Salem, Zenhom E.; Atwia, Mohamed G.; El-Horiny, Mohamed M.

2015-12-01

Agricultural reclamation activities during the last few decades in the Western Nile Delta have led to great changes in the groundwater levels and quality. In Egypt, changing the desert land into agricultural land has been done using transferred Nile water (through irrigation canal systems) or/and groundwater. This research investigates the hydrogeochemical changes accompanying the reclamation processes in the small basin of Abu Mina, which is part of the Western Nile Delta region. In summer 2008, 23 groundwater samples were collected and groundwater levels were measured in 40 observation wells. Comparing the groundwater data of the pre-reclamation (1974) and the post-reclamation (2008) periods, groundwater seems to have been subjected to many changes: rise in water level, modification of the flow system, improvement of water quality, and addition of new salts through dissolution processes. Generally, Abu Mina basin is subdivided into two areas, recharge and discharge. The dissolution and mixing were recognized in the recharge areas, while the groundwater of the discharge region carries the signature of the diluted pre-reclamation groundwater. The salts of soil and aquifer deposits play an important role in the salt content of the post and pre-reclamation groundwater. NaCl was the predominant water type in the pre-reclamation groundwater, while CaSO4, NaCl and MgSO4 are the common chemical facies in the post-reclamation groundwater. The post-reclamation groundwater mostly indicates mixing between the pre-reclamation groundwater and the infiltrated freshwater with addition of some ions due to interaction with soil and sediments.

Factor weighting in DRASTIC modelling for assessing the groundwater vulnerability in Salatiga groundwater basin, Central Java Province, Indonesia

NASA Astrophysics Data System (ADS)

Kesuma, D. A.; Purwanto, P.; Putranto, T. T.; Rahmani, T. P. D.

2017-06-01

The increase in human population as well as area development in Salatiga Groundwater Basin, Central Java Province, will increase the potency of groundwater contamination in that area. Groundwater quality, especially the shallow groundwater, is very vulnerable to the contamination from industrial waste, fertilizer/agricultural waste, and domestic waste. The first step in the conservation of groundwater quality is by conducting the mapping of the groundwater vulnerability zonation against the contamination. The result of this research was groundwater vulnerability map which showed the areas vulnerable to the groundwater contamination. In this study, groundwater vulnerability map was assessed based on the DRASTIC Method and was processed spatially using Geographic Information System. The DRASTIC method is used to assess the level of groundwater vulnerability based on weighting on seven parameters, which are: depth to the water table (D), recharge (R), aquifer material (A), soil media (S), topography (T), impact of vadose zone (I), and hydraulic conductivity (C). The higher the DRASTIC Index will result in the higher vulnerability level of groundwater contamination in that area. The DRASTIC Indexes in the researched area were 85 - 100 (low vulnerability level), 101 -120 (low to moderate vulnerability level), 121 - 140 (moderate vulnerability level), 141 - 150, (moderate to high vulnerability level), and 151 - 159 (high vulnerability level). The output of this study can be used by local authority as a tool for consideration to arrange the policy for sustainable area development, especially the development in an area affecting the quality of Salatiga Groundwater Basin.

The Hydroclimatic Response of the Whitewater River Basin: Influence of Groundwater Time Scales

NASA Astrophysics Data System (ADS)

Beeson, P. C.; Springer, E. P.; Duffy, C. J.

2003-12-01

A near-surface groundwater model was developed to assess the impact of land use and climate variability on the overall water budget of the Whitewater River Basin. The watershed is located in southeastern Kansas within the ARM-SGP as part of the DOE Water Cycle Pilot Study. The Whitewater River Basin has an area of 1,100 square-kilometers, an elevation range of 380 - 470m (amsl), and an average annual precipitation of 858 millimeters. The approach presented here attempts to examine the importance of groundwater in the water budget and hydroclimatic response at the river basin scale. In order to identify the time scales of groundwater in this system, time series and geospatial analyses were used to identify significant spatial structure and dominant temporal modes in the climate, runoff and groundwater response. In this research, we show that the time scales of groundwater baseflow to the river network are proportional to drainage density and position in the hydrologic landscape. The concept of a hydrologic landscape (Winter, JAWRA, April 2001) defines three zones: recharge (upland), translation (intervening steep slopes), and discharge (lowland), and the hydrologic landscape is useful for standardizing the evaluation of physical properties within any watershed. Singular spectrum analysis was used for a 50-year simulation to determine dominant modes and time scales for the hydrologic landscape units in the Whitewater River Basin. We found that the time scale of groundwater baseflow response increases with increasing drainage density. The sensitivity of this response is important to understand and close the water budget for a river basin through observation network design. The effects of climate forcing, both precipitation and evapotranspiration, can be seen through the hydrologic landscapes and channel networks by changes in the baseflow response time. Los Alamos National Laboratory, an affirmative action/equal opportunity employer, is operated by the University of California for the U.S. Department of Energy under contract W-7405-ENG-36.

System dynamics modeling of nitrogen removal in a stormwater infiltration basin with biosorption-activated media.

PubMed

Xuan, Zhemin; Chang, Ni-Bin; Wanielista, Martin P; Williams, Evan Shane

2013-07-01

Stormwater infiltration basins, one of the typical stormwater best management practices, are commonly constructed for surface water pollution control, flood mitigation, and groundwater restoration in rural or residential areas. These basins have soils with better infiltration capacity than the native soil; however, the ever-increasing contribution of nutrients to groundwater from stormwater due to urban expansion makes existing infiltration basins unable to meet groundwater quality criteria related to environmental sustainability and public health. This issue requires retrofitting current infiltration basins for flood control as well as nutrient control before the stormwater enters the groundwater. An existing stormwater infiltration basin in north-central Florida was selected, retrofitted, and monitored to identify subsurface physiochemical and biological processes during 2007-2010 to investigate nutrient control processes. This implementation in the nexus of contaminant hydrology and ecological engineering adopted amended soil layers packed with biosorption activated media (BAM; tire crumb, silt, clay, and sand) to perform nutrient removal in a partitioned forebay using a berm. This study presents an infiltration basin-nitrogen removal (IBNR) model, a system dynamics model that simulates nitrogen cycling in this BAM-based stormwater infiltration basin with respect to changing hydrologic conditions and varying dissolved nitrogen concentrations. Modeling outputs of IBNR indicate that denitrification is the biogeochemical indicator in the BAM layer that accounted for a loss of about one third of the total dissolved nitrogen mass input. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The effect of modeled recharge distribution on simulated groundwater availability and capture.

PubMed

Tillman, F D; Pool, D R; Leake, S A

2015-01-01

Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins along mountain fronts, by flowing overland to infiltrate along ephemeral channels that often traverse basins in the area, or by some combination of these processes. The importance of accurately simulating recharge distributions is a current topic of discussion among hydrologists and water managers in the region, but no comparative study has been performed to analyze the effects of different recharge distributions on groundwater simulations. This study investigates the importance of the distribution of aquifer recharge in simulating regional groundwater flow in basin-fill aquifers by calibrating a groundwater-flow model to four different recharge distributions, all with the same total amount of recharge. Similarities are seen in results from steady-state models for optimized hydraulic conductivity values, fit of simulated to observed hydraulic heads, and composite scaled sensitivities of conductivity parameter zones. Transient simulations with hypothetical storage properties and pumping rates produce similar capture rates and storage change results, but differences are noted in the rate of drawdown at some well locations owing to the differences in optimized hydraulic conductivity. Depending on whether the purpose of the groundwater model is to simulate changes in groundwater levels or changes in storage and capture, the distribution of aquifer recharge may or may not be of primary importance. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Ground-Water Hydrology of the Upper Deschutes Basin, Oregon

USGS Publications Warehouse

Gannett, Marshall W.; Lite, Kenneth E.; Morgan, David S.; Collins, Charles A.

2001-01-01

The upper Deschutes Basin is among the fastest growing regions in Oregon. The rapid population growth has been accompanied by increased demand for water. Surface streams, however, have been administratively closed to additional appropriation for many years, and surface water is not generally available to support new development. Consequently, ground water is being relied upon to satisfy the growth in water demand. Oregon water law requires that the potential effects of ground-water development on streamflow be evaluated when considering applications for new ground-water rights. Prior to this study, hydrologic understanding has been insufficient to quantitatively evaluate the connection between ground water and streamflow, and the behavior of the regional ground-water flow system in general. This report describes the results of a hydrologic investigation undertaken to provide that understanding. The investigation encompasses about 4,500 square miles of the upper Deschutes River drainage basin.A large proportion of the precipitation in the upper Deschutes Basin falls in the Cascade Range, making it the principal ground-water recharge area for the basin. Water-balance calculations indicate that the average annual rate of ground- water recharge from precipitation is about 3,500 ft3/s (cubic feet per second). Water-budget calculations indicate that in addition to recharge from precipitation, water enters the ground-water system through interbasin flow. Approximately 800 ft3/s flows into the Metolius River drainage from the west and about 50 ft3/s flows into the southeastern part of the study area from the Fort Rock Basin. East of the Cascade Range, there is little or no ground-water recharge from precipitation, but leaking irrigation canals are a significant source of artificial recharge north of Bend. The average annual rate of canal leakage during 1994 was estimated to be about 490 ft3/s. Ground water flows from the Cascade Range through permeable volcanic rocks eastward out into the basin and then generally northward. About one-half the ground water flowing from the Cascade Range discharges to spring-fed streams along the margins of the range, including the upper Metolius River and its tributaries. The remaining ground water flows through the subsurface, primarily through rocks of the Deschutes Formation, and eventually discharges to streams near the confluence of the Deschutes, Crooked, and Metolius Rivers. Substantial ground-water discharge occurs along the lower 2 miles of Squaw Creek, the Deschutes River between Lower Bridge and Pelton Dam, the lower Crooked River between Osborne Canyon and the mouth, and in Lake Billy Chinook (a reservoir that inundates the confluence of the Deschutes, Crooked, and Metolius Rivers).The large amount of ground-water discharge in the confluence area is primarily caused by geologic factors. North (downstream) of the confluence area, the upper Deschutes Basin is transected by a broad region of low-permeability rock of the John Day Formation. The Deschutes River flows north across the low-permeability region, but the permeable Deschutes Formation, through which most of the regional ground water flows, ends against this rampart of low-permeability rock. The northward-flowing ground water discharges to the streams in this area because the permeable strata through which it flows terminate, forcing the water to discharge to the surface. Virtually all of the regional ground water in the upper Deschutes Basin discharges to surface streams south of the area where the Deschutes River enters this low-permeability terrane, at roughly the location of Pelton Dam.The effects of ground-water withdrawal on streamflow cannot presently be measured because of measurement error and the large amount of natural variability in ground-water discharge. The summer streamflow near Madras, which is made up largely of ground-water discharge, is approximately 4,000 ft3/s. Estimated consumptive ground-water use in the basin i

Seasonal estimates of riparian evapotranspiration using remote and in situ measurements

USGS Publications Warehouse

Goodrich, D.C.; Scott, R.; Qi, J.; Goff, B.; Unkrich, C.L.; Moran, M.S.; Williams, D.; Schaeffer, S.; Snyder, K.; MacNish, R.; Maddock, T.; Pool, D.; Chehbouni, A.; Cooper, D.I.; Eichinger, W.E.; Shuttleworth, W.J.; Kerr, Y.; Marsett, R.; Ni, W.

2000-01-01

In many semi-arid basins during extended periods when surface snowmelt or storm runoff is absent, groundwater constitutes the primary water source for human habitation, agriculture and riparian ecosystems. Utilizing regional groundwater models in the management of these water resources requires accurate estimates of basin boundary conditions. A critical groundwater boundary condition that is closely coupled to atmospheric processes and is typically known with little certainty is seasonal riparian evapotranspiration ET). This quantity can often be a significant factor in the basin water balance in semi-arid regions yet is very difficult to estimate over a large area. Better understanding and quantification of seasonal, large-area riparian ET is a primary objective of the Semi-Arid Land-Surface-Atmosphere (SALSA) Program. To address this objective, a series of interdisciplinary experimental Campaigns were conducted in 1997 in the San Pedro Basin in southeastern Arizona. The riparian system in this basin is primarily made up of three vegetation communities: mesquite (Prosopis velutina), sacaton grasses (Sporobolus wrightii), and a cottonwood (Populus fremontii)/willow (Salix goodingii) forest gallery. Micrometeorological measurement techniques were used to estimate ET from the mesquite and grasses. These techniques could not be utilized to estimate fluxes from the cottonwood/willow (C/W) forest gallery due to the height (20-30 m) and non-uniform linear nature of the forest gallery. Short-term (2-4 days) sap flux measurements were made to estimate canopy transpiration over several periods of the riparian growing season. Simultaneous remote sensing measurements were used to spatially extrapolate tree and stand measurements. Scaled C/W stand level sap flux estimates were utilized to calibrate a Penman-Monteith model to enable temporal extrapolation between Synoptic measurement periods. With this model and set of measurements, seasonal riparian vegetation water use estimates for the riparian corridor were obtained. To validate these models, a 90-day pre-monsoon water balance over a 10 km section of the river was carried out. All components of the water balance, including riparian ET, were independently estimated. The closure of the water balance was roughly 5% of total inflows. The ET models were then used to provide riparian ET estimates over the entire corridor for the growing season. These estimates were approximately 14% less than those obtained from the most recent groundwater model of the basin for a comparable river reach.

Depletion of the Complex Multiple Aquifer System of Jordan

NASA Astrophysics Data System (ADS)

Rödiger, T.; Siebert, C.; Geyer, S.; Merz, R.

2017-12-01

In many countries worldwide water scarcity pose a significant risk to the environment and the socio-economy. Particularly in countries where the available water resources are strongly limited by climatic conditions an accurate determination of the available water resources is of high priority, especially when water supply predominantly rely oon groundwater resources and their recharge. If groundwater abstraction exceeds the natural groundwater recharge in heavily used well field areas, overexploitation or persistent groundwater depletion occurs. This is the case in the Kingdom of Jordan, where a multi-layer aquifer complex forms the eastern subsurface catchment of the Dead Sea basin. Since the begin of the industrial and agricultural development of the country, dramatically falling groundwater levels, the disappearance of springs and saltwater intrusions from deeper aquifers is documented nation-wide. The total water budget is influenced by (i) a high climatic gradient from hyperarid to semiarid and (ii) the intnese anthropogenic abstraction. For this multi-layered aquifer system we developed a methodology to evaluate groundwater depletion by linking a hydrological and a numerical flow model including estimates of groundwater abstraction. Hence, we define groundwater depletion as the rate of groundwater abstraction in excess of natural recharge rate. Restricting our analysis, we calculated a range of groundwater depletion from 0% in the eastern Hamad basin to around 40% in the central part of Jordan and to extreme values of 100% of depletion in the Azraq and Disi basin.

Simulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska

USGS Publications Warehouse

Peterson, Steven M.; Stanton, Jennifer S.; Saunders, Amanda T.; Bradley, Jesse R.

2008-01-01

Irrigated agriculture is vital to the livelihood of communities in the Elkhorn and Loup River Basins in Nebraska, and ground water is used to irrigate most of the cropland. Concerns about the sustainability of ground-water and surface-water resources have prompted State and regional agencies to evaluate the cumulative effects of ground-water irrigation in this area. To facilitate understanding of the effects of ground-water irrigation, a numerical computer model was developed to simulate ground-water flow and assess the effects of ground-water irrigation (including ground-water withdrawals, hereinafter referred to as pumpage, and enhanced recharge) on stream base flow. The study area covers approximately 30,800 square miles, and includes the Elkhorn River Basin upstream from Norfolk, Nebraska, and the Loup River Basin upstream from Columbus, Nebraska. The water-table aquifer consists of Quaternary-age sands and gravels and Tertiary-age silts, sands, and gravels. The simulation was constructed using one layer with 2-mile by 2-mile cell size. Simulations were constructed to represent the ground-water system before 1940 and from 1940 through 2005, and to simulate hypothetical conditions from 2006 through 2045 or 2055. The first simulation represents steady-state conditions of the system before anthropogenic effects, and then simulates the effects of early surface-water development activities and recharge of water leaking from canals during 1895 to 1940. The first simulation ends at 1940 because before that time, very little pumpage for irrigation occurred, but after that time it became increasingly commonplace. The pre-1940 simulation was calibrated against measured water levels and estimated long-term base flow, and the 1940 through 2005 simulation was calibrated against measured water-level changes and estimated long-term base flow. The calibrated 1940 through 2005 simulation was used as the basis for analyzing hypothetical scenarios to evaluate the effects of ground-water irrigation on stream base flow for 1940 through 2005 and for 2006 through 2045. Simulated base flows were compared for scenarios that alternately did or did not include a representation of the effects of ground-water irrigation. The difference between simulated base flows for the two scenarios represents the predicted effects of ground-water irrigation on base flow. Comparison of base flows between simulations with ground-water irrigation and no ground-water irrigation indicated that ground-water irrigation has cumulatively reduced streamflows from 1940 through 2005 by 888,000 acre-feet in the Elkhorn River Basin and by 2,273,000 acre-feet in the Loup River Basin. Generally, predicted cumulative effects of ground-water irrigation on base flow were 5 to 10 times larger from 2006 through 2045 than from 1940 through 2005, and were 7,678,000 acre-feet for the Elkhorn River Basin and 14,784,000 acre-feet for the Loup River Basin. The calibrated simulation also was used to estimate base-flow depletion as a percentage of pumping volumes for a 50-year future time period, because base-flow depletion percentages are used to guide the placement of management boundaries in Nebraska. Mapped results of the base-flow depletion analysis conducted for most of the interior of the study area indicated that pumpage of one additional theoretical well simulated for a future 50-year period generally would result in more than 80 percent depletion when it was located close to the stream, except in areas where depletion was partly offset by reduced ground-water discharge to evapotranspiration in wetland areas. In many areas, depletion for the 50-year future period composed greater than 10 percent of the pumped water volume for theoretical wells placed less than 7 or 8 miles from the stream, though considerable variations existed because of the heterogeneity of the natural system represented in the simulation. For a few streams, predicted future simulated base flows dec

Hydrochemical evolution and groundwater flow processes in the Galilee and Eromanga basins, Great Artesian Basin, Australia: a multivariate statistical approach.

PubMed

Moya, Claudio E; Raiber, Matthias; Taulis, Mauricio; Cox, Malcolm E

2015-03-01

The Galilee and Eromanga basins are sub-basins of the Great Artesian Basin (GAB). In this study, a multivariate statistical approach (hierarchical cluster analysis, principal component analysis and factor analysis) is carried out to identify hydrochemical patterns and assess the processes that control hydrochemical evolution within key aquifers of the GAB in these basins. The results of the hydrochemical assessment are integrated into a 3D geological model (previously developed) to support the analysis of spatial patterns of hydrochemistry, and to identify the hydrochemical and hydrological processes that control hydrochemical variability. In this area of the GAB, the hydrochemical evolution of groundwater is dominated by evapotranspiration near the recharge area resulting in a dominance of the Na-Cl water types. This is shown conceptually using two selected cross-sections which represent discrete groundwater flow paths from the recharge areas to the deeper parts of the basins. With increasing distance from the recharge area, a shift towards a dominance of carbonate (e.g. Na-HCO3 water type) has been observed. The assessment of hydrochemical changes along groundwater flow paths highlights how aquifers are separated in some areas, and how mixing between groundwater from different aquifers occurs elsewhere controlled by geological structures, including between GAB aquifers and coal bearing strata of the Galilee Basin. The results of this study suggest that distinct hydrochemical differences can be observed within the previously defined Early Cretaceous-Jurassic aquifer sequence of the GAB. A revision of the two previously recognised hydrochemical sequences is being proposed, resulting in three hydrochemical sequences based on systematic differences in hydrochemistry, salinity and dominant hydrochemical processes. The integrated approach presented in this study which combines different complementary multivariate statistical techniques with a detailed assessment of the geological framework of these sedimentary basins, can be adopted in other complex multi-aquifer systems to assess hydrochemical evolution and its geological controls. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of nearshore recharge on groundwater interactions with a lake in mantled karst terrain

USGS Publications Warehouse

Lee, Terrie M.

2000-01-01

The recharge and discharge of groundwater were investigated for a lake basin in the mantled karst terrain of central Florida to determine the relative importance of transient groundwater inflow to the lake water budget. Variably saturated groundwater flow modeling simulated water table responses observed beneath two hillsides radiating outward from the groundwater flow‐through lake. Modeling results indicated that transient water table mounding and groundwater flow reversals in the nearshore region following large daily rainfall events generated most of the net groundwater inflow to the lake. Simulated daily groundwater inflow was greatest following water table mounding near the lake, not following subsequent peaks in the water level of upper basin wells. Transient mounding generated net groundwater inflow to the lake, that is, groundwater inflow in excess of the outflow occurring through the deeper lake bottom. The timing of the modeled net groundwater inflow agreed with an independent lake water budget; however, the quantity was considerably less than the budget‐derived value.

Spatial and temporal connections in groundwater contribution to evaporation

NASA Astrophysics Data System (ADS)

Lam, A.; Karssenberg, D.; van den Hurk, B. J. J. M.; Bierkens, M. F. P.

2011-02-01

In climate models, lateral terrestrial water fluxes are usually neglected. We estimated the contribution of vertical and lateral groundwater fluxes to the land surface water budget at a subcontinental scale, by modelling convergence of groundwater and surfacewater fluxes. We present a hydrological model of the entire Danube Basin at 5 km resolution, and use it to show the importance of groundwater for the surface climate. The contribution of groundwater to evaporation is significant, and can be upwards of 30% in summer. We show that this contribution is local by presenting the groundwater travel times and the magnitude of groundwater convergence. Throughout the Danube Basin the lateral fluxes of groundwater are negligible when modelling at this scale and resolution. Also, it is shown that the contribution of groundwater to evaporation has important temporal characteristics. An experiment with the same model shows that a wet episode influences groundwaters contribution to summer evaporation for several years afterwards. This indicates that modelling groundwater flow has the potential to augment the multi-year memory of climate models.

Hydrology of the coastal springs ground-water basin and adjacent parts of Pasco, Hernando, and Citrus Counties, Florida

USGS Publications Warehouse

Knochenmus, Lari A.; Yobbi, Dann K.

2001-01-01

The coastal springs in Pasco, Hernando, and Citrus Counties, Florida consist of three first-order magnitude springs and numerous smaller springs, which are points of substantial ground-water discharge from the Upper Floridan aquifer. Spring flow is proportional to the water-level altitude in the aquifer and is affected primarily by the magnitude and timing of rainfall. Ground-water levels in 206 Upper Floridan aquifer wells, and surface-water stage, flow, and specific conductance of water from springs at 10 gaging stations were measured to define the hydrologic variability (temporally and spatially) in the Coastal Springs Ground-Water Basin and adjacent parts of Pasco, Hernando, and Citrus Counties. Rainfall at 46 stations and ground-water withdrawals for three counties, were used to calculate water budgets, to evaluate long-term changes in hydrologic conditions, and to evaluate relations among the hydrologic components. Predictive equations to estimate daily spring flow were developed for eight gaging stations using regression techniques. Regression techniques included ordinary least squares and multiple linear regression techniques. The predictive equations indicate that ground-water levels in the Upper Floridan aquifer are directly related to spring flow. At tidally affected gaging stations, spring flow is inversely related to spring-pool altitude. The springs have similar seasonal flow patterns throughout the area. Water-budget analysis provided insight into the relative importance of the hydrologic components expected to influence spring flow. Four water budgets were constructed for small ground-water basins that form the Coastal Springs Ground-Water Basin. Rainfall averaged 55 inches per year and was the only source of inflow to the Basin. The pathways for outflow were evapotranspiration (34 inches per year), runoff by spring flow (8 inches per year), ground-water outflow from upward leakage (11 inches per year), and ground-water withdrawal (2 inches per year). Recharge (rainfall minus evapotranspiration) to the Upper Floridan aquifer consists of vertical leakage through the surficial deposits. Discharge is primarily through springs and diffuse upward leakage that maintains the extensive swamps along the Gulf of Mexico. The ground-water basins had slightly different partitioning of hydrologic components, reflecting variation among the regions. Trends in hydrologic data were identified using nonparametric statistical techniques to infer long-term changes in hydrologic conditions, and yielded mixed results. No trend in rainfall was detected during the past century. No trend in spring flow was detected in 1931-98. Although monotonic trends were not detected, rainfall patterns are naturally variable from month to month and year to year; this variability is reflected in ground-water levels and spring flows. A decreasing trend in ground-water levels was detected in the Weeki Wachee well (1966-98), but the trend was statistically weak. At current ground-water withdrawal rates, there is no discernible affect on ground-water levels and spring flows. Sporadic data records, lack of continuous data, and inconsistent periods of record among the hydrologic components impeded analysis of long-term changes to the hydrologic system and interrelations among components. The ongoing collection of hydrologic data from index sites could provide much needed information to assess the hydrologic factors affecting the quantity and quality of spring flow in the Coastal Springs Ground-Water Basin.

Geochemical Evolution of Groundwater in the Medicine Lodge Creek Drainage Basin with Implications for the Eastern Snake River Plain Aquifer, Eastern Idaho

NASA Astrophysics Data System (ADS)

Ginsbach, M. L.; Rattray, G. W.; McCurry, M. O.; Welhan, J. A.

2012-12-01

The eastern Snake River Plain aquifer (ESRPA) is an unconfined, continuous aquifer located in a northeast-trending structural basin filled with basaltic lava flows and sedimentary interbeds in eastern Idaho. The ESPRA is not an inert transport system, as it acts as both a sink and source for solutes found in the water. More than 90% of the water recharged naturally to the ESRPA is from the surrounding mountain drainage basins. Consequently, in order to understand the natural geochemistry of water within the ESRPA, the chemistry of the groundwater from the mountain drainage basins must be characterized and the processes that control the chemistry need to be understood. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy and Idaho State University, has been studying these mountain drainage basins to help understand the movement of waste solutes in the ESRPA at the Idaho National Laboratory (INL) in eastern Idaho. This study focuses on the Medicine Lodge Creek drainage basin, which originates in the Beaverhead Mountains, extends onto the eastern Snake River Plain, and contributes recharge to the ESRPA beneath the INL as underflow along the northeastern INL boundary. Water and rock samples taken from the Medicine Lodge Creek drainage basin were analyzed to better understand water/rock interactions occurring in this system and to define the groundwater geochemistry of this drainage basin. Water samples were collected at 10 locations in the drainage basin during June 2012: 6 groundwater wells used for agricultural irrigation or domestic use and 4 springs. These water samples were analyzed for major ions, nutrients, trace metals, isotopes, and dissolved gasses. Samples of rock representative of the basalt, rhyolite, and sediments that occur within the drainage basin also were collected. These samples were analyzed using x-ray diffraction and petrographic study to determine the mineralogical constituents of the rock and the presence and composition of alteration products. The lithologic variability in this area leads to differing water-rock interactions occurring in different parts of the drainage basin. Anthropogenic influences also affect the water; at the far downgradient end of the drainage basin, increased levels of chloride and sulfate in the groundwater suggest an increased influence of irrigation recharge. Results from both water and rock analyses are combined in geochemical modeling software to determine plausible reactions that occur in groundwater collected at the sampling sites.

Geohydrology of Big Bear Valley, California: phase 1--geologic framework, recharge, and preliminary assessment of the source and age of groundwater

USGS Publications Warehouse

Flint, Lorraine E.; Brandt, Justin; Christensen, Allen H.; Flint, Alan L.; Hevesi, Joseph A.; Jachens, Robert; Kulongoski, Justin T.; Martin, Peter; Sneed, Michelle

2012-01-01

The Big Bear Valley, located in the San Bernardino Mountains of southern California, has increased in population in recent years. Most of the water supply for the area is pumped from the alluvial deposits that form the Big Bear Valley groundwater basin. This study was conducted to better understand the thickness and structure of the groundwater basin in order to estimate the quantity and distribution of natural recharge to Big Bear Valley. A gravity survey was used to estimate the thickness of the alluvial deposits that form the Big Bear Valley groundwater basin. This determined that the alluvial deposits reach a maximum thickness of 1,500 to 2,000 feet beneath the center of Big Bear Lake and the area between Big Bear and Baldwin Lakes, and decrease to less than 500 feet thick beneath the eastern end of Big Bear Lake. Interferometric Synthetic Aperture Radar (InSAR) was used to measure pumping-induced land subsidence and to locate structures, such as faults, that could affect groundwater movement. The measurements indicated small amounts of land deformation (uplift and subsidence) in the area between Big Bear Lake and Baldwin Lake, the area near the city of Big Bear Lake, and the area near Sugarloaf, California. Both the gravity and InSAR measurements indicated the possible presence of subsurface faults in subbasins between Big Bear and Baldwin Lakes, but additional data are required for confirmation. The distribution and quantity of groundwater recharge in the area were evaluated by using a regional water-balance model (Basin Characterization Model, or BCM) and a daily rainfall-runoff model (INFILv3). The BCM calculated spatially distributed potential recharge in the study area of approximately 12,700 acre-feet per year (acre-ft/yr) of potential in-place recharge and 30,800 acre-ft/yr of potential runoff. Using the assumption that only 10 percent of the runoff becomes recharge, this approach indicated there is approximately 15,800 acre-ft/yr of total recharge in Big Bear Valley. The INFILv3 model was modified for this study to include a perched zone beneath the root zone to better simulate lateral seepage and recharge in the shallow subsurface in mountainous terrain. The climate input used in the INFILv3 model was developed by using daily climate data from 84 National Climatic Data Center stations and published Parameter Regression on Independent Slopes Model (PRISM) average monthly precipitation maps to match the drier average monthly precipitation measured in the Baldwin Lake drainage basin. This model resulted in a good representation of localized rain-shadow effects and calibrated well to measured lake volumes at Big Bear and Baldwin Lakes. The simulated average annual recharge was about 5,480 acre-ft/yr in the Big Bear study area, with about 2,800 acre-ft/yr in the Big Bear Lake surface-water drainage basin and about 2,680 acre-ft/yr in the Baldwin Lake surface-water drainage basin. One spring and eight wells were sampled and analyzed for chemical and isotopic data in 2005 and 2006 to determine if isotopic techniques could be used to assess the sources and ages of groundwater in the Big Bear Valley. This approach showed that the predominant source of recharge to the Big Bear Valley is winter precipitation falling on the surrounding mountains. The tritium and uncorrected carbon-14 ages of samples collected from wells for this study indicated that the groundwater basin contains water of different ages, ranging from modern to about 17,200-years old.The results of these investigations provide an understanding of the lateral and vertical extent of the groundwater basin, the spatial distribution of groundwater recharge, the processes responsible for the recharge, and the source and age of groundwater in the groundwater basin. Although the studies do not provide an understanding of the detailed water-bearing properties necessary to determine the groundwater availability of the basin, they do provide a framework for the future development of a groundwater model that would help to improve the understanding of the potential hydrologic effects of water-management alternatives in Big Bear Valley.

Geochemical conditions and the occurrence of selected trace elements in groundwater basins used for public drinking-water supply, Desert and Basin and Range hydrogeologic provinces, 2006-11: California GAMA Priority Basin Project

USGS Publications Warehouse

Wright, Michael T.; Fram, Miranda S.; Belitz, Kenneth

2015-01-01

Concentrations of strontium, which exists primarily in a cationic form (Sr2+), were not significantly correlated with either groundwater age or pH. Strontium concentrations showed a strong positive correlation with total dissolved solids (TDS). Dissolved constituents, such as Sr, that interact with mineral surfaces through outer-sphere complexation become increasingly soluble with increasing TDS concentrations of groundwater. Boron concentrations also showed a significant positive correlation with TDS, indicating the B may interact to a large degree with mineral surfaces through outer-sphere complexation.

Effects of anthropogenic groundwater exploitation on land surface processes: A case study of the Haihe River Basin, Northern China

NASA Astrophysics Data System (ADS)

Xie, Z.; Zou, J.; Qin, P.; Sun, Q.

2014-12-01

In this study, we incorporated a groundwater exploitation scheme into the land surface model CLM3.5 to investigate the effects of the anthropogenic exploitation of groundwater on land surface processes in a river basin. Simulations of the Haihe River Basin in northern China were conducted for the years 1965-2000 using the model. A control simulation without exploitation and three exploitation simulations with different water demands derived from socioeconomic data related to the Basin were conducted. The results showed that groundwater exploitation for human activities resulted in increased wetting and cooling effects at the land surface and reduced groundwater storage. A lowering of the groundwater table, increased upper soil moisture, reduced 2 m air temperature, and enhanced latent heat flux were detected by the end of the simulated period, and the changes at the land surface were related linearly to the water demands. To determine the possible responses of the land surface processes in extreme cases (i.e., in which the exploitation process either continued or ceased), additional hypothetical simulations for the coming 200 years with constant climate forcing were conducted, regardless of changes in climate. The simulations revealed that the local groundwater storage on the plains could not contend with high-intensity exploitation for long if the exploitation process continues at the current rate. Changes attributable to groundwater exploitation reached extreme values and then weakened within decades with the depletion of groundwater resources and the exploitation process will therefore cease. However, if exploitation is stopped completely to allow groundwater to recover, drying and warming effects, such as increased temperature, reduced soil moisture, and reduced total runoff, would occur in the Basin within the early decades of the simulation period. The effects of exploitation will then gradually disappear, and the land surface variables will approach the natural state and stabilize at different rates. Simulations were also conducted for cases in which exploitation either continues or ceases using future climate scenario outputs from a general circulation model. The resulting trends were almost the same as those of the simulations with constant climate forcing.

Aspects of choosing appropriate concepts for modelling groundwater resources in regional integrated water resources management Examples from the Neckar (Germany) and Ouémé catchment (Benin)

NASA Astrophysics Data System (ADS)

Barthel, R.; Jagelke, J.; Götzinger, J.; Gaiser, T.; Printz, Andreas

Two regional groundwater flow models (Neckar catchment, Germany, 14,000 km 2, and Southern Ouémé Basin, Benin, 11,000 km 2) were developed within the framework of the integrated management project ‘RIVERTWIN’ ( www.rivertwin.org). Both models were evaluated with respect to the question if the chosen modelling approaches (multi-layered finite difference numerical flow modelling, steady state and transient) are appropriate in view of the existing management problems in the catchments, the data availability and the hydrogeological and hydrological conditions in the basins. It is shown that neither the model in the well-investigated, data-rich basin in Western Europe with its highly developed water related infrastructure, nor the model in the hydrogeologically less well-known and less developed basin in Western Africa provide results that are fully applicable to the main regional management tasks. In the case of the Ouémé, the groundwater related problems are foremost of local character and therefore cannot be addressed by regional models in a meaningful way. Data scarcity and complex, unfavourable geological conditions (crystalline rocks, discontinuous aquifers) support the conclusion that numerical 3D groundwater flow models are currently not helpful to manage groundwater related management problems in the Ouémé basin. A better understanding of regional hydrological surface and subsurface processes is required first. Methods for a reliable estimation of groundwater recharge and subsequently groundwater availability were identified as the most urgently needed tool for meaningful groundwater management in view of climatic, demographic and land use change. In the Neckar catchment the results of the analysis are less pronounced; here regional groundwater problems could clearly benefit from a physically based 3D model since the hydrogeological system is strictly stratified with several important aquifers in the vertical sequence. As a general conclusion it can be stated that regional scale groundwater flow modelling concepts seem to be difficult to integrate in management systems and difficult to transfer from one basin to another. This means the question of how to represent the groundwater resources appropriately has to be discussed very thoroughly for any new integrated water resources management problem. It is not possible to give a final recommendation on which modelling concept is the most appropriate one in regional integrated modelling and management. Hence, this article is only intended to provide an in depth discussion of the aspects that need to be considered in the process of choosing appropriate modelling concepts.

Land subsidence and earth fissures in south-central and southern Arizona, USA

NASA Astrophysics Data System (ADS)

Conway, Brian D.

2016-05-01

Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth fissure attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth fissuring. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005-2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth fissures. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR's InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal.

Generalized hydrogeology and ground-water budget for the C Aquifer, Little Colorado River Basin and parts of the Verde and Salt River Basins, Arizona and New Mexico

USGS Publications Warehouse

Hart, Robert J.; Ward, John J.; Bills, Donald J.; Flynn, Marilyn E.

2002-01-01

The C aquifer underlies the Little Colorado River Basin and parts of the Verde and Salt River Basins and is named for the primary water-bearing rock unit of the aquifer, the Coconino Sandstone. The areal extent of this aquifer is more than 27,000 square miles. More than 1,000 well and spring sites were identified in the U.S. Geological Survey database for the C aquifer in Arizona and New Mexico. The C aquifer is the most productive aquifer in the Little Colorado River Basin. The Little Colorado River is the primary surface-water feature in the area, and it has a direct hydraulic connection with the C aquifer in some areas. Spring discharge as base flow from the C aquifer occurs predominantly in the lower 13 miles of the Little Colorado River subsequent to downward leakage into the deeper Redwall-Muav Limestone aquifer. Ground-water mounds or divides exist along the southern and northeastern boundaries of the Little Colorado River Basin. The ground-water divides are significant boundaries of the C aquifer; however, the location and persistence of the divides potentially can be affected by ground-water withdrawals. Ground-water development in the C aquifer has increased steadily since the 1940s because population growth has produced an increased need for agricultural, industrial, and public water supply. Ground-water pumpage from the C aquifer during 1995 was about 140,000 acre-feet. Ground-water budget components for the C aquifer were evaluated using measured or estimated discharge values. The system was assumed to be in a steady-state condition with respect to natural recharge and discharge, and the stability of discharge from major springs during the past several decades supported the steady-state assumption. Downward leakage to the Redwall-Muav Limestone aquifer is a major discharge component for the ground-water budget. Discharge from the C aquifer is estimated to be 319,000 acre-feet per year.

Groundwater seepage controls salinity in a hydrologically terminal basin of semi-arid northwest Australia

NASA Astrophysics Data System (ADS)

Skrzypek, Grzegorz; Dogramaci, Shawan; Rouillard, Alexandra; Grierson, Pauline F.

2016-11-01

Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (∼1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of <0.0001 and a small 'alluvial outlet' of 0.35 km2 because of relatively high bedrock elevation. However, FM groundwater salinity is far below saturation with respect to halite (TDS < 160 g/L), episodic flood water is fresh to brackish, and salt efflorescences are very sparse and evident only when the FM is dry. We show that if the FM was 100% "leakage free" i.e., a true terminal basin, groundwater would have achieved halite saturation (>300 g/L) after ∼45 ka. We calculated that only a very small seepage of ∼2G L/yr (∼0.03% of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ∼60 to ∼165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.

Water-quality conditions and an evaluation of ground- and surface-water sampling programs in the Livermore-Amador Valley, California

USGS Publications Warehouse

Sorenson, S.K.; Cascos, P.V.; Glass, R.L.

1984-01-01

A program to monitor the ground- and surface water quality in the Livermore-Amador Valley has been operated since 1976. As of 1982, this monitoring network consisted of approximately 130 wells, about 100 of which were constructed specifically for this program, and 9 surface water stations. Increased demand on the groundwater for municipal and industrial water supply in the past has caused a decline in water levels and a gradual buildup of salts from natural surface-water recharge and land disposal of treated wastewater from waste treatment plants. Results of this study identify the salt buildup to be the major problem with the groundwater quality. Established water quality objectives for dissolved solids are exceeded in 52 of 130 wells. Concentrations of dissolved nitrate are also in excess of basin objectives and health standards. Water quality in both surface and groundwater is highly variable areally. Magnesium to calcium magnesium bicarbonate groundwater are found in the areas where most of the high volume municipal wells are located. Large areas of sodium bicarbonate water occur in the northern part of the valley. Except for two stations on Arroyo Las Positas which has sodium chloride water, surface water is mixed-cation bicarbonate water. (USGS)

Inventory of ground-water resources in the Kabul Basin, Afghanistan

USGS Publications Warehouse

Broshears, Robert E.; Akbari, M. Amin; Chornack, Michael P.; Mueller, David K.; Ruddy, Barbara C.

2005-01-01

In 2004, the U.S. Geological Survey began working with engineers at the Afghanistan Geological Survey to provide hydrologic training and equipment and to apply these tools to build an inventory of water wells in the Kabul Basin of Afghanistan. An inventory of 148 wells now includes information on well location, depth, and access. Water-level and water-quality measurements have been made at most of these wells. A water-level elevation map has been constructed, and general directions of ground-water flow have been defined. Ground-water flow in the Kabul Basin is primarily through saturated alluvium and other basin-fill sediments. The water-table surface generally mirrors topography, and ground water generally flows in the directions of surface-water discharge. The quality of ground water in the Kabul Basin varies widely. In some areas, ground-water quality is excellent, with low concentrations of dissolved solids and no problematic constituents. In other areas, however, high concentrations of dissolved solids and the presence of some constituents at concentrations deemed harmful to humans and crops render untreated ground water marginal or unsuitable for public supply and/or agricultural use. Of particular concern are elevated concentrations of nitrate, boron, and dissolved solids, and an indication of fecal pollution in some parts of the basin. As Afghanistan emerges from years of conflict, as institutional capacities rejuvenate and grow, and as the need for wise water-management decisions continues, adequate data and a fuller understanding of the ground-water resource in the Kabul Basin will be imperative. The work described in this report represents only a modest beginning in what will be a long-term data-collection and interpretive effort.

Regional groundwater-flow model of the Redwall-Muav, Coconino, and alluvial basin aquifer systems of northern and central Arizona

USGS Publications Warehouse

Pool, D.R.; Blasch, Kyle W.; Callegary, James B.; Leake, Stanley A.; Graser, Leslie F.

2011-01-01

A numerical flow model (MODFLOW) of the groundwater flow system in the primary aquifers in northern Arizona was developed to simulate interactions between the aquifers, perennial streams, and springs for predevelopment and transient conditions during 1910 through 2005. Simulated aquifers include the Redwall-Muav, Coconino, and basin-fill aquifers. Perennial stream reaches and springs that derive base flow from the aquifers were simulated, including the Colorado River, Little Colorado River, Salt River, Verde River, and perennial reaches of tributary streams. Simulated major springs include Blue Spring, Del Rio Springs, Havasu Springs, Verde River headwater springs, several springs that discharge adjacent to major Verde River tributaries, and many springs that discharge to the Colorado River. Estimates of aquifer hydraulic properties and groundwater budgets were developed from published reports and groundwater-flow models. Spatial extents of aquifers and confining units were developed from geologic data, geophysical models, a groundwater-flow model for the Prescott Active Management Area, drill logs, geologic logs, and geophysical logs. Spatial and temporal distributions of natural recharge were developed by using a water-balance model that estimates recharge from direct infiltration. Additional natural recharge from ephemeral channel infiltration was simulated in alluvial basins. Recharge at wastewater treatment facilities and incidental recharge at agricultural fields and golf courses were also simulated. Estimates of predevelopment rates of groundwater discharge to streams, springs, and evapotranspiration by phreatophytes were derived from previous reports and on the basis of streamflow records at gages. Annual estimates of groundwater withdrawals for agriculture, municipal, industrial, and domestic uses were developed from several sources, including reported withdrawals for nonexempt wells, estimated crop requirements for agricultural wells, and estimated per capita water use for exempt wells. Accuracy of the simulated groundwater-flow system was evaluated by using observational control from water levels in wells, estimates of base flow from streamflow records, and estimates of spring discharge. Major results from the simulations include the importance of variations in recharge rates throughout the study area and recharge along ephemeral and losing stream reaches in alluvial basins. Insights about the groundwater-flow systems in individual basins include the hydrologic influence of geologic structures in some areas and that stream-aquifer interactions along the lower part of the Little Colorado River are an effective control on water level distributions throughout the Little Colorado River Plateau basin. Better information on several aspects of the groundwater flow system are needed to reduce uncertainty of the simulated system. Many areas lack documentation of the response of the groundwater system to changes in withdrawals and recharge. Data needed to define groundwater flow between vertically adjacent water-bearing units is lacking in many areas. Distributions of recharge along losing stream reaches are poorly defined. Extents of aquifers and alluvial lithologies are poorly defined in parts of the Big Chino and Verde Valley sub-basins. Aquifer storage properties are poorly defined throughout most of the study area. Little data exist to define the hydrologic importance of geologic structures such as faults and fractures. Discharge of regional groundwater flow to the Verde River is difficult to identify in the Verde Valley sub-basin because of unknown contributions from deep percolation of excess surface water irrigation.

Hydrogeologic framework and estimates of groundwater storage for the Hualapai Valley, Detrital Valley, and Sacramento Valley basins, Mohave County, Arizona

USGS Publications Warehouse

Truini, Margot; Beard, L. Sue; Kennedy, Jeffrey; Anning, Dave W.

2013-01-01

We have investigated the hydrogeology of the Hualapai Valley, Detrital Valley, and Sacramento Valley basins of Mohave County in northwestern Arizona to develop a better understanding of groundwater storage within the basin fill aquifers. In our investigation we used geologic maps, well-log data, and geophysical surveys to delineate the sedimentary textures and lithology of the basin fill. We used gravity data to construct a basin geometry model that defines smaller subbasins within the larger basins, and airborne transient-electromagnetic modeled results along with well-log lithology data to infer the subsurface distribution of basin fill within the subbasins. Hydrogeologic units (HGUs) are delineated within the subbasins on the basis of the inferred lithology of saturated basin fill. We used the extent and size of HGUs to estimate groundwater storage to depths of 400 meters (m) below land surface (bls). The basin geometry model for the Hualapai Valley basin consists of three subbasins: the Kingman, Hualapai, and southern Gregg subbasins. In the Kingman subbasin, which is estimated to be 1,200 m deep, saturated basin fill consists of a mixture of fine- to coarse-grained sedimentary deposits. The Hualapai subbasin, which is the largest of the subbasins, contains a thick halite body from about 400 m to about 4,300 m bls. Saturated basin fill overlying the salt body consists predominately of fine-grained older playa deposits. In the southern Gregg subbasin, which is estimated to be 1,400 m deep, saturated basin fill is interpreted to consist primarily of fine- to coarse-grained sedimentary deposits. Groundwater storage to 400 m bls in the Hualapai Valley basin is estimated to be 14.1 cubic kilometers (km3). The basin geometry model for the Detrital Valley basin consists of three subbasins: northern Detrital, central Detrital, and southern Detrital subbasins. The northern and central Detrital subbasins are characterized by a predominance of playa evaporite and fine-grained clastic deposits; evaporite deposits in the northern Detrital subbasin include halite. The northern Detrital subbasin is estimated to be 600 m deep and the middle Detrital subbasin is estimated to be 700 m deep. The southern Detrital subbasin, which is estimated to be 1,500 m deep, is characterized by a mixture of fine- to coarse-grained basin fill deposits. Groundwater storage to 400 m bls in the Detrital Valley basin is estimated to be 9.8 km3. The basin geometry model for the Sacramento Valley basin consists of three subbasins: the Chloride, Golden Valley, and Dutch Flat subbasins. The Chloride subbasin, which is estimated to be 900 m deep, is characterized by fine- to coarse-grained basin fill deposits. In the Golden Valley subbasin, which is elongated north-south, and is estimated to be 1,300 m deep, basin fill includes fine-grained sedimentary deposits overlain by coarse-grained sedimentary deposits in much of the subbasin. The Dutch Flat subbasin is estimated to be 2,600 m deep, and well-log lithologic data suggest that the basin fill consists of interlayers of gravel, sand, and clay. Groundwater storage to 400 m bls in the Sacramento Valley basin is estimated to be 35.1 km3.

Estimating discharge of shallow groundwater by transpiration from greasewood in the Northern Great Basin

USGS Publications Warehouse

Nichols, William D.

1993-01-01

Evapotranspiration from bare soil and phreatophytes is a principal mechanism of groundwater discharge in arid and semiarid regions of the midwestern and western United States including the Great Basin. The imbalance between independent estimates of groundwater recharge from precipitation and of groundwater discharge based on estimates of groundwater evapotranspiration leads to large uncertainties in groundwater budgets. Few studies have addressed this problem. Energy budget micrometeorological field studies were conducted in a stand of sparse-canopy greasewood growing in an area of shallow groundwater in the western Great Basin during the summer of 1989. The data were used to calculate above-canopy fluxes of sensible and latent heat using the energy budget-Bowen ratio method. The calculated energy budget fluxes were used, with soil surface and plant canopy temperature measurements, to calibrate and apply a two-component, energy-combination model that partitions the energy and heat fluxes between bare soil and the canopy. This permitted the separation of evaporation from the soil and transpiration from greasewood. The calibrated model was used to estimate daily transpiration of groundwater by greasewood growing in an area with a depth to water of about 2 m. The daily rate of groundwater discharge by transpiration during July and August was estimated to be 2.4 mm. A period of 100 days for groundwater discharge at this rate was assumed to estimate an annual discharge of groundwater of 24 cm at the study site.

Water resources data, Idaho, 2004; Volume 2. Surface water records for Upper Columbia River basin and Great Basin below King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2005-01-01

Water resources data for the 2004 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 209 stream-gaging stations and 8 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 39 stream-gaging stations and partial record sites, 3 lakes sites, and 395 groundwater wells; and water levels for 425 observation network wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Water resources data, Idaho, 2003; Volume 2. Surface water records for Upper Columbia River basin and Great Basin below King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2004-01-01

Water resources data for the 2003 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 208 stream-gaging stations and 14 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 50 stream-gaging stations and partial record sites, 3 lakes sites, and 398 groundwater wells; and water levels for 427 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Water resources data, Idaho, 2003; Volume 1. Surface water records for Great Basin and Snake River basin above King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2004-01-01

Water resources data for the 2003 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 208 stream-gaging stations and 14 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 50 stream-gaging stations and partial record sites, 3 lakes sites, and 398 groundwater wells; and water levels for 427 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Water resources data, Idaho, 2004; Volume 1. Surface water records for Great Basin and Snake River basin above King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2005-01-01

Water resources data for the 2004 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 209 stream-gaging stations and 8 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 39 stream-gaging stations and partial record sites, 3 lakes sites, and 395 groundwater wells; and water levels for 425 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Contrasting distributions of groundwater arsenic and uranium in the western Hetao basin, Inner Mongolia: Implication for origins and fate controls

USGS Publications Warehouse

Guo, Huaming; Jia, Yongfeng; Wanty, Richard B.; Jiang, Yuxiao; Zhao, Weiguang; Xiu, Wei; Shen, Jiaxing; Li, Yuan; Cao, Yongsheng; Wu, Yang; Zhang, Di; Wei, Chao; Zhang, Yilong; Cao, Wengeng; Foster, Andrea L.

2016-01-01

Although As concentrations have been investigated in shallow groundwater from the Hetao basin, China, less is known about U and As distributions in deep groundwater, which would help to better understand their origins and fate controls. Two hundred and ninety-nine groundwater samples, 122 sediment samples, and 14 rock samples were taken from the northwest portion of the Hetao basin, and analyzed for geochemical parameters. Results showed contrasting distributions of groundwater U and As, with high U and low As concentrations in the alluvial fans along the basin margins, and low U and high As concentrations downgradient in the flat plain. The probable sources of both As and U in groundwater were ultimately traced to the bedrocks in the local mountains (the Langshan Mountains). Chemical weathering of U-bearing rocks (schist, phyllite, and carbonate veins) released and mobilized U as UO2(CO3)22 − and UO2(CO3)34 − species in the alluvial fans under oxic conditions and suboxic conditions where reductions of Mn and NO3− were favorable (OSO), resulting in high groundwater U concentrations. Conversely, the recent weathering of As-bearing rocks (schist, phyllite, and sulfides) led to the formation of As-bearing Fe(III) (hydr)oxides in sediments, resulting in low groundwater As concentrations. Arsenic mobilization and U immobilization occurred in suboxic conditions where reduction of Fe(III) oxides was favorable and reducing conditions (SOR). Reduction of As-bearing Fe(III) (hydr)oxides, which were formed during palaeo-weathering and transported and deposited as Quaternary aquifer sediments, was believed to release As into groundwater. Reduction of U(VI) to U(IV) would lead to the formation of uraninite, and therefore remove U from groundwater. We conclude that the contrasting distributions of groundwater As and U present a challenge to ensuring safe drinking water in analogous areas, especially with high background values of U and As.

Combining numerical modeling and stable isotope values to quantify groundwater recharge from the Chilean Andes to the Pampa del Tamarugal Basin, Atacama Desert, northern Chile

NASA Astrophysics Data System (ADS)

Dodd, J. P.; Pollyea, R.

2014-12-01

The Atacama Desert of northern Chile is one of the driest regions on Earth and receives less than 5mm of precipitation annually. The Pampa del Tamarugal (PdT) Basin contains the largest aquifer system in the region, yet the mechanisms and timing of aquifer recharge and continental-scale groundwater flux are poorly understood. Although there is little debate that the source of groundwater recharge is the higher elevation regions of the Andean Altiplano to the east of the PdT Basin, there remains much uncertainty surrounding the mechanisms and timing of aquifer recharge and continental-scale groundwater flux. Most recharge models of the PdT focus on surface water runoff and alluvial fan recharge on shorter time scales, but many of these models explicitly neglect deep flow pathways. Previous investigators have combined the thermal aquifer profile and 14C groundwater ages to propose an alternative conceptual model in which cold meteoric water infiltrates deep into the Cordillera before circulating upward into the PdT by thermal convection through fault-controlled migration pathways. Although this conceptual model provides a convincing theoretical argument for deep fluid circulation, it cannot constrain the magnitude of this deep recharge flux. In this work, we revisit deep-flow conceptual model by combining the spatial distribution of hydrogen and oxygen isotope values as groundwater tracers with a non-isothermal model of continental scale groundwater flow through a two-dimensional transect from the Chilean Andes to the PdT Basin. This work provides first-order estimates on the contribution of deep groundwater circulation within the PdT Aquifer, while providing a framework for (1) quantifying boundary conditions for high resolution models of groundwater resources within the PdT Aquifer, (2) assessing the influence of variable future climate scenarios for groundwater availability in the region, and (3) further integrating conservative tracers and numerical models for groundwater resource evaluation in hyperarid environments.

Spatial analysis of groundwater electrical conductivity using ordinary kriging and artificial intelligence methods (Case study: Maharlu-Bakhtegan and Tashk salt lakes basin, Iran)

NASA Astrophysics Data System (ADS)

Ghader, Fatemeh; Aljoumani, Basem; Tröger, Uwe

2017-04-01

The main resources of fresh water are the groundwater. In Iran, the quality and quantity of groundwater is affected significantly by rapid population growth and unsustainable water management in the agricultural and industrial sectors. in Maharlu-Bakhtegan and Tashk salt lakes basin, the overexploitation of groundwater for irrigation purpose caused the salt water intrusion from the lakes to the area's aquifers, moreover, the basin is located in south of Iran with semiarid climate, faces a significant decline in rainfall. All these reasons cause the degradation of ground water quality. For this study, geographical coordinates of 406 observation wells will be defined as inputs and groundwater electrical conductivities (EC) will be set as output. Ordinary kriging (OK) and artificial neural networks (ANN) will be investigated for modeling groundwater salinity. Eighty percent of data will be randomly selected to train and develop mentioned models and twenty percent of data will be used for testing and validating. Finally, the outputs of models will be compared with the corresponding measured values in observation wells.

Mapping groundwater development costs for the transboundary Western Aquifer Basin, Palestine/Israel

NASA Astrophysics Data System (ADS)

MacDonald, A. M.; Ó Dochartaigh, B. É.; Calow, R. C.; Shalabi, Y.; Selah, K.; Merrett, S.

2009-11-01

The costs of developing groundwater in the Western Aquifer Basin vary considerably across the West Bank and Israel. One of the main reasons for this variability is the diverse hydrogeological conditions within the aquifer. Using data from recent hydrogeological investigations, an estimate of the variation of both the drilling and pumping costs was calculated and then mapped across the Upper and Lower Aquifers within the Western Aquifer Basin. These groundwater cost maps proved helpful in analyzing the impacts of hydrogeology on water supply, and also in communicating complex hydrogeological information to a broader audience. The maps clearly demonstrate that the most cost-effective area to develop groundwater is along the Green Line—the 1949 armistice boundary between Israel and the Palestinian West Bank. Any migration of this boundary eastwards will affect the cost and feasibility of developing groundwater within Palestine, making abstraction from the Upper Aquifer impracticable, and increasing the cost of developing the Lower Aquifer. Therefore, the separation wall, which is being constructed to the east of the Armistice Line in Palestinian territory, will significantly reduce the ability of the Palestinians to develop groundwater resources.

The background state leading to arsenic contamination of Bengal basin groundwater.

PubMed

Adel, Miah M

2005-12-01

The Bengal basin has the world's densest water diversion constructions on the natural courses of rivers. The most damaging water diversion construction is the Farakka Barrage upon the international River Ganges. The diversion of water through this barrage and other constructions upstream of it has reduced the Ganges flow rate by 2.5 times. The resulting downstream effects are the depletion of surface water resources, more withdrawal than recharge of groundwater, sinking groundwater table, spread in depth and extension of the vadose zone, changes in surface features, climatic changes, etc. An investigation was carried out to find the contributions of water diversion to the arsenic contamination of groundwater in the Bengal basin. The reasonable scenario for arsenic contamination is the oxygen deficiency in groundwater and aeration of arsenopyrites buried in the sediment that would remain under water prior to 1975. The mineral forms water-soluble compounds of arsenic when react with atmospheric oxygen. These soluble arsenic compounds infiltrates to the groundwater. This article summarizes the short-time and incomplete study-based quick conclusions reached by investigators that have totally avoided the vital issue of water diversion. It then shows the depleting condition of the water resources under continuing diversions, the generation of favorable condition for arsenic release, the reasons for low sulfur concentration, the reason for first contamination in the Hugly basin, and the hindrance to water's self-purification. The articles advocates that the restoration of the virgin wetland ecosystems in the Bengal basin following the stoppage of the inordinate amount of unilateral upstream water withdrawals can remove the catastrophe.

Ecological effects and potential risks of the water diversion project in the Heihe River Basin.

PubMed

Zhang, Mengmeng; Wang, Shuai; Fu, Bojie; Gao, Guangyao; Shen, Qin

2018-04-01

To curb the severe ecological deterioration in the lower Heihe River Basin (HRB) in northwest China, a water diversion project was initiated in 2000. A comprehensive analysis of the ecological effects and potential risks associated with the project is needed. We assessed the hydrological and ecological achievements, and also analyzed the potential problems after the project was completed. We found that since the project began the hydrological regime has changed, with more than 57.82% of the upstream water being discharged to the lower reaches on average. As a result, the groundwater level in the lower reaches has risen; the terminal lake has gradually expanded to a maximum area in excess of 50km 2 since 2010, and there has been a significant recovery of vegetation in the riparian zone and the Ejin core oases, which represents the initial rehabilitation of the degraded downstream environment. Additionally, the economy of Ejin has developed spectacularly, with an annual growth rate of 28.06%. However, in the middle reaches, the average groundwater level has continuously declined by a total of 5.8m and significant degradation of the vegetation has occurred along the river course. The discrepancy in the water allocation between the middle and lower reaches has intensified. This highlights the inability of the current water diversion scheme to realize further ecological restoration and achieve sustainable development throughout the whole basin. In future water management programs, we recommend that water allocation is coordinated by considering the basin as an integrated entity and to scientifically determine the size of the midstream farmland and downstream oasis; restrict non-ecological water use in the lower reaches, and jointly dispatch the surface water and groundwater. Copyright © 2017 Elsevier B.V. All rights reserved.

76 FR 3655 - Bunker Hill Groundwater Basin, Riverside-Corona Feeder Project, San Bernardino and Riverside...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Bunker Hill Groundwater Basin, Riverside-Corona... Draft Environmental Impact Statement (SDEIR/DEIS) for the proposed Riverside-Corona Feeder (RCF) Project... Bernardino, California 92410 Corona Public Library, 650 South Main Street, Corona, California 92882 Riverside...

Multi-scale analysis of the fluxes between terrestrial water storage, groundwater, and stream discharge in the Columbia River Basin

EPA Science Inventory

The temporal relationships between the measurements of terrestrial water storage (TWS), groundwater, and stream discharge were analyzed at three different scales in the Columbia River Basin (CRB) for water years 2004 - 2012. Our nested watershed approach examined the Snake River ...

Groundwater and surface-water interaction and potential for underground water storage in the Buena Vista-Salida Basin, Chaffee County, Colorado, 2011

USGS Publications Warehouse

Watts, Kenneth R.; Ivahnenko, Tamara I.; Stogner, Sr., Robert W.; Bruce, James F.

2014-01-01

By 2030, the population of the Arkansas Headwaters Region, which includes all of Chaffee and Lake Counties and parts of Custer, Fremont, and Park Counties, Colorado, is forecast to increase about 73 percent. As the region’s population increases, it is anticipated that groundwater will be used to meet much of the increased demand. In September 2009, the U.S. Geological Survey, in cooperation with the Upper Arkansas Water Conservancy District and with support from the Colorado Water Conservation Board; Chaffee, Custer, and Fremont Counties; Buena Vista, Cañon City, Poncha Springs, and Salida; and Round Mountain Water and Sanitation District, began a 3-year study of groundwater and surface-water conditions in the Buena Vista-Salida Basin. This report presents results from the study of the Buena Vista-Salida Basin including synoptic gain-loss measurements and water budgets of Cottonwood, Chalk, and Browns Creeks, changes in groundwater storage, estimates of specific yield, transmissivity and hydraulic conductivity from aquifer tests and slug tests, an evaluation of areas with potential for underground water storage, and estimates of stream-accretion response-time factors for hypothetical recharge and selected streams in the basin. The four synoptic measurements of flow of Cottonwood, Chalk, and Browns Creeks, suggest quantifiable groundwater gains and losses in selected segments in all three perennial streams. The synoptic measurements of flow of Cottonwood and Browns Creeks suggest a seasonal variability, where positive later-irrigation season values in these creeks suggest groundwater discharge, possibly as infiltrated irrigation water. The overall sum of gains and losses on Chalk Creek does not indicate a seasonal variability but indicates a gaining stream in April and August/September. Gains and losses in the measured upper segments of Chalk Creek likely are affected by the Chalk Cliffs Rearing Unit (fish hatchery). Monthly water budgets were estimated for selected segments of five perennial streams (Cottonwood, North Cottonwood, Chalk, and Browns Creeks, and South Arkansas River) in the Buena Vista-Salida Basin for calendar year 2011. Differences between reported diversions and estimated crop irrigation requirements were used to estimate groundwater recharge in the areas irrigated by water supplied from the diversions. The amount of groundwater recharge in all the basins varied monthly; however, the greatest amount of recharge was during June and July for Cottonwood, North Cottonwood, and Chalk Creeks and South Arkansas River. The greatest amount of recharge in 2011 in Browns Creek occurred in July and August. The large seasonal fluctuations of groundwater near irrigated areas in the Buena Vista-Salida Basin indicate that the increased groundwater storage resulting from infiltration of surface-water diversions has dissipated by the following spring. Areas within the Buena Vista-Salida Basin with the potential for underground storage were identified using geographic information system data, including topographic, geologic, and hydrologic data, excluding the mountainous areas that border the Buena Vista-Salida Basin and igneous and metamorphic rock outcrop areas. The areas that met the selection criteria for underground water storage are located on terrace deposits near the Arkansas River and adjacent to its major tributaries. The selected areas also contain much of the irrigated land within the basin; consequently, irrigation ditches and canals could provide a means of conveying water to potential recharge sites.

Studies of geology and hydrology in the Basin and Range Province, Southwestern United States, for isolation of high-level radioactive waste - Basis of characterization and evaluation

USGS Publications Warehouse

Bedinger, M.S.; Sargent, K.A.; Langer, William H.; Sherman, Frank B.; Reed, J.E.; Brady, B.T.

1989-01-01

The geologic and hydrologic factors in selected regions of the Basin and Range province were examined to identify prospective areas for further study that may provide isolation of high-level radioactive waste from the accessible environment. The six regions selected for study were characterized with respect to the following guidelines: (1) Potential repository media; (2) Quaternary tectonic conditions; (3) climatic change and geomorphic processes; (4) ground-water conditions; (5) ground-water quality; and (6) mineral and energy resources.The repository medium will function as the first natural barrier to radionuclide travel by virtue of associated slow ground-water velocity. The principal rock types considered as host media include granitic, intermediate, and mafic intrusive rocks; argillaceous rocks; salt and anhydrite; volcanic mudflow (laharic) breccias; some intrusive rhyolitic plugs and stocks; partially zeolitized tuff; and metamorphic rocks. In the unsaturated zone, the permeability and hydrologic properties of the rocks and the hydrologic setting are more important than the rock type. Media ideally should be permeable to provide drainage and should have a minimal water fluxThe ground-water flow path from a repository to the accessible environment needs to present major barriers to the transport of radionuclides. Factors considered in evaluating the ground-water conditions include ground-water traveltimes and quality, confining beds, and earth materials favorable for retardation of radionuclides. Ground-water velocities in the regions were calculated from estimated hydraulic properties of the rocks and gradients. Because site-specific data on hydraulic properties are not available, data from the literature were assembled and synthesized to obtain values for use in estimating ground-water velocities. Hydraulic conductivities for many rock types having granular and fracture permeability follow a log-normal distribution. Porosity for granular and very weathered crystalline rock tends to be normally distributed; porosity of fractured crystalline rock probably follows a log-normal distribution.The tectonic setting needs to prevent an increase in radionuclides to the accessible environment. Data on historic seismicity and heat flow, Quaternary faults, volcanism, and uplift were used to assess the tectonic conditions. Long-term late Cenozoic rates of vertical crustal movement in the Basin and Range province range from less than 2 meters per 104 years to greater than 20 meters per 104 years. Shortterm rates of vertical movement may be more than an order of magnitude greater, based on geodetic leveling. Changes in tectonic and climatic processes may potentially cause changes in hydrologic conditions and geomorphology that could affect the integrity of a deep, mined repository either adversely or beneficially.The transition from a full-glacial climate to the current interglacial condition has occurred within the past 15,000 years. Reconstructions of the last full-glacial climate indicate that, at that time, there was greater water availability for runoff and vegetation growth than there is now. Based on the increased water availability and depending on seasonal distribution of precipitation, on soil characteristics, on topography, and on other characteristics, ground-water recharge during the full-glacial climate is estimated to have been possibly 2 to 10 or more times the modern rate. During the full-glacial climate, more than 100 lakes occupied closed basins in the province. Any increase in ground-water recharge and refilling of Pleistocene lakes will tend to decrease the distance of ground-water flow and its time of travel. The unsaturated zone this zone is considered a potential host medium where the thickness is greater than 150 m will be decreased by these changes. In contrast, incision of streams and other geomorphic, tectonic, or climatically induced changes that lower the ground-water discharge level will tend to increase the thickness of the unsaturated zone. Aggradation in basinal troughs may either decrease or increase the thickness of the unsaturated zone. Aggradation in basins that causes the ground-water discharge level to rise will tend to decrease the thickness of unsaturated zone in the adjacent uplands; aggradation in basins where the ground-water discharge level remains the same or is lowered will increase the unsaturated thickness of basin fill.Records show that, throughout late Cenozoic time in the Basin and Range province, continued vertical crustal movements have tended to maintain mountain ranges and closed basins, whereas aggradation of the basins and erosion of the mountain ranges have tended to decrease the topographic relief. Maximum rates of denudation for small basins in areas climatically similar to the Basin and Range province are about 2 meters per 104 years. For sites unaffected by stream incision and scarp retreat, a conservative estimate of erosion affecting long-term changes in depth of burial would appear to be 2 meters per 104 years, or, equal to the long-term rate of vertical crustal movement where greater than 2 meters per 104 years. The response of the ground-water conditions to climatic and geomorphically induced boundary conditions is significant from the points of: (1) The potential maximum change in the ground-water flow system; (2) the time of response of the ground-water system; and (3) the present state of the ground-water system as a result of past changes. Effects of longterm climatic and tectonic changes on hydrologic and geomorphic conditions differ from area to area, and rates of change of geomorphic and hydrologic conditions may vary significantly. Therefore, sitespecific studies need to be made to assess the long-term integrity of deep, mined repositories.

Identifying three-dimensional nested groundwater flow systems in a Tóthian basin

NASA Astrophysics Data System (ADS)

Wang, Xu-Sheng; Wan, Li; Jiang, Xiao-Wei; Li, Hailong; Zhou, Yangxiao; Wang, Junzhi; Ji, Xiaohui

2017-10-01

Nested groundwater flow systems have been revealed in Tóth's theory as the structural property of basin-scale groundwater circulation but were only well known with two-dimensional (2D) profile models. The method of searching special streamlines across stagnation points for partitioning flow systems, which has been successfully applied in the 2D models, has never been implemented for three-dimensional (3D) Tóthian basins because of the difficulty in solving the dual stream functions. Alternatively, a new method is developed to investigate 3D nested groundwater flow systems without determination of stagnation points. Connective indices are defined to quantify the connection between individual recharge and discharge zones along streamlines. Groundwater circulation cells (GWCCs) are identified according to the distribution of the connective indices and then grouped into local, intermediate and regional flow systems. This method requires existing solution of the flow velocity vector and is implemented via particle tracking technique. It is applied in a hypothetical 3D Tóthian basin with an analytical solution of the flow field and in a real-world basin with a numerical modeling approach. Different spatial patterns of flow systems compared to 2D profile models are found. The outcrops boundaries of GWCCs on water table may significantly deviate from and are not parallel to the nearby water table divides. Topological network is proposed to represent the linked recharge-discharge zones through closed and open GWCCs. Sensitivity analysis indicates that the development of GWCCs depends on the basin geometry, hydraulic parameters and water table shape.

Modes, hydrodynamic processes and ecological impacts exerted by river-groundwater transformation in Junggar Basin, China

NASA Astrophysics Data System (ADS)

Wang, Wenke; Wang, Zhan; Hou, Rongzhe; Guan, Longyao; Dang, Yan; Zhang, Zaiyong; Wang, Hao; Duan, Lei; Wang, Zhoufeng

2018-05-01

The hydrodynamic processes and impacts exerted by river-groundwater transformation need to be studied at regional and catchment scale, especially with respect to diverse geology and lithology. This work adopted an integrated method to study four typical modes (characterized primarily by lithology, flow subsystems, and gaining/losing river status) and the associated hydrodynamic processes and ecological impacts in the southern part of Junggar Basin, China. River-groundwater transformation occurs one to four times along the basin route. For mode classification, such transformation occurs: once or twice, controlled by lithological factors (mode 1); twice, impacted by geomorphic features and lithological structures (mode 2); and three or four times, controlled by both geological and lithological structures (modes 3 and 4). Results also suggest: (1) there exist local and regional groundwater flow subsystems at 400 m depth, which form a multistage nested groundwater flow system. The groundwater flow velocities are 0.1-1.0 and <0.1 m/day for each of two subsystems; (2) the primary groundwater hydro-chemical type takes on apparent horizontal and vertical zoning characteristics, and the TDS of the groundwater evidently increases along the direction of groundwater flow, driven by hydrodynamic processes; (3) the streams, wetland and terminal lakes are the end-points of the local and regional groundwater flow systems. This work indicates that not only are groundwater and river water derived from the same source, but also hydrodynamic and hydro-chemical processes and ecological effects, as a whole in arid areas, are controlled by stream-groundwater transformation.

Climate impact on groundwater systems: the past is the key to the future

NASA Astrophysics Data System (ADS)

van der Ploeg, Martine; Cendón, Dioni; Haldorsen, Sylvi; Chen, Jinyao; Gurdak, Jason; Tujchneider, Ofelia; Vaikmäe, Rein; Purtschert, Roland; Chkir Ben Jemâa, Najiba

2013-04-01

Groundwater is a significant part of the global hydrological cycle and supplies fresh drinking water to almost half of the world's population. While groundwater supplies are buffered against short-term effects of climate variability, they can be impacted over longer time scales through changes in precipitation, ,evaporation, recharge rate, melting of glaciers or permafrost, vegetation, and land-use. Moreover, uncontrolled groundwater extraction has and will lead to irreversible depletion of fresh water resources in many areas. The impact of climate variability and groundwater extraction on the resilience of groundwater systems is still not fully understood (Green et al. 2011). Groundwater stores environmental and climatic information acquired during the recharge process, which integrates different signals, like recharge temperature, origin of precipitation, and dissolved constituents. This information can be used to estimate palaeo recharge temperatures, palaeo atmospheric dynamics and residence time of groundwater within the aquifer (Stute et al. 1995, Clark and Fritz 1997, Collon et al. 2000, Edmunds et al. 2003, Cartwright et al. 2007, Kreuzer et al. 2009, Currell et al. 2010, Raidla et al. 2012, Salem et al. 2012). The climatic signals incorporated by groundwater during recharge have the potential to provide a regionally integrated proxy of climatic variations at the time of recharge. Groundwater palaeoclimate information is affected by diffusion-dispersion processes (Davison and Airey, 1982) and/or water-rock interaction (Clark and Fritz, 1997), making palaeoclimate information deduced from groundwater inherently a low resolution record. While the signal resolution can be limited, recharge follows major climatic events, and more importantly, shows how those aquifers and their associated recharge varies under climatic forcing. While the characterization of groundwater resources, surface-groundwater interactions and their link to the global water cycle are an important focus, little attention has been given to groundwater as a potential record of past climate variations. A groundwater system's history is vital to forecast its vulnerability under future and potentially adverse climatic changes. By processing groundwater information from vast regions and different continents, recharge and palaeoclimate can be correlated at a global scale. To successfully evaluate the sustainability of groundwater resources, "the past is the key to the future". To address the identified lack of palaeoclimatic data available from groundwater studies, a global collaboration has been set-up in 2011 called Groundwater@Global Palaeoclimate Signals (www.gw-gps.com), and has already more than 70 participants from 5 continents. Since 2012 G@GPS receives seed funding to support meetings by the International Geoscience Programme, the International Union for Quaternary Research and UNESCO-GRAPHIC International Hydrologic Project. This collaboration targets groundwater basins on five continents —Africa, America, Asia, Australia, Europe — containing vast groundwater resources with an estimated dependence of tens of millions of people. We will present G@GPS, show examples from groundwater basins, and discuss possibilities to integrate groundwater information from these basins. References Cartwright, I. et al. 2007. Consraining modern and historical recharge from bore hydrographs, 3H, 14C, and chloride concentrations: Applications to dual-porosity aquifers in dryland salinity areas, Murray Basin, Australia. J. Hydrol. 332: 69-92. Clark, I. and P. Fritz. 1997. Environmental isotopes in hydrogeology, Lewis Publishers. Collon, P. et al. 2000. 81Kr in the Great Artesian Basin, Australia: a new method for dating very old groundwater. Earth and Planetary Science Letters 182: 103-113. Currell, M. J. et al. 2010. Recharge history and controls on groundwater quality in the Yuncheng Basin, north China, J. Hydrol. 385: 216-229. Davison, M. R. and P. L. Airey. 1982. The effect of dispersion on the establishment of a paleoclimatic record from groundwater. J. Hydrol. 58: 131-147. Edmunds, W. M. et al. 2003. Groundwater evolution in the Continental Intercalaire aquifer of southern Algeria and Tunisia: trace element and isotopic indicators, Applied Geochemistry 18: 805-822. Green, T.R. et al. 2011. Beneath the surface of global change: Impacts of climate change on groundwater. J. Hydrol 405: 532-560. Kreuzer, A. M. et al. 2009. A record of temperature and monsoon intensity over the past 40 kyr from groundwater in the North China Plain, Chemical Geology 259: 168-180. Raidla, V., Kirsimäe, K., Vaikmäe, R., Kaup, E., and Martma, T., 2012, Carbon isotope systematics of the Cambrian-Vendian aquifer system in the northern Baltic Basin: Implications to the age and evolution of groundwater: Applied Geochemistry, v. 27(10), p. 2042-2052. Salem, S.B.H., Chkir, N., Zouari, K., Cognard-Plancq , A. L., Valles, V, and Marc, V., 2012, Natural and artificial recharge investigation in the Zéroud Basin,Central Tunisia: impact of Sidi Saad Dam storage. Environmental Earth Sciences, v., 66, p. 1099-1110. Stute M., Forster M., Frischkorn H., Serejo A., Clark J. F., Schlosser P., Broecker W. S., and Bonani G. (1995) Cooling of tropical Brazil (5 °C) during the Last Glacial Maximum. Science 269, 379-383.

Great Salt Lake basins study unit

USGS Publications Warehouse

Waddell, Kidd M.; Baskin, Robert L.

1994-01-01

In 1991, the U.S. Geological Survey (USGS) began implementing a full-scale National Water-Quality Assessment (NAWQA) Program.The long-term goals of the NAWQA Program are to describe the status and trends in the quality of a large, representative part of the Nation’s surface- and ground-water resources and to provide a sound, scientific understanding of the primary natural and human factors that affect the quality of these resources. In meeting these goals, the program will produce a wealth of water-quality information that will be useful to policy makers and managers at Federal, State, and local levels.A major design feature of the NAWQA Program will enable water-quality information at different areal scales to be integrated. A major component of the program is study-unit investigations, which ae the principal building blocks of the program upon which national-level assessment activities will be based. The 60 study-unit investigations that make up the program are hydrologic systems that include principal river basins and aquifer systems throughout the Nation. These study units cover areas from less than 1.000 to greater than 60,000 mi2 and incorporate from about 60 to 70 percent of the Nation’s water use and population served by public water supply. In 1993, assessment activities began in the Great Salt Lake Basins NAWQA study unit.

Simulation of Ground-Water Flow in the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

USGS Publications Warehouse

Densmore, Jill N.

2003-01-01

Ground-water pumping in the Irwin Basin at Fort Irwin National Training Center, California resulted in water-level declines of about 30 feet from 1941 to 1996. Since 1992, artificial recharge from wastewater-effluent infiltration and irrigation-return flow has stabilized water levels, but there is concern that future water demands associated with expansion of the base may cause a resumption of water-level declines. To address these concerns, a ground-water flow model of the Irwin Basin was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Historical data show that ground-water-level declines in the Irwin Basin between 1941 and 1996, caused the formation of a pumping depression near the pumped wells, and that recharge from the wastewater-treatment facility and disposal area caused the formation of a recharge mound. There have been two periods of water-level recovery in the Irwin Basin since the development of ground water in this basin; these periods coincide with a period of decreased pumpage from the basin and a period of increased recharge of water imported from the Bicycle Basin beginning in 1967 and from the Langford Basin beginning in 1992. Since 1992, artificial recharge has exceeded pumpage in the Irwin Basin and has stabilized water-level declines. A two-layer ground-water flow model was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Boundary conditions, hydraulic conductivity, altitude of the bottom of the layers, vertical conductance, storage coefficient, recharge, and discharge were determined using existing geohydrologic data. Rates and distribution of recharge and discharge were determined from existing data and estimated when unavailable. Results of predictive simulations indicate that in 50 years, if artificial recharge continues to exceed pumpage in Irwin Basin, water levels could rise as much as 65 feet beneath the pumping depression, and as much as 10 feet in the wastewater-treatment facility and disposal area. Particle-tracking simulations were used to determine the pathlines and the traveltimes of water high in dissolved solids into the main pumping area. The pathlines of particles from two areas with high dissolved-solids concentrations show that in 50 years water from these areas almost reaches the nearest pumped well.

Ground-water and water-chemistry data for the upper Deschutes Basin, Oregon

USGS Publications Warehouse

Caldwell, Rodney R.; Truini, Margot

1997-01-01

This report presents ground-water data collected and compiled as part of a study of the ground-water resources of the upper Deschutes Basin, Oregon. Data in this report include tabulated information and a location map for more than 1,500 field-located water wells, hydrographs showing water-level fluctuations over various time periods for 102 of the wells, and water-chemistry analyses from 26 wells, 7 springs, and 5 surface-water sites.

Results from the Big Spring basin water quality monitoring and demonstration projects, Iowa, USA

USGS Publications Warehouse

Rowden, R.D.; Liu, H.; Libra, R.D.

2001-01-01

Agricultural practices, hydrology, and water quality of the 267-km2 Big Spring groundwater drainage basin in Clayton County, Iowa, have been monitored since 1981. Land use is agricultural; nitrate-nitrogen (-N) and herbicides are the resulting contaminants in groundwater and surface water. Ordovician Galena Group carbonate rocks comprise the main aquifer in the basin. Recharge to this karstic aquifer is by infiltration, augmented by sinkhole-captured runoff. Groundwater is discharged at Big Spring, where quantity and quality of the discharge are monitored. Monitoring has shown a threefold increase in groundwater nitrate-N concentrations from the 1960s to the early 1980s. The nitrate-N discharged from the basin typically is equivalent to over one-third of the nitrogen fertilizer applied, with larger losses during wetter years. Atrazine is present in groundwater all year; however, contaminant concentrations in the groundwater respond directly to recharge events, and unique chemical signatures of infiltration versus runoff recharge are detectable in the discharge from Big Spring. Education and demonstration efforts have reduced nitrogen fertilizer application rates by one-third since 1981. Relating declines in nitrate and pesticide concentrations to inputs of nitrogen fertilizer and pesticides at Big Spring is problematic. Annual recharge has varied five-fold during monitoring, overshadowing any water-quality improvements resulting from incrementally decreased inputs. ?? Springer-Verlag 2001.

Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America

NASA Astrophysics Data System (ADS)

Neff, K. L.; Meixner, T.; Ajami, H.; De La Cruz, L.

2015-12-01

For water-scarce communities in the western U.S., it is critical to understand groundwater recharge regimes and how those regimes might shift in the face of climate change and impact groundwater resources. Watersheds in the Basin and Range Geological Province are characterized by a variable precipitation regime of wet winters and variable summer precipitation. The relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation recharge dominant in the northern parts of the region, and recharge from summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon (NAM) extends its influence. Stable water isotope data of groundwater and seasonal precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to estimate and compare groundwater recharge seasonality throughout the region. Contributions of winter precipitation to annual recharge vary from 69% ± 41% in the southernmost Río San Miguel Basin in Sonora, Mexico, to 100% ± 36% in the westernmost Mojave Desert of California. The Normalized Seasonal Wetness Index (NSWI), a simple water budget method for estimating recharge seasonality from climatic data, was shown to approximate recharge seasonality well in several winter precipitation-dominated systems, but less well in basins with significant summer precipitation.

Quality of ground water in the Payette River basin, Idaho

USGS Publications Warehouse

Parliman, D.J.

1986-01-01

As part of a study to obtain groundwater quality data in areas of Idaho were land- and water-resource development is expected to increase, water quality, geologic, and hydrologic data were collected for 74 wells in the Payette River basin, west-central Idaho, from July to October 1982. Historical (pre-1982) data from 13 wells were compiled with more recent (1982) data to define, on a reconnaissance level, water quality conditions in major aquifers and to identify factors that may have affected groundwater quality. Water from the major aquifers generally contains predominantly calcium, magnesium, and bicarbonate plus carbonate ions. Sodium and bicarbonate or sulfate are the predominant ions in groundwater from 25% of the 1982 samples. Areally, groundwater from the upper Payette River basin has proportionately lower ion concentrations than water from the lower Payette River basin. Water samples from wells < 100 ft deep generally have lower ion concentrations than samples from wells > 100 ft deep. Variations in groundwater quality probably are most affected by differences in aquifer composition and proximity to source(s) of recharge. Groundwater in the study area is generally suitable for most uses. In localized areas, pH and concentrations of hardness, alkalinity, dissolved solids, or dissolved nitrite plus nitrate as nitrogen, sulfate, fluoride, iron, or manganese exceed Federal drinking water limits and may restrict some uses of the water.

The Grand Challenge of Basin-Scale Groundwater Quality Management Modelling

NASA Astrophysics Data System (ADS)

Fogg, G. E.

2017-12-01

The last 50+ years of agricultural, urban and industrial land and water use practices have accelerated the degradation of groundwater quality in the upper portions of many major aquifer systems upon which much of the world relies for water supply. In the deepest and most extensive systems (e.g., sedimentary basins) that typically have the largest groundwater production rates and hold fresh groundwaters on decadal to millennial time scales, most of the groundwater is not yet contaminated. Predicting the long-term future groundwater quality in such basins is a grand scientific challenge. Moreover, determining what changes in land and water use practices would avert future, irreversible degradation of these massive freshwater stores is a grand challenge both scientifically and societally. It is naïve to think that the problem can be solved by eliminating or reducing enough of the contaminant sources, for human exploitation of land and water resources will likely always result in some contamination. The key lies in both reducing the contaminant sources and more proactively managing recharge in terms of both quantity and quality, such that the net influx of contaminants is sufficiently moderate and appropriately distributed in space and time to reverse ongoing groundwater quality degradation. Just as sustainable groundwater quantity management is greatly facilitated with groundwater flow management models, sustainable groundwater quality management will require the use of groundwater quality management models. This is a new genre of hydrologic models do not yet exist, partly because of the lack of modeling tools and the supporting research to model non-reactive as well as reactive transport on large space and time scales. It is essential that the contaminant hydrogeology community, which has heretofore focused almost entirely on point-source plume-scale problems, direct it's efforts toward the development of process-based transport modeling tools and analyses capable of appropriately upscaling advection-dispersion and reactions at the basin scale (10^2 km). A road map for research and development in groundwater quality management modeling and its application toward securing future groundwater resources will be discussed.

Hydrogeologic framework, groundwater and surface-water systems, land use, pumpage, and water budget of the Chamokane Creek basin, Stevens County, Washington

USGS Publications Warehouse

Kahle, Sue C.; Taylor, William A.; Lin, Sonja; Sumioka, Steven S.; Olsen, Theresa D.

2010-01-01

A study of the water resources of the unconsolidated groundwater system of the Chamokane Creek basin was conducted to determine the hydrogeologic framework, interactions of shallow and deep parts of the groundwater system with each other and the surface-water system, changes in land use and land cover, and water-use estimates. Chamokane Creek basin is a 179 mi2 area that borders and partially overlaps the Spokane Indian Reservation in southern Stevens County in northeastern Washington State. Aquifers within the Chamokane Creek basin are part of a sequence of glaciofluvial and glaciolacustrine sediment that may reach total thicknesses of about 600 ft. In 1979, most of the water rights in the Chamokane Creek basin were adjudicated by the United States District Court requiring regulation in favor of the Spokane Tribe of Indians' senior water right. The Spokane Tribe, the State of Washington, and the United States are concerned about the effects of additional groundwater development within the basin on Chamokane Creek. Information provided by this study will be used to evaluate the effects of potential increases in groundwater withdrawals on groundwater and surface-water resources within the basin. The hydrogeologic framework consists of six hydrogeologic units: The Upper outwash aquifer, the Landslide Unit, the Valley Confining Unit, the Lower Aquifer, the Basalt Unit, and the Bedrock Unit. The Upper outwash aquifer occurs along the valley floors of the study area and consists of sand, gravel, cobbles, boulders, with minor silt and (or) clay interbeds in places. The Lower aquifer is a confined aquifer consisting of sand and gravel that occurs at depth below the Valley confining unit. Median horizontal hydraulic conductivity values for the Upper outwash aquifer, Valley confining unit, Lower aquifer, and Basalt unit were estimated to be 540, 10, 19, and 3.7 ft/d, respectively. Many low-flow stream discharge measurements at sites on Chamokane Creek and its tributaries were at or near zero flow. The most notable exception is where Chamokane Creek is supported by discharge of large springs from the Upper outwash aquifer in the southern part of the basin. Most high-flow measurements indicated gains in streamflow (groundwater discharging to the stream). Large streamflow losses, however, were recorded near the north end of Walkers Prairie where streamflow directly recharges the Upper outwash aquifer. The similarity in seasonal water-level fluctuations in the Upper outwash aquifer and the Lower aquifer indicate that these systems may be fairly well connected. Land use and land cover change analysis indicates that Chamokane Creek basin has been dominated by forests with some pasture and agricultural lands with sparse residential development from the 1980s to present. Loss in forest cover represents the largest change in land cover in the basin between 1987 and 2009. This appears to be mostly due to forestry activities, especially in the northern part of the basin. Since 1987, more than 18,000 acres of evergreen forest have been logged and are at various stages of regrowth. Estimated average annual total groundwater pumpage in the basin increased from 224 million gallons per year (Mgal/yr) in 1980 to 1,330 Mgal/yr in 2007. The largest withdrawals during 2007 were to supply two fish hatcheries, with a combined total annual pumpage of about 1,150 Mgal. Annual groundwater pumpage values from 1980 through 2007 for the study area ranged from 21.1 to 28.9 Mgal/yr for domestic wells and 0.38 to 23.7 Mgal/yr for public supply. An approximate water budget for a typical year in the Chamokane Creek basin indicates that 19.6 in. of precipitation are balanced by 4.7 in. of streamflow discharge from the basin, and 14.9 in. of evapotranspiration.

Effects of anthropogenic groundwater exploitation on land surface processes: A case study of the Haihe River Basin, northern China

NASA Astrophysics Data System (ADS)

Zou, Jing; Xie, Zhenghui; Zhan, Chesheng; Qin, Peihua; Sun, Qin; Jia, Binghao; Xia, Jun

2015-05-01

In this study, we incorporated a groundwater exploitation scheme into the land surface model CLM3.5 to investigate the effects of the anthropogenic exploitation of groundwater on land surface processes in a river basin. Simulations of the Haihe River Basin in northern China were conducted for the years 1965-2000 using the model. A control simulation without exploitation and three exploitation simulations with different water demands derived from socioeconomic data related to the Basin were conducted. The results showed that groundwater exploitation for human activities resulted in increased wetting and cooling effects at the land surface and reduced groundwater storage. A lowering of the groundwater table, increased upper soil moisture, reduced 2 m air temperature, and enhanced latent heat flux were detected by the end of the simulated period, and the changes at the land surface were related linearly to the water demands. To determine the possible responses of the land surface processes in extreme cases (i.e., in which the exploitation process either continued or ceased), additional hypothetical simulations for the coming 200 years with constant climate forcing were conducted, regardless of changes in climate. The simulations revealed that the local groundwater storage on the plains could not contend with high-intensity exploitation for long if the exploitation process continues at the current rate. Changes attributable to groundwater exploitation reached extreme values and then weakened within decades with the depletion of groundwater resources and the exploitation process will therefore cease. However, if exploitation is stopped completely to allow groundwater to recover, drying and warming effects, such as increased temperature, reduced soil moisture, and reduced total runoff, would occur in the Basin within the early decades of the simulation period. The effects of exploitation will then gradually disappear, and the variables will approach the natural state and stabilize at different rates. Simulations were also conducted for cases in which exploitation either continues or ceases using future climate scenario outputs from a general circulation model. The resulting trends were almost the same as those of the simulations with constant climate forcing, despite differences in the climate data input. Therefore, a balance between slow groundwater restoration and rapid human development of the land must be achieved to maintain a sustainable water resource.

Hybrid Genetic Algorithm - Local Search Method for Ground-Water Management

NASA Astrophysics Data System (ADS)

Chiu, Y.; Nishikawa, T.; Martin, P.

2008-12-01

Ground-water management problems commonly are formulated as a mixed-integer, non-linear programming problem (MINLP). Relying only on conventional gradient-search methods to solve the management problem is computationally fast; however, the methods may become trapped in a local optimum. Global-optimization schemes can identify the global optimum, but the convergence is very slow when the optimal solution approaches the global optimum. In this study, we developed a hybrid optimization scheme, which includes a genetic algorithm and a gradient-search method, to solve the MINLP. The genetic algorithm identifies a near- optimal solution, and the gradient search uses the near optimum to identify the global optimum. Our methodology is applied to a conjunctive-use project in the Warren ground-water basin, California. Hi- Desert Water District (HDWD), the primary water-manager in the basin, plans to construct a wastewater treatment plant to reduce future septic-tank effluent from reaching the ground-water system. The treated wastewater instead will recharge the ground-water basin via percolation ponds as part of a larger conjunctive-use strategy, subject to State regulations (e.g. minimum distances and travel times). HDWD wishes to identify the least-cost conjunctive-use strategies that control ground-water levels, meet regulations, and identify new production-well locations. As formulated, the MINLP objective is to minimize water-delivery costs subject to constraints including pump capacities, available recharge water, water-supply demand, water-level constraints, and potential new-well locations. The methodology was demonstrated by an enumerative search of the entire feasible solution and comparing the optimum solution with results from the branch-and-bound algorithm. The results also indicate that the hybrid method identifies the global optimum within an affordable computation time. Sensitivity analyses, which include testing different recharge-rate scenarios, pond layouts, and water-supply constraints, indicate that the number of new wells is insensitive to water-supply constraints; however, pumping rates and patterns of the existing wells are sensitive. The locations of new wells are mildly sensitive to the pond layout.

The watershed and river systems management program

USGS Publications Warehouse

Markstrom, S.L.; Frevert, D.; Leavesley, G.H.; ,

2005-01-01

The Watershed and River System Management Program (WaRSMP), a joint effort between the U.S. Geological Survey (USGS) and the U.S. Bureau of Reclamation (Reclamation), is focused on research and development of decision support systems and their application to achieve an equitable balance among diverse water resource management demands. Considerations include: (1) legal and political constraints; (2) stake holder and consensus-building; (3) sound technical knowledge; (4) flood control, consumptive use, and hydropower; (5) water transfers; (6) irrigation return flows and water quality; (7) recreation; (8) habitat for endangered species; (9) water supply and proration; (10) near-surface groundwater; and (11) water ownership, accounting, and rights. To address the interdisciplinary and multi-stake holder needs of real-time watershed management, WaRSMP has developed a decision support system toolbox. The USGS Object User Interface facilitates the coupling of Reclamation's RiverWare reservoir operations model with the USGS Modular Modeling and Precipitation Runoff Modeling Systems through a central database. This integration is accomplished through the use of Model and Data Management Interfaces. WaRSMP applications include Colorado River Main stem and Gunnison Basin, the Yakima Basin, the Middle Rio Grande Basin, the Truckee-Carson Basin, and the Umatilla Basin.

Past and future water conflicts in the Upper Klamath Basin: An economic appraisal

NASA Astrophysics Data System (ADS)

Boehlert, Brent B.; Jaeger, William K.

2010-10-01

The water conflict in the Upper Klamath Basin typifies the growing competition between agricultural and environmental water uses. In 2001, drought conditions triggered Endangered Species Act-related requirements that curtailed irrigation diversions to the Klamath Reclamation Project, costing irrigators tens of millions of dollars. Although this event has significantly elevated the perceived risk of future economic catastrophe in the basin (and therefore the level of conflict among water users), several key changes related to water availability have occurred since 2001. These changes include reduced ESA requirements and increased groundwater pumping capacity, which have lowered the actual risk and severity of future water shortages. In this paper, we use a mathematical programming model to evaluate how these changes alter the likelihood and economic consequences of future shortages. We also consider the effect of more flexible transfers among irrigators via water markets. Our analysis indicates that future drought conditions like those seen in 2001 would have more modest economic impacts than in 2001 and that when combined with contingent groundwater supplementation and water transfer mechanisms such as water markets, both the likelihood and magnitude of economic losses among irrigators would be greatly reduced.

Summary of U.S. Geological Survey and City of Albuquerque hydrologic investigations program

DOE Office of Scientific and Technical Information (OSTI.GOV)

McAda, D.

1995-12-31

The US Geological Survey and Albuquerque have been cooperating in data collection programs and interpretive studies since 1982. The paper presents summaries on recently completed and ongoing projects, detailing the objectives, principal investigator, period of the project, and reports released or reports in progress on each study. Project names are: Ground-water-level monitoring network in the Albuquerque Basin; Water budget of the Rio Grande flood plain in the Albuquerque area; Modeling of groundwater flow in the Albuquerque Basin; Continuation of ground water flow modeling in the Albuquerque Basin; Evaluation of methods to quantify the hydrologic relations between the Rio Grande andmore » the Santa Fe Group aquifer system, near Albuquerque; Aquifer compaction and land subsidence in the Albuquerque, NM area; Aquifer test at the Griegos Well Field, Albuquerque, NM; Quality of urban stormwater runoff; Rio Grande water quality; Determining accurate concentrations and loads of trace elements and other selected chemical constituents in the Rio Grande, Albuquerque, NM; Digital geophysical-log data base; and Water quality data for the Albuquerque Basin.« less

Microbial Community in High Arsenic Shallow Groundwater Aquifers in Hetao Basin of Inner Mongolia, China

PubMed Central

Li, Ping; Wang, Yanhong; Dai, Xinyue; Zhang, Rui; Jiang, Zhou; Jiang, Dawei; Wang, Shang; Jiang, Hongchen; Wang, Yanxin; Dong, Hailiang

2015-01-01

A survey was carried out on the microbial community of 20 groundwater samples (4 low and 16 high arsenic groundwater) and 19 sediments from three boreholes (two high arsenic and one low arsenic boreholes) in a high arsenic groundwater system located in Hetao Basin, Inner Mongolia, using the 454 pyrosequencing approach. A total of 233,704 sequence reads were obtained and classified into 12–267 operational taxonomic units (OTUs). Groundwater and sediment samples were divided into low and high arsenic groups based on measured geochemical parameters and microbial communities, by hierarchical clustering and principal coordinates analysis. Richness and diversity of the microbial communities in high arsenic sediments are higher than those in high arsenic groundwater. Microbial community structure was significantly different either between low and high arsenic samples or between groundwater and sediments. Acinetobacter, Pseudomonas, Psychrobacter and Alishewanella were the top four genera in high arsenic groundwater, while Thiobacillus, Pseudomonas, Hydrogenophaga, Enterobacteriaceae, Sulfuricurvum and Arthrobacter dominated high arsenic sediments. Archaeal sequences in high arsenic groundwater were mostly related to methanogens. Biota-environment matching and co-inertia analyses showed that arsenic, total organic carbon, SO4 2-, SO4 2-/total sulfur ratio, and Fe2+ were important environmental factors shaping the observed microbial communities. The results of this study expand our current understanding of microbial ecology in high arsenic groundwater aquifers and emphasize the potential importance of microbes in arsenic transformation in the Hetao Basin, Inner Mongolia. PMID:25970606

Microbial community in high arsenic shallow groundwater aquifers in Hetao Basin of Inner Mongolia, China.

PubMed

Li, Ping; Wang, Yanhong; Dai, Xinyue; Zhang, Rui; Jiang, Zhou; Jiang, Dawei; Wang, Shang; Jiang, Hongchen; Wang, Yanxin; Dong, Hailiang

2015-01-01

A survey was carried out on the microbial community of 20 groundwater samples (4 low and 16 high arsenic groundwater) and 19 sediments from three boreholes (two high arsenic and one low arsenic boreholes) in a high arsenic groundwater system located in Hetao Basin, Inner Mongolia, using the 454 pyrosequencing approach. A total of 233,704 sequence reads were obtained and classified into 12-267 operational taxonomic units (OTUs). Groundwater and sediment samples were divided into low and high arsenic groups based on measured geochemical parameters and microbial communities, by hierarchical clustering and principal coordinates analysis. Richness and diversity of the microbial communities in high arsenic sediments are higher than those in high arsenic groundwater. Microbial community structure was significantly different either between low and high arsenic samples or between groundwater and sediments. Acinetobacter, Pseudomonas, Psychrobacter and Alishewanella were the top four genera in high arsenic groundwater, while Thiobacillus, Pseudomonas, Hydrogenophaga, Enterobacteriaceae, Sulfuricurvum and Arthrobacter dominated high arsenic sediments. Archaeal sequences in high arsenic groundwater were mostly related to methanogens. Biota-environment matching and co-inertia analyses showed that arsenic, total organic carbon, SO4(2-), SO4(2-)/total sulfur ratio, and Fe(2+) were important environmental factors shaping the observed microbial communities. The results of this study expand our current understanding of microbial ecology in high arsenic groundwater aquifers and emphasize the potential importance of microbes in arsenic transformation in the Hetao Basin, Inner Mongolia.

The National Water-Quality Assessment Program of the United States: Strategies for Monitoring Trends and Results from the First Two Decades of Study: 1991-2011

NASA Astrophysics Data System (ADS)

Lindsey, B.; McMahon, P.; Rupert, M.; Tesoriero, J.; Starn, J.; Anning, D.; Green, C.

2012-04-01

The U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program was implemented in 1991 to provide long-term, consistent, and comparable information on the quality of surface and groundwater resources of the United States. Findings are used to support national, regional, state, and local information needs with respect to water quality. The three main goals of the program are to 1) assess the condition of the nation's streams, rivers, groundwater, and aquatic systems; 2) assess how conditions are changing over time; and 3) determine how natural features and human activities affect these conditions, and where those effects are most pronounced. As data collection progressed into the second decade, the emphasis of the interpretation of the data has shifted from primarily understanding status, to evaluation of trends. The program has conducted national and regional evaluations of change in the quality of water in streams, rivers, groundwater, and health of aquatic systems. Evaluating trends in environmental systems requires complex analytical and statistical methods, and a periodic re-evaluation of the monitoring methods used to collect these data. Examples given herein summarize the lessons learned from the evaluation of changes in water quality during the past two decades with an emphasis on the finding with respect to groundwater. The analysis of trends in groundwater is based on 56 well networks located in 22 principal aquifers of the United States. Analysis has focused on 3 approaches: 1) a statistical analysis of results of sampling over various time scales, 2) studies of factors affecting trends in groundwater quality, and 3) use of models to simulate groundwater trends and forecast future trends. Data collection for analysis of changes in groundwater-quality has focused on decadal resampling of wells. Understanding the trends in groundwater quality and the factors affecting those trends has been conducted using quarterly sampling, biennial sampling, and more recently continuous monitoring of selected parameters in a small number of wells. Models such as MODFLOW have been used for simulation and forecasting of future trends. Important outcomes from the groundwater-trends studies include issues involving statistics, sampling frequency, changes in laboratory analytical methods over time, the need for groundwater age-dating information, the value of understanding geochemical conditions and contaminant degradation, the need to understand groundwater-surface water interaction, and the value of modeling in understanding trends and forecasting potential future conditions. Statistically significant increases in chloride, dissolved solids, and nitrate concentrations were found in a large number of well networks over the first decadal sampling period. Statistically significant decreases of chloride, dissolved solids, and nitrate concentrations were found in a very small number of networks. Trends in surface-water are analyzed within 8 large major river basins within the United States with a focus on issues of regional importance. Examples of regional surface-water issues include an analysis of trends in dissolved solids in the Southeastern United States, trends in pesticides in the north-central United States, and trends in nitrate in the Mississippi River Basin. Evaluations of ecological indicators of water quality include temporal changes in stream habitat, and aquatic-invertebrate and fish assemblages.

Subsidence (2004-2009) in and near lakebeds of the Mojave River and Morongo groundwater basins, southwest Mojave Desert, California

USGS Publications Warehouse

Solt, Mike; Sneed, Michelle

2014-01-01

Subsidence, in the vicinity of dry lakebeds, within the Mojave River and Morongo groundwater basins of the southwest Mojave Desert has been measured by Interferometric Synthetic Aperture Radar (InSAR). The investigation has focused on determining the location, extent, and magnitude of changes in land-surface elevation. In addition, the relation of changes in land-surface elevation to changes in groundwater levels and lithology was explored. This report is the third in a series of reports investigating land-surface elevation changes in the Mojave and Morongo Groundwater Basins, California. The first report, U.S. Geological Survey (USGS) Water-Resources Investigations Report 03-4015 by Sneed and others (2003), describes historical subsidence and groundwater-level changes in the southwest Mojave Desert from 1969 to 1999. The second report, U.S. Geological Survey Water-Resources Investigations Report 07-5097, an online interactive report and map, by Sneed and Brandt (2007), describes subsidence and groundwater-level changes in the southwest Mojave Desert from 1999 to 2004. The purpose of this report is to document an updated assessment of subsidence in these lakebeds and selected neighboring areas from 2004 to 2009 as measured by InSAR methods. In addition, continuous Global Positioning System (GPS)(2005-10), groundwater level (1951-2010), and lithologic data, if available, were used to characterize compaction mechanisms in these areas. The USGS California Water Science Center’s interactive website for the Mojave River and Morongo groundwater basins was created to centralize information pertaining to land subsidence and water levels and to allow readers to access available data and related reports online. An interactive map of land subsidence and water levels in the Mojave River and Morongo groundwater basins displays InSAR interferograms, subsidence areas, subsidence contours, hydrographs, well information, and water-level contours. Background information, including a basic description of the mechanics of land subsidence and InSAR, as well as a description of the study area, is presented within the Mojave Water Resources Interactive Map and report.

The Mojave River from sink to source: The 2018 Desert Symposium Field Trip Road Log

USGS Publications Warehouse

Miller, David; Reynolds, R.E.; Groover, Krishangi D.; Buesch, David C.; Brown, H. J.; Cromwell, Geoffrey; Densmore-Judy, Jill; Garcia, A.L.; Hughson, D.; Knott, J.R.; Lovich, Jeffrey E.

2018-01-01

The Mojave River evolved over the past few million years by “fill and spill” from upper basins near its source in the Transverse Ranges to lower basins. Each newly “spilled into” basin in the series? sustained a long-lived lake but gradually filled with Mojave River sediment, leading to spill to a yet lower elevation? basin. The Mojave River currently terminates at Silver Lake, near Baker, CA, but previously overflowed this terminus onward to Lake Manly in Death Valley during the last glacial cycle. The river’s origin and evolution are intricately interwoven with tectonic, climatic, and geomorphic processes through time, beginning with San Andreas fault interactions that created a mountain range across a former externally draining river. We will see and discuss the Mojave River’s predecessor streams and basins, its evolution as it lengthened to reach the central Mojave Desert, local and regional tectonic controls, groundwater flow, flood history, and support of isolated perennial stream reaches that host endemic species. In association with these subjects are supporting studies such as paleoclimate records, location and timing for groundwater and wetlands in the central Mojave Desert, and effects of modern water usage. The trip introduces new findings for the groundwater basin of Hinkley Valley, including an ongoing remediation project that provides a wealth of information on past and present river flow and associated development of the groundwater system.

Das Bremerhavener Grundwasser im Klimawandel - Eine FREEWAT-Fallstudie

NASA Astrophysics Data System (ADS)

Panteleit, Björn; Jensen, Sven; Seiter, Katherina; Siebert, Yvonne

2018-01-01

A 3D structural model was created for the state of Bremen based on an extensive borehole database. Parameters were assigned to the model by interpretation and interpolation of the borehole descriptions. This structural model was transferred into a flow model via the FREEWAT platform, an open-source plug-in of the free QGIS software, with connection to the MODFLOW code. This groundwater management tool is intended for long-term use. As a case study for the FREEWAT Project, possible effects of climate change on groundwater levels in the Bremerhaven area have been simulated. In addition to the calibration year 2010, scenarios with a sea-level rise and decreasing groundwater recharge were simulated for the years 2040, 2070 and 2100. In addition to seawater intrusion in the coastal area, declining groundwater levels are also a concern. Possibilities for future groundwater management already include active control of the water level of a lake and the harbor basin. With the help of a focused groundwater monitoring program based on the model results, the planned flow model can become an important forecasting tool for groundwater management within the framework of the planned continuous model management and for representing the effects of changing climatic conditions and mitigation measures.

Structural interpretation of the Ifal Basin in north-western Saudi Arabia from aeromagnetic data: hydrogeological and environmental implications

NASA Astrophysics Data System (ADS)

Elawadi, Eslam; Zaman, Haider; Batayneh, Awni; Mogren, Saad; Laboun, Abdalaziz; Ghrefat, Habes; Zumlot, Taisser

2013-09-01

The Ifal (Midyan) Basin is one of the well defined basins along the Red Sea coast, north-western Saudi Arabia. Location, geometry, thick sedimentary cover and structural framework qualify this basin for groundwater, oil and mineral occurrences. In spite of being studied by two airborne magnetic surveys during 1962 and 1983, structural interpretation of the area from a magnetic perspective, and its uses for hydrogeological and environmental investigations, has not been attempted. This work thus presents interpretation of the aeromagnetic data for basement depth estimation and tectonic framework delineation, which both have a role in controlling groundwater flow and accumulation in the Ifal Basin. A maximum depth of 3.5km is estimated for the basement surface by this study. In addition, several faulted and tilted blocks, perpendicularly dissected by NE-trending faults, are delineated within the structural framework of the study area. It is also observed that the studied basin is bounded by NW- and NE-trending faults. All these multi-directional faults/fracture systems in the Ifal Basin could be considered as conduits for groundwater accumulation, but with a possibility of environmental contamination from the surrounding soils and rock bodies.

Origin of hexavalent chromium in groundwater: The example of Sarigkiol Basin, Northern Greece.

PubMed

Kazakis, N; Kantiranis, N; Kalaitzidou, K; Kaprara, E; Mitrakas, M; Frei, R; Vargemezis, G; Tsourlos, P; Zouboulis, A; Filippidis, A

2017-09-01

Hexavalent chromium constitutes a serious deterioration factor for the groundwater quality of several regions around the world. High concentrations of this contaminant have been also reported in the groundwater of the Sarigkiol hydrological basin (near Kozani city, NW Greece). Specific interest was paid to this particular study area due to the co-existence here of two important factors both expected to contribute to Cr(VI) presence and groundwater pollution; namely the area's exposed ophiolitic rocks and its substantial fly ash deposits originating from the local lignite burning power plant. Accordingly, detailed geochemical, mineralogical, hydro-chemical, geophysical and hydrogeological studies were performed on the rocks, soils, sediments and water resources of this basin. Cr(VI) concentrations varied in the different aquifers, with the highest concentration (up to 120μgL -1 ) recorded in the groundwater of the unconfined porous aquifer situated near the temporary fly ash disposal site. Recharge of the porous aquifer is related mainly to precipitation infiltration and occasional surface run-off. Nevertheless, a hydraulic connection between the porous and neighboring karst aquifers could not be delineated. Therefore, the presence of Cr(VI) in the groundwater of this area is thought to originate from both the ophiolitic rock weathering products in the soils, and the local leaching of Cr(VI) from the diffused fly ash located in the area surrounding the lignite power plant. This conclusion was corroborated by factor analysis, and the strongly positively fractionated Cr isotopes (δ 53 Cr up to 0.83‰) recorded in groundwater, an ash leachate, and the bulk fly ash. An anthropogenic source of Cr(VI) that possibly influences groundwater quality is especially apparent in the eastern part of the Sarigkiol basin. Copyright © 2017 Elsevier B.V. All rights reserved.

Geophysical Tools for an Improved Hydrogeologic Conceptual Model of the Big Chino Sub-basin, Central Arizona

NASA Astrophysics Data System (ADS)

Macy, J. P.; Kennedy, J.

2017-12-01

Water users and managers who rely on the Verde River system and its aquifers for water supplies have an intrinsic interest in developing the best possible tools for assessing the effects of groundwater withdrawals. Past, present, and future groundwater withdrawals from the Big Chino sub-basin will affect groundwater levels in the Big Chino area and groundwater discharge at the headwaters of the Verde River, specifically at the Upper Verde Springs, which is believed to be a major discharge zone of groundwater from the sub-basin. The amount and timing of reduced discharge as base flow is a function of connections between hydrogeologic (aquifer) units, aquifer storage properties and transmissivity, and proximity of withdrawal locations to discharge areas. To better define the aquifer units and aquifer storage properties, the United States Geological Survey, Cities of Prescott and Prescott Valley, and Salt River Project have initiated an ongoing geophysical study using controlled-source audio-frequency magnetotellurics (CSAMT) and repeat microgravity methods. CSAMT, a high-energy electromagnetic method sensitive to lithologic variations between rock and sediment types, is useful for defining aquifers at depths of up to 600 meters. Visual display of CSAMT profiles using Google Earth is useful for understanding and visualizing the relation between geophysics and Big Chino Sub-basin hydrogeology. Initial results from repeat microgravity surveys, which measure changes in subsurface mass (and therefore aquifer storage) over time, reveal spatial variation in the relation between aquifer storage changes and groundwater level changes. This variation reflects different confining conditions and multiple aquifer systems in different parts of the aquifer. Information about confining conditions and multiple aquifers could improve numerical groundwater models and predictions of future groundwater-level and base-flow depletion.

Influence of permafrost distribution on groundwater flow in the context of climate-driven permafrost thaw: example from Yukon Flats Basin, Alaska, United States

USGS Publications Warehouse

Walvoord, Michelle Ann; Voss, Clifford I.; Wellman, Tristan P.

2012-01-01

Understanding the role of permafrost in controlling groundwater flow paths and fluxes is central in studies aimed at assessing potential climate change impacts on vegetation, species habitat, biogeochemical cycling, and biodiversity. Recent field studies in interior Alaska show evidence of hydrologic changes hypothesized to result from permafrost degradation. This study assesses the hydrologic control exerted by permafrost, elucidates modes of regional groundwater flow for various spatial permafrost patterns, and evaluates potential hydrologic consequences of permafrost degradation. The Yukon Flats Basin (YFB), a large (118,340 km2) subbasin within the Yukon River Basin, provides the basis for this investigation. Model simulations that represent an assumed permafrost thaw sequence reveal the following trends with decreasing permafrost coverage: (1) increased groundwater discharge to rivers, consistent with historical trends in base flow observations in the Yukon River Basin, (2) potential for increased overall groundwater flux, (3) increased spatial extent of groundwater discharge in lowlands, and (4) decreased proportion of suprapermafrost (shallow) groundwater contribution to total base flow. These trends directly affect the chemical composition and residence time of riverine exports, the state of groundwater-influenced lakes and wetlands, seasonal river-ice thickness, and stream temperatures. Presently, the YFB is coarsely mapped as spanning the continuous-discontinuous permafrost transition that model analysis shows to be a critical threshold; thus, the YFB may be on the verge of major hydrologic change should the current permafrost extent decrease. This possibility underscores the need for improved characterization of permafrost and other hydrogeologic information in the region via geophysical techniques, remote sensing, and ground-based observations.

75 FR 8395 - Bunker Hill Groundwater Basin, Riverside-Corona Feeder Project, San Bernardino and Riverside...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Bunker Hill Groundwater Basin, Riverside-Corona...) will prepare a joint EIS/EIR for the proposed Riverside-Corona Feeder Project. The public and agencies... participate in the planning, design, and construction of the Riverside-Corona Feeder Project including: (i) 20...

78 FR 35314 - Availability of Final Environmental Impact Statement; Bunker Hill Groundwater Basin, Riverside...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-12

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation [A10-1999-6000-100-00-0-0-3, 3501000] Availability of Final Environmental Impact Statement; Bunker Hill Groundwater Basin, Riverside-Corona Feeder... proposed Riverside-Corona Feeder Project. DATES: The Bureau of Reclamation will not make a decision on the...

Simulation of groundwater and surface-water resources and evaluation of water-management alternatives for the Chamokane Creek basin, Stevens County, Washington

USGS Publications Warehouse

Ely, D. Matthew; Kahle, Sue C.

2012-01-01

A three-dimensional, transient numerical model of groundwater and surface-water flow was constructed for Chamokane Creek basin to better understand the groundwater-flow system and its relation to surface-water resources. The model described in this report can be used as a tool by water-management agencies and other stakeholders to quantitatively evaluate the effects of potential increases in groundwater pumping on groundwater and surface-water resources in the basin. The Chamokane Creek model was constructed using the U.S. Geological Survey (USGS) integrated model, GSFLOW. GSFLOW was developed to simulate coupled groundwater and surface-water resources. The model uses 1,000-foot grid cells that subdivide the model domain by 102 rows and 106 columns. Six hydrogeologic units in the model are represented using eight model layers. Daily precipitation and temperature were spatially distributed and subsequent groundwater recharge was computed within GSFLOW. Streamflows in Chamokane Creek and its major tributaries are simulated in the model by routing streamflow within a stream network that is coupled to the groundwater-flow system. Groundwater pumpage and surface-water diversions and returns specified in the model were derived from monthly and annual pumpage values previously estimated from another component of this study and new data reported by study partners. The model simulation period is water years 1980-2010 (October 1, 1979, to September 30, 2010), but the model was calibrated to the transient conditions for water years 1999-2010 (October 1, 1998, to September 30, 2010). Calibration was completed by using traditional trial-and-error methods and automated parameter-estimation techniques. The model adequately reproduces the measured time-series groundwater levels and daily streamflows. At well observation points, the mean difference between simulated and measured hydraulic heads is 7 feet with a root-mean-square error divided by the total difference in water levels of 4.7 percent. Simulated streamflow was compared to measured streamflow at the USGS streamflow-gaging station-Chamokane Creek below Falls, near Long Lake (12433200). Annual differences between measured and simulated streamflow for the site ranged from -63 to 22 percent. Calibrated model output includes a 31-year estimate of monthly water budget components for the hydrologic system. Five model applications (scenarios) were completed to obtain a better understanding of the relation between groundwater pumping and surface-water resources. The calibrated transient model was used to evaluate: (1) the connection between the upper- and middle-basin groundwater systems, (2) the effect of surface-water and groundwater uses in the middle basin, (3) the cumulative impacts of claims registry use and permit-exempt wells on Chamokane Creek streamflow, (4) the frequency of regulation due to impacted streamflow, and (5) the levels of domestic and stockwater use that can be regulated. The simulation results indicated that streamflow is affected by existing groundwater pumping in the upper and middle basins. Simulated water-management scenarios show streamflow increased relative to historical conditions as groundwater and surface-water withdrawals decreased.

Distribution and migration mechanism of fluoride in groundwater in the Manas River Basin, Northwest China

NASA Astrophysics Data System (ADS)

Liu, Yalei; Jin, Menggui; Ma, Bin; Wang, Jianjun

2018-04-01

Elevated fluoride (F) concentration in groundwater is posing a public health risk in the Manas River Basin (MRB), Northwest China. Based on the characterization of regional groundwater flow, 90 groundwater samples from aquifers were analyzed, along with top-soil leachate and pore-water samples from aquitards. Stable oxygen (δ18O) and hydrogen isotopes, radiocarbon and hydrochemical analyses of the groundwater and pore-water samples were conducted to trace groundwater hydrological and hydrochemical processes and thereby understand the distribution and migration mechanism of F. The groundwater is recharged by meteoric precipitation through vapor condensation processes in the Tianshan Mountains. The F concentration in groundwater samples from this basin ranged from 0.11 to 48.15 mg/L (mean 2.56 mg/L). In 37 of the 90 groundwater samples, the F concentrations were above the safe level for drinking water. The F concentrations progressively increased with the residence time and well depths in the northwest of the alluvial-fluvial plain, where groundwater is overexploited for agricultural and domestic use. Positive correlations between F and sodium (Na)/calcium (Ca) indicate that the enrichment and migration of F are influenced by cation exchange processes under high-Na and alkaline pH conditions. The relationships between δ18O and F and chloride (Cl) concentrations were nonlinear due to leaching and mixing processes. This shows that vertical leaching by irrigation return flow and mixing with pore water are the dominant processes driving the migration of F in the groundwater flow system of MRB, in addition to geochemical processes.

Response of the groundwater system in the Guanzhong Basin (central China) to climate change and human activities

NASA Astrophysics Data System (ADS)

Wang, Wenke; Zhang, Zaiyong; Duan, Lei; Wang, Zhoufeng; Zhao, Yaqian; Zhang, Qian; Dai, Meiling; Liu, Huizhong; Zheng, Xiaoyan; Sun, Yibo

2018-03-01

The Guanzhong Basin in central China features a booming economy and has suffered severe drought, resulting in serious groundwater depletion in the last 30 years. As a major water resource, groundwater plays a significant role in water supply. The combined impact of climate change and intensive human activities has caused a substantial decline in groundwater recharge and groundwater levels, as well as degradation of groundwater quality and associated changes in the ecosystems. Based on observational data, an integrated approach was used to assess the impact of climate change and human activities on the groundwater system and the base flow of the river basin. Methods included: river runoff records and a multivariate statistical analysis of data including historical groundwater levels and climate; hydro-chemical investigation and trend analysis of the historical hydro-chemical data; wavelet analysis of climate data; and the base flow index. The analyses indicate a clear warming trend and a decreasing trend in rainfall since the 1960s, in addition to increased human activities since the 1970s. The reduction of groundwater recharge in the past 30 years has led to a continuous depletion of groundwater levels, complex changes of the hydro-chemical environment, localized salinization, and a strong decline of the base flow to the river. It is expected that the results will contribute to a more comprehensive management plan for groundwater and the related eco-environment in the face of growing pressures from intensive human activities superimposed on climate change in this region.

Isotopes and Sustainability of the Shallow Groundwater System in Spring and Snake Valleys, Eastern White Pine County, Nevada

NASA Astrophysics Data System (ADS)

Acheampong, S. Y.

2007-12-01

A critical component to managing water resources is understanding the source of ground water that is extracted from a well. Detail information on the source of recharge and the age of groundwater is thus vital for the proper assessment, development, management, and monitoring of the groundwater resources in an area. Great differences in the isotopic composition of groundwater in a basin and the basin precipitation imply that the groundwater in the basin originates from a source outside the basin or is recharged under different climatic conditions. The stable isotopes of oxygen and hydrogen in precipitation were compared with the isotopic composition of water from wells, springs, and creeks to evaluate the source of the shallow groundwater recharge in Spring and Snake Valleys, Nevada, as part of an evaluation of the water resources in the area. Delta deuterium and delta oxygen-18 composition of springs, wells, creeks, and precipitation in Spring and Snake Valleys show that groundwater recharge occurs primarily from winter precipitation in the surrounding mountains. The carbon-14 content of the groundwater ranged from 30 to 95 percent modern carbon (pmc). Twenty two of the thirty samples had carbon-14 values of greater than 50 pmc. The relatively high carbon-14 values suggest that groundwater in the area is recharged by modern precipitation and the waters have rapid travel times. Total dissolved solids content of the samples outside the playa areas are generally low, and suggests that the water has a relatively short travel time between the recharge areas and sample sites. The presence of tritium in some of the springs and wells also indicate that groundwater mixes with post 1952 precipitation. Hydrogen bomb tests which began in 1952 in the northern hemisphere added large amounts of tritium to the atmosphere and reached a peak in 1963. The stable isotopic composition, the high carbon-14 activities, and the presence of tritium, show that the shallow groundwater in Snake and Spring Valleys originates as modern recharge. The shallow groundwater in these valleys is thus a renewable resource and can be developed in a sustainable manner using the appropriate planning and management tools.

Balancing Ground-Water Withdrawals and Streamflow in the Hunt-Annaquatucket-Pettaquamscutt Basin, Rhode Island

USGS Publications Warehouse

Barlow, Paul M.; Dickerman, David C.

2001-01-01

Ground water withdrawn for water supply reduces streamflow in the Hunt-Annaquatucket-Pettaquamscutt Basin in Rhode Island. These reductions may adversely affect aquatic habitats. A hydrologic model was prepared by the U.S. Geological Survey in cooperation with the Rhode Island Water Resources Board, Town of North Kingstown, Rhode Island Department of Environmental Management, and Rhode Island Economic Development Corporation to aid water-resource planning in the basin. Results of the model provide information that helps water suppliers and natural-resource managers evaluate strategies for balancing ground-water development and streamflow reductions in the basin.

Water resources data, Idaho, 2002; Volume 1. Great Basin and Snake River basin above King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; Campbell, A.M.; O'Dell, I.; Beattie, S.E.

2003-01-01

Water resources data for the 2002 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The two volumes of this report contain discharge records for 196 stream-gaging stations and 15 irrigation diversions; stage only records for 5 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 78 stream-gaging stations and partial record sites, 3 lakes sites, and 383 groundwater wells; and water levels for 425 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Water resources data, Idaho, 2002; Volume 2. Upper Columbia River basin and Snake River basin below King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; Campbell, A.M.; O'Dell, I.; Beattie, S.E.

2003-01-01

Water resources data for the 2002 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The two volumes of this report contain discharge records for 196 stream-gaging stations and 15 irrigation diversions; stage only records for 5 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 78 stream-gaging stations and partial record sites, 3 lakes sites, and 383 groundwater wells; and water levels for 425 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Nitrate source identification in groundwater of multiple land-use areas by combining isotopes and multivariate statistical analysis: A case study of Asopos basin (Central Greece).

PubMed

Matiatos, Ioannis

2016-01-15

Nitrate (NO3) is one of the most common contaminants in aquatic environments and groundwater. Nitrate concentrations and environmental isotope data (δ(15)N-NO3 and δ(18)O-NO3) from groundwater of Asopos basin, which has different land-use types, i.e., a large number of industries (e.g., textile, metal processing, food, fertilizers, paint), urban and agricultural areas and livestock breeding facilities, were analyzed to identify the nitrate sources of water contamination and N-biogeochemical transformations. A Bayesian isotope mixing model (SIAR) and multivariate statistical analysis of hydrochemical data were used to estimate the proportional contribution of different NO3 sources and to identify the dominant factors controlling the nitrate content of the groundwater in the region. The comparison of SIAR and Principal Component Analysis showed that wastes originating from urban and industrial zones of the basin are mainly responsible for nitrate contamination of groundwater in these areas. Agricultural fertilizers and manure likely contribute to groundwater contamination away from urban fabric and industrial land-use areas. Soil contribution to nitrate contamination due to organic matter is higher in the south-western part of the area far from the industries and the urban settlements. The present study aims to highlight the use of environmental isotopes combined with multivariate statistical analysis in locating sources of nitrate contamination in groundwater leading to a more effective planning of environmental measures and remediation strategies in river basins and water bodies as defined by the European Water Frame Directive (Directive 2000/60/EC).

Status and understanding of groundwater quality in the northern San Joaquin Basin, 2005

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth; Jurgens, Bryant C.

2010-01-01

Groundwater quality in the 2,079 square mile Northern San Joaquin Basin (Northern San Joaquin) study unit was investigated from December 2004 through February 2005 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 that was passed by the State of California and is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The Northern San Joaquin study unit was the third study unit to be designed and sampled as part of the Priority Basin Project. Results of the study provide a spatially unbiased assessment of the quality of raw (untreated) groundwater, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 61 wells in parts of Alameda, Amador, Calaveras, Contra Costa, San Joaquin, and Stanislaus Counties; 51 of the wells were selected using a spatially distributed, randomized grid-based approach to provide statistical representation of the study area (grid wells), and 10 of the wells were sampled to increase spatial density and provide additional information for the evaluation of water chemistry in the study unit (understanding/flowpath wells). The primary aquifer systems (hereinafter, primary aquifers) assessed in this study are defined by the depth intervals of the wells in the California Department of Public Health database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. Two types of assessments were made: (1) status, assessment of the current quality of the groundwater resource; and (2) understanding, identification of the natural and human factors affecting groundwater quality. Relative-concentrations (sample concentrations divided by benchmark concentrations) were used for evaluating groundwater quality for those constituents that have Federal or California regulatory or non-regulatory benchmarks for drinking-water quality. Benchmarks used in this study were either health-based (regulatory and non-regulatory) or aesthetic based (non-regulatory). For inorganic constituents, relative-concentrations were classified as high (equal to or greater than 1.0), indicating relative-concentrations greater than benchmarks; moderate (equal to or greater than 0.5, and less than 1.0); or, low (less than 0.5). For organic and special- interest constituents [1,2,3-trichloropropane (1,2,3-TCP), N-nitrosodimethylamine (NDMA), and perchlorate], relative- concentrations were classified as high (equal to or greater than 1.0); moderate (equal to or greater than 0.1 and less than 1.0); or, low (less than 0.1). Aquifer-scale proportion was used as the primary metric in the status assessment for groundwater quality. High aquifer- scale proportion is defined as the percentage of the primary aquifer with relative-concentrations greater than 1.0; moderate and low aquifer-scale proportions are defined as the percentage of the primary aquifer with moderate and low relative- concentrations, respectively. The methods used to calculate aquifer-scale proportions are based on an equal-area grid; thus, the proportions are areal rather than volumetric. Two statistical approaches - grid-based, which used one value per grid cell, and spatially weighted, which used the full dataset - were used to calculate aquifer-scale proportions for individual constituents and classes of constituents. The spatially weighted estimates of high aquifer-scale proportions were within the 90-percent confidence intervals of the grid-based estimates in all cases. The understanding assessment used statistical correlations between constituent relative-concentrations and

Assessment of processes controlling the regional distribution of fluoride and arsenic in groundwater of the Pampeano Aquifer in the Del Azul Creek basin (Argentina)

NASA Astrophysics Data System (ADS)

Zabala, M. E.; Manzano, M.; Vives, L.

2016-10-01

Groundwater in the upper 50 m of the Pampeano Aquifer in the Del Azul Creek basin (Argentina) has F and As contents above the WHO safe drinking levels. This basin is situated to the SE of the Chaco-Pampean plain, in Buenos Aires Province. The Pampeano Aquifer is a major water source for all uses. The aim of the study is to assess the primary processes controlling the regional distribution of F and As in the most exploited part of the aquifer. The study involved sampling for chemical and isotopic analyses, interpretation of data with different methods (diagrams, bivariate analyses, mineral saturation states, Principal Component Analysis) and deduction of leading processes. Information about aquifer mineralogy and hydrogeochemical processes involved in F and As solubilization in the aquifer has been taken from previous works of the same and other authors. Groundwater salinity increases to the NE, in the direction of the regional groundwater flow. Chemical types evolve from Ca/Mg-HCO3 in the upper part of the basin, to Na-HCO3 in the middle part and to Na-ClSO4 and Na-Cl in the lower part. The regional distribution of F is controlled by hydrogeochemical processes. The distribution of As is controlled by two types of processes dominating in different areas: hydrogeochemical controls prevail in the low to moderately mineralized groundwater of the middle and lower parts of the basin; hydrogeological controls lead to the NE of the lower basin and beyond it. In the last zone there are abundant lagoons and seasonal flooding is frequent, making evapoconcentration an important process for groundwater mineralization. The main hydrogeochemical processes involved in both F and As distribution are cation exchange, with Na release and Ca uptake, carbonate dissolution and pH increase. Arsenic release induced by redox processes may play to the NE, but its results would be masked by the effect of evaporation.

Groundwater arsenic contamination from parts of the Ghaghara Basin, India: influence of fluvial geomorphology and Quaternary morphostratigraphy

NASA Astrophysics Data System (ADS)

Shah, Babar Ali

2017-09-01

A groundwater arsenic (As) distribution in Faizabad, Gonda, and Basti districts of Uttar Pradesh is shown in the entrenched channels and floodplains of the Ghaghara River. Tubewell water samples were analysed for As through flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) system. About 38, 61, and 42 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As >10 µg/l (WHO guideline). Moreover, 15, 45, and 26 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As above 50 µg/l. About 86, 69, and 35 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, are from shallow depth (21-45 m), and it is worth noticing that 47 % As-contaminated (As >10 µg/l) tubewells in these three districts are located within the depth of 10-35 m in Holocene Newer Alluvium aquifers. The high content of As (7.11 mg/kg) is measured in suspended river sediments of the Ghaghara River. Most of the As-contaminated villages in the Ghaghara Basin are located close to abandoned or present meander channels and floodplains of the Ghaghara River. In contrast, tubewells in Faizabad, Ayodhya, and Nawabganj towns are As-safe because of their positions on the Pleistocene Older Alluvium upland surfaces. Quaternary geomorphology plays an important role in groundwater arsenic contamination in the Ghaghara Basin. The sources of groundwater arsenic are geogenic and perennial mountainous rivers in the Ghaghara Basin supplied high sediment loads. The arsenic in groundwater of Ghaghara Basin is getting released from associated sediments which were likely deposited from the Himalayas. The process of release of groundwater arsenic is reductive dissolution of iron hydroxides.

Water-balance and groundwater-flow estimation for an arid environment: San Diego region, California

NASA Astrophysics Data System (ADS)

Flint, L. E.; Flint, A. L.; Stolp, B. J.; Danskin, W. R.

2012-03-01

The coastal-plain aquifer that underlies the San Diego City metropolitan area in southern California is a groundwater resource. The understanding of the region-wide water balance and the recharge of water from the high elevation mountains to the east needs to be improved to quantify the subsurface inflows to the coastal plain in order to develop the groundwater as a long term resource. This study is intended to enhance the conceptual understanding of the water balance and related recharge processes in this arid environment by developing a regional model of the San Diego region and all watersheds adjacent or draining to the coastal plain, including the Tijuana River basin. This model was used to quantify the various components of the water balance, including semi-quantitative estimates of subsurface groundwater flow to the coastal plain. Other approaches relying on independent data were used to test or constrain the scoping estimates of recharge and runoff, including a reconnaissance-level groundwater model of the San Diego River basin, one of three main rivers draining to the coastal plain. Estimates of subsurface flow delivered to the coastal plain from the river basins ranged from 12.3 to 28.8 million m3 yr-1 from the San Diego River basin for the calibration period (1982-2009) to 48.8 million m3 yr-1 from all major river basins for the entire coastal plain for the long-term period 1940-2009. This range of scoping estimates represents the impact of climatic variability and realistically bounds the likely groundwater availability, while falling well within the variable estimates of regional recharge. However, the scarcity of physical and hydrologic data in this region hinders the exercise to narrow the range and reduce the uncertainty.

Spatial and temporal connections in groundwater contribution to evaporation

NASA Astrophysics Data System (ADS)

Lam, A.; Karssenberg, D.; van den Hurk, B. J. J. M.; Bierkens, M. F. P.

2011-08-01

In climate models, lateral terrestrial water fluxes are usually neglected. We estimated the contribution of vertical and lateral groundwater fluxes to the land surface water budget at a subcontinental scale, by modeling convergence of groundwater and surfacewater fluxes. We present a hydrological model of the entire Danube Basin at 5 km resolution, and use it to show the importance of groundwater for the surface climate. Results show that the contribution of groundwater to evaporation is significant, and can locally be higher than 30 % in summer. We demonstrate through the same model that this contribution also has important temporal characteristics. A wet episode can influence groundwater contribution to summer evaporation for several years afterwards. This indicates that modeling groundwater flow has the potential to augment the multi-year memory of climate models. We also show that the groundwater contribution to evaporation is local by presenting the groundwater travel times and the magnitude of groundwater convergence. Throughout the Danube Basin the lateral fluxes of groundwater are negligible when modeling at this scale and resolution. This suggests that groundwater can be adequately added in land surface models by including a lower closed groundwater reservoir of sufficient size with two-way interaction with surface water and the overlying soil layers.

Evaluation of the sustainability of deep groundwater as an arsenic-safe resource in the Bengal Basin

USGS Publications Warehouse

Michael, H.A.; Voss, C.I.

2008-01-01

Tens of millions of people in the Bengal Basin region of Bangladesh and India drink groundwater containing unsafe concentrations of arsenic. This high-arsenic groundwater is produced from shallow (150 m where groundwater arsenic concentrations are nearly uniformly low, and many more wells are needed, however, the sustainability of deep, arsenic-safe ground-water has not been previously assessed. Deeper pumping could induce downward migration of dissolved arsenic, permanently destroying the deep resource. Here, it is shown, through quantitative, large-scale hydrogeologic analysis and simulation of the entire basin, that the deeper part of the aquifer system may provide a sustainable source of arsenic-safe water if its utilization is limited to domestic supply. Simulations provide two explanations for this result: deep domestic pumping only slightly perturbs the deep groundwater flow system, and substantial shallow pumping for irrigation forms a hydraulic barrier that protects deeper resources from shallow arsenic sources. Additional analysis indicates that this simple management approach could provide arsenic-safe drinking water to >90% of the arsenic-impacted region over a 1,000-year timescale. This insight may assist water-resources managers in alleviating one of the world's largest groundwater contamination problems. ?? 2008 by The National Academy of Sciences of the USA.

Groundwater quality in the Madera and Chowchilla subbasins of the San Joaquin Valley, California

USGS Publications Warehouse

Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

2013-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. The Madera and Chowchilla subbasins of the San Joaquin Valley constitute one of the study units being evaluated. The Madera-Chowchilla study unit is about 860 square miles and consists of the Madera and Chowchilla groundwater subbasins of the San Joaquin Valley Basin (California Department of Water Resources, 2003; Shelton and others, 2009). The study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 11 to 15 inches, most of which occurs between November and February. The main surface-water features in the study unit are the San Joaquin, Fresno, and Chowchilla Rivers, and the Madera and Chowchilla canals. Land use in the study unit is about 69 percent (%) agricultural, 28% natural (mainly grasslands), and 3% urban. The primary crops are orchards and vineyards. The largest urban area is the city of Madera. The primary aquifer system is defined as those parts of the aquifer corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. In the Madera-Chowchilla study unit, these wells typically are drilled to depths between 200 and 800 feet, consist of a solid casing from land surface to a depth of about 140 to 400 feet, and are perforated below the solid casing. Water quality in the primary aquifer system may differ from that in the shallower and deeper parts of the aquifer system. The primary aquifer system in the study unit consists of Quaternary-age alluvial-fan and fluvial deposits that were formed by the rivers draining the Sierra Nevada. Sediments consist of gravels, sands, silts, and clays and generally are coarser closest to the Sierra Nevada and become finer towards the center of the basin. The structure and composition of the deposits in the Madera-Chowchilla study unit are different from those in other parts of the eastern San Joaquin Valley because the Fresno and Chowchilla Rivers primarily drain the Sierra Nevada foothills, whereas the larger rivers drain higher elevations with greater sediment supply. These differences in the sources of sediments are important because they may affect the groundwater chemistry and the physical structure of the sedimentary deposits. Some of the clay layers are lacustrine deposits, the most extensive of which, the Corcoran Clay, underlies the western part of the study unit and divides the primary aquifer system into an unconfined to semi-confined upper system and a largely confined lower system. Regional lateral flow of groundwater is southwest towards the valley trough. Irrigation return flows are the major source of groundwater recharge, and groundwater pumping is the major source of discharge. Groundwater on a lateral flow path may be repeatedly extracted by pumping wells and reapplied at the surface multiple times before reaching the valley trough, resulting in a substantial component of downward vertical flow (Burow and others, 2004; Phillips and others, 2007; Faunt, 2009). This flow pattern enhances movement of water from shallow depths to the primary aquifer system.

National Water-Quality Assessment Program: Central Arizona Basins

USGS Publications Warehouse

Cordy, Gail E.

1994-01-01

In 1991, the U.S. Geological Survey (USGS) began to implement a full-scale National Water-Quality Assessment (NAWQA) program. The long-term goals of the NAWQA program are to describe the status and trends in the quality of a large, representative part of the Nation's surface-water and ground-water resources and to provide a sound, scientific understanding of the primary natural and human factors affecting the quality of these resources. In meeting these goals, the program will produce a wealth of water-quality information that will be useful to policymakers and managers at the National, State, and local levels. Studies of 60 hydrologic systems that include parts of most major river basins and aquifer systems (study-unit investigations) are the building blocks of the national assessment. The 60 study units range in size from 1,000 to about 60,000 mi2 and represent 60 to 70 percent of the Nation's water use and population served by public water supplies. Twenty study-unit investigations were started in 1991, 20 additional studies started in 1994, and 20 more are planned to start in 1997. The Central Arizona Basins study unit began assessment activities in 1994.

Hydrogeology of the Little Spokane River Basin, Spokane, Stevens, and Pend Oreille Counties, Washington

USGS Publications Warehouse

Kahle, Sue C.; Olsen, Theresa D.; Fasser, Elisabeth T.

2013-01-01

A study of the hydrogeologic framework of the Little Spokane River Basin was conducted to identify and describe the principal hydrogeologic units in the study area, their hydraulic characteristics, and general directions of groundwater movement. The Little Spokane River Basin includes an area of 679 square miles in northeastern Washington State covering parts of Spokane, Stevens, and Pend Oreille Counties. The groundwater system consists of unconsolidated sedimentary deposits and isolated, remnant basalt layers overlying crystalline bedrock. In 1976, a water resources program for the Little Spokane River was adopted into rule by the State of Washington, setting instream flows for the river and closing its tributaries to further uses. Spokane County representatives are concerned about the effects that additional groundwater development within the basin might have on the Little Spokane River and on existing groundwater resources. Information provided by this study will be used in future investigations to evaluate the effects of potential increases in groundwater withdrawals on groundwater and surface-water resources in the basin. The hydrogeologic framework consists of eight hydrogeologic units: the Upper aquifer, Upper confining unit, Lower aquifers, Lower confining unit, Wanapum basalt unit, Latah unit, Grande Ronde basalt unit, and Bedrock. The Upper aquifer is composed mostly of sand and gravel and varies in thickness from 4 to 360 ft, with an average thickness of 70 ft. The aquifer is generally finer grained in areas farther from main outwash channels. The estimated horizontal hydraulic conductivity ranges from 4.4 to 410,000 feet per day (ft/d), with a median hydraulic conductivity of 900 ft/d. The Upper confining unit is a low-permeability unit consisting mostly of silt and clay, and varies in thickness from 5 to 400 ft, with an average thickness of 100 ft. The estimated horizontal hydraulic conductivity ranges from 0.5 to 5,600 ft/d, with a median hydraulic conductivity of 8.2 ft/d. The Lower aquifers unit consists of localized confined aquifers or lenses consisting mostly of sand that occur at depth in various places in the basin; thickness of the unit ranges from 8 to 150 ft, with an average thickness of 50 ft. The Lower confining unit is a low-permeability unit consisting mostly of silt and clay; thickness of the unit ranges from 35 to 310 ft, with an average thickness of 130 ft. The Wanapum basalt unit includes the Wanapum Basalt of the Columbia River Basalt Group, thin sedimentary interbeds, and, in some places, overlying loess. The unit occurs as isolated remnants on the basalt bluffs in the study area and ranges in thickness from 7 to 140 ft, with an average thickness of 60 ft. The Latah unit is a mostly low-permeability unit consisting of silt, clay, and sand that underlies and is interbedded with the basalt units. The Latah unit ranges in thickness from 10 to 700 ft, with an average thickness of 250 ft. The estimated horizontal hydraulic conductivity ranges from 0.19 to 15 ft/d, with a median hydraulic conductivity of 0.56 ft/d. The Grande Ronde unit includes the Grande Ronde Basalt of the Columbia River Basalt Group and sedimentary interbeds. Unit thickness ranges from 30 to 260 ft, with an average thickness of 140 ft. The estimated horizontal hydraulic conductivity ranges from 0.03 to 13 ft/d, with a median hydraulic conductivity of 2.9 ft/d. The Bedrock unit is the only available source of groundwater where overlying sediments are absent or insufficiently saturated. The estimated horizontal hydraulic conductivity ranges from 0.01 to 5,000 ft/d, with a median hydraulic conductivity of 1.4 ft/d. The altitude of the buried bedrock surface ranges from about 2,200 ft to about 1,200 ft. Groundwater movement in the Little Spokane River Basin mimics the surface-water drainage pattern of the basin, moving from the topographically high tributary-basin areas toward the topographically lower valley floors. Water-level altitudes range from more than 2,700 ft to about 1,500 ft near the basin’s outlet.

Geochemistry of ground water in alluvial basins of Arizona and adjacent parts of Nevada, New Mexico, and California

USGS Publications Warehouse

Robertson, Frederick N.

1991-01-01

Chemical and isotope analyses of ground water from 28 basins in the Basin and Range physiographic province of Arizona and parts of adjacent States were used to evaluate ground-water quality, determine processes that control ground-water chemistry, provide independent insight into the hydrologic flow system, and develop information transfer. The area is characterized by north- to northwest-trending mountains separated by alluvial basins that form a regional topography of alternating mountains and valleys. On the basis of ground-water divides or zones of minimal basin interconnection, the area was divided into 72 basins, each representing an individual aquifer system. These systems are joined in a dendritic pattern and collectively constitute the major water resource in the region. Geochemical models were developed to identify reactions and mass transfer responsible for the chemical evolution of the ground water. On the basis of mineralogy and chemistry of the two major rock associations of the area, a felsic model and a mafic model were developed to illustrate geologic, climatic, and physiographic effects on ground-water chemistry. Two distinct hydrochemical processes were identified: (1) reactions of meteoric water with minerals and gases in recharge areas and (2) reactions of ground water as it moves down the hydraulic gradient. Reactions occurring in recharge and downgradient areas can be described by a 13-component system. Major reactions are the dissolution and precipitation of calcite and dolomite, the weathering of feldspars and ferromagnesian minerals, the formation of montmorillonite, iron oxyhydroxides, and probably silica, and, in some basins, ion exchange. The geochemical modeling demonstrated that relatively few phases are required to derive the ground-water chemistry; 14 phases-12 mineral and 2 gas-consistently account for the chemical evolution in each basin. The final phases were selected through analysis of X-ray diffraction and fluorescence data, aqueous speciation and saturation data, and mass-balance and isotopic constraints and through chemical models developed from mineral combinations among the 27 phases that were considered realistic in these geologically and mineralogically complex basins. X-ray diffraction of basin-fill sediments confirm the presence of the postulated minerals and their weathering sequences. High partial pressures of soil CO2 and large concentrations of dissolved CO2 in recharge areas, and the rapid depletion of CO2 downgradient, accompanied by high weathering rates of the silicates which also decrease downgradient, indicate that carbonic acid is the impetus in the weathering process. Reactions in the soil zone and the unsaturated zone are influential and, in some instances, are as important as the mineralogy of the source rock in determining ground-water compositions. The basins can be divided geochemically into two general categories-closed systems, which evolve under closed hydrologic conditions, and open systems, which are open to CO2 and other constituents along the flow path. The ground-water chemistry of the unconfined aquifers in the eastern part of the study area and of the aquifers underlying the flood plain along the Colorado River generally evolves under open conditions. The ground-water chemistry of most basins in the central and western parts and of the confined aquifers in the eastern part evolves under closed conditions. The factors that determine whether a basin is an open or closed system are the amount of and the spatial and seasonal distribution of annual precipitation and the presence or absence of fine-grained confining units. The basins along the Colorado River are unique among basins in the region. Virtually all ground water underlying the flood plain originated as seepage or overbank flow from the Colorado River. Initial deuterium content of about -120 per mil is indicative of precipitation from the central part of Colorado. Using chemical m

Analysis of 1997–2008 groundwater level changes in the upper Deschutes Basin, Central Oregon

USGS Publications Warehouse

Gannett, Marshall W.; Lite, Kenneth E.

2013-01-01

Groundwater-level monitoring in the upper Deschutes Basin of central Oregon from 1997 to 2008 shows water-level declines in some places that are larger than might be expected from climate variations alone, raising questions regarding the influence of groundwater pumping, canal lining (which decreases recharge), and other human influences. Between the mid-1990s and mid-2000s, water levels in the central part of the basin near Redmond steadily declined as much as 14 feet. Water levels in the Cascade Range, in contrast, rose more than 20 feet from the mid-1990s to about 2000, and then declined into the mid-2000s, with little or no net change. An existing U.S. Geological Survey regional groundwater-flow model was used to gain insights into groundwater-level changes from 1997 to 2008, and to determine the relative influence of climate, groundwater pumping, and irrigation canal lining on observed water-level trends. To utilize the model, input datasets had to be extended to include post-1997 changes in groundwater pumping, changes in recharge from precipitation, irrigation canal leakage, and deep percolation of applied irrigation water (also known as on-farm loss). Mean annual groundwater recharge from precipitation during the 1999–2008 period was 25 percent less than during the 1979–88 period because of drying climate conditions. This decrease in groundwater recharge is consistent with measured decreases in streamflow and discharge to springs. For example, the mean annual discharge of Fall River, which is a spring-fed stream, decreased 12 percent between the 1979–88 and 1999–2008 periods. Between the mid-1990s and late 2000s, groundwater pumping for public-supply and irrigation uses increased from about 32,500 to 52,000 acre-feet per year, partially because of population growth. Between 1997 and 2008, the rate of recharge from leaking irrigation canals decreased by about 58,000 acre-feet per year as a result of lining and piping of canals. Decreases in recharge from on-farm losses over the past decade were relatively small, approaching an estimated 1,000 acre-feet per year by the late 2000s. All these changes in the hydrologic budget contributed to declines in groundwater levels. Groundwater flow model simulations indicate that climate variations have the largest influence on groundwater levels throughout the upper Deschutes Basin, and that impacts from pumping and canal lining also contribute but are largely restricted to the central part of the basin that extends north from near Benham Falls to Lower Bridge, and east from Sisters to the community of Powell Butte. Outside of this central area, the water-level response from changes in pumping and irrigation canal leakage cannot be discerned from the larger response to climate-driven changes in recharge. Within this central area, where measured water-level declines have generally ranged from about 5 to 14 feet since the mid-1990s, climate variations are still the dominant factor influencing groundwater levels, accounting for approximately 60–70 percent of the measured declines. Post-1994 increases in groundwater pumping account for about 20–30 percent of the measured declines in the central part of the basin, depending on location, and decreases in recharge due to canal lining account for about 10 percent of the measured declines. Decreases in recharge from on-farm losses were simulated, but the effects were negligible compared to climate influences, groundwater pumping, and the effects of canal lining and piping. Observation well data and model simulation results indicate that water levels in the Cascade Range rose and declined tens of feet in response to wet and dry climate cycles over the past two decades. Water levels in the central part of the basin, in contrast, steadily declined during the same period, with the rate of decline lessening during wet periods. This difference is because the water-level response from recharge is damped as water moves (diffuses) from the principal recharge area in the Cascade Range to discharge points along the main stems of the Deschutes, Crooked, and Metolius Rivers in the central part of the basin. Water levels in the central part of the basin respond more to multi-decadal climate trends than shorter term changes. Groundwater-flow simulations show that the effects from increased pumping and decreased irrigation canal leakage extend south into the Bend area. However, the only wells presently monitored in the Bend area are heavily influenced by the Deschutes River, which dampens any response of water levels to external stresses such as groundwater pumping, changes in canal leakage, or climate variations.

MX Siting Investigation. Water Resources Program, Technical Summary Report. Volume II.

DTIC Science & Technology

1981-11-30

Selected digital computer techniques for groundwater resource evaluation, Illinois State Water Survey, Bulletin No. 55. Robinson, B. P., Thordarson , W., and...34, American Geophysical Union Transactions, v. 16. Thordarson , W., and Robinson, B. P., 1971, Wells and springs in California and Nevada within 100... Thordarson , W., 1975, Hydrogeologic and hydro- chemical framework, south-central Great Basin, Nevada- * California, with special reference to the Nevada

Regional paleohydrologic and paleoclimatic settings of wetland/lacustrine depositional systems in the Morrison Formation (Upper Jurassic), Western Interior, USA

USGS Publications Warehouse

Dunagan, S.P.; Turner, C.E.

2004-01-01

During deposition of the Upper Jurassic Morrison Formation, water that originated as precipitation in uplands to the west of the Western Interior depositional basin infiltrated regional aquifers that underlay the basin. This regional groundwater system delivered water into the otherwise dry continental interior basin where it discharged to form two major wetland/lacustrine successions. A freshwater carbonate wetland/lacustrine succession formed in the distal reaches of the basin, where regional groundwater discharged into the Denver-Julesburg Basin, which was a smaller structural basin within the more extensive Western Interior depositional basin. An alkaline-saline wetland/lacustrine complex (Lake T'oo'dichi') formed farther upstream, where shallower aquifers discharged into the San Juan/Paradox Basin, which was another small structural basin in the Western Interior depositional basin. These were both wetlands in the sense that groundwater was the major source of water. Input from surface and meteoric water was limited. In both basins, lacustrine conditions developed during episodes of increased input of surface water. Inclusion of wetlands in our interpretation of what had previously been considered largely lacustrine systems has important implications for paleohydrology and paleoclimatology. The distal carbonate wetland/lacustrine deposits are well developed in the Morrison Formation of east-central Colorado, occupying a stratigraphic interval that is equivalent to the "lower" Morrison but extends into the "upper" Morrison Formation. Sedimentologic, paleontologic, and isotopic evidence indicate that regional groundwater discharge maintained shallow, hydrologically open, well oxygenated, perennial carbonate wetlands and lakes despite the semi-arid climate. Wetland deposits include charophyte-rich wackestone and green mudstone. Lacustrine episodes, in which surface water input was significant, were times of carbonate and siliciclastic deposition in scarce deltaic and shoreline deposits. Marginal lacustrine deposits include ooid and skeletal packstone-grainstone, siltstone, and sandstone. Distal lacustrine units are skeletal mudstone-wackestone, microbialites, and laminated (siliciclastic) mudstone. Differentiation between wetlands and distal lacustrine units is not always possible. Palustrine features, Magadi-type chert (MTC), and evaporites record episodes of increased aridity and exposure. Farther upstream, during deposition of the upper part of the Brushy Basin Member, the ancestral Uncompahgre Uplift imposed a barrier to shallow, eastward-flowing groundwater that discharged into the San Juan/Paradox Basin on the upstream side of the uplift. This created the closed hydrologic setting necessary for development of an alkaline-saline wetland/lacustrine complex ("Lake" T'oo'dichi'). Silicic volcanic ash, delivered by prevailing winds from calderas west and southwest of the basin, contributed to the pore-water evolution in the sediments. A distinctive lateral hydrogeochemical gradient, reflecting increasing salinity and alkalinity in the pore waters, altered the ash to a variety of authigenic minerals that define concentric zones within the basin. The basinward progression of diagenetic mineral zones is smectite???clinoptilolite???analcime ??potassium feldspar???albite. The groundwater-fed wetlands were shallow and frequently evaporated to dryness. Scarce laminated gray mudstone beds record distinct episodes of freshwater lacustrine deposition that resulted from intermittent streams that carried detritus well out into the basin. ?? 2004 Elsevier B.V. All rights reserved.

Characterization of Surface Water and Groundwater Quality in the Lower Tano River Basin Using Statistical and Isotopic Approach.

NASA Astrophysics Data System (ADS)

Edjah, Adwoba; Stenni, Barbara; Cozzi, Giulio; Turetta, Clara; Dreossi, Giuliano; Tetteh Akiti, Thomas; Yidana, Sandow

2017-04-01

Adwoba Kua- Manza Edjaha, Barbara Stennib,c,Giuliano Dreossib, Giulio Cozzic, Clara Turetta c,T.T Akitid ,Sandow Yidanae a,eDepartment of Earth Science, University of Ghana Legon, Ghana West Africa bDepartment of Enviromental Sciences, Informatics and Statistics, Ca Foscari University of Venice, Italy cInstitute for the Dynamics of Environmental Processes, CNR, Venice, Italy dDepartment of Nuclear Application and Techniques, Graduate School of Nuclear and Allied Sciences University of Ghana Legon This research is part of a PhD research work "Hydrogeological Assessment of the Lower Tano river basin for sustainable economic usage, Ghana, West - Africa". In this study, the researcher investigated surface water and groundwater quality in the Lower Tano river basin. This assessment was based on some selected sampling sites associated with mining activities, and the development of oil and gas. Statistical approach was applied to characterize the quality of surface water and groundwater. Also, water stable isotopes, which is a natural tracer of the hydrological cycle was used to investigate the origin of groundwater recharge in the basin. The study revealed that Pb and Ni values of the surface water and groundwater samples exceeded the WHO standards for drinking water. In addition, water quality index (WQI), based on physicochemical parameters(EC, TDS, pH) and major ions(Ca2+, Na+, Mg2+, HCO3-,NO3-, CL-, SO42-, K+) exhibited good quality water for 60% of the sampled surface water and groundwater. Other statistical techniques, such as Heavy metal pollution index (HPI), degree of contamination (Cd), and heavy metal evaluation index (HEI), based on trace element parameters in the water samples, reveal that 90% of the surface water and groundwater samples belong to high level of pollution. Principal component analysis (PCA) also suggests that the water quality in the basin is likely affected by rock - water interaction and anthropogenic activities (sea water intrusion). This was confirm by further statistical analysis (cluster analysis and correlation matrix) of the water quality parameters. Spatial distribution of water quality parameters, trace elements and the results obtained from the statistical analysis was determined by geographical information system (GIS). In addition, the isotopic analysis of the sampled surface water and groundwater revealed that most of the surface water and groundwater were of meteoric origin with little or no isotopic variations. It is expected that outcomes of this research will form a baseline for making appropriate decision on water quality management by decision makers in the Lower Tano river Basin. Keywords: Water stable isotopes, Trace elements, Multivariate statistics, Evaluation indices, Lower Tano river basin.

A Comparison of Groundwater Storage Using GRACE Data, Groundwater Levels, and a Hydrological Model in Californias Central Valley

NASA Technical Reports Server (NTRS)

Kuss, Amber; Brandt, William; Randall, Joshua; Floyd, Bridget; Bourai, Abdelwahab; Newcomer, Michelle; Skiles, Joseph; Schmidt, Cindy

2011-01-01

The Gravity Recovery and Climate Experiment (GRACE) measures changes in total water storage (TWS) remotely, and may provide additional insight to the use of well-based data in California's agriculturally productive Central Valley region. Under current California law, well owners are not required to report groundwater extraction rates, making estimation of total groundwater extraction difficult. As a result, other groundwater change detection techniques may prove useful. From October 2002 to September 2009, GRACE was used to map changes in TWS for the three hydrological regions (the Sacramento River Basin, the San Joaquin River Basin, and the Tulare Lake Basin) encompassing the Central Valley aquifer. Net groundwater storage changes were calculated from the changes in TWS for each of the three hydrological regions and by incorporating estimates for additional components of the hydrological budget including precipitation, evapotranspiration, soil moisture, snow pack, and surface water storage. The calculated changes in groundwater storage were then compared to simulated values from the California Department of Water Resource's Central Valley Groundwater- Surface Water Simulation Model (C2VSIM) and their Water Data Library (WDL) Geographic Information System (GIS) change in storage tool. The results from the three methods were compared. Downscaling GRACE data into the 21 smaller Central Valley sub-regions included in C2VSIM was also evaluated. This work has the potential to improve California's groundwater resource management and use of existing hydrological models for the Central Valley.

Stable isotopes and volatile organic compounds along seven ground-water flow paths in divergent and convergent flow systems, southern California, 2000

USGS Publications Warehouse

Milby Dawson, Barbara J.; Belitz, Kenneth; Land, Michael; Danskin, Wesley R.

2003-01-01

Ground water is a major source of drinking water in southern California. In an effort to understand factors influencing the susceptibility of ground water tapped by public supply wells, the U.S. Geological Survey has undertaken studies in cooperation with the California State Water Resources Control Board. The vertical and lateral distribution of stable isotopes (deuterium and oxygen-18) and volatile organic compounds (VOC) were examined along seven ground-water flow paths in three urban ground-water basins in southern California: Central Basin in Los Angeles County, Main Basin in Orange County, and Bunker Hill Basin in San Bernardino County. Forty-seven monitoring wells and 100 public supply wells were sampled. The results of this study suggest that the direction of flow and perhaps the degree of confinement in an aquifer system are important controls on the distribution of VOCs. Ground-water flow in the Central and Main Basins in the southern California coastal plain is characterized as radially divergent, with ground-water flow directions moving outward from focused areas of recharge in the unconfined part of the aquifer system toward dispersed areas of discharge in the more confined part. In these basins, there is a volume of water containing VOCs that extends out into a volume of water containing no VOCs. This pattern suggests that radially divergent flow systems disperse VOCs in distal areas. The overall pattern also suggests that ground water in the pressure area is generally insulated from compounds introduced at land surface. These two factors?dispersion of VOCs due to divergence of flow and insulation from land-surface inputs?suggest that the susceptibility of public supply wells to surface contamination decreases with distance in radially divergent, well confined ground-water flow system. In the inland Bunker Hill Basin, ground-water flow is characterized as radially convergent; ground-water flow directions move inward from dispersed recharge areas in the unconfined part of the aquifer system, toward an area of focused discharge in the more confined part. The number of VOCs increased and the concentrations of individual VOCs increased, or remained the same, with increasing travel distance. Methyl tert-butyl ether was detected only in wells in the confined part of the aquifer system, suggesting that the confining units present in the distal part of the Bunker Hill Basin do not prevent VOCs from reaching ground water. These results suggest that VOCs in the Bunker Hill Basin are collected and concentrated as ground water moves downgradient because of radial convergenence of flow. They also suggest that ground water in the Bunker Hill Basin has an increasing opportunity to pick up VOCs introduced at land surface as it moves along a flow path. Some of the downgradient increase in VOC occurrence and concentration may be due to pumping that selectively removes cleaner ground water, thus leaving ground water containing more VOCs in the aquifer. These two factors?collection of VOCs due to convergence of flow and increasing opportunity to collect surficial contaminants perhaps due to a relative absence of confinement?suggest that the susceptibility of public supply wells to surface contamination increases with distance in radially convergent ground-water flow systems, particularly those that are unconfined.

Geospatial database of estimates of groundwater discharge to streams in the Upper Colorado River Basin

USGS Publications Warehouse

Garcia, Adriana; Masbruch, Melissa D.; Susong, David D.

2014-01-01

The U.S. Geological Survey, as part of the Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) initiative, compiled published estimates of groundwater discharge to streams in the Upper Colorado River Basin as a geospatial database. For the purpose of this report, groundwater discharge to streams is the baseflow portion of streamflow that includes contributions of groundwater from various flow paths. Reported estimates of groundwater discharge were assigned as attributes to stream reaches derived from the high-resolution National Hydrography Dataset. A total of 235 estimates of groundwater discharge to streams were compiled and included in the dataset. Feature class attributes of the geospatial database include groundwater discharge (acre-feet per year), method of estimation, citation abbreviation, defined reach, and 8-digit hydrologic unit code(s). Baseflow index (BFI) estimates of groundwater discharge were calculated using an existing streamflow characteristics dataset and were included as an attribute in the geospatial database. A comparison of the BFI estimates to the compiled estimates of groundwater discharge found that the BFI estimates were greater than the reported groundwater discharge estimates.

Water resources of Soledad, Poway, and Moosa basins, San Diego County, California

USGS Publications Warehouse

Evenson, K.D.

1989-01-01

Reclaimed water is being considered as as supplemental water supply in the Soledad, Poway, and Moosa basins, San Diego County. This report describes the geology, soils, hydrology, and cultural factors in each of the basins as they relate to use of reclaimed water. Imported water is currently the major water-supply source in the basins. Groundwater supplies are used to a limited extent for both agricultural and domestic needs. Surface water flows are intermittent and, therefore, have not been developed for use in the basins. All three of the basins have the potential for use of reclaimed water, but only the Moosa basin is currently implementing a plan for such use. Concentrations of dissolved solids, chloride, and sulfate in both ground and surface water commonly exceed local basin objectives. As of 1985, plans for use of reclaimed water are oriented toward improving the quality of the groundwater. (USGS)

Quantifying groundwater dependency of riparian surface hydrologic features using the exit gradient

EPA Science Inventory

This study examines groundwater exit gradients as a way to quantify groundwater interactions with surface water. We calibrated high resolution groundwater models for the basin fill sediments in the lower Calapooia watershed, Oregon, using data collected between 1928--2000. The e...

National Water-Quality Assessment program: The Trinity River Basin

USGS Publications Warehouse

Land, Larry F.

1991-01-01

In 1991, the U.S. Geological Survey (USGS) began to implement a full-scale National Water-Quality Assessment (NAWQA) program. The long-term goals of the NAWQA program are to describe the status and trends in the quality of a large, representative part of the Nation's surface- and ground-water resources and to provide a sound, scientific understanding of the primary natural and human factors affecting the quality of these resources. In meeting these goals, the program will produce a wealth of water-quality information that will be useful to policy makers and managers at the national, State, and local levels. A major design feature of the NAWQA program will enable water-quality information at different areal scales to be integrated. A major component of the program is study-unit investigations, which comprise the principal building blocks of the program on which national-level assessment activities will be based. The 60 study-unit investigations that make up the program are hydrologic systems that include parts of most major river basins and aquifer systems. These study units cover areas of 1,200 to more than 65,000 square miles and incorporate about 60 to 70 percent of the Nation's water use and population served by public water supply. In 1991, the Trinity River basin study was among the first 20 NAWQA study units selected for study under the full-scale implementation plan.

Suitability Evaluation on River Bank Filtration of the Second Songhua River, China

NASA Astrophysics Data System (ADS)

Wang, Lixue; Ye, Xueyan; Du, Xinqiang

2016-04-01

The Second Songhua River is the biggest river with the most economic value in Jilin Province, China. In recent years, with the rapid development of economy, water resources and water environment problem is getting prominent, including surface water pollution and over exploitation of groundwater resources, etc. By means of bank filtration, the Second Songhua River basin might realize the combined utilization of regional groundwater and surface water, and thus has important significance for the guarantee of water demand for industrial and agricultural production planning in the basin. The following steps were adopted to evaluate the suitability of bank filtration nearby the Scond Songhua River : Firstly, in order to focus on the most possible area, the evaluation area was divided based on the aspects of natural geographical conditions and hydraulic connection extent between river water and groundwater. Second, the main suitability indexes including water quantity, water quality, interaction intensity between surface water and groundwater, and the exploitation condition of groundwater resource, and nine sub-indexes including hydraulic conductivity, aquifer thickness, river runoff, the status of groundwater quality, the status of surface water quality, groundwater hydraulic gradient, possible influence zone width of surface water under the condition of groundwater exploitation, permeability of riverbed layer and groundwater depth were proposed to establish an evaluation index system for the suitability of river bank filtration. Thirdly, Combined with the natural geography, geology and hydrogeology conditions of the Second Songhua River basin, the ArcGIS technology is used to complete the evaluation of the various indicators. According to the weighted sum of each index, the suitability of river bank filtration in the study area is divided into five grades. The evaluation index system and evaluation method established in this article are applicable to the Second Songhua River basin, which have clear pertinence and limitation. For future generalization of the evaluation index system, the specific evaluation index and its scoring criteria should be modified appropriately based on local conditions.

Ground-Water Hydrology of the Upper Klamath Basin, Oregon and California

USGS Publications Warehouse

Gannett, Marshall W.; Lite, Kenneth E.; La Marche, Jonathan L.; Fisher, Bruce J.; Polette, Danial J.

2007-01-01

The upper Klamath Basin spans the California-Oregon border from the flank of the Cascade Range eastward to the Basin and Range Province, and encompasses the Klamath River drainage basin above Iron Gate Dam. Most of the basin is semiarid, but the Cascade Range and uplands in the interior and eastern parts of the basin receive on average more than 30 inches of precipitation per year. The basin has several perennial streams with mean annual discharges of hundreds of cubic feet per second, and the Klamath River at Iron Gate Dam, which represents drainage from the entire upper basin, has a mean annual discharge of about 2,100 cubic feet per second. The basin once contained three large lakes: Upper and Lower Klamath Lakes and Tule Lake, each of which covered areas of 100 to 150 square miles, including extensive marginal wetlands. Lower Klamath Lake and Tule Lake have been mostly drained, and the former lake beds are now cultivated. Upper Klamath Lake remains, and is an important source of irrigation water. Much of the wetland surrounding Upper Klamath Lake has been diked and drained, although efforts are underway to restore large areas. Upper Klamath Lake and the remaining parts of Lower Klamath and Tule Lakes provide important wildlife habitat, and parts of each are included in the Klamath Basin National Wildlife Refuges Complex. The upper Klamath Basin has a substantial regional ground-water flow system. The late Tertiary to Quaternary volcanic rocks that underlie the region are generally permeable, with transmissivity estimates ranging from 1,000 to 100,000 feet squared per day, and compose a system of variously interconnected aquifers. Interbedded with the volcanic rocks are late Tertiary sedimentary rocks composed primarily of fine-grained lake sediments and basin-filling deposits. These sedimentary deposits have generally low permeability, are not good aquifers, and probably restrict ground-water movement in some areas. The regional ground-water system is underlain and bounded on the east and west by older Tertiary volcanic and sedimentary rocks that have generally low permeability. Eight regional-scale hydrogeologic units are defined in the upper Klamath Basin on the basis of surficial geology and subsurface data. Ground water flows from recharge areas in the Cascade Range and upland areas in the basin interior and eastern margins toward stream valleys and interior subbasins. Ground water discharge to streams throughout the basin, and most streams have some component of ground water (baseflow). Some streams, however, are predominantly ground-water fed and have relatively constant flows throughout the year. Large amounts of ground water discharges in the Wood River subbasin, the lower Williamson River area, and along the margin of the Cascade Range. Much of the inflow to Upper Klamath Lake can be attributed to ground-water discharge to streams and major spring complexes within a dozen or so miles from the lake. This large component of ground water buffers the lake somewhat from climate cycles. There are also ground-water discharge areas in the eastern parts of the basin, for example in the upper Williamson and Sprague River subbasins and in the Lost River subbasin at Bonanza Springs. Irrigated agriculture is an integral part of the economy of the upper Klamath Basin. Although estimates vary somewhat, roughly 500,000 acres are irrigated in the upper Klamath Basin, about 190,000 acres of which are part of the Bureau of Reclamation Klamath Project. Most of this land is irrigated with surface water. Ground water has been used for many decades to irrigate areas where surface water is not available, for example outside of irrigation districts and stream valleys. Ground water has also been used as a supplemental source of water in areas where surface water supplies are limited and during droughts. Ground water use for irrigation has increased in recent years due to drought and shifts in surface-water allocation from irrigati

A geochemical and hydrological investigation of groundwater recharge in the Roswell basin of New Mexico: summary of results and updated listing of tritium determinations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gross, G.W.; Hoy, R.N.

Different approaches were used to study recharge and flow patterns in the Roswell, New Mexico, artesian basin. Isotope determination for tritium, deuterium, and oxygen-18 were made as a function of time and space. Observation well levels, springflow, and precipitation were analyzed by stochastic/numerical approaches. Also, a hydrogeologic survey was made of representative springs in the recharge zone on the basin western flank. An updated listing of tritium activity in precipitation, springs, surface runoff, and subsurface water from over 120 sampling sites in the basin covers 117 pages of the report. Substantial deep leakage contributions from the basin western flank mustmore » be included to account for the basin groundwater budget.« less

Response of deep groundwater to land use change in desert basins of the Trans-Pecos region, Texas, USA: Effects on infiltration, recharge, and nitrogen fluxes

USGS Publications Warehouse

Robertson, Wendy Marie; Böhlke, John Karl; Sharp, John M.

2017-01-01

Quantifying the effects of anthropogenic processes on groundwater in arid regions can be complicated by thick unsaturated zones with long transit times. Human activities can alter water and nutrient fluxes, but their impact on groundwater is not always clear. This study of basins in the Trans-Pecos region of Texas links anthropogenic land use and vegetation change with alterations to unsaturated zone fluxes and regional increases in basin groundwater NO3−concentrations. Median increases in groundwater NO3− (by 0.7–0.9 mg-N/l over periods ranging from 10 to 50+ years) occurred despite low precipitation (220–360 mm/year), high potential evapotranspiration (~1570 mm/year), and thick unsaturated zones (10–150+ m). Recent model simulations indicate net infiltration and groundwater recharge can occur beneath Trans-Pecos basin floors, and may have increased due to irrigation and vegetation change. These processes were investigated further with chemical and isotopic data from groundwater and unsaturated zone cores. Some unsaturated zone solute profiles indicate flushing of natural salt accumulations has occurred. Results are consistent with human-influenced flushing of naturally accumulated unsaturated zone nitrogen as an important source of NO3− to the groundwater. Regional mass balance calculations indicate the mass of natural unsaturated zone NO3− (122–910 kg-N/ha) was sufficient to cause the observed groundwater NO3− increases, especially if augmented locally with the addition of fertilizer N. Groundwater NO3− trends can be explained by small volumes of high NO3− modern recharge mixed with larger volumes of older groundwater in wells. This study illustrates the importance of combining long-term monitoring and targeted process studies to improve understanding of human impacts on recharge and nutrient cycling in arid regions, which are vulnerable to the effects of climate change and increasing human reliance on dryland ecosystems.

Using multi-year reanalysis-derived recharge rates to drive a groundwater model for the Lake Tana region of Blue Nile Basin, Ethiopia

NASA Astrophysics Data System (ADS)

Dokou, Z.; Kheirabadi, M.; Nikolopoulos, E. I.; Moges, S. A.; Bagtzoglou, A. C.; Anagnostou, E. N.

2017-12-01

Ethiopia's high inter-annual variability in local precipitation has resulted in droughts and floods that stress local communities and lead to economic and food insecurity. Better predictions of water availability can supply farmers and water management authorities with critical guidance, enabling informed water resource allocation and management decisions that will in turn ensure food and water security in the region. The work presented here focuses on the development and calibration of a groundwater model of the Lake Tana region, one of the most important sub-basins of the Blue Nile River Basin. Groundwater recharge, which is the major groundwater source in the area, depends mainly on the seasonality of precipitation and the spatial variation in geology. Given that land based precipitation data are sparse in the region, two approaches for estimating groundwater recharge were used and compared that both utilize global atmospheric reanalysis driven by remote sensing datasets. In the first approach, the reanalysis precipitation dataset (ECMWF reanalysis adjusted based on GPCC) together with evapotranspiration and surface run-off estimates are used to calculate the groundwater recharge component using water budget equations. In the second approach, groundwater recharge estimates (subsurface runoff) are taken directly from a Land Surface model (FLDAS Noah), provided at a monthly time scale and 0.1˚ x 0.1˚ spatial resolution. The reanalysis derived recharge rates in both cases are incorporated into the groundwater model MODFLOW, which in combination with a Lake module that simulates the Lake water budget, offers a unique capability of improving the predictability of groundwater and lake levels in the Lake Tana basin. Model simulations using the two approaches are compared against in-situ observations of groundwater and lake levels. This modeling effort can be further used to explore climate variability effects on groundwater and lake levels and provide guidance to governments and development agencies for more efficient management of the water resources of this important region. Acknowledgment: This material is based upon work supported by the National Science Foundation under Grant No. 1545874.

Water resources and potential effects of ground-water development in Maggie, Marys, and Susie Creek basins, Elko and Eureka counties, Nevada

USGS Publications Warehouse

Plume, R.W.

1995-01-01

The basins of Maggie, Marys, and Susie Creeks in northeastern Nevada are along the Carline trend, an area of large, low-grade gold deposits. Pumping of ground water, mostly for pit dewatering at one of the mines, will reach maximum rates of about 70,000 acre-ft/yr (acre-feet per year) around the year 2000. This pumping is expected to affect ground-water levels, streamflow, and possibly the flow of Carlin spring, which is the water supply for the town of Carlin, Nev. Ground water in the upper Maggie Creek Basin moves from recharge areas in mountain ranges toward the basin axis and discharges as evapotranspiration and as inflow to the stream channel. Ground water in the lower Maggie, Marys, and Susie Creek Basins moves southward from recharge areas in mountain ranges and along the channel of lower Maggie Creek to the discharge area along the Humboldt River. Ground-water underflow between basins is through permeable bedrock of Schroeder Mountain from the upper Maggie Creek Basin to the lower Maggie Creek Basin and through permeable volcanic rocks from lower Maggie Creek to Carlin spring in the Marys Creek Basin. The only source of water to the combined area of the three basins is an estimated 420,000 acre-ft/yr of precipitation. Water leaves as runoff (38,000 acre-ft/yr) and evapotranspiration of soil moisture and ground water (380,000 acre-ft/yr). A small part of annual precipitation (about 25,000 acre-ft/yr) infiltrates the soil zone and becomes ground-water recharge. This ground water eventually is discharged as evapotranspiration (11,000 acre-ft/yr) and as inflow to the Humboldt River channel and nearby springflow (7,000 acre-ft/yr). Total discharge is estimated to be 18,000 acre-ft/yr.

Integrated Hydrologic Models for Closing the Water Budget: Whitewater River Basin, Kansas

NASA Astrophysics Data System (ADS)

Beeson, P.; Duffy, C.; Springer, E.; Panday, S.

2004-12-01

Groundwater and its recharge are unobserved and unmeasured components of the water cycle of a river basin. The objectives of this study were: 1) to evaluate the groundwater component of the water balance for the Whitewater River Basin using a 3-D saturated groundwater model, 2) to compare the groundwater model results with a fully integrated hydrologic model and, 3) to describe the spectral frequency response of the basin to long-term climate forcing. The basin is the Whitewater River, near Wichita, Kansas. The basin has an area of 1,100 square-kilometers, an elevation range of 380 - 470m (amsl), and an average annual precipitation of 858 millimeters. The near-surface geology is comprised of a weathered shale overlying limestone bedrock of Mississippian age. Streamflow and weather records are available from 1960. A steady-state saturated groundwater model (MODFLOW) was implemented assuming a simple two-layer conceptual model. A total of 422 wells with static water levels were available. Using a subset of the wells, a steady-state calibration of MODFLOW was performed by adjusting permeability between the two layers. Steady-state calibration resulted in an R2 of 0.89 for predicted and observed water levels. The remaining wells were used for validation, with an R2 of 0.92. The next step constructed the transient model using a fixed percentage of rainfall as groundwater recharge. For a single observation well the R2 was 0.89 (observed vs. predicted) for the transient calibration and 0.77 for the validation for a year simulation. The final step was to compare MODFLOW to an integrated model to provide a more complete representation of surface hydrologic dynamics. Here MODHMS (developed by HydroGeologic Inc, Herndon, VA) was used since it is MODFLOW-based with 3D variably-saturated groundwater flow, 2D overland flow, and 1D channel flow. MODHMS allows for canopy interception and evapotranspiration so total precipitation and potential evaporation were input to the model for a better estimate of recharge through complete energy and water balance. Singular spectrum analysis (SSA) was used to analyze the temporal response of precipitation, streamflow and groundwater levels from selected points in the model both for MODFLOW and MODHMS results. This paper demonstrates the use of integrated models for determination of groundwater recharge. Time series analysis proved to be a useful tool in identifying climate response within the watershed.

Groundwater availability as constrained by hydrogeology and environmental flows

USGS Publications Warehouse

Watson, Katelyn A.; Mayer, Alex S.; Reeves, Howard W.

2014-01-01

Groundwater pumping from aquifers in hydraulic connection with nearby streams has the potential to cause adverse impacts by decreasing flows to levels below those necessary to maintain aquatic ecosystems. The recent passage of the Great Lakes-St. Lawrence River Basin Water Resources Compact has brought attention to this issue in the Great Lakes region. In particular, the legislation requires the Great Lakes states to enact measures for limiting water withdrawals that can cause adverse ecosystem impacts. This study explores how both hydrogeologic and environmental flow limitations may constrain groundwater availability in the Great Lakes Basin. A methodology for calculating maximum allowable pumping rates is presented. Groundwater availability across the basin may be constrained by a combination of hydrogeologic yield and environmental flow limitations varying over both local and regional scales. The results are sensitive to factors such as pumping time, regional and local hydrogeology, streambed conductance, and streamflow depletion limits. Understanding how these restrictions constrain groundwater usage and which hydrogeologic characteristics and spatial variables have the most influence on potential streamflow depletions has important water resources policy and management implications.

Monitoring groundwater variation by satellite and implications for in-situ gravity measurements.

PubMed

Fukuda, Yoichi; Yamamoto, Keiko; Hasegawa, Takashi; Nakaegawa, Toshiyuki; Nishijima, Jun; Taniguchi, Makoto

2009-04-15

In order to establish a new technique for monitoring groundwater variations in urban areas, the applicability of precise in-situ gravity measurements and extremely high precision satellite gravity data via GRACE (Gravity Recovery and Climate Experiment) was tested. Using the GRACE data, regional scale water mass variations in four major river basins of the Indochina Peninsula were estimated. The estimated variations were compared with Soil-Vegetation-Atmosphere Transfer Scheme (SVATS) models with a river flow model of 1) globally uniform river velocity, 2) river velocity tuned by each river basin, 3) globally uniform river velocity considering groundwater storage, and 4) river velocity tuned by each river basin considering groundwater storage. Model 3) attained the best fit to the GRACE data, and the model 4) yielded almost the same values. This implies that the groundwater plays an important role in estimating the variation of total terrestrial storage. It also indicates that tuning river velocity, which is based on the in-situ measurements, needs further investigations in combination with the GRACE data. The relationships among GRACE data, SVATS models, and in-situ measurements were also discussed briefly.

Comparative study of factors controlling the groundwater occurrence in Bir Kiseiba and Bir El Shab areas, south western desert, Egypt using hydrogeological and geophysical techniques

NASA Astrophysics Data System (ADS)

Abu Risha, U. A.; Al Temamy, A. M. M.

2016-05-01

This research presents a clear example of the significant role of basement relief on the formation of aquifers and the impact of geologic structures on groundwater occurrence. A basement relief map was constructed using the depth to basement data acquired from 20 vertical electrical soundings (VESes), 3 land magnetic profiles, and 27 drilled wells tapping the basement rocks in addition to the elevations of the basement outcrops in the area of study. The map shows three basins underlying the area. The geoelectric survey shows that these basins were formed as a result of series of step faults. The largest basin underlies El-Shab area. The medium basin underlies the area of Bir Kiseiba whereas the smallest one underlies Bir Abu El-Hussein area. The Nubian Sandstone aquifer occurs only in El-Shab basin whereas the other basins are filled completely with the confining layer of Kiseiba Formation. The depth to basement in El-Shab basin ranges from 11 m. (ves-20) to 197 m. (ves-1) m.b.g.s. The depth to basement in Kiseiba basin ranges from 20 m. (Bir Kurayim magnetic profile) to 122 m. (ves-13) m.b.g.s. The depth to basement in Abu El-Husein basin ranges from 0 (basement outcrops) to 64 m. (Abu El-Husein magnetic profile) m.b.g.s. The aquifer thickness ranges from 0 m (where the aquitard rests directly on the basement) to 153 m. (El Shab well No. 79). The aquifer is uncoformably overlain by Kiseiba Formation which represents the aquitard layer at Bir El-Shab. The thickness of the aquitard ranges from 0 (in areas covered by the Nubian Sandstone) to 120 m (ves-13). Each of the aquifer and aquitard consist of three layers. Two of the aquitard layers are water-bearing. However, the estimated transmissivity of the aquitard is very low (11.9 m2/d). The groundwater moves vertically into the overlying aquitard at Bir El-Shab and subsequently flows in concentric pattern into the surrounding areas. Faulting controls groundwater occurrence and quality. Some springs lie on the basement high associated with step faulting at the edges of El-Shab basin. An ENE low-salinity zone is associated with the basement high which separates El-Shab basin from Kiseiba basin. Focused groundwater recharge through the faults and fractures from paleo playas could be the mechanism of the formation of this anomaly. The isotope data shows local recharge of the groundwater most likely during the Pleistocene time. Two-dimension (2D) Electrical Resistivity Tomography (ERT) profiles reveal that the evaporation process has the main role in increasing the salinity of some water points. It is highly recommended to delineate the southern boundary of El-Shab basin which is expected to extend into Sudan.

Characteristics of Southern California coastal aquifer systems

USGS Publications Warehouse

Edwards, B.D.; Hanson, R.T.; Reichard, E.G.; Johnson, T.A.

2009-01-01

Most groundwater produced within coastal Southern California occurs within three main types of siliciclastic basins: (1) deep (>600 m), elongate basins of the Transverse Ranges Physiographic Province, where basin axes and related fluvial systems strike parallel to tectonic structure, (2) deep (>6000 m), broad basins of the Los Angeles and Orange County coastal plains in the northern part of the Peninsular Ranges Physiographic Province, where fluvial systems cut across tectonic structure at high angles, and (3) shallow (75-350 m), relatively narrow fluvial valleys of the generally mountainous southern part of the Peninsular Ranges Physiographic Province in San Diego County. Groundwater pumped for agricultural, industrial, municipal, and private use from coastal aquifers within these basins increased with population growth since the mid-1850s. Despite a significant influx of imported water into the region in recent times, groundwater, although reduced as a component of total consumption, still constitutes a significant component of water supply. Historically, overdraft from the aquifers has caused land surface subsidence, flow between water basins with related migration of groundwater contaminants, as well as seawater intrusion into many shallow coastal aquifers. Although these effects have impacted water quality, most basins, particularly those with deeper aquifer systems, meet or exceed state and national primary and secondary drinking water standards. Municipalities, academicians, and local water and governmental agencies have studied the stratigraphy of these basins intensely since the early 1900s with the goals of understanding and better managing the important groundwater resource. Lack of a coordinated effort, due in part to jurisdictional issues, combined with the application of lithostratigraphic correlation techniques (based primarily on well cuttings coupled with limited borehole geophysics) have produced an often confusing, and occasionally conflicting, litany of names for the various formations, lithofacies, and aquifer systems identified within these basins. Despite these nomenclatural problems, available data show that most basins contain similar sequences of deposits and share similar geologic histories dominated by glacio-eustatic sea-level fluctuations, and overprinted by syndepositional and postdepositional tectonic deformation. Impermeable, indurated mid-Tertiary units typically form the base of each siliciclastic groundwater basin. These units are overlain by stacked sequences of Pliocene to Holocene interbedded marine, paralic, fluvial, and alluvial sediment (weakly indurated, folded, and fractured) that commonly contain the historically named "80-foot sand," "200-foot sand," and "400-foot gravel" in the upper part of the section. An unconformity, cut during the latest Pleistocene lowstand (??18O stage 2; ca. 18 ka), forms a major sequence boundary that separates these units from the overlying Holocene fluvial sands and gravels. Unconfined aquifers occur in amalgamated coarse facies near the bounding mountains (forebay area). These units are inferred to become lithologically more complex toward the center of the basins and coast line, where interbedded permeable and low-permeability alluvial, fluvial, paralic, and marine facies contain confined aquifers (pressure area). Coastal bounding faults limit intrabasin and/or interbasin flow in parts of many basins. ?? 2009 Geological Society of America.

Estimates of Ground-Water Recharge in Wadis of Arid, Mountainous Areas Using the Chloride Mass-Balance Approach

NASA Astrophysics Data System (ADS)

Wood, W. W.; Wood, W. W.

2001-05-01

Evaluation of ground-water supply in arid areas requires estimation of annual recharge. Traditional physical-based hydrologic estimates of ground-water recharge result in large uncertainties when applied in arid, mountainous environments because of infrequent, intense rainfall events, destruction of water-measuring structures associated with those events, and consequent short periods of hydrologic records. To avoid these problems and reduce the uncertainty of recharge estimates, a chloride mass-balance (CMB) approach was used to provide a time-integrated estimate. Seven basins exhibiting dry-stream beds (wadis) in the Asir and Hijaz Mountains, western Saudi Arabia, were selected to evaluate the method. Precipitation among the basins ranged from less than 70 mm/y to nearly 320 mm/y. Rain collected from 35 locations in these basins averaged 2.0 mg/L chloride. Ground water from 140 locations in the wadi alluvium averaged 200 mg/L chloride. This chloride concentration ratio of precipitation to ground water suggests that on average, approximately 1 percent of the rainfall is recharged, while the remainder is lost to evaporation. Ground-water recharge from precipitation in individual basins ranged from less than 1 to nearly 4 percent and was directly proportional to total precipitation. Independent calculations of recharge using Darcy's Law were consistent with these findings and are within the range typically found in other arid areas of the world. Development of ground water has lowered the water level beneath the wadis and provided more storage thus minimizing chloride loss from the basin by river discharge. Any loss of chloride from the basin results in an overestimate of the recharge flux by the chloride-mass balance approach. In well-constrained systems recharge in arid, mountainous areas where the mass of chloride entering and leaving the basin is known or can be reasonably estimated, the CMB approach provides a rapid, inexpensive method for estimating time-integrated ground-water recharge.

Hydrology of the Johnson Creek Basin, Oregon

USGS Publications Warehouse

Lee, Karl K.; Snyder, Daniel T.

2009-01-01

The Johnson Creek basin is an important resource in the Portland, Oregon, metropolitan area. Johnson Creek forms a wildlife and recreational corridor through densely populated areas of the cities of Milwaukie, Portland, and Gresham, and rural and agricultural areas of Multnomah and Clackamas Counties. The basin has changed as a result of agricultural and urban development, stream channelization, and construction of roads, drains, and other features characteristic of human occupation. Flooding of Johnson Creek is a concern for the public and for water management officials. The interaction of the groundwater and surface-water systems in the Johnson Creek basin also is important. The occurrence of flooding from high groundwater discharge and from a rising water table prompted this study. As the Portland metropolitan area continues to grow, human-induced effects on streams in the Johnson Creek basin will continue. This report provides information on the groundwater and surface-water systems over a range of hydrologic conditions, as well as the interaction these of systems, and will aid in management of water resources in the area. High and low flows of Crystal Springs Creek, a tributary to Johnson Creek, were explained by streamflow and groundwater levels collected for this study, and results from previous studies. High flows of Crystal Springs Creek began in summer 1996, and did not diminish until 2000. Low streamflow of Crystal Springs Creek occurred in 2005. Flow of Crystal Springs Creek related to water-level fluctuations in a nearby well, enabling prediction of streamflow based on groundwater level. Holgate Lake is an ephemeral lake in Southeast Portland that has inundated residential areas several times since the 1940s. The water-surface elevation of the lake closely tracked the elevation of the water table in a nearby well, indicating that the occurrence of the lake is an expression of the water table. Antecedent conditions of the groundwater level and autumn and winter precipitation totals were used to anticipate flooding of Holgate Lake. Several factors affect annual mean flow of Johnson Creek. More precipitation falls in the southeastern area of the basin because of the topographic setting. Runoff from much of the northern and western areas of the basin does not flow into Johnson Creek due to permeable deposits, interception by combined sewer systems, and by groundwater flow away from Johnson Creek. Inflow from Crystal Springs Creek accounts for one-half of the increase in streamflow of Johnson Creek between the Sycamore and Milwaukie sites. Low flows of Johnson Creek vary as a result of fluctuations in groundwater discharge to the creek, although past water uses may have decreased flows. The groundwater contributions to streamflow upstream of river mile (RM) 5.5 are small compared to contributions downstream of this point. Comparison of flows to a nearby basin indicates that diversions of surface water may have resulted in a 50 percent decrease in low flows from about 1955 to 1977. Runoff from the drainage basin area upstream of the Johnson Creek at Sycamore site contributes more to peak streamflow and peak volume than the drainage basin area between the Sycamore and Milwaukie sites. The average increase in annual peak streamflow and annual peak volume between the two sites was 11 and 24 percent, respectively. Decreased contribution in the lower area of the drainage basin is a result of infiltration, interception by drywell and combined sewer systems, and temporary overbank storage. Trends in flow typically associated with increasing urban development were absent in Johnson Creek. Annual, low, and high flows showed no trend from 1941 to 2006. Much of the infrastructure that may affect runoff from agricultural, residential, and urban development was in place prior to collection of hydrologic data in the basin. Management of stormwater in the urban areas by routing runoff from impervious surfaces to dry

Simulation of groundwater storage changes in the eastern Pasco Basin, Washington

USGS Publications Warehouse

Heywood, Charles E.; Kahle, Sue C.; Olsen, Theresa D.; Patterson, James D.; Burns, Erick

2016-03-29

The Miocene Columbia River Basalt Group and younger sedimentary deposits of lacustrine, fluvial, eolian, and cataclysmic-flood origins compose the aquifer system of the Pasco Basin in eastern Washington. Irrigation return flow and canal leakage from the Columbia Basin Project have caused groundwater levels to rise substantially in some areas, contributing to landslides along the Columbia River. Water resource managers are considering extraction of additional stored groundwater to supply increasing demand and possibly mitigate problems caused by the increased water levels. To help address these concerns, the transient groundwater model of the Pasco Basin documented in this report was developed to quantify the changes in groundwater flow and storage. The MODFLOW model uses a 1-kilometer finite-difference grid and is constrained by logs and water levels from 846 wells in the study area. Eight model layers represent five sedimentary hydrogeologic units and underlying basalt formations. Head‑dependent flux boundaries represent the Columbia and Snake Rivers to the west and south, respectively, underflow to and (or) from adjacent areas to the northeast, and discharge to agricultural drains, springs, and groundwater withdrawal wells. Specified flux boundaries represent recharge from infiltrated precipitation and anthropogenic sources, including irrigation return flow and leakage from water-distribution canals. The model was calibrated with the parameter‑estimation code PEST++ to groundwater levels measured from 1907 through 2013 and measured discharge to springs and estimated discharge to agricultural drains. Increased recharge since pre-development resulted in a 6.8 million acre-feet increase in storage in the 508-14 administrative area of the Pasco Basin. Four groundwater-management scenarios simulate the 7-year drawdown resulting from withdrawals in different locations. Withdrawals of 2 million gallons per day (Mgal/d) from a hypothetical well field in the upper Ringold Formation along the Columbia River could generate 30–70 feet of drawdown, which may reduce landslide susceptibility along the White Bluffs. Drawdowns resulting from a 1 Mgal/d withdrawal from wells screened in either Pasco gravels, upper Ringold Formation, or both Ringold Formation and underlying basalt are simulated in the other three scenarios, and differ because of the contrasting hydraulic conductivities within the screened intervals.

Shallow ground-water quality adjacent to burley tobacco fields in northeastern Tennessee and southwestern Virginia, spring 1997

USGS Publications Warehouse

Johnson, G.C.; Connell, J.F.

2001-01-01

In 1994, the U.S. Geological Survey began an assessment of the upper Tennessee River Basin as part of the National Water-Quality Assessment (NAWQA) Program. A ground-water land-use study conducted in 1996 focused on areas with burley tobacco production in northeastern Tennessee and southwestern Virginia. Land-use studies are designed to focus on specific land uses and to examine natural and human factors that affect the quality of shallow ground water underlying specific types of land use. Thirty wells were drilled in shallow regolith adjacent to and downgradient of tobacco fields in the Valley and Ridge Physiographic Province of the upper Tennessee River Basin. Ground-water samples were collected between June 4 and July 9, 1997, to coincide with the application of the majority of pesticides and fertilizers used in tobacco production. Ground-water samples were analyzed for nutrients, major ions, 79 pesticides, 7 pesticide degradation products, 86 volatile organic compounds, and dissolved organic carbon. Nutrient concentrations were lower than the levels found in similar NAWQA studies across the United States during 1993-95. Five of 30 upper Tennessee River Basin wells (16.7 percent) had nitrate levels exceeding 10 mg/L while 19 percent of agricultural land-use wells nationally and 7.9 percent in the Southeast had nitrate concentrations exceeding 10 mg/L. Median nutrient concentrations were equal to or less than national median concentrations. All pesticide concentrations in the basin were less than established drinking water standards, and pesticides were detected less frequently than average for other NAWQA study units. Atrazine was detected at 8 of 30 (27 percent) of the wells, and deethylatrazine (an atrazine degradation product) was found in 9 (30 percent) of the wells. Metalaxyl was found in 17 percent of the wells, and prometon, flumetralin, dimethomorph, 2,4,5-T, 2,4-D, dichlorprop, and silvex were detected once each (3 percent). Volatile organic compounds were detected in 27 of 30 wells. Although none of the volatile organic compound concentrations exceeded drinking water standards, the detection frequency was higher than the average for the other NAWQA study units.

Characterizating Multi-layered Coastal Aquifer using Pneumatic Slug Tests

NASA Astrophysics Data System (ADS)

Malama, B.; Abere, M.; Mikenna, M.

2016-12-01

Results of pneumatic slug tests conducted in a monitoring wells of a shallow aquifer on the California Central Coast are presented. The aquifer is in the Los Osos groundwater basin on the California Central Coast, a semi-closed near-triangular groundwater basin bounded to the north and south by impermeable igneousbed rock and to the west by the Pacific Ocean. The groundwater basin is a multi-layered system comprising a perched, near-surface semi-confined, and a deep confined aquifer. The unincorporated community of Los Osos is wholly dependent on the groundwater basin that is threatened with seawater intrusion and nitratecontamination. The slug tests reported here were performed in the perched and semi-confined aquifers as part of a seawater intrusion characterization study. The semi-confined and confined aquifers show evidence of seawater intrusion with upconing in some deep aquifer municipal wells. The upconing has beeninterpreted by previous studies as evidence of preferential flow through a high permeability channel. The objective of the work was to test this hypothesis by mapping the horizontal and vertical spatial variability of hydraulic parameters across the basin and establish the extent of the high permeability unit.Here only preliminary results of slug tests conducted across the basin for vertically averaged hydraulic parameters are reported. The results provide an indication of the horizontal variability of hydraulic parameters. An additional study will be performed to characterize the vertical variability to investigate the probableexistsence of a high permeability channel.

Against the current— The Mojave River from sink to source: The 2018 Desert Symposium field trip road log

USGS Publications Warehouse

Miller, David; Reynolds, R.E.; Groover, Krishangi D.; Buesch, David C.; Brown, H. J.; Cromwell, Geoffrey; Densmore-Judy, Jill; Garcia, A.L.; Hughson, D.; Knott, J.R.; Lovich, Jeffrey E.

2018-01-01

The Mojave River evolved over the past few million years by “fill and spill” from upper basins near its source in the Transverse Ranges to lower basins. Each newly “spilled into” basin in the series? sustained a long-lived lake but gradually filled with Mojave River sediment, leading to spill to a yet lower elevation? basin. The Mojave River currently terminates at Silver Lake, near Baker, CA, but previously overflowed this terminus onward to Lake Manly in Death Valley during the last glacial cycle. The river’s origin and evolution are intricately interwoven with tectonic, climatic, and geomorphic processes through time, beginning with San Andreas fault interactions that created a mountain range across a former externally draining river. We will see and discuss the Mojave River’s predecessor streams and basins, its evolution as it lengthened to reach the central Mojave Desert, local and regional tectonic controls, groundwater flow, flood history, and support of isolated perennial stream reaches that host endemic species. In association with these subjects are supporting studies such as paleoclimate records, location and timing for groundwater and wetlands in the central Mojave Desert, and effects of modern water usage. The trip introduces new findings for the groundwater basin of Hinkley Valley, including an ongoing remediation project that provides a wealth of information on past and present river flow and associated development of the groundwater system.

Evolution of dissolved inorganic carbon in groundwater recharged by cyclones and groundwater age estimations using the 14C statistical approach

NASA Astrophysics Data System (ADS)

Meredith, K. T.; Han, L. F.; Cendón, D. I.; Crawford, J.; Hankin, S.; Peterson, M.; Hollins, S. E.

2018-01-01

The Canning Basin is the largest sedimentary basin in Western Australia and is located in one of the most cyclone prone regions of Australia. Despite its importance as a future resource, limited groundwater data is available for the Basin. The main aims of this paper are to provide a detailed understanding of the source of groundwater recharge, the chemical evolution of dissolved inorganic carbon (DIC) and provide groundwater age estimations using radiocarbon (14CDIC). To do this we combine hydrochemical and isotopic techniques to investigate the type of precipitation that recharge the aquifer and identify the carbon processes influencing 14CDIC, δ13CDIC, and [DIC]. This enables us to select an appropriate model for calculating radiocarbon ages in groundwater. The aquifer was found to be recharged by precipitation originating from tropical cyclones imparting lower average δ2H and δ18O values in groundwater (-56.9‰ and -7.87‰, respectively). Water recharges the soil zone rapidly after these events and the groundwater undergoes silicate mineral weathering and clay mineral transformation processes. It was also found that partial carbonate dissolution processes occur within the saturated zone under closed system conditions. Additionally, the processes could be lumped into a pseudo-first-order process and the age could be estimated using the 14C statistical approach. In the single-sample-based 14C models, 14C0 is the initial 14CDIC value used in the decay equation that considers only 14C decay rate. A major advantage of using the statistical approach is that both 14C decay and geochemical processes that cause the decrease in 14CDIC are accounted for in the calculation. The 14CDIC values of groundwater were found to increase from 89 pmc in the south east to around 16 pmc along the groundwater flow path towards the coast indicating ages ranging from modern to 5.3 ka. A test of the sensitivity of this method showed that a ∼15% error could be found for the oldest water. This error was low when compared to single-sample-based models. This study not only provides the first groundwater age estimations for the Canning Basin but is the first groundwater dating study to test the sensitivity of the statistical approach and provide meaningful error calculations for groundwater dating.

Distributed parallel computing in stochastic modeling of groundwater systems.

PubMed

Dong, Yanhui; Li, Guomin; Xu, Haizhen

2013-03-01

Stochastic modeling is a rapidly evolving, popular approach to the study of the uncertainty and heterogeneity of groundwater systems. However, the use of Monte Carlo-type simulations to solve practical groundwater problems often encounters computational bottlenecks that hinder the acquisition of meaningful results. To improve the computational efficiency, a system that combines stochastic model generation with MODFLOW-related programs and distributed parallel processing is investigated. The distributed computing framework, called the Java Parallel Processing Framework, is integrated into the system to allow the batch processing of stochastic models in distributed and parallel systems. As an example, the system is applied to the stochastic delineation of well capture zones in the Pinggu Basin in Beijing. Through the use of 50 processing threads on a cluster with 10 multicore nodes, the execution times of 500 realizations are reduced to 3% compared with those of a serial execution. Through this application, the system demonstrates its potential in solving difficult computational problems in practical stochastic modeling. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

Ground-water resources of the Cahaba River basin in Alabama - Subarea 7 of the Apalachicola-Chattahoochee-Flint and Alabama-Coosa-Tallapoosa river basins

USGS Publications Warehouse

Mooty, Will S.; Kidd, Robert E.

1997-01-01

Drought conditions in the 1980's focused attention on the multiple uses of the surface- and ground-water resources in the Apalachicola-Chattahooochee-Flint and Alabama-Coosa-Tallapoosa River basins in Georgia, Alabama, and Florida. State and Federal agencies also have proposed projects that would require additional water resources and revise operating practices within the river basins. The existing and proposed water projects create conflicting demands for water by the States and emphasize the problem of water-resource allocation. This study was initiated to describe ground-water availablity in the Cahaba River basin in Alabama, Subarea 7 of the Apalachicola-Chattahoochee-Flint and Alabama-Coosa-Tallapoosa River basins, and to estimate the possible effects of increased ground-water use within the basin. Subarea 7 encompasses about 1,030 square miles in north-central Alabama. Subarea 7 encompasses parts of the Piedmont, Valley and Ridge, and Coastal Plain physiographic provinces. The Piedmont Province is underlain by a two-component aquifer system that is composed of a fractured, crystalline-rock aquifer characterized by little or no primary porosity or permeability; and the overlying regolith, which can behave as a porous-media aquifer. The Valley and Ridge Province is underlain by fracture- and solution-conduit aquifer systems, similar in some ways to those in the Piedmont Province. Fracture-conduit aquifers predominante in the well-consolidated sandstones and shales of Paleozoic age; solution-conduit aquifers dedominate in the carbonate rocks of Paleozoic age. The Coastal Plain is underlain by southward-dipping, poorly consolidated deposits of sand, gravel, and clay of fluvial and marine origin. The conceptual model described for this study qualitatively subdivides the ground-water flow system into local (shallow), intermediate, and regional (deep) flow regimes. Ground- water discharge to tributaries mainly is from local and intermediate flow regimes and varies seasonally. The regional flow regime probably approximates steady-state conditions and discharges chiefly to major drains such as the Cahaba River. Ground-water discharge to major drains originates from all flow regimes. Mean-annual ground-water discharge to streams (baseflow) is considered to approximate the long-term, average recharge to ground water. The mean-annual baseflow was estimated using an atuomated hydrograph-separation method, and represents discharge from the local, intermediate, and regional flow regimes of the ground-water flow system. Mean-annual baseflow in Georgia was estimated to be 763 cubic feet per second at Centreville, Ala., where the Cahaba River exits Subarea 7 into Subarea 8. Mean-annual baseflow represented about 48 percent of total mean-annual stream discharge for the period of record. Stream discharge for selected sites on the Cahaba River and its tributaries were compiled for the years 1941, 1954, and 1986, during which sustained droughts occurred throughout most of the Apalachicola-Chattahoochee-Flint and Alabama-Coosa-Tallapoosa River basin area. Stream discharges were assumed to be sustained entirely by baseflow during the latter periods of these droughts. Estimated baseflow near the end of these droughts averaged about 21 percent of the estimated mean-annual baseflow in Subarea 7 (ranged from about 16 to 25 percent for individual drought years). The potential exists for the development of ground-water resources on a regional scale throughout Subarea 7. Estimated ground-water use in 1990 was about 2 percent of the estimated mean-annual baseflow, and 9.7 percent of the average drought baseflow near the end of the droughts of 1941, 1954, and 1986. Because ground- water use in Subarea 7 represents a relatively minor percentage of ground- water recharge, even a large increase in ground-water use in Subarea 7 is likely to have little effect on ground-water and surface-water occurrernce in Alabama. Indications of long-term ground-water dec

Assessing groundwater policy with coupled economic-groundwater hydrologic modeling

NASA Astrophysics Data System (ADS)

Mulligan, Kevin B.; Brown, Casey; Yang, Yi-Chen E.; Ahlfeld, David P.

2014-03-01

This study explores groundwater management policies and the effect of modeling assumptions on the projected performance of those policies. The study compares an optimal economic allocation for groundwater use subject to streamflow constraints, achieved by a central planner with perfect foresight, with a uniform tax on groundwater use and a uniform quota on groundwater use. The policies are compared with two modeling approaches, the Optimal Control Model (OCM) and the Multi-Agent System Simulation (MASS). The economic decision models are coupled with a physically based representation of the aquifer using a calibrated MODFLOW groundwater model. The results indicate that uniformly applied policies perform poorly when simulated with more realistic, heterogeneous, myopic, and self-interested agents. In particular, the effects of the physical heterogeneity of the basin and the agents undercut the perceived benefits of policy instruments assessed with simple, single-cell groundwater modeling. This study demonstrates the results of coupling realistic hydrogeology and human behavior models to assess groundwater management policies. The Republican River Basin, which overlies a portion of the Ogallala aquifer in the High Plains of the United States, is used as a case study for this analysis.

Characterization of potential transport pathways and implications for groundwater management near an anticline in the Central Basin area, Los Angeles County, California

USGS Publications Warehouse

Ponti, Daniel J.; Wagner, Brian J.; Land, Michael; Landon, Matthew K.

2014-01-01

The Central Groundwater Basin (Central Basin) of southern Los Angeles County includes ~280 mi2 of the Los Angeles Coastal Plain and serves as the primary source of water for more than two million residents. In the Santa Fe Springs–Whittier–Norwalk area, located in the northeastern part of the basin, several sources of volatile organic compounds have been identified. The volatile organic compunds are thought to have contributed to a large, commingled contaminant plume in groundwater that extends south-southwest downgradient from the Omega Chemical Corporation Superfund Site across folded geologic strata, known as the Santa Fe Springs Anticline. A multifaceted study—that incorporated a three-dimensional sequence-stratigraphic geologic model, two-dimensional groundwater particle-tracking simulations, and new groundwater chemistry data—was conducted to gain insight into the geologic and hydrologic controls on contaminant migration in the study area and to assess the potential for this shallow groundwater contamination to migrate into producing aquifer zones. Conceptual flow models were developed along a flow-parallel cross section based on the modeled stratigraphic architecture, observed geochemistry, and numerical model simulations that generally agree with observed water levels and contaminant distributions. These models predict that contaminants introduced into groundwater at shallow depths near the Omega Chemical Corporation Superfund Site and along the study cross section will likely migrate downgradient to depths intercepted by public supply wells. These conclusions, however, are subject to limitations and simplifications inherent in the modeling approaches used, as well as a significant scarcity of available geologic and hydrogeochemical information at depth and in the downgradient parts of the study area.

A Hydrologically-based Method for Calculating Sustainable Yield under California's Sustainable Groundwater Management Act

NASA Astrophysics Data System (ADS)

Miro, M.; Famiglietti, J. S.

2016-12-01

In California, traditional water management has focused heavily on surface water, leaving many basins in a state of critical overdraft and lacking in established frameworks for groundwater management. However, new groundwater legislation, the 2014 Sustainable Groundwater Management Act (SGMA), presents an important opportunity for water managers and hydrologists to develop novel methods for managing statewide groundwater resources. Integrating scientific advances in groundwater monitoring with hydrologically-sound methods can go a long way in creating a system that can better govern the resource. SGMA mandates that groundwater management agencies employ the concept of sustainable yield as their primary management goal but does not clearly define a method to calculate it. This study will develop a hydrologically-based method to quantify sustainable yield that follows the threshold framework under SGMA. Using this method, sustainable yield will be calculated for two critically-overdrafted groundwater basins in California's Central Valley. This measure will also utilize groundwater monitoring data and downscaled remote sensing estimates of groundwater storage change from NASA's GRACE satellite to illustrate why data matters for successful management. This method can be used as a basis for the development of SGMA's groundwater management plans (GSPs) throughout California.

Coupled production and emission of short chain perfluoroalkyl acids from a fast developing fluorochemical industry: Evidence from yearly and seasonal monitoring in Daling River Basin, China.

PubMed

Wang, Pei; Lu, Yonglong; Wang, Tieyu; Zhu, Zhaoyun; Li, Qifeng; Meng, Jing; Su, Hongqiao; Johnson, Andrew C; Sweetman, Andrew J

2016-11-01

Short chain perfluoroalkyl acids (PFAAs) have been developed since 2002 by the major manufacturers to replace the conventional C8 and higher homologues, with much of the world production shifted to China in recent years. In this study, we conducted a continuous monitoring program over the period 2011-2014 with seasonal monitoring in 2013 for PFAAs emitted from two rapidly developing fluorochemical industry parks located in the Daling River Basin, Northern China. The trend of PFAA contamination was identified, dominated by perfluorobutane sulfonic acid (PFBS), perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA), with the maximum concentrations of 3.78 μg/L, 3.70 μg/L, and 1.95 μg/L, respectively. Seasonal monitoring uncovered the occasional emission of perfluorooctane sulfonic acid (PFOS). Construction trends of new facilities and associated manufacturing capacity of the main products were also analyzed to assess correlations with PFAA emissions. An assessment of the data over the period 2011-2014 found a positive correlation with fluorocarbon alcohol (FCA) production and emission of PFAAs. Groundwater and tap water around the main source indicated that the dominant PFAAs had different diffusion behaviors. PFBS levels were higher in surface water, while PFBA was dominant in groundwater and tap water, with PFOA levels being higher in downstream groundwater. Considering the continuous expansion and development of fluorochemical industry in the Daling River Basin, this study will provide abundant information on the effectiveness of risk assessment and management. Copyright © 2016 Elsevier Ltd. All rights reserved.

National Water-Quality Assessment Program: The Sacramento River Basin

USGS Publications Warehouse

Domagalski, Joseph L.; Brown, Larry R.

1994-01-01

In 1991, the U.S. Geological Survey (USGS) began to implement a full-scale National Water-Quality Assessment (NAWQA) program. The long-term goals of the NAWQA program are to describe the status of and trends in the quality of a large, representative part of the Nation's surface- and ground-water resources and to identify the major natural and human factors that affect the quality of those resources. In addressing these goals, the program will provide a wealth of water- quality information that will be useful to policy makers and managers at the national, State, and local levels. A major asset of the NAWQA program is that it will allow for the integration of water-quality information collected at several scales. A major component of the program is the study-unit investigation-the foundation of national- level assessment. The 60 study units of the NAWQA program are hydrologic systems that include parts of most major river basins and aquifer systems of the conterminous United States. These study units cover areas of 1,000 to more than 60,000 square miles and represent 60 to 70 percent of the Nation's water use and population served by public water supplies. Investigations of the first 20 study units began in 1991. In 1994, the Sacramento River Basin was among the second set of 20 NAWQA study units selected for investigation.

Dissolved solids in basin-fill aquifers and streams in the southwestern United States

USGS Publications Warehouse

Anning, David W.; Bauch, Nancy J.; Gerner, Steven J.; Flynn, Marilyn E.; Hamlin, Scott N.; Moore, Stephanie J.; Schaefer, Donald H.; Anderholm, Scott K.; Spangler, Lawrence E.

2007-01-01

The U.S. Geological Survey National Water-Quality Assessment Program performed a regional study in the Southwestern United States (Southwest) to describe the status and trends of dissolved solids in basin-fill aquifers and streams and to determine the natural and human factors that affect dissolved solids. Basin-fill aquifers, which include the Rio Grande aquifer system, Basin and Range basin-fill aquifers, and California Coastal Basin aquifers, are the most extensively used ground-water supplies in the Southwest. Rivers, such as the Colorado, the Rio Grande, and their tributaries, are also important water supplies, as are several smaller river systems that drain internally within the Southwest, or drain externally to the Pacific Ocean in southern California. The study included four components that characterize (1) the spatial distribution of dissolved-solids concentrations in basin-fill aquifers, and dissolved-solids concentrations, loads, and yields in streams; (2) natural and human factors that affect dissolved-solids concentrations; (3) major sources and areas of accumulation of dissolved solids; and (4) trends in dissolved-solids concentrations over time in basin-fill aquifers and streams, and the relation of trends to natural or human factors.

Spatial and temporal variations of evapotranspiration, groundwater and precipitation in Amazonia

NASA Astrophysics Data System (ADS)

Niu, J.; Riley, W. J.; Shen, C.; Melack, J. M.; Qiu, H.

2017-12-01

We used wavelet coherence analysis to investigate the effects of precipitation (P) and groundwater dynamics (total water storage anomaly, TWSA) on evapotranspiration (ET) at kilometer, sub-basin, and whole basin scales in the Amazon basin. The Amazon-scale averaged ET, P, and TWSA have about the same annual periodicity. The phase lag between ET and P (ΦET-P) is 1 to 3 months, and between ET and TWSA (ΦET-TWSA) is 3 to 7 months. The phase patterns have a south-north divide due to significant variation in climatic conditions. The correlation between ΦET-P and ΦET-TWSA is affected by the aridity index (the ratio between potential ET (PET) and P, PET / P), of each sub-basin, as determined using the Budyko framework at the sub-basin level. The spatial structure of ΦET-P is negatively correlated with the spatial structure of annual ET. At Amazon-scale during a drought year (e.g., 2010), both phases decreased, while in the subsequent years, ΦET-TWSA increased, indicating strong groundwater effects on ET immediately following dry years Amazon-wide.

Groundwater Quality Data in the Mojave Study Unit, 2008: Results from the California GAMA Program

USGS Publications Warehouse

Mathany, Timothy M.; Belitz, Kenneth

2009-01-01

Groundwater quality in the approximately 1,500 square-mile Mojave (MOJO) study unit was investigated from February to April 2008, as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). MOJO was the 23rd of 37 study units to be sampled as part of the GAMA Priority Basin Project. The MOJO study was designed to provide a spatially unbiased assessment of the quality of untreated ground water used for public water supplies within MOJO, and to facilitate statistically consistent comparisons of groundwater quality throughout California. Samples were collected from 59 wells in San Bernardino and Los Angeles Counties. Fifty-two of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (grid wells), and seven were selected to aid in evaluation of specific water-quality issues (understanding wells). The groundwater samples were analyzed for a large number of organic constituents [volatile organic compounds (VOCs), pesticides and pesticide degradates, and pharmaceutical compounds], constituents of special interest (perchlorate and N-nitrosodimethylamine [NDMA]) naturally occurring inorganic constituents (nutrients, dissolved organic carbon [DOC], major and minor ions, silica, total dissolved solids [TDS], and trace elements), and radioactive constituents (gross alpha and gross beta radioactivity, radium isotopes, and radon-222). Naturally occurring isotopes (stable isotopes of hydrogen, oxygen, and carbon, stable isotopes of nitrogen and oxygen in nitrate, and activities of tritium and carbon-14), and dissolved noble gases also were measured to help identify the sources and ages of the sampled ground water. In total, over 230 constituents and water-quality indicators (field parameters) were investigated. Three types of quality-control samples (blanks, replicates, and matrix spikes) each were collected at approximately 5-8 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a significant source of bias in the data for the groundwater samples. Differences between replicate samples generally were within acceptable ranges, indicating acceptable analytical reproducibility. Matrix spike recoveries were within acceptable ranges for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, untreated groundwater typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to untreated ground water. However, to provide some context for the results, concentrations of constituents measured in the untreated ground water were compared with regulatory and non-regulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH) and thresholds established for aesthetic and technical concerns by CDPH. Comparisons between data collected for this study and thresholds for drinking-water are for illustrative purposes only, and are not indicative of compliance or non-compliance with those thresholds. Most constituents that were detected in groundwater samples in the 59 wells in MOJO were found at concentrations below drinking-water thresholds. In MOJO's 52 grid wells, volatile organic compounds (VOCs) were detected in 40 percent of the wells, and pesticides and pesticide degradates were detected in 23 percent of the grid wel

REACH SPECIFIC CHANNEL STABILIZATION BASED ON COMPREHENSIVE EVALUATION OF VALLEY FILL HISTORY, ALLUVIAL ARCHITECTURE AND GROUNDWATER HYDROLOGY IN A MOUNTAIN STREAM IN THE CENTRAL GREAT BASIN, NEVADA

EPA Science Inventory

Kingston meadow, located in the Toiyabe Range, is one of many wet meadow complexes threatened by rapid channel incision in the mountain ranges of the central Great Basin. Channel incision can lower the baselevel for groundwater discharge and de-water meadow complexes resulting in...

Analysis of potential water-supply management options, 2010-60, and documentation of revisions to the model of the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

USGS Publications Warehouse

Voronin, Lois M.; Densmore, Jill N.; Martin, Peter

2014-01-01

The Fort Irwin National Training Center is considering several alternatives to manage their limited water-supply sources in the Irwin Basin. An existing three-dimensional, finite-difference groundwater-flow model—the U.S. Geological Survey’s MODFLOW—of the aquifer system in the basin was updated and the initial input dataset was supplemented with groundwater withdrawal data for the period 2000–10. The updated model was then used to simulate four combinations, or scenarios, of groundwater withdrawal and recharge over the next 50 years (January 2011 through December 2060). The scenarios included combinations of continuing withdrawals from currently active production wells, supplementing any increases in demand with withdrawals from an inactive production well, reducing withdrawal amounts and rates, and reducing the discharge of treated wastewater to infiltration ponds that provide a recharge source to the underlying aquifer. Results of the simulations indicated that, depending on the scenario implemented, groundwater levels would rise (over the next 50 years) from 40 feet to as much as 65 feet in the northwestern part of the Irwin Basin, and from 5 feet to 10 feet in the southeastern part.

An analytical study on groundwater flow in drainage basins with horizontal wells

NASA Astrophysics Data System (ADS)

Wang, Jun-Zhi; Jiang, Xiao-Wei; Wan, Li; Wang, Xu-Sheng; Li, Hailong

2014-06-01

Analytical studies on release/capture zones are often limited to a uniform background groundwater flow. In fact, for basin-scale problems, the undulating water table would lead to the development of hierarchically nested flow systems, which are more complex than a uniform flow. Under the premise that the water table is a replica of undulating topography and hardly influenced by wells, an analytical solution of hydraulic head is derived for a two-dimensional cross section of a drainage basin with horizontal injection/pumping wells. Based on the analytical solution, distributions of hydraulic head, stagnation points and flow systems (including release/capture zones) are explored. The superposition of injection/pumping wells onto the background flow field leads to the development of new internal stagnation points and new flow systems (including release/capture zones). Generally speaking, the existence of n injection/pumping wells would result in up to n new internal stagnation points and up to 2n new flow systems (including release/capture zones). The analytical study presented, which integrates traditional well hydraulics with the theory of regional groundwater flow, is useful in understanding basin-scale groundwater flow influenced by human activities.

Regional scale groundwater modelling study for Ganga River basin

NASA Astrophysics Data System (ADS)

Maheswaran, R.; Khosa, R.; Gosain, A. K.; Lahari, S.; Sinha, S. K.; Chahar, B. R.; Dhanya, C. T.

2016-10-01

Subsurface movement of water within the alluvial formations of Ganga Basin System of North and East India, extending over an area of 1 million km2, was simulated using Visual MODFLOW based transient numerical model. The study incorporates historical groundwater developments as recorded by various concerned agencies and also accommodates the role of some of the major tributaries of River Ganga as geo-hydrological boundaries. Geo-stratigraphic structures, along with corresponding hydrological parameters,were obtained from Central Groundwater Board, India,and used in the study which was carried out over a time horizon of 4.5 years. The model parameters were fine tuned for calibration using Parameter Estimation (PEST) simulations. Analyses of the stream aquifer interaction using Zone Budget has allowed demarcation of the losing and gaining stretches along the main stem of River Ganga as well as some of its principal tributaries. From a management perspective,and entirely consistent with general understanding, it is seen that unabated long term groundwater extraction within the study basin has induced a sharp decrease in critical dry weather base flow contributions. In view of a surge in demand for dry season irrigation water for agriculture in the area, numerical models can be a useful tool to generate not only an understanding of the underlying groundwater system but also facilitate development of basin-wide detailed impact scenarios as inputs for management and policy action.

The risk of supply of Surface/groundwater in the Laja River Basin in the State of Guanajuato, Mexico

NASA Astrophysics Data System (ADS)

Li, Yanmei; Knappett, Peter; Giardino, John Rick; Horacio Hernandez, Jesus; Aviles, Manuel; Rodriguez, Rodrigo Mauricio; Deng, Chao

2016-04-01

Water supply in Laja River Basin, located in an arid, semi-arid area of Central Mexico, is dependent primarily on groundwater. Although multiple users depend on this groundwater, the majority of the groundwater is used for commercial irrigation. The water table is swiftly being lowered, as the result of a rapidly growing population, expanding industries and increased commercial agriculture production in the State of Guanajuato. The average historic drawdown rate, measured in various wells across the aquifer, is ~1 m/yr; some wells approach 4 m/yr. Hydraulic heads are lower in wells in the central, low-lying areas of the basin, near the main branch of Laja River, than in wells located along the outer edges of the basin. The resulting water depth ranges from 70-130 m in most of the area. As wells are drilled deeper, at increased costs, to access the falling groundwater table, toxic levels of fluoride (F) and arsenic (As) are being reported for these wells. These increases in toxicity are possibly caused by induced upwelling of deeper groundwater. Based on analysis of the water, we suggest that the groundwater is fresh and suggest that the reservoir rock is not very reactive or the groundwater is young. Unfortunately, F and As were found to exceed Maximum Contaminant Levels (MCL) in several wells. Concentrations of F and As were correlated to Total Dissolved Solids (TDS) suggesting a mixing with older, deeper groundwater. Mapping of the watershed and channel geomorphology indicates that the Laja River tends to be gravel bedded in some locations and sand-bedded in other locations with highly erodible banks. At multiple sample locations, as many as four terraces were present, suggesting an actively down-cutting channel. Geophysical measurements suggest the river is well connected to the alluvial aquifer. Thus, prior to intensive pumping in the 1950's the Laja River may have been recharged by aquifers. Whereas the discharge in the Laja River is decreasing yearly, a resulting sharp decrease in supply to the downstream reservoir, Ignacio Allende, is occurring. Both quantity and quality of water in the Laja River Basin is at a high risk not only in the short-term, but also the future.

Simulating the effect of climate extremes on groundwater flow through a lakebed

USGS Publications Warehouse

Virdi, Makhan L.; Lee, Terrie M.; Swancar, Amy; Niswonger, Richard G.

2012-01-01

Groundwater exchanges with lakes resulting from cyclical wet and dry climate extremes maintain lake levels in the environment in ways that are not well understood, in part because they remain difficult to simulate. To better understand the atypical groundwater interactions with lakes caused by climatic extremes, an original conceptual approach is introduced using MODFLOW-2005 and a kinematic-wave approximation to variably saturated flow that allows lake size and position in the basin to change while accurately representing the daily lake volume and three-dimensional variably saturated groundwater flow responses in the basin. Daily groundwater interactions are simulated for a calibrated lake basin in Florida over a decade that included historic wet and dry departures from the average rainfall. The divergent climate extremes subjected nearly 70% of the maximum lakebed area and 75% of the maximum shoreline perimeter to both groundwater inflow and lake leakage. About half of the lakebed area subject to flow reversals also went dry. A flow-through pattern present for 73% of the decade caused net leakage from the lake 80% of the time. Runoff from the saturated lake margin offset the groundwater deficit only about half of that time. A centripetal flow pattern present for 6% of the decade was important for maintaining the lake stage and generated 30% of all net groundwater inflow. Pumping effects superimposed on dry climate extremes induced the least frequent but most cautionary flow pattern with leakage from over 90% of the actual lakebed area.

Groundwater balance in the Khor Arbaat basin, Red Sea State, eastern Sudan

NASA Astrophysics Data System (ADS)

Elsheikh, Abdalla E. M.; Zeielabdein, Khalid A. Elsayed; Babikir, Ibrahim A. A.

2009-12-01

The Khor Arbaat basin is the main source of potable water supply for the more than 750,000 inhabitants of Port Sudan, eastern Sudan. The variation in hydraulic conductivity and storage capacity is due to the heterogeneity of the sediments, which range from clay and silt to gravely sand and boulders. The water table rises during the summer and winter rainy seasons; it reaches its lowest level in the dry season. The storage capacity of the Khor Arbaat aquifer is estimated to be 21.75 × 106 m3. The annual recharge through the infiltration of flood water is about 1.93 × 106 m3. The groundwater recharge, calculated as underground inflow at the ‘upper gate’, is 1.33 × 105 m3/year. The total annual groundwater recharge is 2.06 × 106 m3. The annual discharge through underground outflow at the ‘lower gate’ (through which groundwater flows onto the coastal plain) is 3.29 × 105 m3/year. Groundwater discharge due to pumping from Khor Arbaat basin is 4.38 × 106 m3/year on average. The total annual groundwater discharge is about 4.7 × 106 m3. A deficit of 2.6 × 106 m3/year is calculated. Although the total annual discharge is twice the estimated annual recharge, additional groundwater flow from the fractured basement probably balances the annual groundwater budget since no decline is observed in the piezometric levels.

Altitude and configuration of the potentiometric surface in the Lower White Clay Creek and Upper Christina River Basins including portions of Franklin, London Britain, New Garden, and New London Townships, Chester County, Pennsylvania, June through September 2005

USGS Publications Warehouse

Hale, Lindsay B.

2006-01-01

Since 1984, the U.S. Geological Survey (USGS) has been mapping the altitude and configuration of the potentiometric surface in Chester County as part of an ongoing cooperative program to measure and describe the water resources of the county.  Areas where the potentiometric surface has been mapped are shown on figure 1.  These maps can be used to determine the general direction of ground-water flow and are frequently referenced by municipalities and developers to evaluate ground-water conditions for water supply and resource-protection requirements (Wood, 1998).

Hydrogeologic framework and preliminary simulation of ground-water flow in the Mimbres Basin, southwestern New Mexico

USGS Publications Warehouse

Hanson, R.T.; McLean, J.S.; Miller, Ryan S.

1994-01-01

The bolson-fill aquifer, the major water-yielding unit in the Mimbres Basin, southwestern New Mexico, ranges in thickness from 0 to about 3,700 feet. Recharge to the bolson-fill aquifer occurs by infiltration of ephemeral streams that cross the basin margin, infiltration from precipitation and streamflow, ground-water underflow from adjacent basins, and infiltration of springflow from adjacent bedrock units within the basin. Ground water generally flows southward from the northern highland areas of the basin. Ground-water discharge consists of pumpage from wells, transpiration by plants, outflow to playas and springs in the Los Muertos Basin in Mexico, discharge to the Mimbres River, and ground-water flow to the Mesilla Basin near Mason Draw. Before 1910, ground-water recharge and discharge were approximately equal; by 1975, however, about 75 percent of the 146,000 acre-feet withdrawn annually was ground water, most of it from aquifer storage. The transmissivity of the bolson-fill aquifer determined from aquifer tests and specific-capacity data ranges from 10 to 50,000 feet squared per day. Hydraulic conductivity, calculated from saturated thickness and transmissivity, ranges from 0.03 to 800 feet per day, with median values of about 18 feet per day in the Deming area and 6 feet per day elsewhere. Reported storage-coefficient values representing confined parts of the aquifer range from 0.00036 to 0.0036, and those representing unconfined parts of the aquifer range from 0.02 to 0.24. Water quality in the north and central parts of the Mimbres Basin is suitable for most uses. Due to its large salinity and alkalinity, some of the ground water in the south and southeastern areas of the bolson-fill aquifer may not be suitable for irrigation or domestic use. A preliminary two-dimensional digital model was constructed to evaluate ground-water flow in the bolson-fill aquifer. The model was divided into zones of uniform hydraulic conductivity corresponding to the major structural elements of the basin. For simulation purposes, hydraulic conductivity in the central part of the basin ranged from 2.2 to 4.4 feet per day, whereas locally along the edges of the aquifer less certain values ranged from 0.003 to 62 feet per day Analysis of the results of this predevelopment model indicated that use of the mountain-front recharge method overestimates total recharge and that evapotranspiration is substantial. The simulated total inflow was about 55 percent of that estimated in a water budget for the Mimbres Basin.Ground-water development between 1930 and 1985 was simulated using storage-coefficient values of 0.01 and 0.02 for the Gila Conglomerate, 0.04 to 0.17 for bolson-fill deposits, and 0.001 for bolson fill capped with lacustrine clay. The simulated transient water budget indicated that most of the water pumped by 1985 came from storage, and lesser but substantial amounts came from reductions in evapotranspiration.

Assessment of Managed Aquifer Recharge Site Suitability Using a GIS and Modeling.

PubMed

Russo, Tess A; Fisher, Andrew T; Lockwood, Brian S

2015-01-01

We completed a two-step regional analysis of a coastal groundwater basin to (1) assess regional suitability for managed aquifer recharge (MAR), and (2) quantify the relative impact of MAR activities on groundwater levels and sea water intrusion. The first step comprised an analysis of surface and subsurface hydrologic properties and conditions, using a geographic information system (GIS). Surface and subsurface data coverages were compiled, georeferenced, reclassified, and integrated (including novel approaches for combining related datasets) to derive a spatial distribution of MAR suitability values. In the second step, results from the GIS analysis were used with a regional groundwater model to assess the hydrologic impact of potential MAR placement and operating scenarios. For the region evaluated in this study, the Pajaro Valley Groundwater Basin, California, GIS results suggest that about 7% (15 km2) of the basin may be highly suitable for MAR. Modeling suggests that simulated MAR projects placed near the coast help to reduce sea water intrusion more rapidly, but these projects also result in increased groundwater flows to the ocean. In contrast, projects placed farther inland result in more long-term reduction in sea water intrusion and less groundwater flowing to the ocean. This work shows how combined GIS analysis and modeling can assist with regional water supply planning, including evaluation of options for enhancing groundwater resources. © 2014, National Ground Water Association.

Sources of low-arsenic groundwater in the Bengal Basin: investigating the influence of the last glacial maximum palaeosol using a 115-km traverse across Bangladesh

NASA Astrophysics Data System (ADS)

Hoque, M. A.; McArthur, J. M.; Sikdar, P. K.

2014-05-01

Pollution of groundwater in the Bengal Basin (Bangladesh and West Bengal, India) by arsenic (As) puts at risk the health of more than 100 million consumers. Using 1,580 borehole lithological logs and published hydrochemistry on 2,387 wells, it was predicted that low-As (<10 μg/L) groundwater exists, in palaeo-interfluvial aquifers of brown sand capped by a protective palaeosol, beneath at least 45,000 km2 of the Bengal Basin. The aquifers were predicted to be at a depth of as little as 25 m below ground level (mbgl), and typically no more than 50 mbgl. The predictions were confirmed along an east-west traverse 115 km in length (i.e. across half of Bangladesh) by drilling 28 new boreholes to 91-m depth to reveal subsurface sedimentology, and by mapping As distribution in groundwater. The aquifers identified occur at typically <40 mbgl and so are accessible with local drilling methods. A protective palaeosol that caps the palaeo-interfluvial aquifers prevents downward movement into them of As-polluted groundwater present in shallower palaeo-channel aquifers and ensures that the palaeo-interfluvial aquifers will yield low-As groundwater for the foreseeable future. Their use, in place of the shallower As-polluted palaeo-channel aquifers, would rapidly mitigate the health risks from consumption of As-polluted groundwater.

Decreasing Agricultural Irrigation has not reversed Groundwater Depletion in the Yellow River Basin

NASA Astrophysics Data System (ADS)

Kang, Z.; Xie, X.; Zhu, B.

2017-12-01

Agricultural irrigation is considered as the major water use sector accounting for over 60% of the global freshwater withdrawals. Especially in the arid and semiarid areas, irrigation from groundwater storage substantially sustain crop growth and food security. China's Yellow River Basin (YRB) is a typical arid and semiarid area with average annual precipitation about 450 mm. In this basin, more than 52 million hm2 of arable land needs irrigation for planting wheat, cotton, paddy rice etc, and groundwater contributes over one-third irrigation water. However, agricultural irrigation remained a certain level or decreased to some degree due to water-saving technologies and returning farmland to forest projects. Then an interesting question arises: has the groundwater storage (GWS) in YRB kept a consistent variation with the agricultural irrigation? In this study, to address this question, we employed multi-source data from ground measurements, remote sensing monitoring and large-scale hydrological modeling. Specifically, groundwater storage variation was identified using Gravity Recovery and Climate Experiment (GRACE) data and ground observations, and groundwater recharge was estimated based on the Variable Infiltration Capacity (VIC) modeling. Results indicated that GWS in YRB still holds a significant depletion with a rate of about -3 mm per year during the past decade, which was consistently demonstrated by the GRACE and the ground observations. Ground water recharge shows negligible upward trends despite climate change. The roles of different sectors contributing to groundwater depletion have changed. Agricultural irrigation accounting for over 60% of groundwater depletion, but its impact decreased. However, the domestic and the industrial purposes play an increasing role in shaping groundwater depletion.

Geochemical and isotopic determination of deep groundwater contributions and salinity to the shallow groundwater and surface water systems, Mesilla Basin, New Mexico, Texas, and Mexico

NASA Astrophysics Data System (ADS)

Robertson, A.; Carroll, K. C.; Kubicki, C.; Purtshert, R.

2017-12-01

The Mesilla Basin/Conejos-Médanos aquifer system, extending from southern New Mexico to Chihuahua, Mexico, is a priority transboundary aquifer under the 2006 United States­-Mexico Transboundary Aquifer Assessment Act. Declining water levels, deteriorating water quality, and increasing groundwater use by municipal, industrial, and agricultural users on both sides of the international border raise concerns about long-term aquifer sustainability. Relative contributions of present-day and "paleo" recharge to sustainable fresh groundwater yields has not been determined and evidence suggests that a large source of salinity at the distal end of the Mesilla Basin is saline discharge from deep groundwater flow. The magnitude and distribution of those deep saline flow paths are not determined. The contribution of deep groundwater to discharge and salinity in the shallow groundwater and surface water of the Mesilla Basin will be determined by collecting discrete groundwater samples and analyzing for aqueous geochemical and isotopic tracers, as well as the radioisotopes of argon and krypton. Analytes include major ions, trace elements, the stable isotopes of water, strontium and boron isotopes, uranium isotopes, the carbon isotopes of dissolved inorganic carbon, noble gas concentrations and helium isotope ratios. Dissolved gases are extracted and captured from groundwater wells using membrane contactors in a process known as ultra-trace sampling. Gas samples are analyzed for radioisotope ratios of krypton by the ATTA method and argon by low-level counting. Effectiveness of the ultra-trace sampling device and method was evaluated by comparing results of tritium concentrations to the krypton-85 content. Good agreement between the analyses, especially in samples with undetectable tritium, indicates that the ultra-trace procedure is effective and confirms that introduction of atmospheric air has not occurred. The geochemistry data indicate a complex system of geochemical endmembers, and mixing between these endmembers. Ongoing work seeks to better constrain groundwater ages and mixing models through the coupled use of conventional aqueous geochemical and isotopic analysis and the ultra-trace constituents.

Stable-isotope geochemistry of groundwaters in the Delaware Basin of southeastern New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambert, S.J.; Harvey, D.M.

/sup 18/O//sup 16/O and D/H ratio measurements have been made on groundwaters sampled from the Rustler Formation (Ochoan, Permian) and related rocks in the northern Delaware Basin of southeastern New Mexico. Most confined Rustler waters at the Waste Isolation Pilot Plant (WIPP) site and to the west in Nash Draw and confined waters from the Capitan limestone constitute one population in deltaD/delta/sup 18/O space, while unconfined groundwaters inferred to originate as modern surface recharge to alluvium, sandstones in the Ogallala Formation, the near-surface Rustler in southwestern Nash Draw, and the Capitan vadose zone in the Guadalupe Mountains (Carlsbad Caverns) constitutemore » a distinctly different population; the two do not overlap. A likely explanation for this distinction is that meteoric recharge to most of the Rustler and Capitan took place in the geologic past under climatic conditions significantly different from the present. Available tritium and radiocarbon data are consistent with this hypothesis, and the apparent age of confined groundwaters is in excess of 12,000 radiocarbon years, suggesting that recharge took place under wetter conditions in the late Pleistocene. Processes governing recharge in the Delaware Basin are significantly different from those in the nearby Roswell Artesian Basin, but may be similar to those previously described for the Albuquerque (New Mexico) and Murray (South Australia) Basins. 133 refs.« less

Assessment of groundwater quality in the Al- Burayhi and Hedran sub-basin, Taiz, Yemen - A GIS approach

NASA Astrophysics Data System (ADS)

Naser, Ramzy; El Bakkali, Mohammed; Darwesh, Nabil; El Kharrim, Khadija; Belghyti, Driss

2018-05-01

In many parts of the world, groundwater sources are the single most important supply for the production of drinking water, particularly in areas with limited or polluted surface water sources. Fresh water has become a scarce commodity due to over exploitation and pollution of water. Many countries and international organizations, including Wolrd Health Organization, are seeking to promote people's access to safe drinking water. The situation in Yemen is no exception. Although we rely on groundwater significantly in our lives and our survival, we do not manage it in a way that ensures its sustainability and maintenance of pollution. The objective of this study is to determine the suitability of the groundwater in Al Burayhi and Hedran sub-basin (one of the sub-basins of the Upper Valley Rasyan) as a source of drinking water in the shade of the expected deterioration due to natural processes (water interaction with rocks, semi-dry climate) and human activities.

Hydrochemical characterization and pollution sources identification of groundwater in Salawusu aquifer system of Ordos Basin, China.

PubMed

Yang, Qingchun; Wang, Luchen; Ma, Hongyun; Yu, Kun; Martín, Jordi Delgado

2016-09-01

Ordos Basin is located in an arid and semi-arid region of northwestern China, which is the most important energy source bases in China. Salawusu Formation (Q3 s) is one of the most important aquifer systems of Ordos Basin, which is adjacent to Jurassic coalfield areas. A large-scale exploitation of Jurassic coal resources over ten years results in series of influences to the coal minerals, such as exposed to the oxidation process and dissolution into the groundwater due to the precipitation infiltration. Therefore, how these processes impact groundwater quality is of great concerns. In this paper, the descriptive statistical method, Piper trilinear diagram, ratios of major ions and canonical correspondence analysis are employed to investigate the hydrochemical evolution, determine the possible sources of pollution processes, and assess the controls on groundwater compositions using the monitored data in 2004 and 2014 (before and after large-scale coal mining). Results showed that long-term exploration of coal resources do not result in serious groundwater pollution. The hydrochemical types changed from HCO3(-)-CO3(2-) facies to SO4(2-)-Cl facies during 10 years. Groundwater hardness, nitrate and sulfate pollution were identified in 2014, which was most likely caused by agricultural activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Depletion mapping and constrained optimization to support managing groundwater extraction

USGS Publications Warehouse

Fienen, Michael N.; Bradbury, Kenneth R.; Kniffin, Maribeth; Barlow, Paul M.

2018-01-01

Groundwater models often serve as management tools to evaluate competing water uses including ecosystems, irrigated agriculture, industry, municipal supply, and others. Depletion potential mapping—showing the model-calculated potential impacts that wells have on stream baseflow—can form the basis for multiple potential management approaches in an oversubscribed basin. Specific management approaches can include scenarios proposed by stakeholders, systematic changes in well pumping based on depletion potential, and formal constrained optimization, which can be used to quantify the tradeoff between water use and stream baseflow. Variables such as the maximum amount of reduction allowed in each well and various groupings of wells using, for example, K-means clustering considering spatial proximity and depletion potential are considered. These approaches provide a potential starting point and guidance for resource managers and stakeholders to make decisions about groundwater management in a basin, spreading responsibility in different ways. We illustrate these approaches in the Little Plover River basin in central Wisconsin, United States—home to a rich agricultural tradition, with farmland and urban areas both in close proximity to a groundwater-dependent trout stream. Groundwater withdrawals have reduced baseflow supplying the Little Plover River below a legally established minimum. The techniques in this work were developed in response to engaged stakeholders with various interests and goals for the basin. They sought to develop a collaborative management plan at a watershed scale that restores the flow rate in the river in a manner that incorporates principles of shared governance and results in effective and minimally disruptive changes in groundwater extraction practices.

Depletion Mapping and Constrained Optimization to Support Managing Groundwater Extraction.

PubMed

Fienen, Michael N; Bradbury, Kenneth R; Kniffin, Maribeth; Barlow, Paul M

2018-01-01

Groundwater models often serve as management tools to evaluate competing water uses including ecosystems, irrigated agriculture, industry, municipal supply, and others. Depletion potential mapping-showing the model-calculated potential impacts that wells have on stream baseflow-can form the basis for multiple potential management approaches in an oversubscribed basin. Specific management approaches can include scenarios proposed by stakeholders, systematic changes in well pumping based on depletion potential, and formal constrained optimization, which can be used to quantify the tradeoff between water use and stream baseflow. Variables such as the maximum amount of reduction allowed in each well and various groupings of wells using, for example, K-means clustering considering spatial proximity and depletion potential are considered. These approaches provide a potential starting point and guidance for resource managers and stakeholders to make decisions about groundwater management in a basin, spreading responsibility in different ways. We illustrate these approaches in the Little Plover River basin in central Wisconsin, United States-home to a rich agricultural tradition, with farmland and urban areas both in close proximity to a groundwater-dependent trout stream. Groundwater withdrawals have reduced baseflow supplying the Little Plover River below a legally established minimum. The techniques in this work were developed in response to engaged stakeholders with various interests and goals for the basin. They sought to develop a collaborative management plan at a watershed scale that restores the flow rate in the river in a manner that incorporates principles of shared governance and results in effective and minimally disruptive changes in groundwater extraction practices. © 2017, National Ground Water Association.

Pharmaceuticals and personal care products (PPCPs) and artificial sweeteners (ASs) in surface and ground waters and their application as indication of wastewater contamination.

PubMed

Yang, Yuan-Yuan; Zhao, Jian-Liang; Liu, You-Sheng; Liu, Wang-Rong; Zhang, Qian-Qian; Yao, Li; Hu, Li-Xin; Zhang, Jin-Na; Jiang, Yu-Xia; Ying, Guang-Guo

2018-03-01

We systematically investigated the occurrence and distribution of 93 pharmaceuticals and personal care products (PPCPs) and 5 artificial sweeteners (ASs) in surface water and groundwater of Dongjiang River basin in south China. In surface water, 52 compounds were detected with median concentrations ranging from 0.06ng/L to 504ng/L, while in groundwater, 33 compounds were detected with concentrations up to 4580ng/L for acesulfame. PPCPs and ASs were widely detected in the surface water and groundwater samples, which indicated contamination by domestic wastewater in the surface water and groundwater of Dongjiang River basin. Temporal and spatial variations of the detected chemicals were observed in surface water. Acesulfame, sucralose and cyclamate can be used as wastewater indicators to imply contamination in groundwater caused by domestic wastewater due to their hydrophilicity, anthropogenic sources and ubiquity in groundwater. Moreover, the detection of the readily degradable ASs, cyclamate, was a strong indication of untreated wastewater in groundwater. Sucralose was found to be a suitable wastewater indicator to reflect domestic wastewater contamination in surface water and groundwater qualitatively and quantitatively, and it can be used to evaluate wastewater burden in surface water and groundwater of Dongjiang River basin. The wastewater burden data from this survey implied serious contamination in surface water and groundwater by domestic wastewater at Shima River, a tributary of the Dongjiang River. The findings from this study suggest that the selected labile and conservative chemicals can be used as indication of wastewater contamination for aquatic environments qualitatively and quantitatively. Copyright © 2017 Elsevier B.V. All rights reserved.

Groundwater quality assessment of the quaternary unconsolidated sedimentary basin near the Pi river using fuzzy evaluation technique

NASA Astrophysics Data System (ADS)

Mohamed, Adam Khalifa; Liu, Dan; Mohamed, Mohamed A. A.; Song, Kai

2018-05-01

The present study was carried out to assess the groundwater quality for drinking purposes in the Quaternary Unconsolidated Sedimentary Basin of the North Chengdu Plain, China. Six groups of water samples (S1, S2, S3, S4, S5, and S6) are selected in the study area. These samples were analyzed for 19 different physicochemical water quality parameters to assess groundwater quality. The physicochemical parameters of groundwater were compared with China's Quality Standards for Groundwater (GB/T14848-93). Interpretation of physicochemical data revealed that groundwater in the basin was slightly alkaline. Total hardness and total dissolved solid values show that the investigated water is classified as very hard and fresh water, respectively. The sustainability of groundwater for drinking purposes was assessed based on the fuzzy mathematics evaluation (FME) method. The results of the assessment were classified into five groups based on their relative suitability for portable use (grade I = most suitable to grade V = least suitable), according to (GB/T 14848-93). The assessment results reveal that the quality of groundwater in most of the wells was class I, II and III and suitable for drinking purposes, but well (S2) has been found to be in class V, which is classified as very poor and cannot be used for drinking. Also, the FME method was compared with the comprehensive evaluation method. The FME method was found to be more comprehensive and reasonable to assess groundwater quality. This study can provide an important frame of reference for decision making on improving groundwater quality in the study area and nearby surrounding.

Hydrogeology and water quality of the Chakari Basin, Afghanistan

USGS Publications Warehouse

Mack, Thomas J.; Chornack, Michael P.; Flanagan, Sarah M.; Chalmers, Ann T.

2014-01-01

The hydrogeology and water quality of the Chakari Basin, a 391-square-kilometer (km2) watershed near Kabul, Afghanistan, was assessed by the U.S. Geological Survey and the Afghanistan Geological Survey to provide an understanding of the water resources in an area of Afghanistan with considerable copper and other mineral resources. Water quality, chemical, and isotopic samples were collected at eight wells, four springs, one kareze, and the Chakari River in a basin-fill aquifer in the Chakari Basin by the Afghanistan Geological Survey. Results of water-quality analyses indicate that some water samples in the basin had concentrations of chemical constituents that exceeded World Health Organization guidelines for nitrate, sodium, and dissolved solids and some of the samples also had elevated concentrations of trace elements, such as copper, selenium, strontium, uranium, and zinc. Chemical and isotopic analyses, including for tritium, chlorofluorocarbons, and carbon-14, indicate that most wells contain water with a mixture of ages from young (years to decades) to old (several thousand years). Three wells contained groundwater that had modeled ages ranging from 7,200 to 7,900 years old. Recharge from precipitation directly on the basin-fill aquifer, which covers an area of about 150 km2, is likely to be very low (7 × 10-5 meters per day) or near zero. Most recharge to this aquifer is likely from rain and snowmelt on upland areas and seepage losses and infiltration of water from streams crossing the basin-fill aquifer. It is likely that the older water in the basin-fill aquifer is groundwater that has travelled along long and (or) slow flow paths through the fractured bedrock mountains surrounding the basin. The saturated basin-fill sediments in most areas of the basin are probably about 20 meters thick and may be about 30 to 60 meters thick in most areas near the center of the Chakari Basin. The combination of low recharge and little storage indicates that groundwater resources are likely to be limited. Groundwater use in the villages of the basin is generally supplied by hand-pumped wells, whereas agricultural needs are met by surface-water flows. New or increased water uses in the basin, or activities that may affect water quality, should be carefully evaluated to avoid affecting existing uses.

Geophysical Framework Investigations Influencing Ground-Water Resources in East-Central Nevada and West-Central Utah

USGS Publications Warehouse

Watt, Janet T.; Ponce, David A.

2007-01-01

A geophysical investigation was undertaken as part of an effort to characterize the geologic framework influencing ground-water resources in east-central Nevada and west-central Utah. New gravity data were combined with existing aeromagnetic, drill-hole, and geologic data to help determine basin geometry, infer structural features, estimate depth to pre-Cenozoic basement rocks, and further constrain the horizontal extents of exposed and buried plutons. In addition, a three-dimensional (3D) geologic model was constructed to help illustrate the often complex geometries of individual basins and aid in assessing the connectivity of adjacent basins. In general, the thirteen major valleys within the study area have axes oriented north-south and frequently contain one or more sub-basins. These basins are often asymmetric and typically reach depths of 2 km. Analysis of gravity data helped delineate geophysical lineaments and accommodation zones. Structural complexities may further compartmentalize ground-water flow within basins and the influence of tectonics on basin sedimentation further complicates their hydrologic properties. The horizontal extent of exposed and, in particular, buried plutons was estimated over the entire study area. The location and subsurface extents of these plutons will be very important for regional water resource assessments, as these features may act as either barriers or pathways for groundwater flow. A previously identified basement gravity low strikes NW within the study area and occurs within a highly extended terrane between the Butte and Confusion synclinoria. Evidence from geophysical, geologic, and seismic reflection data suggests relatively lower density plutonic rocks may extend to moderate crustal depths and rocks of similar composition may be the source of the entire basement gravity anomaly.

Optimisation of groundwater level monitoring networks using geostatistical modelling based on the Spartan family variogram and a genetic algorithm method

NASA Astrophysics Data System (ADS)

Parasyris, Antonios E.; Spanoudaki, Katerina; Kampanis, Nikolaos A.

2016-04-01

Groundwater level monitoring networks provide essential information for water resources management, especially in areas with significant groundwater exploitation for agricultural and domestic use. Given the high maintenance costs of these networks, development of tools, which can be used by regulators for efficient network design is essential. In this work, a monitoring network optimisation tool is presented. The network optimisation tool couples geostatistical modelling based on the Spartan family variogram with a genetic algorithm method and is applied to Mires basin in Crete, Greece, an area of high socioeconomic and agricultural interest, which suffers from groundwater overexploitation leading to a dramatic decrease of groundwater levels. The purpose of the optimisation tool is to determine which wells to exclude from the monitoring network because they add little or no beneficial information to groundwater level mapping of the area. Unlike previous relevant investigations, the network optimisation tool presented here uses Ordinary Kriging with the recently-established non-differentiable Spartan variogram for groundwater level mapping, which, based on a previous geostatistical study in the area leads to optimal groundwater level mapping. Seventy boreholes operate in the area for groundwater abstraction and water level monitoring. The Spartan variogram gives overall the most accurate groundwater level estimates followed closely by the power-law model. The geostatistical model is coupled to an integer genetic algorithm method programmed in MATLAB 2015a. The algorithm is used to find the set of wells whose removal leads to the minimum error between the original water level mapping using all the available wells in the network and the groundwater level mapping using the reduced well network (error is defined as the 2-norm of the difference between the original mapping matrix with 70 wells and the mapping matrix of the reduced well network). The solution to the optimization problem (the best wells to retain in the monitoring network) depends on the total number of wells removed; this number is a management decision. The water level monitoring network of Mires basin has been optimized 6 times by removing 5, 8, 12, 15, 20 and 25 wells from the original network. In order to achieve the optimum solution in the minimum possible computational time, a stall generations criterion was set for each optimisation scenario. An improvement made to the classic genetic algorithm was the change of the mutation and crossover fraction in respect to the change of the mean fitness value. This results to a randomness in reproduction, if the solution converges, to avoid local minima, or, in a more educated reproduction (higher crossover ratio) when there is higher change in the mean fitness value. The choice of integer genetic algorithm in MATLAB 2015a poses the restriction of adding custom selection and crossover-mutation functions. Therefore, custom population and crossover-mutation-selection functions have been created to set the initial population type to custom and have the ability to change the mutation crossover probability in respect to the convergence of the genetic algorithm, achieving thus higher accuracy. The application of the network optimisation tool to Mires basin indicates that 25 wells can be removed with a relatively small deterioration of the groundwater level map. The results indicate the robustness of the network optimisation tool: Wells were removed from high well-density areas while preserving the spatial pattern of the original groundwater level map. Varouchakis, E. A. and D. T. Hristopulos (2013). "Improvement of groundwater level prediction in sparsely gauged basins using physical laws and local geographic features as auxiliary variables." Advances in Water Resources 52: 34-49.

Soil and geologic controls on recharge and groundwater flow response to climate perturbation: A case study of the Yakima River Basin

NASA Astrophysics Data System (ADS)

Nguyen, T. T.; Pham, H. V.; Bachmann, M.; Tague, C.; Adam, J. C.

2017-12-01

The Yakima River Basin (YRB) is one of the most important agricultural basins in Washington State with annual revenues in excess of $3.2 billion. This intensively irrigated basin is, however, one of the state's most climatically sensitive water resources system as it heavily relies on winter snowpack and limited reservoir storage. Water shortages and drought are expected to be more frequent with climate change, population growth and increasing agricultural demand. This could result in significant impacts on the groundwater system and subsequently the Yakima River. The goal of this study is to assess how soil and geologic characteristics affect catchment recharge and groundwater flow across three catchments within the YRB using a coupled framework including a physically based hydro-ecological model, the Regional Hydro-Ecologic Simulation System (RHESSys) and a groundwater model, MODFLOW. Soil and geologic-related parameters were randomly sampled to use within the Distributed Evaluation of Local Sensitivity Analysis (DELSA) framework to explore their roles in governing catchment recharge and groundwater flow to climate perturbation. Preliminarily results show that catchment recharge is most sensitive to variation in soil transmissivity in two catchments. However, in the other catchment, recharge is more influenced by soil field capacity and bypass recharge. Recharge is also more sensitive to geologic related parameters in catchments where a portion of its flow comes from deep groundwater. When including the effect of climate perturbations, the sensitivity of recharge responses to soil and geologic characteristics varies with temperature and precipitation change. On the other hand, horizontal hydraulic conductivity is the dominant factor that controls groundwater flow responses in catchments with low permeability soil; alternatively, specific storage (and, to some extent, vertical anisotropy) are important in catchments with more conductive soil. The modeling framework developed in this study will be used to investigate the impacts of both climate and drought-relief supplemental pumping on potential recharge, groundwater and streamflow changes in the YRB.

Dissolved methane in groundwater, Upper Delaware River Basin, Pennsylvania and New York, 2007-12

USGS Publications Warehouse

Kappel, William M.

2013-01-01

The prospect of natural gas development from the Marcellus and Utica Shales has raised concerns about freshwater aquifers being vulnerable to contamination. Well owners are asking questions about subsurface methane, such as, “Does my well water have methane and is it safe to drink the water?” and “Is my well system at risk of an explosion hazard associated with a combustible gas like methane in groundwater?” This newfound awareness of methane contamination of water wells by stray gas migration is based upon studies such as Molofsky and others (2011) who document the widespread natural occurrence of methane in drinking-water wells in Susquehanna County, Pennsylvania. In the same county, Osborn and others (2011) identified elevated methane concentrations in selected drinking-water wells in the vicinity of Marcellus Shale gas-development activities, although pre-development groundwater samples were not available for comparison. A compilation of dissolved methane concentrations in groundwater for New York State was published by Kappel and Nystrom (2012). Recent work documenting the occurrence and distribution of methane in groundwater was completed in southern Sullivan County, Pennsylvania (Sloto, 2013). Additional work is ongoing with respect to monitoring for stray gases in groundwater (Jackson and others, 2013). These studies and their results indicate the importance of collecting baseline or pre-development data. While such data are being collected in some areas, published data on methane in groundwater are sparse in the Upper Delaware River Basin of Pennsylvania, New York, and New Jersey. To manage drinking-water resources in areas of gas-well drilling and hydraulic fracturing in the Upper Delaware River Basin, the natural occurrence of methane in the tri-state aquifers needs to be documented. The purpose of this report is to present data on dissolved methane concentrations in the groundwater in the Upper Delaware River Basin. The scope is restricted to data for Pennsylvania and New York, no U.S. Geological Survey (USGS) methane analyses are presently available for northwestern New Jersey.

Use of Absolute Gravity Measurements to Monitor Groundwater in the Española Basin, New Mexico

NASA Astrophysics Data System (ADS)

Cogbill, A. H.; Ferguson, J. F.; Keating, E. H.

2005-05-01

We present early results of three-year project using absolute gravity instrumentation to monitor groundwater in an arid to semi-arid region in northern New Mexico. Over 100 permanent gravity stations have been established in the groundwater basin. A-10 absolute gravity meters, manufactured by Micro-g Solutions, Inc., have been used to monitor long-term gravity changes in the groundwater basin. Over fifty A-10 sites have been established; other gravity sites have been established by reference to the primary A-10 sites using Scintrex CG-3M relative gravimeters. We have used geodetic-quality GPS surveys to directly measure any possible elevation changes at the gravity sites; thus far, no significant changes in elevation have been observed. For the A-10 gravity sites, we have learned that sites must be constructed rather carefully to minimize noise levels due to certain characteristics of the A-10 measurement system. At good sites, away from regions where we expect changes due to groundwater removal, reproducibility of the A-10 measurements is ±4~μGal. To date, we have data from repeat campaigns over a period of 22 months. We have observed systematic changes in gravity of as much as 14~μGal at certain sites. We have directly incorporated gravity modeling into a detailed 3D groundwater model of the basin. On the basis of groundwater modeling, we believe that such gravity changes are due to increased recharge at some sites, as precipitation began to return to normal amounts after a long, pronounced drought about a year into the study. Somewhat surprisingly, no significant gravity changes have been observed at the Buckman Well Field, a spatially small well field that is heavily pumped as a municipal supply field for Santa Fe, New Mexico. One interpretation of this observation is that pumping at the Buckman Field is accessing nearby surface sources rather than groundwater, despite the fact that pumping is occurring from more than 300~m depth.

Estimates of ground-water pumpage from the Yakima River Basin aquifer system, Washington, 1960-2000

USGS Publications Warehouse

Vaccaro, J.J.; Sumioka, S.S.

2006-01-01

Ground-water pumpage in the Yakima River Basin, Washington, was estimated for eight categories of use for 1960-2000 as part of an investigation to assess groundwater availability in the basin. Methods used, pumpage estimates, reliability of the estimates, and a comparison with appropriated quantities are described. The eight categories of pumpage were public water supply, self-supplied domestic (exempt wells), irrigation, frost protection, livestock and dairy operations, industrial and commercial, fish and wildlife propagation, and ground-water claims. Pumpage estimates were based on methods that varied by the category and primarily represent pumpage for groundwater rights. Washington State Department of Ecology’s digital database has 2,874 active ground-water rights in the basin that can withdraw an annual quantity of about 529,231 acre-feet during dry years. Irrigation rights are for irrigation of about 129,570 acres. All but 220 of the rights were associated with well drillers’ logs, allowing for a spatial representation of the pumpage. Five-hundred and sixty of the irrigation rights were estimated to be standby/reserve rights. During this study, another 30 rights were identified that were not in the digital database. These rights can withdraw an annual quantity of about 20,969 acre-feet; about 6,700 acre-feet of these rights are near but outside the basin. In 1960, total annual pumpage in the basin, excluding standby/reserve pumpage, was about 115,776 acre-feet. By 2000, total annual pumpage was estimated to be 395,096 acre-feet, and excluding the standby/reserve rights, the total was 312,284 acre-feet. Irrigation accounts for about 60 percent of the pumpage, followed by public water supply at about 12 percent. The smallest category of pumpage was for livestock use with pumpage estimated to be 6,726 acre-feet. Total annual pumpage in 2000 was about 430 cubic feet per second, which is about 11 percent of the surface-water demand. Maximum pumpage is in July and August and during 2000, was about 100 cubic feet per second each month averaged over the Yakima River Basin aquifer system. During 2000, non-standby/reserve pumpage associated with ground-water rights was estimated to total 253,454 acre-feet, or about 198,290 acre-feet less than the appropriated quantity. The unused part of the appropriated value is about equivalent to the irrigation pumpage for primary rights.

Influences of groundwater extraction on flow dynamics and arsenic levels in the western Hetao Basin, Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Zhang, Zhuo; Guo, Huaming; Zhao, Weiguang; Liu, Shuai; Cao, Yongsheng; Jia, Yongfeng

2018-04-01

Data on spatiotemporal variations in groundwater levels are crucial for understanding arsenic (As) behavior and dynamics in groundwater systems. Little is known about the influences of groundwater extraction on the transport and mobilization of As in the Hetao Basin, Inner Mongolia (China), so groundwater levels were recorded in five monitoring wells from 2011 to 2016 and in 57 irrigation wells and two multilevel wells in 2016. Results showed that groundwater level in the groundwater irrigation area had two troughs each year, induced by extensive groundwater extraction, while groundwater levels in the river-diverted (Yellow River) water irrigation area had two peaks each year, resulting from surface-water irrigation. From 2011 to 2016, groundwater levels in the groundwater irrigation area presented a decreasing trend due to the overextraction. Groundwater samples were taken for geochemical analysis each year in July from 2011 to 2016. Increasing trends were observed in groundwater total dissolved solids (TDS) and As. Owing to the reverse groundwater flow direction, the Shahai Lake acts as a new groundwater recharge source. Lake water had flushed the near-surface sediments, which contain abundant soluble components, and increased groundwater salinity. In addition, groundwater extraction induced strong downward hydraulic gradients, which led to leakage recharge from shallow high-TDS groundwater to the deep semiconfined aquifer. The most plausible explanation for similar variations among As, Fe(II) and total organic carbon (TOC) concentrations is the expected dissimilatory reduction of Fe(III) oxyhydroxides.

Assessment of hydrochemical trends in the highly anthropised Guadalhorce River basin (southern Spain) in terms of compliance with the European groundwater directive for 2015.

PubMed

Urresti-Estala, Begoña; Gavilán, Pablo Jiménez; Pérez, Iñaki Vadillo; Cantos, Francisco Carrasco

2016-08-01

One of the key aspects introduced by the European Water Framework Directive 2000/60/EC (WFD) and developed by Groundwater Directive 2006/118/EC was the need to analyse pollution trends in groundwater bodies in order to meet the environmental objectives set in Article 4 WFD. According to this Directive, the main goal of "good status" should be achieved by the year 2015, and having reached this horizon, now is a suitable time to assess the changes that have taken place with the progressive implementation of the WFD. An extensive database is available for the Guadalhorce River basin, and this was used not only to identify in groundwater but also to draw real conclusions with respect to the degree of success in meeting the targets established for this main deadline (2015) The geographic and climate context of the Guadalhorce basin has facilitated the development of a variety of economic activities, but the one affecting the largest surface area is agriculture (which is practised on over 50 % of the river basin). The main environmental impacts identified in the basin aquifers arise from the widespread use of fertilisers and manures, together with the input of sewage from population centres. In consequence, some of the groundwater bodies located in the basin have historically had very high nitrate concentrations, often exceeding 200 mg/L. In addition, return flows, the use of fertilisers and other pressures promote the entry of other pollutants into the groundwater, as well as the salinisation of the main aquifers in the basin. In order to assess the hydrochemical changes that have taken place since the entry into force of the WFD, we performed a detailed trends analysis, based on data from the official sampling networks. In some cases, over 35 years of water quality data are available, but these statistics also present significant limitations, due to some deficiencies in the design or management; thus, data are missing for many years, the results are subject to seasonality effects, there are gaps in the historical records obtained by the monitoring networks and other shortcomings. The results obtained were analysed with the non-parametric Mann-Kendall test and revealed a general upward trend of pollutants in the areas affected by major pressures. In this analysis, we evaluated not only the increase or decrease in pollutants but also the different processes detected and the sources of pollution within the basin area. Our evaluation shows that robust measures should be taken in order to prevent further major degradation of groundwater quality and to enable "good quality" status to be achieved in future extensions of the WFD.

Water-resources activities in New York, 1987-88

USGS Publications Warehouse

Marshall, Mary P.; Finch, Anne J.

1988-01-01

The U.S. Geological Survey conducted more than 35 water resources projects in New York in 1987-88. These studies, done largely through cooperative joint-funding programs with the state, County, and local agencies, encompass statewide networks of measurement stations that provide continuous records of streamflow, groundwater levels, and water quality; they also address regional and local problems as well as critical problems of national scope. Some of the questions addressed by these studies are the effect of sewers on groundwater levels and streamflow on Long Island; the occurrence and transport of PCB residues within the upper Hudson River basin; the effect of acid rain on streams in the Catskill Mountains; the frequency and magnitude of floods statewide; the role of wetlands in improving the chemical quality of landfill leachate; the direction of groundwater movement from waste disposal sites near the Niagara River; and the location and potential well yields of stratified-drift aquifers in upstate New York. (USGS)

Identifying the location and population served by domestic wells in California

USGS Publications Warehouse

Johnson, Tyler D.; Belitz, Kenneth

2015-01-01

Aggregating the results indicates that three hydrogeologic provinces contain nearly 80% of all domestic wells and also have the highest density of domestic well users: Central Valley (31.6%), Sierra Nevada (31.5%), and Northern Coast Ranges (16.6%). Results were also aggregated into groundwater basins and highland areas, collectively called Groundwater Units (GUs). Twenty-eight of the 938 GUs contain more than 50% of the total population served by domestic wells, 70 GUs contain more than 75%, and 150 GUs contain 90%. The 28 GUs are mostly located in the eastern and southern San Joaquin Valley (11), the Sacramento Valley (7), and the western foothills of the Sierra Nevada province (5). Using the information presented in this research along with other information about domestic-well use, the US Geological Survey has begun sampling high-use GUs for the Shallow Aquifer Assessment component of the Groundwater Ambient Assessment (GAMA) program.

Evaluating connection of aquifers to springs and streams, Great Basin National Park and vicinity, Nevada

USGS Publications Warehouse

Prudic, David E.; Sweetkind, Donald S.; Jackson, Tracie R.; Dotson, K. Elaine; Plume, Russell W.; Hatch, Christine E.; Halford, Keith J.

2015-12-22

Groundwater flow from southern Spring Valley continues through the western side of Hamlin Valley before being directed northeast toward the south end of Snake Valley. This flow is constrained by southward-flowing groundwater from Big Spring Wash and northward-flowing groundwater beneath central Hamlin Valley. The redirection to the northeast corresponds to a narrowing of the width of flow in southern Snake Valley caused by a constriction formed by a steeply dipping middle Paleozoic siliciclastic confining unit exposed in the flanks of the mountains and hills on the east side of southern Snake Valley and shallowly buried beneath basin fill in the valley. The narrowing of groundwater flow could be responsible for the large area where groundwater flows to springs or is lost to evapotranspiration between Big Springs in Nevada and Pruess Lake in Utah.

Groundwater quality in the Northern Coast Ranges Basins, California

USGS Publications Warehouse

Mathany, Timothy M.; Belitz, Kenneth

2015-01-01

Recharge to the groundwater system is primarily from mixture of ambient sources, including direct percolation of precipitation and irrigation waters, infiltration of runoff from surrounding hills/areas, seepage from rivers and creeks, and subsurface inflow (from non-alluvial geologic units that bound the alluvial basins). The primary sources of discharge are evaporation, discharge to streams, and water pumped for municipal supply and irrigation.

Knowledge and Understanding of the Hydrogeology of the Salt Basin in South-Central New Mexico and Future Study Needs

USGS Publications Warehouse

Huff, G.F.; Chace, D.A.

2006-01-01

The Salt Basin covers about 2,400 square miles of south-central New Mexico and extends across the State line into Texas. As much as 57 million acre-feet of ground water may be stored within the New Mexico part of the Salt Basin of which 15 million acre-feet are potentially potable and recoverable. Recent work suggests that the volume of ground water in storage within the New Mexico portion of the Salt Basin may be substantially greater than 57 million acre-feet. In this report, aquifers contained in the San Andres, Bone Spring, and Victorio Peak Limestones and in the Yeso, Hueco, and Abo Formations are collectively referred to as the carbonate aquifer. Porosity and permeability of the major aquifer are primarily determined by the density and interconnectedness of fractures and karstic solution channels. The spatial variability of these fractures and karstic features leads to a large spatial variability in hydraulic properties in the carbonate aquifer. Ground water generally moves southward away from recharge areas along the northern border of the Salt Basin and generally moves eastward to southeastward away from areas of distributed recharge on the Otero Mesa and the Diablo Plateau. Ground water originating from these recharge areas generally moves toward the central valley. Present day discharge is mostly through ground-water withdrawal for agricultural irrigation. A zone of relatively low hydraulic gradient, corresponding to the location of the Otero Break, extends from near the Sacramento River watershed southward toward Dell City, Texas. Ground water in the carbonate aquifer generally is very hard and has dissolved-solids concentrations ranging from 500 to 6,500 milligrams per liter. Substantial variability exists in current estimates of (1) ground-water recharge, (2) natural ground-water discharge, (3) the volume of ground water in storage, (4) the volume of recoverable ground water, (5) the conceptual model of ground-water flow, (6) the distribution of ground-water quality, and (7) the distribution of hydraulic characteristics. Future study could reduce uncertainty in these estimates and allow for better management of ground-water resources in the Salt Basin.

Hydrologic reconnaissance of the Unalakleet River basin, Alaska, 1982-83

USGS Publications Warehouse

Sloan, C.E.; Kernodle, D.R.; Huntsinger, Ronald

1986-01-01

The Unalakleet River, Alaska, from its headwaters to the confluence of the Chiroskey River has been designated as a wild river and is included in the National Wild and Scenic Rivers System. Yearly low flow, which occurs during the winter, is sustained by groundwater discharge; there are few lakes in the basin and the cold climate prevents winter runoff. The amount of winter streamflow was greatest in the lower parts of streams with the exception of the South River and was apparently proportional to the amount of unfrozen alluvium upstream from the measuring sites. Unit discharge in late winter ranged from nearly zero at the mouth of the South River to 0.24 cu ft/sec/sq mi in the Unalakleet River main stem below Tenmile River. Summer runoff at the time of the reconnaissance may have been slightly higher than normal owing to recent rains. Unit runoff ranged from a low of 1.0 cu ft/sec/sq mi at the South River, to a high value of 2.4 cu ft/sec/sq mi at the North Fork Unalakleet River. Flood marks were present in the basin well above streambank levels but suitable sections to measure the maximum evident flood by slope-area methods were not found. Flood peaks were calculated for the Unalakleet River and its tributaries using basin characteristics. Calculated unit runoff for the 50-year flood ranged from about 17 to 45 cu ft/sec/sq mi. Water quality was good throughout the basin, and an abundant and diversified community of benthic invertebrates was found in samples collected during the summer reconnaissance. Permafrost underlies most of the basin, but groundwater can be found in unfrozen alluvium in the stream valleys, most abundantly in the lower part of the main tributaries and along the main stem of the Unalakleet River. Groundwater sustains river flow through the winter; an estimate of its quantity can be found through low-flow measurements. Groundwater quality in the basin appears to be satisfactory for most uses. Currently, little groundwater is used within the basin. The water supply for Unalakleet is obtained from a well and gallery in a small valley north of the airport, outside the Unalakleet River basin. (Author 's abstract)

Impact of suburban residential development on water resources in the area of Winslow Township, Camden County, New Jersey

USGS Publications Warehouse

Fusillo, Thomas V.

1981-01-01

Surface-water and ground-water quality, streamflow, and data on ground-water levels in the upper Great Egg Harbor River basin in the vicinity of the Winslow Crossing residential development in Winslow Township are evaluated. The data include continuous streamflow at four sites, monthly stream water quality at seven sites, ground-water levels and periodic ground-water quality in four wells from 1972 through 1978. Pumpage from the Cohansey Sand in the study area was lower than anticipated because of a slowdown in construction. The average pumpage of 0.48 million gallons per day during 1978 had little effect on ground-water levels. Dissolved-solids concentrations were lower in a well upgradient from the urbanized area. Elevated levels of dissolved solids, specific conductance, chloride, nitrate, and phosphorus were found in the shallow ground water in the vicinity of the Winslow wastewater treatment plant because of effluent infiltration ponds. Nitrate was greatly reduced in October 1974 by a change in the treatment process, which increased denitrification. Phosphorus concentrations in the ground water remained elevated, however. Water from the most urbanized drainage basin was a magnesium bicarbonate type, while the less developed basins had sodium chloride sulfate type waters. Water from the two developed basins had higher median pH (7.1) compared with that of the other basins (5.6-6.3). Winslow Crossing?s development had only a slight effect on the quality of water in Great Egg Harbor River. The river receives point and non-point discharges upstream from Winslow Crossing, and the quality of the water generally improves as the river flows downstream. Streamflow and rainfall were slightly above normal. Unit hydrograph analysis of one basin showed an 80 percent increase in the peak discharge of a 60-minute unit hydrograph (from approximately 150 to 270 cubic feet per second) after the development of 14 percent of the basin. Installation of a stormwater detention basin reduced the peak discharge to 220 ft3/s. Sediment discharge from this basin averaged 0.24 tons/d/mi2 during construction but decreased to the preconstruction level of 0.06 tons/d/mi2 after the completion of construction and the installation of the detention

The ESPAT tool: a general-purpose DSS shell for solving stochastic optimization problems in complex river-aquifer systems

NASA Astrophysics Data System (ADS)

Macian-Sorribes, Hector; Pulido-Velazquez, Manuel; Tilmant, Amaury

2015-04-01

Stochastic programming methods are better suited to deal with the inherent uncertainty of inflow time series in water resource management. However, one of the most important hurdles in their use in practical implementations is the lack of generalized Decision Support System (DSS) shells, usually based on a deterministic approach. The purpose of this contribution is to present a general-purpose DSS shell, named Explicit Stochastic Programming Advanced Tool (ESPAT), able to build and solve stochastic programming problems for most water resource systems. It implements a hydro-economic approach, optimizing the total system benefits as the sum of the benefits obtained by each user. It has been coded using GAMS, and implements a Microsoft Excel interface with a GAMS-Excel link that allows the user to introduce the required data and recover the results. Therefore, no GAMS skills are required to run the program. The tool is divided into four modules according to its capabilities: 1) the ESPATR module, which performs stochastic optimization procedures in surface water systems using a Stochastic Dual Dynamic Programming (SDDP) approach; 2) the ESPAT_RA module, which optimizes coupled surface-groundwater systems using a modified SDDP approach; 3) the ESPAT_SDP module, capable of performing stochastic optimization procedures in small-size surface systems using a standard SDP approach; and 4) the ESPAT_DET module, which implements a deterministic programming procedure using non-linear programming, able to solve deterministic optimization problems in complex surface-groundwater river basins. The case study of the Mijares river basin (Spain) is used to illustrate the method. It consists in two reservoirs in series, one aquifer and four agricultural demand sites currently managed using historical (XIV century) rights, which give priority to the most traditional irrigation district over the XX century agricultural developments. Its size makes it possible to use either the SDP or the SDDP methods. The independent use of surface and groundwater can be examined with and without the aquifer. The ESPAT_DET, ESPATR and ESPAT_SDP modules were executed for the surface system, while the ESPAT_RA and the ESPAT_DET modules were run for the surface-groundwater system. The surface system's results show a similar performance between the ESPAT_SDP and ESPATR modules, with outperform the one showed by the current policies besides being outperformed by the ESPAT_DET results, which have the advantage of the perfect foresight. The surface-groundwater system's results show a robust situation in which the differences between the module's results and the current policies are lower due the use of pumped groundwater in the XX century crops when surface water is scarce. The results are realistic, with the deterministic optimization outperforming the stochastic one, which at the same time outperforms the current policies; showing that the tool is able to stochastically optimize river-aquifer water resources systems. We are currently working in the application of these tools in the analysis of changes in systems' operation under global change conditions. ACKNOWLEDGEMENT: This study has been partially supported by the IMPADAPT project (CGL2013-48424-C2-1-R) with Spanish MINECO (Ministerio de Economía y Competitividad) funds.

Focused ground-water recharge in the Amargosa Desert basin: Chapter E in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Stonestrom, David A.; Prudic, David E.; Walvoord, Michelle Ann; Abraham, Jared D.; Stewart-Deaker, Amy E.; Glancy, Patrick A.; Constantz, Jim; Laczniak, Randell J.; Andraski, Brian J.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

The Amargosa River is an approximately 300-kilometer long regional drainage connecting the northern highlands on the Nevada Test Site in Nye County, Nev., to the floor of Death Valley in Inyo County, Calif. Streamflow analysis indicates that the Amargosa Desert portion of the river is dry more than 98 percent of the time. Infiltration losses during ephemeral flows of the Amargosa River and Fortymile Wash provide the main sources of ground-water recharge on the desert-basin floor. The primary use of ground water is for irrigated agriculture. The current study examined ground-water recharge from ephemeral flows in the Amargosa River by using streamflow data and environmental tracers. The USGS streamflow-gaging station at Beatty, Nev., provided high-frequency data on base flow and storm runoff entering the basin during water years 1998–2001. Discharge into the basin during the four-year period totaled 3.03 million cubic meters, three quarters of which was base flow. Streambed temperature anomalies indicated the distribution of ephemeral flows and infiltration losses within the basin. Major storms that produced regional flow during the four-year period occurred in February 1998, during a strong El Niño that more than doubled annual precipitation, and in July 1999. The study also quantified recharge beneath undisturbed native vegetation and irrigation return flow beneath irrigated fields. Vertical profiles of water potential and environmental tracers in the unsaturated zone provided estimates of recharge beneath the river channel (0.04–0.09 meter per year) and irrigated fields (0.1–0.5 meter per year). Chloride mass-balance estimates indicate that 12–15 percent of channel infiltration becomes ground-water recharge, together with 9–22 percent of infiltrated irrigation. Profiles of potential and chloride beneath the dominant desert-shrub vegetation suggest that ground-water recharge has been negligible throughout most of the basin since at least the early Holocene. Surface-based electrical-resistivity imaging provided areal extension of borehole information from sampled profiles. These images indicate narrowly focused recharge beneath the Amargosa River channel, flanked by large tracts of recharge-free basin floor.

Impact of textile dyeing industries effluent on groundwater quality in Karur Amaravathi River basin, Tamil Nadu (India)--a field study.

PubMed

Rajamanickam, R; Nagan, S

2010-10-01

Karur is an industrial town located on the bank of river Amaravathi. There are 487 textile processing units in operation and discharge about 14610 kilo litres per day of treated effluent into the river. The groundwater quality in the downstream is deteriorated due to continuous discharge of effluent. In order to assess the present quality of groundwater, 13 open wells were identified in the river basin around Karur and samples were collected during pre-monsoon, post monsoon and summer, and analyzed for physico-chemical parameters. TDS, total alkalinity, total hardness, calcium, chlorides and sulphates exceeded the desirable limit. Amaravathi River water samples were also colleted at the upstream and downstream of Karur and the result shows the river is polluted. During summer season, there is no flow in the river and the river acts as a drainage for the effluent. Hence, there is severe impact on the groundwater quality in the downstream. The best option to protect the groundwater quality in the river basin is that the textile processing units should adopt zero liquid discharge (ZLD) system and completely recycle the treated effluent.

Influence of groundwater pumping on streamflow restoration following upstream dam removal

USGS Publications Warehouse

Constantz, J.; Essaid, H.

2007-01-01

We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watersbed streamflow comparisons were performed for several rivers flowing into the east side of the Central Valley, CA. Results suggest that, in the absence of upland dams supporting large reservoirs, some reaches of these rivers might develop ephemeral streamflow in late summer. As a quantitative analysis, we conducted a series of streamflow/ groundwater simulations (using MODFLOW-2000 plus the streamflow routing package, SFR1) for a representative hypothetical watershed, with an upland dam and groundwater pumping in the downstream basin, under humid, semi-arid, and and conditions. As a result of including the impact of groundwater pumping, post-dam removal simulated streamflow was significantly less than natural streamflow. The model predicts extensive ephemeral conditions in the basin during September for both the arid and semi-arid cases. The model predicts continued perennial conditions in the humid case, but spatially weighted, average streamflow of only 71% of natural September streamflow, as a result of continued pumping after dam removal.

Dynamics of dissolved organic carbon (DOC) through stormwater basins designed for groundwater recharge in urban area: Assessment of retention efficiency.

PubMed

Mermillod-Blondin, Florian; Simon, Laurent; Maazouzi, Chafik; Foulquier, Arnaud; Delolme, Cécile; Marmonier, Pierre

2015-09-15

Managed aquifer recharge (MAR) has been developed in many countries to limit the risk of urban flooding and compensate for reduced groundwater recharge in urban areas. The environmental performances of MAR systems like infiltration basins depend on the efficiency of soil and vadose zone to retain stormwater-derived contaminants. However, these performances need to be finely evaluated for stormwater-derived dissolved organic matter (DOM) that can affect groundwater quality. Therefore, this study examined the performance of MAR systems to process DOM during its transfer from infiltration basins to an urban aquifer. DOM characteristics (fluorescent spectroscopic properties, biodegradable and refractory fractions of dissolved organic carbon -DOC-, consumption by micro-organisms during incubation in slow filtration sediment columns) were measured in stormwater during its transfer through three infiltration basins during a stormwater event. DOC concentrations sharply decreased from surface to the aquifer for the three MAR sites. This pattern was largely due to the retention of biodegradable DOC which was more than 75% for the three MAR sites, whereas the retention of refractory DOC was more variable and globally less important (from 18% to 61% depending on MAR site). Slow filtration column experiments also showed that DOC retention during stormwater infiltration through soil and vadose zone was mainly due to aerobic microbial consumption of the biodegradable fraction of DOC. In parallel, measurements of DOM characteristics from groundwaters influenced or not by MAR demonstrated that stormwater infiltration increased DOC quantity without affecting its quality (% of biodegradable DOC and relative aromatic carbon content -estimated by SUVA254-). The present study demonstrated that processes occurring in soil and vadose zone of MAR sites were enough efficient to limit DOC fluxes to the aquifer. Nevertheless, the enrichments of DOC concentrations measured in groundwater below infiltration basins need to be considered in future studies to especially assess their impact on groundwater quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

Groundwater chemical baseline values to assess the Recovery Plan in the Matanza-Riachuelo River basin, Argentina.

PubMed

Zabala, M E; Martínez, S; Manzano, M; Vives, L

2016-01-15

The two most exploited aquifers in the Matanza-Riachuelo River basin are being monitored in the framework of the Integrated Environmental Sanitation Plan that implements the Basin Authority, Autoridad de Cuenca Matanza Riachuelo. In this context, this work identifies the groundwater chemical types and the natural processes behind them; determines spatial and temporal changes; establishes ranges of variation for chemical components, and proposes concentration values for the upper limit of the natural chemical background. A total of 1007 samples from three aquifer-layers (Upper Aquifer, top and bottom of Puelche Aquifer) have been studied. As concrete guidelines for practical determination of baseline values are not available in the region, the methodology used follows the proposals of European projects which assessed European water directives. The groundwater composition is very stable in terms of both chemical facies and mineralization degree, and the changes observed in the dry and wet periods analysed are subtle in general. Most of the groundwater is Na-HCO3 type, except a few samples that are Ca-HCO3, Na-ClSO4 and Na-Cl types. The Ca-HCO3 waters are the result of calcium carbonate dissolution, Na-HCO3 waters result from cation exchange and carbonate dissolution, while in the Na-ClSO4 and Na-Cl waters, mixing with connate and with encroached old marine water from the underlying and overlying sediments are the most relevant processes. The proposed values for the upper limit of the natural background consider the influence of geology and Holocene marine ingressions in the baseline of coastal groundwater. This study allowed to know the initial chemical conditions of the groundwater system of the Matanza-Riachuelo River basin and to establish the reference from which Basin Authority can start to evaluate trends and monitor the recovery plan. At the same time, it sets a precedent for future studies in the region. Copyright © 2015 Elsevier B.V. All rights reserved.

Transitioning Groundwater from an Extractive Resource to a Managed Water Storage Resource: Geology and Recharge in Sedimentary Basins

NASA Astrophysics Data System (ADS)

Maples, S.; Fogg, G. E.; Maxwell, R. M.; Liu, Y.

2017-12-01

Civilizations have typically obtained water from natural and constructed surface-water resources throughout most of human history. Only during the last 50-70 years has a significant quantity of water for humans been obtained through pumping from wells. During this short time, alarming levels of groundwater depletion have been observed worldwide, especially in some semi-arid and arid regions that rely heavily on groundwater pumping from clastic sedimentary basins. In order to reverse the negative effects of over-exploitation of groundwater resources, we must transition from treating groundwater mainly as an extractive resource to one in which recharge and subsurface storage are pursued more aggressively. However, this remains a challenge because unlike surface-water reservoirs which are typically replenished over annual timescales, the complex geologic architecture of clastic sedimentary basins impedes natural groundwater recharge rates resulting in decadal or longer timescales for aquifer replenishment. In parts of California's Central Valley alluvial aquifer system, groundwater pumping has outpaced natural groundwater recharge for decades. Managed aquifer recharge (MAR) has been promoted to offset continued groundwater overdraft, but MAR to the confined aquifer system remains a challenge because multiple laterally-extensive silt and clay aquitards limit recharge rates in most locations. Here, we simulate the dynamics of MAR and identify potential recharge pathways in this system using a novel combination of (1) a high-resolution model of the subsurface geologic heterogeneity and (2) a physically-based model of variably-saturated, three-dimensional water flow. Unlike most groundwater models, which have coarse spatial resolution that obscures the detailed subsurface geologic architecture of these systems, our high-resolution model can pinpoint specific geologic features and locations that have the potential to `short-circuit' aquitards and provide orders-of-magnitude greater recharge rates and volumes than would be possible over the rest of the landscape. Our results highlight the importance of capturing detailed geologic heterogeneity and physical processes that are not typically included in groundwater models when evaluating groundwater recharge potential.

Potential effects of groundwater pumping on water levels, phreatophytes, and spring discharges in Spring and Snake Valleys, White Pine County, Nevada, and adjacent areas in Nevada and Utah

USGS Publications Warehouse

Halford, Keith J.; Plume, Russell W.

2011-01-01

Assessing hydrologic effects of developing groundwater supplies in Snake Valley required numerical, groundwater-flow models to estimate the timing and magnitude of capture from streams, springs, wetlands, and phreatophytes. Estimating general water-table decline also required groundwater simulation. The hydraulic conductivity of basin fill and transmissivity of basement-rock distributions in Spring and Snake Valleys were refined by calibrating a steady state, three-dimensional, MODFLOW model of the carbonate-rock province to predevelopment conditions. Hydraulic properties and boundary conditions were defined primarily from the Regional Aquifer-System Analysis (RASA) model except in Spring and Snake Valleys. This locally refined model was referred to as the Great Basin National Park calibration (GBNP-C) model. Groundwater discharges from phreatophyte areas and springs in Spring and Snake Valleys were simulated as specified discharges in the GBNP-C model. These discharges equaled mapped rates and measured discharges, respectively. Recharge, hydraulic conductivity, and transmissivity were distributed throughout Spring and Snake Valleys with pilot points and interpolated to model cells with kriging in geologically similar areas. Transmissivity of the basement rocks was estimated because thickness is correlated poorly with transmissivity. Transmissivity estimates were constrained by aquifer-test results in basin-fill and carbonate-rock aquifers. Recharge, hydraulic conductivity, and transmissivity distributions of the GBNP-C model were estimated by minimizing a weighted composite, sum-of-squares objective function that included measurement and Tikhonov regularization observations. Tikhonov regularization observations were equations that defined preferred relations between the pilot points. Measured water levels, water levels that were simulated with RASA, depth-to-water beneath distributed groundwater and spring discharges, land-surface altitudes, spring discharge at Fish Springs, and changes in discharge on selected creek reaches were measurement observations. The effects of uncertain distributed groundwater-discharge estimates in Spring and Snake Valleys on transmissivity estimates were bounded with alternative models. Annual distributed groundwater discharges from Spring and Snake Valleys in the alternative models totaled 151,000 and 227,000 acre-feet, respectively and represented 20 percent differences from the 187,000 acre-feet per year that discharges from the GBNP-C model. Transmissivity estimates in the basin fill between Baker and Big Springs changed less than 50 percent between the two alternative models. Potential effects of pumping from Snake Valley were estimated with the Great Basin National Park predictive (GBNP-P) model, which is a transient groundwater-flow model. The hydraulic conductivity of basin fill and transmissivity of basement rock were the GBNP-C model distributions. Specific yields were defined from aquifer tests. Captures of distributed groundwater and spring discharges were simulated in the GBNP-P model using a combination of well and drain packages in MODFLOW. Simulated groundwater captures could not exceed measured groundwater-discharge rates. Four groundwater-development scenarios were investigated where total annual withdrawals ranged from 10,000 to 50,000 acre-feet during a 200-year pumping period. Four additional scenarios also were simulated that added the effects of existing pumping in Snake Valley. Potential groundwater pumping locations were limited to nine proposed points of diversion. Results are presented as maps of groundwater capture and drawdown, time series of drawdowns and discharges from selected wells, and time series of discharge reductions from selected springs and control volumes. Simulated drawdown propagation was attenuated where groundwater discharge could be captured. General patterns of groundwater capture and water-table declines were similar for all scenarios. Simulated drawdowns greater than 1 ft propagated outside of Spring and Snake Valleys after 200 years of pumping in all scenarios.

Simulation of Groundwater Mounding Beneath Hypothetical Stormwater Infiltration Basins

USGS Publications Warehouse

Carleton, Glen B.

2010-01-01

Groundwater mounding occurs beneath stormwater management structures designed to infiltrate stormwater runoff. Concentrating recharge in a small area can cause groundwater mounding that affects the basements of nearby homes and other structures. Methods for quantitatively predicting the height and extent of groundwater mounding beneath and near stormwater Finite-difference groundwater-flow simulations of infiltration from hypothetical stormwater infiltration structures (which are typically constructed as basins or dry wells) were done for 10-acre and 1-acre developments. Aquifer and stormwater-runoff characteristics in the model were changed to determine which factors are most likely to have the greatest effect on simulating the maximum height and maximum extent of groundwater mounding. Aquifer characteristics that were changed include soil permeability, aquifer thickness, and specific yield. Stormwater-runoff variables that were changed include magnitude of design storm, percentage of impervious area, infiltration-structure depth (maximum depth of standing water), and infiltration-basin shape. Values used for all variables are representative of typical physical conditions and stormwater management designs in New Jersey but do not include all possible values. Results are considered to be a representative, but not all-inclusive, subset of likely results. Maximum heights of simulated groundwater mounds beneath stormwater infiltration structures are the most sensitive to (show the greatest change with changes to) soil permeability. The maximum height of the groundwater mound is higher when values of soil permeability, aquifer thickness, or specific yield are decreased or when basin depth is increased or the basin shape is square (and values of other variables are held constant). Changing soil permeability, aquifer thickness, specific yield, infiltration-structure depth, or infiltration-structure shape does not change the volume of water infiltrated, it changes the shape or height of the groundwater mound resulting from the infiltration. An aquifer with a greater soil permeability or aquifer thickness has an increased ability to transmit water away from the source of infiltration than aquifers with lower soil permeability; therefore, the maximum height of the groundwater mound will be lower, and the areal extent of mounding will be larger. The maximum height of groundwater mounding is higher when values of design storm magnitude or percentage of impervious cover (from which runoff is captured) are increased (and other variables are held constant) because the total volume of water to be infiltrated is larger. The larger the volume of infiltrated water the higher the head required to move that water away from the source of recharge if the physical characteristics of the aquifer are unchanged. The areal extent of groundwater mounding increases when soil permeability, aquifer thickness, design-storm magnitude, or percentage of impervious cover are increased (and values of other variables are held constant). For 10-acre sites, the maximum heights of the simulated groundwater mound range from 0.1 to 18.5 feet (ft). The median of the maximum-height distribution from 576 simulations is 1.8 ft. The maximum areal extent (measured from the edge of the infiltration basins) of groundwater mounding of 0.25-ft ranges from 0 to 300 ft with a median of 51 ft for 576 simulations. Stormwater infiltration at a 1-acre development was simulated, incorporating the assumption that the hypothetical infiltration structure would be a pre-cast concrete dry well having side openings and an open bottom. The maximum heights of the simulated groundwater-mounds range from 0.01 to 14.0 ft. The median of the maximum-height distribution from 432 simulations is 1.0 ft. The maximum areal extent of groundwater mounding of 0.25-ft ranges from 0 to 100 ft with a median of 10 ft for 432 simulations. Simulated height and extent of groundwater mounding associ

Subsurface structure of the East Bay Plain ground-water basin: San Francisco Bay to the Hayward fault, Alameda County, California

USGS Publications Warehouse

Catchings, R.D.; Borchers, J.W.; Goldman, M.R.; Gandhok, G.; Ponce, D.A.; Steedman, C.E.

2006-01-01

The area of California between the San Francisco Bay, San Pablo Bay, Santa Clara Valley, and the Diablo Ranges (East Bay Hills), commonly referred to as the 'East Bay', contains the East Bay Plain and Niles Cone ground-water basins. The area has a population of 1.46 million (2003 US Census), largely distributed among several cities, including Alameda, Berkeley, Fremont, Hayward, Newark, Oakland, San Leandro, San Lorenzo, and Union City. Major known tectonic structures in the East Bay area include the Hayward Fault and the Diablo Range to the east and a relatively deep sedimentary basin known as the San Leandro Basin beneath the eastern part of the bay. Known active faults, such as the Hayward, Calaveras, and San Andreas pose significant earthquake hazards to the region, and these and related faults also affect ground-water flow in the San Francisco Bay area. Because most of the valley comprising the San Francisco Bay area is covered by Holocene alluvium or water at the surface, our knowledge of the existence and locations of such faults, their potential hazards, and their effects on ground-water flow within the alluvial basins is incomplete. To better understand the subsurface stratigraphy and structures and their effects on ground-water and earthquake hazards, the U.S. Geological Survey (USGS), in cooperation with the East Bay Municipal Utility District (EBMUD), acquired a series of high-resolution seismic reflection and refraction profiles across the East Bay Plain near San Leandro in June 2002. In this report, we present results of the seismic imaging investigations, with emphasis on ground water.

Robust, non-invasive methods for metering groundwater well extraction in remote environments

NASA Astrophysics Data System (ADS)

Bulovic, Nevenka; Keir, Greg; McIntyre, Neil

2017-04-01

Quantifying the rate of extraction from groundwater wells can be essential for regional scale groundwater management and impact assessment. This is especially the case in regions heavily dependent on groundwater such as the semi-arid Surat and Bowen Basins in Queensland, Australia. Of the 30 000+ groundwater wells in this area, the majority of which are used for stock watering and domestic purposes, almost none have flow metering devices installed. As part of a research project to estimate regional groundwater extraction, we have undertaken a small scale flow metering program on a selected set of wells. Conventional in-line flow meters were unsuitable for our project, as both non-invasiveness and adaptability / suitability to a variety of discharge pipe characteristics was critical. We describe the use of two metering technologies not widely used in groundwater applications, non-invasive, clamp-on ultrasonic transit time flow meters and tipping bucket flow meters, as semi-permanent installations on discharge pipes of various artesian and sub-artesian groundwater wells. We present examples of detailed extraction rate time-series, which are of particular value in developing predictive models of water well extraction in data limited areas where water use dynamics and drivers are poorly understood. We conclude by discussing future project trajectories, which include expansion of the monitoring network through development of novel metering techniques and telemetry across large areas of poor connectivity.

Ground-water monitoring in the Albuquerque area

USGS Publications Warehouse

Thorn, Condé R.

1996-01-01

At present (1996), all drinking water for Albuquerque residents comes from ground-water reserves. The Albuquerque area is the largest population center in the State and the largest consumer of ground water. Recent reports concerning the water resources of the Albuquerque area suggest that the Albuquerque Basin may soon face serious water-availability and water-quality problems due to anticipated ground-water development. Recent studies completed by the U.S. Geological Survey (USGS) have improved the understanding of the ground-water resources in the Albuquerque Basin. These studies have indicated that the more permeable units within the aquifer system--the upper Santa Fe Group--are less extensive than previously thought, and that water-levels have declined as much as 160 feet.

South Platte River Basin - Colorado, Nebraska, and Wyoming

USGS Publications Warehouse

Dennehy, Kevin F.; Litke, David W.; Tate, Cathy M.; Heiny, Janet S.

1993-01-01

The South Platte River Basin was one of 20 study units selected in 1991 for investigation under the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program. One of the initial tasks undertaken by the study unit team was to review the environmental setting of the basin and assemble ancillary data on natural and anthropogenic factors in the basin. The physical, chemical, and biological quality of the water in the South Platte River Basin is explicitly tied to its environmental setting. The resulting water quality is the product of the natural conditions and human factors that make up the environmental setting of the basin.This description of the environmental setting of the South Platte River Basin and its implications to the water quality will help guide the design of the South Platte NAWQA study. Natural conditions such as physiography, climate, geology, and soils affect the ambient water quality while anthropogenic factors such as water use, population, land use and water-management practices can have a pronounced effect on water quality in the basin. The relative effects of mining, urban, and agricultural land- and water-uses on water-quality constituents are not well understood. The interrelation of the surface-water and ground-water systems and the chemical and biological processes that affect the transport of constituents needs to be addressed. Interactions between biological communities and the water resources also should be considered. The NAWQA program and the South Platte River Basin study will provide information to minimize existing knowledge gaps, so that we may better understand the effect these natural conditions and human factors have on the water-quality conditions in the basin, now and in the future.

Potential for a significant deep basin geothermal system in Tintic Valley, Utah

NASA Astrophysics Data System (ADS)

Hardwick, C.; Kirby, S.

2014-12-01

The combination of regionally high heat flow, deep basins, and permeable reservoir rocks in the eastern Great Basin may yield substantial new geothermal resources. We explore a deep sedimentary basin geothermal prospect beneath Tintic Valley in central Utah using new 2D and 3D models coupled with existing estimates of heat flow, geothermometry, and shallow hydrologic data. Tintic Valley is a sediment-filled basin bounded to the east and west by bedrock mountain ranges where heat-flow values vary from 85 to over 240 mW/m2. Based on modeling of new and existing gravity data, a prominent 30 mGal low indicates basin fill thickness may exceed 2 km. The insulating effect of relatively low thermal conductivity basin fill in Tintic Valley, combined with typical Great Basin heat flow, predict temperatures greater than 150 °C at 3 km depth. The potential reservoir beneath the basin fill is comprised of Paleozoic carbonate and clastic rocks. The hydrology of the Tintic Valley is characterized by a shallow, cool groundwater system that recharges along the upper reaches of the basin and discharges along the valley axis and to a series of wells. The east mountain block is warm and dry, with groundwater levels just above the basin floor and temperatures >50 °C at depth. The west mountain block contains a shallow, cool meteoric groundwater system. Fluid temperatures over 50 °C are sufficient for direct-use applications, such as greenhouses and aquaculture, while temperatures exceeding 140°C are suitable for binary geothermal power plants. The geologic setting and regionally high heat flow in Tintic Valley suggest a geothermal resource capable of supporting direct-use geothermal applications and binary power production could be present.

Coupling Agent-Based and Groundwater Modeling to Explore Demand Management Strategies for Shared Resources

NASA Astrophysics Data System (ADS)

Al-Amin, S.

2015-12-01

Municipal water demands in growing population centers in the arid southwest US are typically met through increased groundwater withdrawals. Hydro-climatic uncertainties attributed to climate change and land use conversions may also alter demands and impact the replenishment of groundwater supply. Groundwater aquifers are not necessarily confined within municipal and management boundaries, and multiple diverse agencies may manage a shared resource in a decentralized approach, based on individual concerns and resources. The interactions among water managers, consumers, and the environment influence the performance of local management strategies and regional groundwater resources. This research couples an agent-based modeling (ABM) framework and a groundwater model to analyze the effects of different management approaches on shared groundwater resources. The ABM captures the dynamic interactions between household-level consumers and policy makers to simulate water demands under climate change and population growth uncertainties. The groundwater model is used to analyze the relative effects of management approaches on reducing demands and replenishing groundwater resources. The framework is applied for municipalities located in the Verde River Basin, Arizona that withdraw groundwater from the Verde Formation-Basin Fill-Carbonate aquifer system. Insights gained through this simulation study can be used to guide groundwater policy-making under changing hydro-climatic scenarios for a long-term planning horizon.

Hydrogeologic framework and groundwater/surface-water interactions of the South Fork Nooksack River Basin, northwestern Washington

USGS Publications Warehouse

Gendaszek, Andrew S.

2014-01-01

A hydrogeologic framework of the South Fork (SF) Nooksack River Basin in northwestern Washington was developed and hydrologic data were collected to characterize the groundwater-flow system and its interaction with surface‑water features. In addition to domestic, agricultural, and commercial uses of groundwater within the SF Nooksack River Basin, groundwater has the potential to provide ecological benefits by maintaining late-summer streamflows and buffering stream temperatures. Cold-water refugia, created and maintained in part by groundwater, have been identified by water-resource managers as key elements to restore the health and viability of threatened salmonids in the SF Nooksack River. The SF Nooksack River drains a 183-square mile area of the North Cascades and the Puget Lowland underlain by unconsolidated glacial and alluvial sediments deposited over older sedimentary, metamorphic, and igneous bedrock. The primary aquifer that interacts with the SF Nooksack River was mapped within unconsolidated glacial outwash and alluvial sediment. The lower extent of this unit is bounded by bedrock and fine-grained, poorly sorted unconsolidated glaciomarine and glaciolacustrine sediments. In places, these deposits overlie and confine an aquifer within older glacial sediments. The extent and thickness of the hydrogeologic units were assembled from mapped geologic units and lithostratigraphic logs of field-inventoried wells. Generalized groundwater-flow directions within the surficial aquifer were interpreted from groundwater levels measured in August 2012; and groundwater seepage gains and losses to the SF Nooksack River were calculated from synoptic streamflow measurements made in the SF Nooksack River and its tributaries in September 2012. A subset of the field-inventoried wells was measured at a monthly interval to determine seasonal fluctuations in groundwater levels during water year 2013. Taken together, these data provide the foundation for a future groundwater-flow model of the SF Nooksack River Basin that may be used to investigate the potential effects of future climate change, land use, and groundwater pumping on water resources in the study area. Site-specific hydrologic data, including time series of longitudinal temperature profiles measured with a fiber-optic distributed temperature sensor and continuous monitoring of stream stage and water levels measured in wells in adjacent wetlands and aquifers, also were measured to characterize the interaction among the SF Nooksack River, surficial aquifers, and riparian wetlands.

Source and movement of helium in the eastern Morongo groundwater Basin: The influence of regional tectonics on crustal and mantle helium fluxes

USGS Publications Warehouse

Kulongoski, J.T.; Hilton, David R.; Izbicki, J.A.

2005-01-01

We assess the role of fracturing and seismicity on fluid-driven mass transport of helium using groundwaters from the eastern Morongo Basin (EMB), California, USA. The EMB, located ???200 km east of Los Angeles, lies within a tectonically active region known as the Eastern California Shear Zone that exhibits both strike-slip and extensional deformation. Helium concentrations from 27 groundwaters range from 0.97 to 253.7 ?? 10-7 cm3 STP g-1 H2O, with corresponding 3He/4He ratios falling between 1.0 and 0.26 RA (where RA is the 3He/4He ratio of air). All groundwaters had helium isotope ratios significantly higher than the crustal production value of ???0.02 RA. Dissolved helium concentrations were resolved into components associated with solubility equilibration, air entrainment, in situ production within the aquifer, and extraneous fluxes (both crustal and mantle derived). All samples contained a mantle helium-3 (3Hem) flux in the range of 4.5 to 1351 ?? 10-14 cm3 STP 3He cm-2 yr-1 and a crustal flux (J0) between 0.03 and 300 ?? 10-7 cm3 STP 4He cm-2 yr-1. Groundwaters from the eastern part of the basin contained significantly higher 3Hem and deep crustal helium-4 (4Hedc) concentrations than other areas, suggesting a localized source for these components. 4Hedc and 3Hem are strongly correlated, and are associated with faults in the basin. A shallow thermal anomaly in a >3,000 m deep graben in the eastern basin suggests upflow of fluids through active faults associated with extensional tectonics. Regional tectonics appears to drive large scale crustal fluid transport, whereas episodic hydrofracturing provides an effective mechanism for mantle-crust volatile transport identified by variability in the magnitude of degassing fluxes (3Hem and J0) across the basin. Copyright ?? 2005 Elsevier Ltd.

Geohydrologic framework of the Roswell ground-water basin, Chaves and Eddy Counties, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Welder, G.E.

This report describes the geohydrology of the Roswell ground-water basin and shows the long-term hydrostatic-head changes in the aquifers. The Roswell ground-water basin consists of a carbonate artesian aquifer overlain by a leaky confining bed, which, in turn is overlain by an alluvial water-table aquifer. The water-table aquifer is hydraulically connected to the Pecos River. Ground-water pumpage from about 1500 wells in the basin was about 378,000 acre-feet in 1978. Irrigation use on about 122,000 acres accounted for 95% of that pumpage. Permeable zones in the artesian aquifer are generally controlled by lithologic changes in the Permian San Andres Limestonemore » and Grayburg Formation and by fractures in the carbonate rock. The thickness of the artesian aquifer in the more heavily pumped part of the basin ranges from 260 to 460 feet. The confining bed is composed of slightly to moderately permeable rocks of the Permian Grayburg, Queen, and Seven Rivers Formations. The shallow aquifer is composed of permeable beds of sand and gravel in the valley-fill alluvium, which is Pliocene, Pleistocene, and Holocene in age. In 1975, the maximum saturated thickness of the valley fill was about 250 feet in depressions northeast of Roswell, south of Dexter, and at Artesia. Hydrostatic heads in the artesian aquifer declined 230 feet in the south part of the basin from 1905 to 1975. The maximum decline in the head of the shallow aquifer from 1938 to 1975 was 120 feet. The chloride concentration of ground-water samples collected in 1978 ranged from 15 to 7000 milligrams per liter for the artesian aquifer and from 20 to 3700 milligrams per liter for the shallow aquifer. The chloride content has gradually increased through the years in the eastern parts of both aquifers. 31 refs., 28 figs., 1 tab.« less

Multi-Scale Simulations of Past and Future Projections of Hydrology in Lake Tahoe Basin, California-Nevada (Invited)

NASA Astrophysics Data System (ADS)

Niswonger, R. G.; Huntington, J. L.; Dettinger, M. D.; Rajagopal, S.; Gardner, M.; Morton, C. G.; Reeves, D. M.; Pohll, G. M.

2013-12-01

Water resources in the Tahoe basin are susceptible to long-term climate change and extreme events because it is a middle-altitude, snow-dominated basin that experiences large inter-annual climate variations. Lake Tahoe provides critical water supply for its basin and downstream populations, but changes in water supply are obscured by complex climatic and hydrologic gradients across the high relief, geologically complex basin. An integrated surface and groundwater model of the Lake Tahoe basin has been developed using GSFLOW to assess the effects of climate change and extreme events on surface and groundwater resources. Key hydrologic mechanisms are identified with this model that explains recent changes in water resources of the region. Critical vulnerabilities of regional water-supplies and hazards also were explored. Maintaining a balance between (a) accurate representation of spatial features (e.g., geology, streams, and topography) and hydrologic response (i.e., groundwater, stream, lake, and wetland flows and storages), and (b) computational efficiency, is a necessity for the desired model applications. Potential climatic influences on water resources are analyzed here in simulations of long-term water-availability and flood responses to selected 100-year climate-model projections. GSFLOW is also used to simulate a scenario depicting an especially extreme storm event that was constructed from a combination of two historical atmospheric-river storm events as part of the USGS MultiHazards Demonstration Project. Historical simulated groundwater levels, streamflow, wetlands, and lake levels compare well with measured values for a 30-year historical simulation period. Results are consistent for both small and large model grid cell sizes, due to the model's ability to represent water table altitude, streams, and other hydrologic features at the sub-grid scale. Simulated hydrologic responses are affected by climate change, where less groundwater resources will be available during more frequent droughts. Simulated floods for the region indicate issues related to drainage in the developed areas around Lake Tahoe, and necessary dam releases that create downstream flood risks.

Groundwater quality in the Chemung River, Eastern Lake Ontario, and Lower Hudson River Basins, New York, 2013

USGS Publications Warehouse

Scott, Tia-Marie; Nystrom, Elizabeth A.; Reddy, James E.

2015-11-10

The Lower Hudson River Basin study area covers 5,607 square miles and encompasses the part of the Lower Hudson River Basin that lies within New York plus the parts of the Housatonic, Hackensack, Bronx, and Saugatuck River Basins that are in New York. Twelve of the wells sampled in the Lower Hudson River Basin are completed in sand-and-gravel deposits, and 13 are completed in bedrock. Groundwater in the Lower Hudson River Basin was generally of good quality, although properties and concentrations of some constituents—pH, sodium, chloride, dissolved solids, arsenic, aluminum, iron, manganese, radon-222, total coliform bacteria, fecal coliform bacteria, Escherichia coli bacteria, and heterotrophic plate count—equaled or exceeded primary, secondary, or proposed drinking-water standards. The constituent most frequently detected in concentrations exceeding drinking-water standards (20 of 25 samples) was radon-222.