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Sample records for groundwater pajarito plateau

  1. Radiogenic and Stable Isotope and Hydrogeochemical Investigation of Groundwater, Pajarito Plateau and Surrounding Areas, New Mexico

    SciTech Connect

    Patrick Longmire, Michael Dale, Dale Counce, Andrew Manning, Toti Larson, Kim Granzow, Robert Gray, and Brent Newman

    2007-07-15

    From October 2004 through February 2006, Los Alamos National Laboratory, the New Mexico Environment Department-Department of Energy Oversight Bureau, and the United States Geological Survey conducted a hydrochemical investigation. The purpose of the investigation was to evaluate groundwater flow paths and determine groundwater ages using tritium/helium-3 and carbon-14 along with aqueous inorganic chemistry. Knowledge of groundwater age and flow paths provides a technical basis for selecting wells and springs for monitoring. Groundwater dating is also relevant to groundwater resource management, including aquifer sustainability, especially during periods of long-term drought. At Los Alamos, New Mexico, groundwater is either modern (post-1943), submodern (pre-1943), or mixed (containing both pre- and post-1943 components). The regional aquifer primarily consists of submodern groundwater. Mixed-age groundwater results from initial infiltration of surface water, followed by mixing with perched alluvial and intermediate-depth groundwater and the regional aquifer. No groundwater investigation is complete without using tritium/helium-3 and carbon-14 dating methods to quantify amounts of modern, mixed, and/or submodern components present in samples. Computer models of groundwater flow and transport at Los Alamos should be calibrated to groundwater ages for perched intermediate zones and the regional aquifer determined from this investigation. Results of this study clearly demonstrate the occurrence of multiple flow paths and groundwater ages occurring within the Sierra de los Valles, beneath the Pajarito Plateau, and at the White Rock Canyon springs. Localized groundwater recharge occurs within several canyons dissecting the Pajarito Plateau. Perched intermediate-depth groundwater and the regional aquifer beneath Pueblo Canyon, Los Alamos Canyon, Sandia Canyon, Mortandad Canyon, Pajarito Canyon, and Canon de Valle contain a modern component. This modern component consists

  2. The Pajarito Plateau: a bibliography

    USGS Publications Warehouse

    Mathien, Frances Joan; Steen, Charlie R.; Allen, Craig D.

    1993-01-01

    This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid the staff in evaluating cultural resources on LANL lands. In addition to works that related to the archaeology and history of the area, Steen included notations of a few books and articles in other fields such as geology and natural history. It was hoped that they also would be of value to other organizations and to students of past human activities on the Pajarito Plateau.At the same time, the National Park Service (NPS) was planning a major survey of Bandelier National Monument (BNM). As part of this plan, the author was asked to prepare a background document that described research previously carried out in the area, including an annotated bibliography. Although the survey would be limited to the park boundaries, the larger Pajarito Plateau is a more logical study area from physiographic, environmental, and cultural perspectives; hence the focus was on this larger region. Mathien (1986) also included some references to natural resources studies, particularly those initiated by NPS within Bandelier National Monument.Both bibliographies were made available to Colleen Olinger and Beverly Larson of the Health and Environmental Services Group at Los Alamos. They realized that while neither was complete, each included entries missing from the other. Larson suggested the two bibliographies be combined. (At this time, Craig Allen was studying the landscape of the Jemez Mountains [Allen 1984c, 1989]. His investigations included much detailed information on natural resource studies and were added in 1991 and 1992.)To limit the scope of their work, Steen and Mathien had chosen their parameter: the Pajarito Plateau. Geographically, the

  3. Subsurface geology of the Pajarito Plateau, Espancia Basin, New Mexico

    NASA Astrophysics Data System (ADS)

    Dransfield, B. J.; Gardner, J. N.

    1985-05-01

    Integration of data from wells, geophysical surveys, and surface exposures has enabled construction of structure contour and paleogeologic maps of the pre-Bandelier Tuff surface beneath the Pajarito Plateau. Numerous faults of the Rio Grande rift system cut the pre-Bandelier Tuff surface, and most have down-to-the-west displacements. Cumulative down-to-the-west movements across these faults from the Rio Grande on the east to the Rendija Canyon fault zone on the west exceed 600 ft (185 m). All faults in the area show evidence of recurrent activity, with increasing displacements of progressively older rock units. The southern Pajarito fault zone has over 600 ft (185 m) of pre-Bandelier Tuff down-to-the-east movement. The Pajarito fault zone and a major pre-Bandelier Tuff fault identified herein may constitute the local boundaries of the southern continuation of the intra-rift Velarde graben. The paleogeologic map shows that three major rock units (Cerros del Rio basalts, Tschicoma Formation dacites, and Puye Formation gravels) underlie the Bandelier Tuff and interfinger beneath the central Pajarito Plateau.

  4. Old-field plant succession on the Pajarito Plateau

    SciTech Connect

    Foxx, T.; Mullen, M.; Salisbury, M.; Tierney, G.

    1997-10-01

    Eight fallow historic fields of the ponderosa pine and pinon-juniper cover types were surveyed to determine species composition and distribution. The purpose of the study was to understand plant succession on old fields as related to mechanically manipulated sites such as material disposal areas (MDAs). Additionally, the authors wanted a listing of species on disturbed lands of the Pajarito Plateau to aide in the reclamation planning of MDAs using native species. They also wanted to determine if any species could be used as an indicator of disturbance. The eight historic fields were all within Los Alamos County, New Mexico, and had been abandoned in 1943. Two sites were within the boundaries of Los Alamos National Laboratory and were studied both in 1982 and 1993. The study provides a description of each of the field sites, historic information about the homesteads from patent applications, a photographic record of some of the sites, and a listing of species found within each field. The study showed that there were 78 different plant species found on disturbed sites. Of these 78 species, 23 were found to be dominant on one or more of the MDAs or old fields. Although, the disturbance history of each site is imperfectly known, the study does provide an indication of successional processes within disturbed sites of the Pajarito Plateau. Additionally, it provides a listing of species that will invade disturbed sites, species that may be used in site reclamation.

  5. Holocene stream aggradation and degradation, Pajarito Plateau, northern New Mexico

    SciTech Connect

    Reneau, S.L.; Gardner, J.N. ); Kelson, K.I. ); Hemphill-Haley, M.A. )

    1993-04-01

    Radiocarbon dates obtained from three canyons on the Pajarito Plateau, northern NM document alternating periods of Holocene stream aggradation and degradation that are, at least in part, synchronous between canyons. Four or more Holocene terraces are present in Frijoles Canyon, which has been rapidly incising into easily eroded, non-welded 1.1 Ma Bandelier Tuff. The oldest of these is an extensive fill terrace that is underlain by up to 13 m of stream gravels. This fill terrace records the most significant period of Holocene aggradation in Frijoles Canyon, and a date of 6.2 ka from basal slopewash burying the stream sediments provides a minimum-limiting age for this terrace. After 6.2 ka, temporary pauses in channel incision are recorded by strath terraces dated at ca. 4.6 and 1.6 ka, and an intermediate undated strath terrace. Age data obtained from Rendija and Cabra Canyons, 13 km to the north, indicate periods of stream aggradation similar in age to those in Frijoles Canyon. A minimum of two Holocene terraces are present in Rendija Canyon, and dates of 6.1--6.3 ka from stream sediments beneath the higher terrace and from overlying slopewash correlate it with the major fill terrace in Frijoles Canyon. In Cabra Canyon the unchanneled valley floor is underlain by more than 7 m of unconsolidated sediments, and four or more unconformable sedimentary packages were exposed in a 4-m deep trench. The lowest exposed Holocene sediments yielded an age of ca. 5.7 ka, and three overlying units that back-fill paleo-channels yielded ages of 3.5--3.8, 1.6, and 0.3 ka. In all three canyons the modern floodplains are aggrading, and radiocarbon dates of 0--0.4 ka from the uppermost sediments of the valley floors suggest these streams have been near present level for several hundred years. The similar ages obtained from stream deposits in Pajarito Plateau drainages suggest a climatic control for at least some of the aggradation events.

  6. Micromorphology, mineralogy, and genesis of soils and fracture fills and the Pajarito Plateau, New Mexico

    SciTech Connect

    Davenport, D.W.

    1993-12-01

    The town of Los Alamos, and the Los Alamos National Laboratory (LANL), are located on the Pajarito Plateau in north-central New Mexico. Environmental concerns have recently focused attention on the numerous fractures in the Bandelier Tuff, the series of volcanic rock units that make up most of the plateau. These fractures have come into question as possible conduits for transport of contaminants downward through the tuff. This, study arose out of a need to evaluate the potential for contaminant transport in the fractures. Because the fractures are typically filled, or partially filled, with soil-like material, and appear to be physically continuous with the soils on the surface of the Pajarito Plateau, it was decided to approach the question of the fractures from a soil genesis and morphology standpoint. Specifically, it was believed that soil characterization techniques, including soil micromorphological and mineralogical analyses, could provide information about the dominant processes (past and present) acting in the soils and fractures. The specific objectives of this research were to investigate: (1) the physical, mineralogical and chemical nature of fracture-filling materials in the Bandelier Tuff, as well as associated surface soils; (2) the relationships among fracture-fills, tuff bedrock, and surface soils of the Pajarito Plateau; (3) the processes responsible for the development of the fracture-fills; and (4) the likely sequence of events leading to the present morphology of the soils and fracture-fills.

  7. Boundary layer circulations and dispersion on New Mexico`s Pajarito Plateau

    SciTech Connect

    Costigan, K.R.; Bossert, J.E.

    1997-08-01

    Los Alamos National Laboratory`s Technical Area 54 (TA-54) contains a radioactive waste storage and disposal facility. It is located on Mesita del Buey, which extends east-southeasterly on the New Mexico`s Pajarito Plateau. This mesa is one of a series of narrow mesas, hundreds of meters wide, that define the topography of the plateau. The mesas are separated by steep canyons, tens to hundreds of meters deep. Pajarito Canyon is to the south of Mesita del Buey, while Canada del Buey lies to the north. In general, the entire plateau slopes downward toward the east and the Rio Grande Valley, with the highest peaks of the Jemez Mountains to the west. Meterological observations collected at various sites around the Pajarito Plateau indicate that the atmospheric conditions in the area are complex and strongly influenced by the highly-variable local topography. For this study, numerical simulations of the atmospheric circulations in the area around TA-54 are carried out to produce a more detailed depiction of the wind flow than can be provided by the Laboratory`s network of meterological observation towers. Plumes of particles released into these wind fields are simulated as an indication of transport and diffusion from a hypothetical release. 4 refs., 1 fig.

  8. Erosion and deposition on the Pajarito Plateau, New Mexico, and implications for geomorphic responses to late Quaternary climatic changes

    SciTech Connect

    Reneau, S.L.; McDonald, E.V.; Gardner, J.N.; Longmire, P.A.; Kolbe, T.R.; Carney, J.S.; Watt, P.M.

    1996-04-01

    The Pajarito Plateau of northern New Mexico contains a rich and diverse record of late Quaternary landscape changes in a variety of geomorphic settings that include gently-sloping mesa tops, steep canyon walls, and canyon bottoms. A broad range of investigations during the past decade, motivated by environmental and seismic hazard concerns, have resulted in examination of the characteristics, stratigraphy, and age of sediments and soils at numerous locations throughout the Plateau. Geochronologic control is provided by >140 radiocarbon dates supplemented by soil characterization and tephrochronology. In this paper we first summarize some of the results of recent and ongoing work on late Quaternary deposits on the Pajarito Plateau, illustrating both the complexity of the geomorphic record and some common elements that have been observed in multiple locations. We then use these observations, in combination with other work in the Southwest, to make some inferences about the local geomorphic response to regional climatic changes. Because the geomorphic and paleoclimatic records are fragmentary, and because the relations between large scale climate changes and local variations in precipitation, vegetation, and geomorphic processes are not fully understood, many uncertainties exist concerning the response of the local landscape to past climatic fluctuations. In addition, variations in local landscape sensitivity related to prior erosional history and spatial variations in vegetation, and the localized nature of many storms, probably contribute to the complexity of the geomorphic record. Nevertheless, the work discussed in this paper suggests a strong relation between regional climatic changes and local geomorphic history, and provides a framework for considering relations between modem processes, the record of past landscape changes, and future erosion and deposition on the Plateau and in surrounding areas.

  9. Quaternary erosion and cosmic-ray-exposure history derived from 10Be and 26Al produced in situ—An example from Pajarito plateau, Valles caldera region

    NASA Astrophysics Data System (ADS)

    Albrecht, Achim; Herzog, Gregory F.; Klein, Jeffrey; Dezfouly-Arjomandy, Bijan; Goff, Fraser

    1993-06-01

    10Be and 26Al concentrations measured by accelerator mass spectrometry in 20 samples of quartz separated from rhyolitic volcanic ash-flow tuffs collected on the Pajarito plateau of the Valles caldera, New Mexico, were used to model time-integrated erosion rates and cosmic ray-exposure histories. The model erosion rates determined for different stratigraphic units within the Tshirege member, upper Bandelier Tuff, vary from 0.1 cm/ka for the resistant unit to 1.1 cm/ka for the softer unit. Intermediate erosion rates are thought to indicate earlier age cover by post-tuff lithologies of different hardness. The geographic distribution of these intermediate rates allows an approximate determination of the extent of material now gone (stratigraphic ghosts). Periods of burial can be determined from 26Al/10Be ratios. For the Pajarito plateau, burial most likely resulted from cover by soil and sediment held in place by vegetation. Our data allow us to model the duration and extent of thick forest cover, which today exists only at higher altitudes.

  10. Environmental geochemistry for surface and subsurface waters in the Pajarito Plateau and outlying areas, New Mexico

    SciTech Connect

    Blake, W.D.; Goff, F.; Adams, A.I.; Counce, D.

    1995-05-01

    This report provides background information on waters in the Los Alamos and Santa Fe regions of northern New Mexico. Specifically, the presented data include major element, trace element, and isotope analyses of 130 water samples from 94 different springs, wells, and water bodies in the area. The region considered in this study extends from the western edge of the Valles Caldera to as far east as Santa Fe Lake. For each sample, the presented analysis includes fourteen different major elements, twenty-six trace elements, up to five stable isotopes, and tritium. In addition, this data base contains certain characteristics of the water that are calculated from the aforementioned raw data, including the water`s maximum and minimum residence times, as found from tritium levels assuming no contamination, the water`s recharge elevation, as found from stable isotopes, and the charge balance of the water. The data in this report are meant to provide background information for investigations in groundwater hydrology and geochemistry, and for environmental projects. For the latter projects, the presented information would be useful for determining the presence of contamination it any one location by enabling one to compare potential contaminant levels to the background levels presented here. Likely locations of interest are those possibly effected by anthropogenic activities, including locations in and around Los Alamos National Laboratory, White Rock Canyon, and developed areas in the Rio Grande Valley.

  11. A Kinesthetic Learning Approach to Earth Science for 3rd and 4th Grade Students on the Pajarito Plateau, Los Alamos, NM

    NASA Astrophysics Data System (ADS)

    Wershow, H. N.; Green, M.; Stocker, A.; Staires, D.

    2010-12-01

    Current efforts towards Earth Science literacy in New Mexico are guided by the New Mexico Science Benchmarks [1]. We are geoscience professionals in Los Alamos, NM who believe there is an important role for non-traditional educators utilizing innovative teaching methods. We propose to further Earth Science literacy for local 3rd and 4th grade students using a kinesthetic learning approach, with the goal of fostering an interactive relationship between the students and their geologic environment. We will be working in partnership with the Pajarito Environmental Education Center (PEEC), which teaches the natural heritage of the Pajarito Plateau to 3rd and 4th grade students from the surrounding area, as well as the Family YMCA’s Adventure Programs Director. The Pajarito Plateau provides a remarkable geologic classroom because minimal structural features complicate the stratigraphy and dramatic volcanic and erosional processes are plainly on display and easily accessible. Our methodology consists of two approaches. First, we will build an interpretive display of the local geology at PEEC that will highlight prominent rock formations and geologic processes seen on a daily basis. It will include a simplified stratigraphic section with field specimens and a map linked to each specimen’s location to encourage further exploration. Second, we will develop and implement a kinesthetic curriculum for an exploratory field class. Active engagement with geologic phenomena will take place in many forms, such as a scavenger hunt for precipitated crystals in the vesicles of basalt flows and a search for progressively smaller rhyodacite clasts scattered along an actively eroding canyon. We believe students will be more receptive to origin explanations when they possess a piece of the story. Students will be provided with field books to make drawings of geologic features. This will encourage independent assessment of phenomena and introduce the skill of scientific observation. We

  12. Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

    USGS Publications Warehouse

    Benson, L.V.

    2011-01-01

    Chemical and nutrient analyses of 471 soil samples from 161 sites within four archaeological regions (Pajarito Plateau/Bandelier, Zuni, Mesa Verde, and the Chaco Halo) were combined with historical climate data in order to evaluate the agricultural productivity of each region. In addition, maize productivity and field-life calculations were performed using organic-nitrogen (N) values from the upper 50 cm of soil in each region and a range (1-3%/year) of N-mineralization rates. The endmember values of this range were assumed representative of dry and wet climate states. With respect to precipitation and heat, the Pajarito Plateau area has excellent agricultural potential; the agricultural potentials of the Zuni and Mesa Verde regions are good; and the agricultural potential of the Chaco Halo is poor. Calculations of N mineralization and field life indicate that Morfield Valley in Mesa Verde should be able to provide 10 bu/ac of maize for decades (without the addition of N) when organic N-mineralization rates exceed 2%. Productivity and field-life potential decrease in the following order: Zuni, Mesa Verde, Bandelier, Chaco Halo. The Chaco Halo is very unproductive; e. g., 10 bushels per acre can be achieved within the Halo only from soils having the highest organic N concentration (third quartile) and which undergo the highest rate (3%) of N mineralization. ?? 2010 US Government.

  13. Groundwater resources of the Columbia Plateau regional aquifer system

    USGS Publications Warehouse

    Kahle, Sue C.; Vaccaro, John J.

    2015-09-22

    The Columbia Plateau is a wide basalt plateau between the Cascade Range and the Rocky Mountains that covers parts of Washington, Oregon, and Idaho. The climate over much of the Columbia Plateau is semiarid with precipitation ranging from 7 to 15 in/yr in the central part (Vaccaro and others, 2015), yet the area supports a $6 billion per year agricultural industry, including the production of apples, corn, grapes, hops, mint, potatoes, stone fruit, and wheat. Groundwater pumpage and surface-water diversions supply water to irrigated croplands that account for about 5 percent of the Nation’s irrigated lands. Groundwater also is the primary source of drinking water for about 1.3 million people living on the plateau.

  14. Pajarito Plateau archaeological surveys and excavations. II

    SciTech Connect

    Steen, C R

    1982-04-01

    Los Alamos National Laboratory continues its archaeological program of data gathering and salvage excavations. Sites recently added to the archaeological survey are described, as well as the results of five excavations. Among the more interesting and important discoveries are (1) the apparently well-established local use of anhydrous lime, and (2) a late pre-Columbian use of earlier house sites and middens for garden plots. Evidence indicated that the local puebloan population was the result of an expansion of upper Rio Grande peoples, not an influx of migrants.

  15. Groundwater Annual Status Report for Fiscal Year 1998

    SciTech Connect

    A. K. Stoker; A. S. Johnson; B. D. Newman; B. M. Gallaher; C. L. Nylander; D. B. Rogers; D. E. Broxton; D. Katzman; E. H. Keating; G. L. Cole; K. A. Bitner; K. I. Mullen; P. Longmire; S. G. McLin; W. J. Stone

    1999-04-01

    Groundwater protection activities and hydrogeologic characterization studies are conducted at LANL annually. A summary of fiscal year 1998 results and findings shows increased understanding of the hydrogeologic environment beneath the Pajarito Plateau and significant refinement to elements of the LANL Hydrogeologic Conceptual Model pertaining to areas and sources of recharge to the regional aquifer. Modeling, drilling, monitoring, and data collection activities are proposed for fiscal year 1999.

  16. Groundwater Annual Status Report for Fiscal Year 1999

    SciTech Connect

    C. L. Nylander; K. A. Bitner; K. Henning; A. S. Johnson; E. H. Keating; P. Longmire; B. D. Newman; B. Robinson; D. B. Rogers; W. J. Stone; D. Vaniman

    2000-03-01

    Groundwater protection activities and hydrogeologic characterization studies are conducted at Los Alamos National Laboratory annually. A summary of fiscal year 1999 results and findings shows increased understanding of the hydrogeologic environment beneath the Pajarito Plateau and significant refinement to elements of the LANL. Hydrogeologic Conceptual Model pertaining to areas and sources of recharge to the regional aquifer. Modeling, drilling, monitoring, and data collection activities are proposed for fiscal year 2000.

  17. History of critical experiments at Pajarito Site

    SciTech Connect

    Paxton, H.C.

    1983-03-01

    This account describes critical and subcritical assemblies operated remotely at the Pajarito Canyon Site at the Los Alamos National Laboratory. Earliest assemblies, directed exclusively toward the nuclear weapons program, were for safety tests. Other weapon-related assemblies provided neutronic information to check detailed weapon calculations. Topsy, the first of these critical assemblies, was followed by Lady Godiva, Jezebel, Flattop, and ultimately Big Ten. As reactor programs came to Los Alamos, design studies and mockups were tested at Pajarito Site. For example, nearly all 16 Rover reactors intended for Nevada tests were preceded by zero-power mockups and proof tests at Pajarito Site. Expanded interest and capability led to fast-pulse assemblies, culminating in Godiva IV and Skua, and to the Kinglet and Sheba solution assemblies.

  18. TA-59 North Parking Lot and Pajarito Road Corridor Analysis

    SciTech Connect

    Not Available

    1993-12-01

    The purpose of this report is to provide traffic engineering services for the TA-59 North Parking Lot/Pajarito Road corridor Analysis at Los Alamos National Laboratory. The following tasks were accomplished to assess the development of the north parking lot and Pajarito Road in the vicinity of TA-59: conducted turning-movement counts from 7 AM to 9 AM and from 4 PM to 6 PM at the Pajarito Road/TA-59 intersection; conducted a parking supply and demand survey for all the parking lots within TA-59 on half-hour intervals between 0600--1800 (6 AM to 6 PM); conducted mid-day directional speed study along Pajarito Road, just east or south of the TA-59/Pajarito Road intersection; conducted peak hour gap study on Pajarito Road in the vicinity of TA-59; reviewed the TA-59 Parking Lot North of Pajarito Road, FY-94 Weapons GPP Short List Candidate {number_sign}9 report and other documents pertaining to past transportation studies; reassigned current turning-movement volumes with a 100 space parking lot being built on the north side of Pajarito Road; prepared traffic projections for the Pajarito Road/TA-59 intersection according to the proposed development on the north side of Pajarito Road that would employee 246 people; and assigned pedestrian crossing volumes between the northern lot/future development site and areas south of Pajarito Road.

  19. WATERSHED MANAGEMENT ON THE PAJARITO PLATEAU: PAST, PRESENT, AND FUTURE

    SciTech Connect

    K. MULLEN; K. BITNER

    2001-01-01

    Los Alamos National Laboratory (LANL) developed a draft watershed-management plan that pertains to the 43-mi{sup 2} area within the LANL boundaries. The watershed-management plan was started in 1996 with a number of overall goals: (1) to be a good steward of the natural resources entrusted to the laboratory, (2) to provide long-term evaluation regarding success of the Environmental Restoration Project in acceptably cleaning up sites, (3) compliance with the storm water National Pollution Discharge Elimination System program, and (4) upgrading the LANL environmental surveillance program that has been ongoing since the 1940s. LANL has an extensive network consisting of 53 surface-water-monitoring stations located in every major canyon, upstream and downstream of LANL, and at most confluences. Monitoring of the network has been ongoing for about 20 years. The stations are equipped with ultrasonic transducers that trip automated samplers to collect water samples from every flow event. These data have been reported every year in the report series Environmental Surveillance at Los Alamos, but have not been used to analyze watershed health. The focus of the LANL watershed-management plan is to use water quality data to monitor watershed health and to implement management actions when LANL activities, past or present, adversely impact the health of the watershed.

  20. A Nine-year Record of Groundwater Environmental Tracer Variations in a Weathered Sandstone Plateau Aquifer.

    NASA Astrophysics Data System (ADS)

    Cendon, D. I.; Hankin, S. I.; Hughes, C. E.; Meredith, K.; Peterson, M.; Scheiber, L.; Shimizu, Y.

    2016-12-01

    Most groundwater isotopic studies are limited to one snapshot in time due to high costs associated with sampling and analytical procedures. The timing of sampling within long-term seasonal climatic cycles may affect interpretations, particularly in unconfined or semi-confined aquifer systems. To test the potential influence of decadal climatic trends, particularly on groundwater residence time, we have combined results from a multi-year sampling programme. Hydrogeochemistry and isotopic tracer analysis including H2O stable isotopes, δ13CDIC, 3H, 14CDIC for all samples and 87Sr/86Sr and NO3-δ15N, have been applied to groundwater recovered from the Kulnura - Mangrove Mountain aquifer hosted by a weathered sandstone plateau within the Sydney Basin (Australia). In general, the study area is characterised by alternating dry and wet periods that can be prolonged as they are linked to wider climatic events such as El Niño, La Niña and modulated by the Indian Ocean Dipole. The region experienced above average rainfall from 1985-1990 followed by generally drier conditions (1991-2007) and slightly wetter conditions to 2015. Groundwater results from the first years (2006-2010), under generally dry conditions resulted in lower groundwater levels, revealed important inter-annual variations. These are interpreted to be locally driven by groundwater extraction, resulting in a progressive influx of modern groundwater. The progressive input of modern water has exposed deeper parts of the aquifer to increased NO3- concentrations of anthropogenic origin. The change in chemistry of the groundwater, particularly the lowering of groundwater pH, has accelerated the dissolution of carbonate mineral phases that in turn affects 14C residence time assessments. Subsequent sampling results (2012-2015), under higher rainfall conditions, suggest modern recharge in areas previously without measurable tritium activities. The complex interplay between recharge, anthropogenic influences and

  1. An investigation into variable recharge behaviors among eight alluvial observation wells in Pajarito Canyon, Los Alamos, New Mexico

    NASA Astrophysics Data System (ADS)

    Schmeer, S. R.

    2010-12-01

    Pajarito Canyon in Los Alamos, New Mexico trends west to east through the Pajarito Plateau from the headwaters in the Jemez Mountains, thirteen miles to the Rio Grande. In summer 2008, Los Alamos National Laboratory installed eight shallow wells, numbered PCAO-5, 6, 7a, 7b1, 7b2, 7c, 8 and 9, in the middle four miles of this canyon. Among these wells, five distinct recharge behaviors have been observed. PCAO-5 demonstrates seasonal recharge in response to annual snowmelt. PCAO-6, while just 400 feet further downstream, is considerably flashier and the well is often dry for months at a time. In PCAO-7a, 7b2 and 7c, another two miles downstream, the water level declined steadily since installation, with no recharge until spring 2010. PCAO-7b1 has not contained water since drilling. Downstream a further two miles, PCAO-8 and PCAO-9 were dry for the majority of 2009 and their hydrographs are more attenuated. This investigation was undertaken to explain the recharge behaviors of the wells, with the goal of improving site selection and design of alluvial wells to provide better representation of the alluvial aquifer. Water level data collected since July 2008 were used to compare the water columns of each well. Well construction diagrams were utilized to construct stratigraphic maps in order to compare well construction and lithology. Results indicate that PCAO-5 consistently contains water due to its location above a flood retention structure (FRS) and the placement of its screened interval immediately above the tuff layer, forcing water to travel through the screened interval. PCAO-6’s flashy, intermittent hydrograph is due to its location downstream of the FRS, and because the bottom of the screened interval rests 2.5 feet above the alluvium-tuff interface, providing a conduit below the screen of the well. The similar behaviors of PCAO-7a, 7b2 and 7c result from their near-identical construction, lithology and location. The general decline of water level until

  2. Oil production and groundwater quality in the Edwards-Trinity Plateau Aquifer, Texas.

    PubMed

    Hudak, Paul F

    2003-11-13

    Chloride concentrations and chloride/bromide ratios from 198 water wells in the Edwards-Trinity Plateau Aquifer were compiled, mapped, and evaluated within the context of regional geology and land use. The study area occupies eight counties in west-central Texas, within which oil production and agriculture are predominant land uses. Samples from 49 wells had chloride concentrations above the 250 mg/l secondary drinking water standard, 22 samples had greater than 500 mg/l chloride, and 9 samples exceeded 1000 mg/l chloride. Of the 22 samples above 500 mg/l chloride, 10 had relatively low chloride/bromide ratios of less than 300, consistent with oilfield brine, and 2 had ratios above 2000, consistent with groundwater impacted by evaporite dissolution. The remaining ten samples had chloride/bromide ratios ranging from 300 to 2000, consistent with partial mixing of unimpaired groundwater with evaporite-laden water. There were no significant correlations between chloride concentration and well depth, inconsistent with contaminants originating at the land surface. Results of this study suggest that evaporite dissolution and oilfield brine locally impact the Edwards-Trinity Plateau Aquifer, but the problem is not regionally pervasive.

  3. Selected coal-related ground-water data, Wasatch Plateau-Book Cliffs area, Utah

    USGS Publications Warehouse

    Sumsion, C.T.

    1979-01-01

    The Wasatch Plateau-Book Cliffs%area as used in this report consists of about 8,000 square miles in east-central Utah. The major geographic features included in the area are the Wasatch Plateau, Book Cliffs, San Rafael Swell, Price River basin, and a small part of the Green River basin (pl. 1). The area is defined by approximate drainage-divide boundaries in the Wasatch Plateau and Book Cliffs, by an arbitrary boundary on the south, and by the Utah-Colorado State line on the east.The Wasatch Plateau-Book Cliffs area includes all the operating coal mines in Utah in 1978. Annual coal production in the area is expected to increase from the current (1978) rate of about 8 million tons to as much as 30 million tons within the next 10 years (J. W. Moffitt, U.S. Geological Survey, oral commun., 1978). Ground water is an important source of water supply in the area. As mining increases and mining-related municipalities grow, many sources of ground-water supply may be subjected to increased demands and possibly degradation of chemical quality.Waddell, Vickers, Upton, and Contratto (1978) reported some ground- water data after a reconnaissance of part of the area. The purpose of this report, which was prepared in cooperation with the U.S. Bureau of Land Management, is to present a more detailed compilation of ground-water-related data that were collected and compiled during October 1976 to March 1978. The report is designed to make the data available in an orderly and usable form for local and regional water managers and other users of water data.

  4. Evaluating Contaminant Flux from the Vadose Zone to the Groundwater in the Hanford Central Plateau. SX Tank Farms Case Study

    SciTech Connect

    Truex, Michael J.; Oostrom, Martinus; Last, George V.; Strickland, Christopher E.; Tartakovsky, Guzel D.

    2015-09-01

    At the DOE Hanford Site, contaminants were discharged to the subsurface through engineered waste sites in the Hanford Central Plateau. Additional waste was released through waste storage tank leaks. Much of the contaminant inventory is still present within the unsaturated vadose zone sediments. The nature and extent of future groundwater contaminant plumes and the growth or decline of current groundwater plumes beneath the Hanford Central Plateau are a function of the contaminant flux from the vadose zone to the groundwater. In general, contaminant transport is slow through the vadose zone and it is difficult to directly measure contaminant flux in the vadose zone. Predictive analysis, supported by site characterization and monitoring data, was applied using a structured, systems-based approach to estimate the future contaminant flux to groundwater in support of remediation decisions for the vadose zone and groundwater (Truex and Carroll 2013). The SX Tank Farm was used as a case study because of the existing contaminant inventory in the vadose zone, observations of elevated moisture content in portions of the vadose zone, presence of a limited-extent groundwater plume, and the relatively large amount and wide variety of data available for the site. Although the SX Tank Farm case study is most representative of conditions at tank farm sites, the study has elements that are also relevant to other types of disposal sites in the Hanford Central Plateau.

  5. Ground-Water Availability Assessment for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    USGS Publications Warehouse

    ,

    2008-01-01

    The U.S. Geological Survey (USGS) is assessing the availability and use of the Nation's water resources to gain a clearer understanding of the status of our water resources and the land-use, water-use, and climatic trends that affect them. The goal of the National assessment is to improve our ability to forecast water availability for future economic and environmental uses. Assessments will be completed for regional aquifer systems across the Nation to help characterize how much water we have now, how water availability is changing, and how much water we can expect to have in the future (Reilly and others, 2008). Water availability is a function of many factors, including the quantity and quality of water, and the laws, regulations, economics, and environmental factors that control its use. The focus of the Columbia Plateau regional ground-water availability assessment is to improve fundamental knowledge of the ground-water balance of the region, including the flows, storage, and ground-water use by humans. An improved quantitative understanding of the region's water balance not only provides key information about water quantity, but also can serve as a fundamental basis for many analyses of water quality and ecosystem health.

  6. Ground-water levels spring 1985, and ground-water level changes spring 1983 to spring 1985, in three basalt units underlying the Columbia Plateau, Washington and Oregon

    USGS Publications Warehouse

    Lane, R.C.; Whiteman, K.J.

    1989-01-01

    Groundwater level contour maps for three basalt units of the Columbia Plateau regional aquifer system were constructed by using water levels measured in 1,105 wells during 1985. These measurements then were compared with similar measurements from spring 1983 to assess the changes in groundwater levels over the 2-year period for each of the basalt units. Configuration of the groundwater contours and water level changes reflect (1) recharge and discharge; (2) hydraulic conductivity; (3) use of imported surface water for irrigation; and (4) pumpage of groundwater. The movement of groundwater within each basalt unit is controlled mainly by the major rivers, streams, and coulees, whereas variations in flow directions between units are related to the occurrence, extent, and hydraulic conductivity of the basalt units and sedimentary interbeds and to differences in the amounts of recharge to each unit. (USGS)

  7. Lake volume and groundwater storage variations in Tibetan Plateau's endorheic basin

    NASA Astrophysics Data System (ADS)

    Zhang, Guoqing; Yao, Tandong; Shum, C. K.; Yi, Shuang; Yang, Kun; Xie, Hongjie; Feng, Wei; Bolch, Tobias; Wang, Lei; Behrangi, Ali; Zhang, Hongbo; Wang, Weicai; Xiang, Yang; Yu, Jinyuan

    2017-06-01

    The Tibetan Plateau (TP), the highest and largest plateau in the world, with complex and competing cryospheric-hydrologic-geodynamic processes, is particularly sensitive to anthropogenic warming. The quantitative water mass budget in the TP is poorly known. Here we examine annual changes in lake area, level, and volume during 1970s-2015. We find that a complex pattern of lake volume changes during 1970s-2015: a slight decrease of -2.78 Gt yr-1 during 1970s-1995, followed by a rapid increase of 12.53 Gt yr-1 during 1996-2010, and then a recent deceleration (1.46 Gt yr-1) during 2011-2015. We then estimated the recent water mass budget for the Inner TP, 2003-2009, including changes in terrestrial water storage, lake volume, glacier mass, snow water equivalent (SWE), soil moisture, and permafrost. The dominant components of water mass budget, namely, changes in lake volume (7.72 ± 0.63 Gt yr-1) and groundwater storage (5.01 ± 1.59 Gt yr-1), increased at similar rates. We find that increased net precipitation contributes the majority of water supply (74%) for the lake volume increase, followed by glacier mass loss (13%), and ground ice melt due to permafrost degradation (12%). Other term such as SWE (1%) makes a relatively small contribution. These results suggest that the hydrologic cycle in the TP has intensified remarkably during recent decades.

  8. Thirty-five years at Pajarito Canyon Site

    SciTech Connect

    Paxton, H.C.

    1981-05-01

    A history of the research activities performed at the Pajarito Canyon Site from 1946 to 1981 is presented. Critical assemblies described include: the Topsy assembly; Lady Godiva; Godiva 2; Jezebel; Flattop; the Honeycomb assembly for Rover studies; Kiwi-TNT; PARKA reactor; Big Ten; and Plasma Cavity Assembly.

  9. Groundwater Conditions During 2009 and Changes in Groundwater Levels from 1984 to 2009, Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    USGS Publications Warehouse

    Snyder, Daniel T.; Haynes, Jonathan V.

    2010-01-01

    Groundwater elevations in three basalt units and one unconsolidated hydrogeologic unit in the Columbia Plateau Regional Aquifer System were measured and evaluated to provide a regional overview of groundwater conditions in spring 2009. Water levels for the Saddle Mountains unit, the Wanapum unit, the Grande Ronde unit, and for the overlying Overburden unit were measured in 1,752 wells during spring 2009 by the U.S. Geological Survey (USGS) and 10 other Federal, State, Tribal, and local agencies, including 66 wells located and measured by the USGS specifically for this study. These data were analyzed to determine the presence of spatial correlation of groundwater levels with distance and direction from each other. Groundwater flow in the Palouse Slope structural region showed evidence of being more continuous relative to groundwater flow in the Yakima Fold Belt, where the geologic complexity may contribute to compartmentalization of groundwater flow. This information was used to interpolate the generalized groundwater elevations for each of the basalt hydrogeologic units and to provide information on regional flow. Water-level change maps were constructed for the three basalt hydrogeologic units and the Overburden (unconsolidated) unit. Groundwater levels measured in spring 1984 and 2009 in 470 wells were compared. Small to moderate groundwater-level declines were measured in most wells, although declines greater than 100 ft and as great as 300 ft were measured in many wells. Essentially unchanged groundwater levels were measured in other wells. Of the wells measured in 1984 and 2009, water levels declined in 83 percent of the wells, and declines greater than 25 ft were measured in 29 percent of all wells. The groundwater-level changes were greatest in the deeper hydrogeologic units. Mean groundwater-level changes ranged from a 7 ft decline for the Overburden unit to a 51 ft decline for the Grande Ronde unit. The average annual rates of groundwater-level change for

  10. Groundwater storage changes in the Tibetan Plateau and adjacent areas revealed from GRACE satellite gravity data

    NASA Astrophysics Data System (ADS)

    Xiang, Longwei; Wang, Hansheng; Steffen, Holger; Wu, Patrick; Jia, Lulu; Jiang, Liming; Shen, Qiang

    2016-09-01

    Understanding groundwater storage (GWS) changes is vital to the utilization and control of water resources in the Tibetan Plateau. However, well level observations are rare in this big area, and reliable hydrology models including GWS are not available. We use hydro-geodesy to quantitate GWS changes in the Tibetan Plateau and surroundings from 2003 to 2009 using a combined analysis of satellite gravity and satellite altimetry data, hydrology models as well as a model of glacial isostatic adjustment (GIA). Release-5 GRACE gravity data are jointly used in a mascon fitting method to estimate the terrestrial water storage (TWS) changes during the period, from which the hydrology contributions and the GIA effects are effectively deducted to give the estimates of GWS changes for 12 selected regions of interest. The hydrology contributions are carefully calculated from glaciers and lakes by ICESat-1 satellite altimetry data, permafrost degradation by an Active-Layer Depth (ALD) model, soil moisture and snow water equivalent by multiple hydrology models, and the GIA effects are calculated with the new ICE-6G_C (VM5a) model. Taking into account the measurement errors and the variability of the models, the uncertainties are rigorously estimated for the TWS changes, the hydrology contributions (including GWS changes) and the GIA effect. For the first time, we show explicitly separated GWS changes in the Tibetan Plateau and adjacent areas except for those to the south of the Himalayas. We find increasing trend rates for eight basins: + 2.46 ± 2.24 Gt/yr for the Jinsha River basin, + 1.77 ± 2.09 Gt/yr for the Nujiang-Lancangjiang Rivers Source Region, + 1.86 ± 1.69 Gt/yr for the Yangtze River Source Region, + 1.14 ± 1.39 Gt/yr for the Yellow River Source Region, + 1.52 ± 0.95 Gt/yr for the Qaidam basin, + 1.66 ± 1.52 Gt/yr for the central Qiangtang Nature Reserve, + 5.37 ± 2.17 Gt/yr for the Upper Indus basin and + 2.77 ± 0.99 Gt/yr for the Aksu River basin. All these

  11. Groundwater status and trends for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    USGS Publications Warehouse

    Burns, Erick R.; Snyder, Daniel T.; Haynes, Jonathan V.; Waibel, Michael S.

    2012-01-01

    Well information and groundwater-level measurements for the Columbia Plateau Regional Aquifer System in Washington, Oregon, and Idaho, were compiled from data provided by the U.S. Geological Survey and seven other organizations. From the full set of about 60,000 wells and 450,000 water-level measurements a subset of 761 wells within the aquifers of the Columbia River Basalt Group (CRBG) then was used to develop a simple linear groundwater-level trend map for 1968–2009. The mean of the trends was a decline of 1.9 feet per year (ft/yr), with 72 percent of the water levels in wells declining. Rates of declines greater than 1.0 ft/yr were measured in 50 percent of wells, declines greater than 2.0 ft/yr in 38 percent of wells, declines greater than 4.0 ft/yr in 29 percent of wells, and declines greater than 8.0 ft/yr in 4 percent of wells. Water-level data were used to identify groups of wells with similar hydraulic heads and temporal trends to delineate areas of overall similar groundwater conditions. Discontinuities in hydraulic head between well groups were used to help infer the presence of barriers to groundwater flow such as changes in lithology or the occurrence of folds and faults. In areas without flow barriers, dissimilarities in response of well groups over time resulted from the formation of groundwater mounds caused by recharge from irrigation or regions of decline caused by pumping. The areas of focus for this analysis included the Umatilla area, Oregon, and the Palouse Slope/eastern Yakima Fold Belt in the Columbia Basin Ground Water Management Area (GWMA) consisting of Adams, Franklin, Grant, and Lincoln Counties, Washington. In the Umatilla area, water levels from 286 wells were used to identify multiple areas of high hydraulic gradient that indicate vertical and horizontal barriers to groundwater flow. These barriers divide the groundwater-flow system into several compartments with varying degrees of interconnection. Horizontal flow barriers commonly

  12. Geohydrology and simulation of ground-water flow near Los Alamos, north-central New Mexico

    USGS Publications Warehouse

    Frenzel, P.F.

    1995-01-01

    An existing model was modified in recognition of new geohydrologic interpretations and adjusted to simulate hydrographs in well fields in the Los Alamos area. Hydraulic-head drawdowns at the Buckman well field resulting from two projected ground-water-withdrawal alternatives were estimated with the modified model. The Chaquehui formation (informal usage) is the main new feature of recent hydrologic interpretations for the Los Alamos area. The Chaquehui occupies a 'channel' that was eroded or faulted into the Tesuque Formation, and the Chaquehui is more permeable than the Tesuque. The Chaquehui is a major producing zone in the Pajarito Mesa well field and to a lesser extent in the Guaje well field. Model modification included splitting the four layers of the McAda-Wasiolek model (McAda, D.P., and Wasiolek, Maryann, 1988, Simulation of the regional geohydrology of the Tesuque aquifer system near Santa Fe, New Mexico: U.S. Geological Survey Water- Resources Investigations Report 87-4056, 71 p.) into eight layers to better simulate vertical ground-water movement. Other model modifications were limited as much as possible to the area of interest near Los Alamos and consisted mainly of adjusting hydraulic-conductivity values representing the Tesuque Formation, Chaquehui formation (informal usage), and Puye Formation, and adjusting simulated recharge along the Pajarito Fault Zone west of Los Alamos. Adjustments were based mainly on simulation of fluctuations in measured hydraulic heads near Los Alamos. Two possible alternative plans for replacing Guaje well field production were suggested by Los Alamos National Laboratory. In the first plan (Guaje alternative), the Guaje field would be renewed with four new wells replacing the existing production wells in the Guaje field. In the second plan (Pajarito-Otowi alternative), the Guaje well field would be retired and its former production would be made up by additional withdrawals from the Pajarito Mesa and Otowi well fields. A

  13. Groundwater recharge mechanism in an integrated tableland of the Loess Plateau, northern China: insights from environmental tracers

    NASA Astrophysics Data System (ADS)

    Huang, Tianming; Pang, Zhonghe; Liu, Jilai; Ma, Jinzhu; Gates, John

    2017-05-01

    Assessing groundwater recharge characteristics (recharge rate, history, mechanisms (piston and preferential flow)) and groundwater age in arid and semi-arid environments remains a difficult but important research frontier. Such assessments are particularly important when the unsaturated zone (UZ) is thick and the recharge rate is limited. This study combined evaluations of the thick UZ with those of the saturated zone and used multiple tracers, such as Cl, NO3, Br, 2H, 18O, 13C, 3H and 14C, to study groundwater recharge characteristics in an integrated loess tableland in the Loess Plateau, China, where precipitation infiltration is the only recharge source for shallow groundwater. The results indicate that diffuse recharge beneath crops, as the main land use of the study area, is 55-71 mm yr-1 based on the chloride mass balance of soil profiles. The length of time required for annual precipitation to reach the water table is 160-400 yrs. The groundwater is all pre-modern water and paleowater, with corrected 14C age ranging from 136 to 23,412 yrs. Most of the water that eventually becomes recharge originally infiltrated in July-September. The Cl and NO3 contents in the upper UZ are considerably higher than those in the deep UZ and shallow groundwater because of recent human activities. The shallow groundwater has not been in hydraulic equilibrium with present near-surface boundary conditions. The homogeneous material of the UZ and relatively old groundwater age imply that piston flow is the dominant recharge mechanism for the shallow groundwater in the tableland.

  14. Pajarito Aerosol Couplings to Ecosystems (PACE) Field Campaign Report

    SciTech Connect

    Dubey, M

    2016-03-01

    Laboratory (LANL) worked on the Pajarito Aerosol Couplings to Ecosystems (PACE) intensive operational period (IOP). PACE’s primary goal was to demonstrate routine Mobile Aerosol Observing System (MAOS) field operations and improve instrumental and operational performance. LANL operated the instruments efficiently and effectively with remote guidance by the instrument mentors. This was the first time a complex suite of instruments had been operated under the ARM model and it proved to be a very successful and cost-effective model to build upon.

  15. Impact of groundwater table and plateau zokors (Myospalax baileyi) on ecosystem respiration in the Zoige Peatlands of China.

    PubMed

    Zhou, Yan; Li, Nana; Grace, John; Yang, Meng; Lu, Cai; Geng, Xuemeng; Lei, Guangchun; Zhu, Wei; Deng, Yongfeng

    2014-01-01

    Peatlands contain large amount of carbon stock that is vulnerable to release into the atmosphere. Mostly because of human impact, the peatlands at Zoige Wetlands face severe degradation, and the groundwater table is now lower than before, which has increased the population of the plateau zokor, a burrowing rodent. However, the impact of these changes on ecosystem carbon flows has not been studied. To investigate how the plateau zokor and the groundwater level alter the ecosystem respiration of the Zoige peatlands, we sampled the CO2 flux of hummocks shaped by the zokors and compared it with the CO2 flux of undisturbed sites with different groundwater table levels. The soil organic carbon (SOC), soil water content (SWC) and soil temperature at 5 cm (T5) were measured. SOC showed no significant difference among the four sampling sites and did not correlate with the CO2 flux, while SWC was found to partly determine the CO2 flux. A linear equation could adequately describe the relationship between the natural logarithm of the ecosystem respiration and the soil temperature. It is demonstrated that descending groundwater table might accelerate ecosystem respiration and the CO2 flux from hummocks was higher than the CO2 flux from the control site in the non-growing season. With rising temperature, the CO2 flux from the control site accelerated faster than that from the hummocks. Our results show that ecosystem respiration was significantly lower from hummocks than at the control site in the growing season. The results on the impact of zokors on greenhouse gas emissions presented in this paper provide a useful reference to help properly manage not only this, but other litter-burrowing mammals at peatland sites.

  16. Influence of geochemical processes on hydrochemistry and irrigation suitability of groundwater in part of semi-arid Deccan Plateau, India

    NASA Astrophysics Data System (ADS)

    Vasu, Duraisamy; Singh, Surendra Kumar; Tiwary, Pramod; Sahu, Nisha; Ray, Sanjay Kumar; Butte, Pravin; Duraisami, Veppangadu Perumal

    2017-02-01

    Major ion geochemistry was used to characterise the chemical composition of groundwater in part of semi-arid Deccan plateau region to understand the geochemical evolution and to evaluate the groundwater quality for irrigation. The study area comprises peninsular gneissic complex of Archean age, younger granites and basaltic alluvium. Forty-nine georeferenced groundwater samples were collected and analysed for major ions. The ionic sequence based on relative proportions was Na+ > Mg2+ > Ca2+ > SO4 2- > HCO3 - > Cl- > CO3 2- > BO3 3- > K+. High Na+, Mg2+ and Ca2+ were generally associated with basaltic alluvial formation, whereas pH, electrical conductivity (EC) and total dissolved salts (TDS) were found to be higher in granitic formations. High standard deviation for EC, TDS, Na+, Ca2+ and Mg2+ indicated the dispersion of ionic concentration throughout the study area. Four major hydrochemical facies identified were Na-Mg-HCO3 type; Mg-Na-HCO3 type; Na-Mg-Ca-SO4 and Mg-Na-Ca-SO4 type. The graphical plots indicated that the groundwater chemistry was influenced by rock-water interaction, silicate weathering and reverse ion exchange. Sodium-dominated waters might have impeded the hydraulic properties of soils as a result of long-term irrigation.

  17. Numerical simulation of groundwater flow in the Columbia Plateau Regional Aquifer System, Idaho, Oregon, and Washington

    USGS Publications Warehouse

    Ely, D. Matthew; Burns, Erick R.; Morgan, David S.; Vaccaro, John J.

    2014-01-01

    Groundwater pumping has increased substantially over the past 40–50 years; this increase resulted in declining water levels at depth and decreased base flows over much of the study area. The effects of pumping are mitigated somewhat by the increase of surface-water irrigation, especially in the shallow Overburden unit, and commingling wells in some areas. During dry to average years, groundwater pumping causes a net loss of groundwater in storage and current condition (2000–2007) groundwater pumping exceeds recharge in all but the wettest of years.

  18. Groundwater availability of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    USGS Publications Warehouse

    Vaccaro, J.J.; Kahle, S.C.; Ely, D.M.; Burns, E.R.; Snyder, D.T.; Haynes, J.V.; Olsen, T.D.; Welch, W.B.; Morgan, D.S.

    2015-09-22

    Changes in the system from predevelopment times. The model also is a useful tool for investigating water supply, water demand, management strategies, groundwater-surface water exchanges, and potential effects of changing climate on the hydrologic system.

  19. Ground-water conditions in the Kaiparowits Plateau area, Utah and Arizona, with emphasis on the Navajo Sandstone

    USGS Publications Warehouse

    Blanchard, Paul J.

    1986-01-01

    This report presents results of investigation of ground-water conditions in the Kaiparowits Plateau area of south-central Utah and north-central Arizona (fig. 1). The area is under investigation for development of its large quantities of energy resources, primarily coal. Production and transportation of those energy resources would require attendant development of water resources. The purpose of this study was to determine the availability and quality of ground water in major aquifers in the area - namely aquifers in the Entrada, Navajo, and Wingate Sandstones; emphasis was on the Navajo Sandstone. The study was made by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights. Field work was done intermittently during July through October 1979, and October 1980 through October 1981.

  20. Use of Landsat imagery to estimate ground-water pumpage for irrigation on the Columbia Plateau in eastern Washington, 1985

    USGS Publications Warehouse

    Van Metre, P.C.; Seevers, Paul

    1991-01-01

    A method for estimating ground-water pumpage for irrigation was developed for the Columbia Plateau in eastern Washington. The method combines water-application rates estimated from pumpage data with acreage of irrigated crops that was mapped by using Landsat imagery. The study area consisted of Grant, Lincoln, Adams, and Franklin Counties, an area of approximately 8,900 square miles, and accounts for approximately three-fourths of the ground-water pumpage in the Columbia Plateau in eastern Washington. Data from two passes of Landsat's multispectral scanner were analyzed by using a spectral band ratioing procedure to map irrigated crops for the study area. Data from one pass of Landsat's thematic mapper, covering approximately two-thirds of the study area, also were analyzed for determining irrigated crops in the area resulting in a 6-percent improvement in accuracy over the multispectral scanner analysis. A total of 576 annual water-application rates associated with particular crops, for the 1982 through 1985 seasons, were calculated. A regression equation was developed for estimating annual water-application rates as a function of crop type, annual precipitation, irrigation system type, and available water capacity of the soil. Crops were grouped into three water-use categories: (1) small grains, primarily wheat and barley; (2) high water-use crops consisting of corn, alfalfa, and potatoes; and (3) miscellaneous vegetable and row crops. Annual water-application rates, expressed as a depth of water, then were multiplied by irrigated area determined by Landsat to estimate a volume of water pumped for irrigation for 1985-620,000 acre-feet. An assessment of accuracy for estimating pumpage for 28 of the sites showed that total predicted pumpage was within 4 percent of the total observed pumpage.

  1. Three-dimensional inversion of in-line resistivity data for monitoring a groundwater recharge experiment in a pyroclastic plateau

    NASA Astrophysics Data System (ADS)

    Inoue, Keisuke; Nakazato, Hiroomi; Kubota, Tomijiro; Takeuchi, Mutsuo; Sugimoto, Yoshihiro; Kim, Hee Joon; Furue, Koji

    2017-06-01

    An artificial groundwater recharge experiment was conducted in a pyroclastic plateau in Kagoshima Prefecture in Japan, and time-lapse electrical resistivity data were collected to monitor the recharge process. In the experiment, time-efficient in-line resistivity surveys were performed along four intersecting lines, because a large amount of water was released from two recharge areas and a relatively fast migration of water into the vadose zone was expected. The migration of recharged water may be estimated from changes in electrical resistivity because resistivity in the vadose zone is largely controlled by water saturation variations there. The geological setting at the experiment site was interpreted from the resistivity distribution inverted from the in-line survey data, which were obtained before the recharge experiment. The resistivity distribution showed an approximately layered structure, which could be correlated with four borehole logs in the area. Three-dimensional (3D) distributions of the resistivity change ratio were derived through constrained nonlinear ratio inversion. Three-dimensional inversion of the in-line resistivity data was more suitable than two-dimensional inversion to describe the 3D phenomena associated with groundwater recharge. During the recharge experiment, the zones of decreased resistivity shifted with time, indicating non-uniform penetration of water from the recharge areas into the ground and a horizontal flow of the recharged water, especially in the secondary Shirasu layer, which comprises lacustrine or marine sediments of pyroclastic origin. These interpretations agree with the variation in water content observed in a borehole.

  2. Groundwater-quality data in the Cascade Range and Modoc Plateau study unit, 2010-Results from the California GAMA Program

    USGS Publications Warehouse

    Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the 39,000-square-kilometer Cascade Range and Modoc Plateau (CAMP) study unit was investigated by the U.S. Geological Survey (USGS) from July through October 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The CAMP study unit is the thirty-second study unit to be sampled as part of the GAMA PBP. The GAMA CAMP study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system and to facilitate statistically consistent comparisons of untreated-groundwater quality throughout California. The primary aquifer system is defined as that part of the aquifer corresponding to the open or screened intervals of wells listed in the California Department of Public Health (CDPH) database for the CAMP study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from the quality of groundwater in the primary aquifer system; shallow groundwater may be more vulnerable to surficial contamination. In the CAMP study unit, groundwater samples were collected from 90 wells and springs in 6 study areas (Sacramento Valley Eastside, Honey Lake Valley, Cascade Range and Modoc Plateau Low Use Basins, Shasta Valley and Mount Shasta Volcanic Area, Quaternary Volcanic Areas, and Tertiary Volcanic Areas) in Butte, Lassen, Modoc, Plumas, Shasta, Siskiyou, and Tehama Counties. Wells and springs were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells). Groundwater samples were analyzed for field water-quality indicators, organic constituents, perchlorate, inorganic constituents

  3. Evaluation of Nitrate Fluxes to Groundwater under Agriculture Land Uses across the Loess Plateau - A Catchment Scale Investigation

    NASA Astrophysics Data System (ADS)

    Turkeltaub, T.; Jia, X.; Binley, A. M.

    2016-12-01

    Nitrate management is required for fulfilling the objective of high agriculture productivity and concurrently reduced groundwater contamination to minimum. Yet, nitrate is considered as a non-point contaminant. Therefore, understanding the temporal and spatial processes controls of nitrate transport in the vadose zone are imperative for protection of groundwater. This study is conducted in the Loess Plateau which located in the north-central of mainland China and characterized with a semi-arid climate. Moreover, it accounts for about 6.6% of the Chinese territory and supports over 8.5% of the Chinese population. This area undergoes high pressure from human activities and requiring optimal management interventions. Integrated modelling frameworks, which include unsaturated and saturated processes, are able to simulate nitrate transport under various scenarios, and provide reasonable prediction for the decision-makers. We used data obtained from soil samples collected across a region of 41 × 104 km2 (243 samples, to 5 m depth) to derive unsaturated flow and transport properties. Particle size distributions, saturated hydraulic conductivity, water content at field capacity (0.33 atm) and saturated water content were also obtained for the shallower layers (0-40 cm). The van Genuchten - Mualem soil parameters describing the retention and the unsaturated hydraulic conductivity curves were estimated with the Rosetta code. The analysis of the soil samples indicated that the silt loam soil type is dominant. Hence, a scaling approach was chosen as an adequate method for estimation of representative retention and hydraulic conductivity curves. Water flow and nitrate leaching were simulated with mechanistic based 1-D model for each agriculture land use within the area. The simulated nitrate losses were compared with results of root zone model simulations. Subsequently, the calculated fluxes were input as upper boundary conditions in the Modflow model to examine the regional

  4. Predicting ground-water movement in large mine spoil areas in the Appalachian Plateau

    USGS Publications Warehouse

    Wunsch, D.R.; Dinger, J.S.; Graham, C.D.R.

    1999-01-01

    Spoil created by surface mining can accumulate large quantities of ground-water, which can create geotechnical or regulatory problems, as well as flood active mine pits. A current study at a large (4.1 km2), thick, (up to 90 m) spoil body in eastern Kentucky reveals important factors that control the storage and movement of water. Ground-water recharge occurs along the periphery of the spoil body where surface-water drainage is blocked, as well as from infiltration along the spoil-bedrock contact, recharge from adjacent bedrock, and to a minor extent, through macropores at the spoil's surface. Based on an average saturated thickness of 6.4 m for all spoil wells, and assuming an estimated porosity of 20%, approximately 5.2 x 106 m3 of water is stored within the existing 4.1 km2 of reclaimed spoil. A conceptual model of ground-water flow, based on data from monitoring wells, dye-tracing data, discharge from springs and ponds, hydraulic gradients, chemical data, field reconnaissance, and aerial photographs indicate that three distinct but interconnected saturated zones have been established: one in the spoil's interior, and others in the valley fills that surround the main spoil body at lower elevations. Ground-water movement is sluggish in the spoil's interior, but moves quickly through the valley fills. The conceptual model shows that a prediction of ground-water occurrence, movement, and quality can be made for active or abandoned spoil areas if all or some of the following data are available: structural contour of the base of the lowest coal seam being mined, pre-mining topography, documentation of mining methods employed throughout the mine, overburden characteristics, and aerial photographs of mine progression.Spoil created by surface mining can accumulate large quantities of ground-water, which can create geotechnical or regulatory problems, as well as flood active mine pits. A current study at a large (4.1 km2), thick, (up to 90 m) spoil body in eastern

  5. Hydrogeology of the Mammoth Spring groundwater basin and vicinity, Markagunt Plateau, Garfield, Iron, and Kane Counties, Utah

    USGS Publications Warehouse

    Spangler, Lawrence E.

    2012-01-01

    The Markagunt Plateau, in southwestern Utah, lies at an altitude of about 9,500 feet, largely within Dixie National Forest. The plateau is capped primarily by Tertiary- and Quaternary-age volcanic rocks that overlie Paleocene- to Eocene-age limestone of the Claron Formation, which forms escarpments on the west and south sides of the plateau. In the southwestern part of the plateau, an extensive area of sinkholes has formed that resulted primarily from dissolution of the underlying limestone and subsequent subsidence and (or) collapse of the basalt, producing sinkholes as large as 1,000 feet across and 100 feet deep. Karst development in the Claron Formation likely has been enhanced by high infiltration rates through the basalt. Numerous large springs discharge from the volcanic rocks and underlying limestone on the Markagunt Plateau, including Mammoth Spring, one of the largest in Utah, with discharge that ranges from less than 5 to more than 300 cubic feet per second (ft3/s). In 2007, daily mean peak discharge of Mammoth Spring was bimodal, reaching 54 and 56 ft3/s, while daily mean peak discharge of the spring in 2008 and in 2009 was 199 ft3/s and 224 ft3/s, respectively. In both years, the rise from baseflow, about 6 ft3/s, to peak flow occurred over a 4- to 5-week period. Discharge from Mammoth Spring accounted for about 54 percent of the total peak streamflow in Mammoth Creek in 2007 and 2008, and about 46 percent in 2009, and accounted for most of the total streamflow during the remainder of the year. Results of major-ion analyses for water samples collected from Mammoth and other springs on the plateau during 2006 to 2009 indicated calcium-bicarbonate type water, which contained dissolved-solids concentrations that ranged from 91 to 229 milligrams per liter. Concentrations of major ions, trace elements, and nutrients did not exceed primary or secondary drinking-water standards; however, total and fecal coliform bacteria were present in water from Mammoth and

  6. Ground-water data for the Suck Creek area of Walden Ridge, southern Cumberland Plateau, Marion County, Tennessee

    USGS Publications Warehouse

    Hanchar, D.W.

    1995-01-01

    An investigation was made of the ground-water resources of the Suck Creek area, Marion County, Tennessee, 1990-91. Suck Creek is located on the Walden Ridge section of the Cumberland Plateau, and is about 16 miles northwest of Chattanooga. Eight wells were drilled into bedrock of Pennsylvania age. Drilling sites were chosen at or near fracture traces. Yields of the eight wells ranged from less than 1 to as much as 80 gallons of water per minute. Three wells had yields of 50 gallons per minute or more; two of these had estimated yields of 75 to 80 gallons per minute. These three wells produced water from a well- developed fracture within the Sewanee Conglomerate. Specific capacities for these three wells were 1.1, 1.3, 2.2 gallons per minute per foot of drawdown. Samples of water from six test wells and three domestic wells were analyzed for major inorganic constituents, nurients, major metals, trace elements, and bacteria. In addition, water samples from two of the test wells were analyzed for volatile organic compounds and scanned for the presence of semi-volatile organic compounds. Iron exceeded 300 micrograms per liter in five of the nine samples, and manganese exceeded 50 micrograms per liter in seven of the nine water samples. Toluene, a volatile organic compound, was detected in a concentration slightly above the reporting level; no other volatile organic compounds were detected.

  7. Analysis of the effect of pumping on ground-water flow in the Springfield Plateau and Ozark aquifers near Springfield, Missouri

    USGS Publications Warehouse

    Imes, J.L.

    1989-01-01

    Pumpage of water from the Ozark aquifer for public supply and industry use by the city of Springfield and surrounding communities in southwestern Missouri has significantly altered the potentiometric surface of the aquifer. Springfield is located on a regional groundwater divide that trends east and west across southern Missouri. Groundwater that once flowed north and south from the divide now moves toward Springfield. Drawdown in the Ozark aquifer beneath Springfield has increased about 50 ft near the center of the city since 1974. The area of well influence also has increased, most notably to the south and southwest, because of increased pumpage by Springfield and new groundwater withdrawals in rapidly increasing communities, such as Republic and Nixa. Changes in the potentiometric surface of the Ozark aquifer, and to a lesser extent the Springfield Plateau aquifer, resulting from stresses applied by pumpage of water supply wells has altered the hydrologic budget of the Springfield area. Downward leakage of groundwater through the Ozark confining unit has increased from about 10 cu ft/sec to about 18 cu ft/sec because drawdown in the Ozark aquifer has resulted in an increased vertical hydraulic gradient across the confining unit. Minimal quantities of water are supplied by increased upward leakage through the St. Francois confining unit. Model simulations indicate substantial quantities of water are still (1987) being removed from storage within the Ozark and Springfield Plateau aquifers and the hydrologic system is not in equilibrium at this time. (USGS)

  8. Understanding heat and groundwater flow through continental flood basalt provinces: insights gained from alternative models of permeability/depth relationships for the Columbia Plateau, USA

    SciTech Connect

    Burns, Erick R.; Williams, Colin F.; Ingebritsen, Steven E.; Voss, Clifford I.; Spane, Frank A.; DeAngelo, Jacob

    2015-02-01

    Heat-flow mapping of the western USA has identified an apparent low-heat-flow anomaly coincident with the Columbia Plateau Regional Aquifer System, a thick sequence of basalt aquifers within the Columbia River Basalt Group (CRBG). A heat and mass transport model (SUTRA) was used to evaluate the potential impact of groundwater flow on heat flow along two different regional groundwater flow paths. Limited in situ permeability (k) data from the CRBG are compatible with a steep permeability decrease (approximately 3.5 orders of magnitude) at 600–900 m depth and approximately 40°C. Numerical simulations incorporating this permeability decrease demonstrate that regional groundwater flow can explain lower-than-expected heat flow in these highly anisotropic (kx/kz ~ 104) continental flood basalts. Simulation results indicate that the abrupt reduction in permeability at approximately 600 m depth results in an equivalently abrupt transition from a shallow region where heat flow is affected by groundwater flow to a deeper region of conduction-dominated heat flow. Most existing heat-flow measurements within the CRBG are from shallower than 600 m depth or near regional groundwater discharge zones, so that heat-flow maps generated using these data are likely influenced by groundwater flow. Substantial k decreases at similar temperatures have also been observed in the volcanic rocks of the adjacent Cascade Range volcanic arc and at Kilauea Volcano, Hawaii, where they result from low-temperature hydrothermal alteration.

  9. Understanding heat and groundwater flow through continental flood basalt provinces: insights gained from alternative models of permeability/depth relationships for the Columbia Plateau, USA

    USGS Publications Warehouse

    Burns, Erick R.; Williams, Colin F.; Ingebritsen, Steven E.; Voss, Clifford I.; Spane, Frank A.; DeAngelo, Jacob

    2015-01-01

    Heat-flow mapping of the western USA has identified an apparent low-heat-flow anomaly coincident with the Columbia Plateau Regional Aquifer System, a thick sequence of basalt aquifers within the Columbia River Basalt Group (CRBG). A heat and mass transport model (SUTRA) was used to evaluate the potential impact of groundwater flow on heat flow along two different regional groundwater flow paths. Limited in situ permeability (k) data from the CRBG are compatible with a steep permeability decrease (approximately 3.5 orders of magnitude) at 600–900 m depth and approximately 40°C. Numerical simulations incorporating this permeability decrease demonstrate that regional groundwater flow can explain lower-than-expected heat flow in these highly anisotropic (kx/kz ~ 104) continental flood basalts. Simulation results indicate that the abrupt reduction in permeability at approximately 600 m depth results in an equivalently abrupt transition from a shallow region where heat flow is affected by groundwater flow to a deeper region of conduction-dominated heat flow. Most existing heat-flow measurements within the CRBG are from shallower than 600 m depth or near regional groundwater discharge zones, so that heat-flow maps generated using these data are likely influenced by groundwater flow. Substantial k decreases at similar temperatures have also been observed in the volcanic rocks of the adjacent Cascade Range volcanic arc and at Kilauea Volcano, Hawaii, where they result from low-temperature hydrothermal alteration.

  10. Groundwater.

    ERIC Educational Resources Information Center

    Braids, Olin C.; Gillies, Nola P.

    1978-01-01

    Presents a literature review of groundwater quality covering publications of 1977. This review includes: (1) sources of groundwater contamination; and (2) management of groundwater. A list of 59 references is also presented. (HM)

  11. Groundwater.

    ERIC Educational Resources Information Center

    Braids, Olin C.; Gillies, Nola P.

    1978-01-01

    Presents a literature review of groundwater quality covering publications of 1977. This review includes: (1) sources of groundwater contamination; and (2) management of groundwater. A list of 59 references is also presented. (HM)

  12. Estimating groundwater recharge following land-use change using chloride mass balance of soil profiles: a case study at Guyuan and Xifeng in the Loess Plateau of China

    NASA Astrophysics Data System (ADS)

    Huang, Tianming; Pang, Zhonghe

    2011-02-01

    Groundwater recharge is affected by land use in (semi)arid areas. A new application of the chloride-mass-balance approach has been developed to estimate the reduction in groundwater recharge following land-use change by comparing chloride concentrations below the root zone and above the base of the chloride accumulation zone, before and after the land-use conversion. Two sites in the Loess Plateau of central China have been selected for study. Results from the Guyuan terrace region show that groundwater recharge beneath natural sparse small-grass was 100 mm/year, but the conversion to winter wheat about 100 years ago has reduced groundwater recharge to 55 mm/year. At the Xifeng Loess Plain the conversion from winter wheat, with groundwater recharge at 33 mm/year, to apple orchard 7 years ago has led to chloride accumulation to 5 m below land surface, suggesting the recharge rate has been reduced. This is in agreement with previous studies in these areas which have shown that the regional afforestation and other land-use conversions have resulted in deep soil desiccation and have caused an upper boundary to form with low matrix potential, thus preventing the soil moisture from actually recharging the aquifer.

  13. Technological Advancements: Seismic Refraction on the Pajarito Plateau, Northern New Mexico.

    SciTech Connect

    Nisengard, J. E.; Ferguson, J. F.; Hinz, E.; Isaacson, J.; Gauthier, Rory P.

    2005-01-01

    Geophysical techniques can be used for non-invasive surveys at archaeological sites. Seismic refraction is one such technology that has many potential applications, although it has been under-utilized. It is an inexpensive, efficient way to characterize subsurface deposits, especially at sites in shallow contexts over bedrock. Archaeologists and geophysicists participating in the Summer of Applied Geophysics Experience (SAGE), from Los Alamos National Laboratory (LANL), and Bandelier National Monument are working together to characterize Ancestral Pueblo (A.D. 1200 to 1600) sites. We present the results from three seismic refraction surveys and provide an overview of how seismic refraction works.

  14. BISON ANTIQUUS OCCURRENCE AND PLEISTOCENE-HOLOCENE STRATIGRAPHY, CANADA DEL BUEY, PAJARITO PLATEAU, NEW MEXICO

    SciTech Connect

    RENEAU, STEVEN L.; DRAKOS, PAUL G.; MORGAN, GARY S.

    2007-02-12

    A Bison. (probable Bison antiguus) distal humerus fragment was found within a Pleistocene colluvial deposit on a hillslope above Canada del Buey near White Rock, New Mexico. The Bison fossil is preserved within a buried soil with an inferred age of ca. 50-100 ka, based on soil properties and on stratigraphic position below a deposit of ca. 50-60 ka EI Cajete pumice. This represents the second oldest dated Bison in New Mexico, and one of the few occurrences of this genus in the northern mountains of the state. It is also only the second record of a Pleistocene vertebrate from Los Alamos County, and is a rare occurrence of a pre-25 ka Bison fossil in good stratigraphic context. Hillslopes in the study area are underlain by a sequence of truncated Pleistocene and Holocene soils that are inferred to represent colluvial deposition and soil formation followed by erosion in the mid Pleistocene (buried soil 'b3'), the late Pleistocene (buried soil 'b2'), and the mid-to-late Holocene (buried soil 'b1'). The surface soil is developed in depOSits that overlie 600-800 year-old Ancestral Puebloan sites. Colluvium is dominated by relatively fine-grained (fine to very fine sand) slopewash colluvium deposited by overland flow, but also includes rocky colluvium on hillslopes below mesas. The fine-grained colluvium is likely derived mainly from reworking of eolian deposits. Episodic colluvial deposition appears to, at least in part, accompany and follow episodic eolian events, with intervening periods dominated by erosion and the development of truncated soils.

  15. 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.

  16. Heat and Groundwater Flow through Continental Flood Basalt Provinces: Insights Gained from Alternative Models of Permeability/Depth Relationships for the Columbia Plateau, USA

    NASA Astrophysics Data System (ADS)

    Burns, E. R.; Williams, C. F.; Ingebritsen, S.; Voss, C. I.; Spane, F.; DeAngelo, J.

    2014-12-01

    Heat-flow mapping of the western USA has identified an apparent low-heat-flow anomaly coincident with the Columbia Plateau Regional Aquifer System, a thick sequence of basalt aquifers within the Columbia River Basalt Group (CRBG). A heat and mass transport model (SUTRA) was used to evaluate the potential impact of groundwater flow on heat flow along two different regional groundwater flow paths. Limited in situ permeability (k) data from the CRBG are compatible with a steep permeability decrease (~3.5 orders of magnitude) at 600-900 m depth and ~40oC. Numerical simulations incorporating this permeability decrease demonstrate that regional groundwater flow can explain lower-than-expected heat flow in these highly anisotropic (kx/kz ~104) continental flood basalts. Simulation results indicate that the abrupt reduction in permeability at ~600 m depth results in an equivalently abrupt transition from a shallow region where heat flow is affected by groundwater flow to a deeper region of conduction-dominated heat flow. Abrupt k decreases at similar temperatures have also been observed in the volcanic rocks of the adjacent Cascade Range volcanic arc and at Kilauea Volcano, Hawaii, where they result from low-temperature hydrothermal alteration. Because pore filling hydrothermal minerals are largely controlled by the major mineral assemblages of the volcanic rocks, other continental flood basalt provinces may also have large permeability changes at depths corresponding to ~40oC.

  17. Seasonal variability of oxygen and hydrogen isotopes in a wetland system of the Yunnan-Guizhou Plateau, southwest China: a quantitative assessment of groundwater inflow fluxes

    NASA Astrophysics Data System (ADS)

    Cao, Xingxing; Wu, Pan; Zhou, Shaoqi; Han, Zhiwei; Tu, Han; Zhang, Shui

    2017-07-01

    The Caohai Wetland serves as an important ecosystem on the Yunnan-Guizhou Plateau and as a nationally important nature reserve for migratory birds in China. In this study, surface water, groundwater and wetland water were collected for the measurement of environmental isotopes to reveal the seasonal variability of oxygen and hydrogen isotopes (δ18O, δD), sources of water, and groundwater inflow fluxes. Results showed that surface water and groundwater are of meteoric origin. The isotopes in samples of wetland water were well mixed vertically in seasons of both high-flow (September) and low-flow (April); however, marked seasonal and spatial variations were observed. During the high-flow season, the isotopic composition in surface wetland water varied from -97.13 to -41.73‰ for δD and from -13.17 to -4.70‰ for δ18O. The composition of stable isotopes in the eastern region of this wetland was lower than in the western region. These may have been influenced by uneven evaporation caused by the distribution of aquatic vegetation. During the low-flow season, δD and δ18O in the more open water with dead aquatic vegetation ranged from -37.11 to -11.77‰, and from -4.25 to -0.08‰, respectively. This may result from high evaporation rates in this season with the lowest atmospheric humidity. Groundwater fluxes were calculated by mass transfer and isotope mass balance approaches, suggesting that the water sources of the Caohai Wetland were mainly from groundwater in the high-flow season, while the groundwater has a smaller contribution to wetland water during the low-flow season.

  18. Groundwater quality in the Columbia Plateau, Snake River Plain, and Oahu basaltic-rock and basin-fill aquifers in the Northwestern United States and Hawaii, 1992-2010

    USGS Publications Warehouse

    Frans, Lonna M.; Rupert, Michael G.; Hunt, Charles D.; Skinner, Kenneth D.

    2012-01-01

    Oahu and the Columbia Plateau had some of the highest percentages of soil fumigant detections in groundwater in the United States. Soil fumigants are volatile organic compounds (VOCs) used as pesticides, which are applied to soils to reduce populations of plant parasitic nematodes (harmful rootworms), weeds, fungal pathogens, and other soil-borne microorganisms. They are used in Oahu and the Columbia Plateau on crops such as pineapple and potatoes. All three areas (Columbia Plateau, Snake River Plain, and Oahu) had fumigant concentrations exceeding human-health benchmarks for drinking water.

  19. The quality of our Nation's waters: groundwater quality in the Columbia Plateau and Snake River Plain basin-fill and basaltic-rock aquifers and the Hawaiian volcanic-rock aquifers, Washington, Idaho, and Hawaii, 1993-2005

    USGS Publications Warehouse

    Rupert, Michael G.; Hunt, Charles D.; Skinner, Kenneth D.; Frans, Lonna M.; Mahler, Barbara J.

    2015-01-01

    The Columbia Plateau, Snake River Plain, and Hawaii are large volcanic areas in the western United States and mid-Pacific ocean that contain extensive regional aquifers of a hard, gray, volcanic rock called basalt. Residents of the Columbia Plateau, the Snake River Plain, and the island of Oahu depend on groundwater as their primary source of drinking water. Although the depth to the water table can be several hundred feet, the groundwater is highly vulnerable to contamination because the permeable sediments and rocks allow contaminants to move readily down to the water table. Intense agricultural and urban activities occur above the drinking-water supply and are increasing in some areas. Contaminants, such as nitrate, pesticides, and volatile organic compounds, associated with agricultural and urban activities, have adversely affected groundwater quality.

  20. Groundwater

    USGS Publications Warehouse

    Stonestrom, David A.; Wohl, Ellen E.

    2016-01-01

    Groundwater represents the terrestrial subsurface component of the hydrologic cycle. As such, groundwater is generally in motion, moving from elevated areas of recharge to lower areas of discharge. Groundwater usually moves in accordance with Darcy’s law (Dalmont, Paris: Les Fontaines Publiques de la Ville de Dijon, 1856). Groundwater residence times can be under a day in small upland catchments to over a million years in subcontinental-sized desert basins. The broadest definition of groundwater includes water in the unsaturated zone, considered briefly here. Water chemically bound to minerals, as in gypsum (CaSO4 • 2H2O) or hydrated clays, cannot flow in response to gradients in total hydraulic head (pressure head plus elevation head); such water is thus usually excluded from consideration as groundwater. In 1940, M. King Hubbert showed Darcy’s law to be a special case of thermodynamically based potential field equations governing fluid motion, thereby establishing groundwater hydraulics as a rigorous engineering science (Journal of Geology 48, pp. 785–944). The development of computer-enabled numerical methods for solving the field equations with real-world approximating geometries and boundary conditions in the mid-1960s ushered in the era of digital groundwater modeling. An estimated 30 percent of global fresh water is groundwater, compared to 0.3 percent that is surface water, 0.04 percent atmospheric water, and 70 percent that exists as ice, including permafrost (Shiklomanov and Rodda 2004, cited under Groundwater Occurrence). Groundwater thus constitutes the vast majority—over 98 percent—of the unfrozen fresh-water resources of the planet, excluding surface-water reservoirs. Environmental dimensions of groundwater are equally large, receiving attention on multiple disciplinary fronts. Riparian, streambed, and spring-pool habitats can be sensitively dependent on the amount and quality of groundwater inputs that modulate temperature and solutes

  1. Groundwater Quality in the Shallow Aquifers of the Hadauti Plateau of the District of Baran, Rajasthan, India

    NASA Astrophysics Data System (ADS)

    Kumar, Lokesh; Rakshit, Amitava

    2014-07-01

    With the rapid pace of agricultural development, industrialization and urbanization, the commonly observed geogenic contaminants in groundwater are fluoride and nitrate, whereas nitrate is the dominant anthropogenic contaminant in the south-eastern plains of Rajasthan, India. Samples obtained using a tube well and hand pump in November, 2012, demonstrate that Na-Cl is the dominant salt in the groundwater, and the total salinity of the water is between 211-1056 mg L-1. Moreover, the observed sodium adsorption ratio (SAR) and residual sodium carbonate (RSC) values ranged between 0.87 to 26.22 meq L-1 and -12.5 to 30.5 meq L-1 respectively. The study further shows that 6% of the total samples contain high amounts of nitrate, and 49% contain fluoride. A water quality index (WQI) rating was carried out using nine parameters to quantify the overall groundwater quality status of the area.

  2. The Vapor Plume at Material Disposal Are C in Relation to Pajarito Corridor Facilities

    SciTech Connect

    Masse, William B.

    2012-04-02

    A vapor plume made up of volatile organic compounds is present beneath Material Disposal Area C (MDA C) at Los Alamos National Laboratory (LANL). The location and concentrations within the vapor plume are discussed in relation to existing and planned facilities and construction activities along Pajarito Road (the 'Pajarito Corridor') and in terms of worker health and safety. This document provides information that indicates that the vapor plume does not pose a threat to the health of LANL workers nor will it pose a threat to workers during construction of proposed facilities along Pajarito Road. The Los Alamos National Laboratory (LANL or the Laboratory) monitors emissions, effluents, and environmental media to meet environmental compliance requirements, determine actions to protect the environment, and monitor the long-term health of the local environment. LANL also studies and characterizes 'legacy' waste from past Laboratory operations to make informed decisions regarding eventual corrective actions and the disposition of that waste. Starting in 1969, these activities have been annually reported in the LANL Environmental Report (formerly Environmental Surveillance Report), and are detailed in publicly accessible technical reports meeting environmental compliance requirements. Included among the legacy sites being investigated are several formerly used material disposal areas (MDAs) set aside by the Laboratory for the general on-site disposal of waste from mission-related activities. One such area is MDA C located in Technical Area 50 (TA-50), which was used for waste disposal between 1948 and 1974. The location of TA-50 is depicted in Figure 1. The present paper uses a series of maps and cross sections to address the public concerns raised about the vapor plume at MDA C. As illustrated here, extensive sampling and data interpretation indicate that the vapor plume at MDA C does not pose a threat to the health of LANL workers nor will it pose a threat to workers

  3. Computed solid phases limiting the concentration of dissolved constituents in basalt aquifers of the Columbia Plateau in eastern Washington. Geochemical modeling and nuclide/rock/groundwater interaction studies

    SciTech Connect

    Deutsch, W.J.; Jenne, E.A.; Krupka, K.M.

    1982-08-01

    A speciation-solubility geochemical model, WATEQ2, was used to analyze geographically-diverse, ground-water samples from the aquifers of the Columbia Plateau basalts in eastern Washington. The ground-water samples compute to be at equilibrium with calcite, which provides both a solubility control for dissolved calcium and a pH buffer. Amorphic ferric hydroxide, Fe(OH)/sub 3/(A), is at saturation or modestly oversaturated in the few water samples with measured redox potentials. Most of the ground-water samples compute to be at equilibrium with amorphic silica (glass) and wairakite, a zeolite, and are saturated to oversaturated with respect to allophane, an amorphic aluminosilicate. The water samples are saturated to undersaturated with halloysite, a clay, and are variably oversaturated with regard to other secondary clay minerals. Equilibrium between the ground water and amorphic silica presumably results from the dissolution of the glassy matrix of the basalt. The oversaturation of the clay minerals other than halloysite indicates that their rate of formation lags the dissolution rate of the basaltic glass. The modeling results indicate that metastable amorphic solids limit the concentration of dissolved silicon and suggest the same possibility for aluminum and iron, and that the processes of dissolution of basaltic glass and formation of metastable secondary minerals are continuing even though the basalts are of Miocene age. The computed solubility relations are found to agree with the known assemblages of alteration minerals in the basalt fractures and vesicles. Because the chemical reactivity of the bedrock will influence the transport of solutes in ground water, the observed solubility equilibria are important factors with regard to chemical-retention processes associated with the possible migration of nuclear waste stored in the earth's crust.

  4. Ground-Water Data for the Suck Creek Area of Walden Ridge, Southern Cumberland Plateau, Marion County, Tennessee

    DTIC Science & Technology

    1994-01-01

    Water level, well Ma:N-026 - w Water level, well Ma:N-027 60 gallons per minute Pumping rate: 60 gallons per minute 0 500 1000 1300 PERIOD OF...I0 s n ’ ” m ’ * 1 “‘I - 1 s ‘I A-A Water level, well Ma:N-026 Pumping rate: 105 gallons per minute w Water level, Ma:N-O27 PERIOD OF PUMPING, IN... Carboniferous depositional environments in the Cumberland Plateau of southern Tennessee and northern Alabama: Tennessee Division Geology Report of

  5. [Groundwater].

    PubMed

    González De Posada, Francisco

    2012-01-01

    From the perspective of Hydrogeology, the concept and an introductory general typology of groundwater are established. From the perspective of Geotechnical Engineering works, the physical and mathematical equations of the hydraulics of permeable materials, which are implemented, by electric analogical simulation, to two unique cases of global importance, are considered: the bailing during the construction of the dry dock of the "new shipyard of the Bahia de Cádiz" and the waterproofing of the "Hatillo dam" in the Dominican Republic. From a physical fundamental perspective, the theories which are the subset of "analogical physical theories of Fourier type transport" are related, among which the one constituted by the laws of Adolf Fick in physiology occupies a historic role of some relevance. And finally, as a philosophical abstraction of so much useful mathematical process, the one which is called "the Galilean principle of the mathematical design of the Nature" is dealt with.

  6. Proposed Four Corners-Ambrosia-Pajarito 500 kV transmission project. Draft environmental statement

    SciTech Connect

    Not Available

    1980-01-01

    The Public Service Company of New Mexico proposes to construct and operate a 500 kV alternating current (ac) transmission line in the northwestern portion of New Mexico. The proposed line will extend from the Four Corners Power Plant to Ambrosia Station to a proposed Pajarito Station west of Albuquerque, NM. The proposed line will be approximately 173 miles in length. Construction of the 500 kV transmission line will adversely impact soils, vegetation, visual resources, and possibly in an indirect manner, the cultural resources in the area. These adverse impacts may be made minimal by the practice of erosion protection measures, revegetation, and a sound cultural resource management plan. There will be no appreciable impacts, adverse or otherwise in regard to surface or subsurface water by the construction or operation of the proposed transmission line. No adverse effects may be anticipated in regard to communities or social services. Economic impacts in the area will be short-term and should prove beneficial for the duration of the project. Construction and operation of this line will be beneficial in providing needed additional bulk transmission capacity between the Four Corners Plant and Albuquerque and bulk transmission support to the local western New Mexico area.

  7. Proposed Four Corners-Ambrosia-Pajarito 500 kV transmission project. Final environmental statement

    SciTech Connect

    Not Available

    1980-01-01

    The Public Service Company of New Mexico proposes to construct and operate a 500 kV alternating current (AC) transmission line in the northwestern portion of New Mexico. The proposed line will extend from the Four Corners Power Plant to Ambrosia Station to a proposed Pajarito Station west of Albuquerque, NM. The proposed line will be approximately 173 miles in length. Construction of the 500 kV transmission line will adversely impact soils, vegetation, visual resources, and possibly in an indirect manner, the cultural resources in the area. The adverse impacts may be made minimal by the practice of erosion protection measures, revegetation, and a sound cultural resource management plan. There will be no appreciable impacts, adverse or otherwise in regard to surface or subsurface water by the construction or operation of the proposed transmission line. No adverse effects may be anticipated in regard to communities or social services. Economic impacts in the area will be short-term and should prove beneficial for the duration of the project. Construction and operation of this line will be beneficial in providing needed additional bulk transmission capacity between the Four Corners Plant and Albuquerque and bulk transmission support to the local western New Mexico area.

  8. CENTRAL PLATEAU REMEDIATION

    SciTech Connect

    ROMINE, L.D.

    2006-02-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress.

  9. Paleoseismologic studies of the Pajarito fault system, western margin of the Rio Grande rift near Los Alamos, NM

    SciTech Connect

    Kelson, K.I. ); Hemphill-Haley, M.A.; Wong, I.G. ); Gardner, J.N.; Reneau, S.L. )

    1993-04-01

    As in much of the Basin and Range province, low levels of historical seismicity in the Rio Grande rift (RGR) are inconsistent with abundant geologic evidence for large-magnitude, late Pleistocene and Holocene earthquakes. Recent trenching and surficial mapping along the 40-km-long, north-trending Pajarito fault system (PFS) near Los Alamos provide evidence for multiple surface-rupture events during the late Pleistocene and Holocene. Near Los Alamos, the Pajarito fault (PAF) exhibits an east-facing scarp up to 120 m high that has had at least four surface-rupture events in the past few hundred thousand years. Four trenches across the base of the highest, easternmost fault scarp show that the most-recent rupture occurred prior to about 9 ka, and possible prior to deposition of the 100- to 150-ka El Cajete Pumice. The long-term (post-1.1 Ma) slip rate on the PAF is about 0.1 mm/yr. The down-to-the-west Rendija Canyon (RCF) and Guaje Mountain (GMF) faults both have had at least two surface ruptures since the middle Pleistocene, including most-recent events at about 7.4 ka along the RCF and about 4 to 6 ka along the GMF. Slickensides and other indirect evidence suggest right-oblique normal slip on the RCF and GMF. Long-term (post-1.1 Ma) slip rates on these two faults are approximately an order of magnitude less than that on the PAF. Based on the observed spatial and temporal variations in activity, the subparallel PAF, RCF, and GMF apparently act as independent seismic sources, although they are located only about 1 to 3 km apart. Nevertheless, the average recurrence interval for faults within the PFS is probably comparable to intervals of 10[sup 4] yr estimated along the eastern rift margin near Taos.

  10. Estimating Groundwater Concentrations from Mass Releases to the Aquifer at Integrated Disposal Facility and Tank Farm Locations Within the Central Plateau of the Hanford Site

    SciTech Connect

    Bergeron, Marcel P.; Freeman, Eugene J.

    2005-06-09

    This report summarizes groundwater-related numerical calculations that will support groundwater flow and transport analyses associated with the scheduled 2005 performance assessment of the Integrated Disposal Facility (IDF) at the Hanford Site. The report also provides potential supporting information to other ongoing Hanford Site risk analyses associated with the closure of single-shell tank farms and related actions. The IDF 2005 performance assessment analysis is using well intercept factors (WIFs), as outlined in the 2001 performance assessment of the IDF. The flow and transport analyses applied to these calculations use both a site-wide regional-scale model and a local-scale model of the area near the IDF. The regional-scale model is used to evaluate flow conditions, groundwater transport, and impacts from the IDF in the central part of the Hanford Site, at the core zone boundary around the 200 East and 200 West Areas, and along the Columbia River. The local-scale model is used to evaluate impacts from transport of contaminants to a hypothetical well 100 m downgradient from the IDF boundaries. Analyses similar to the regional-scale analysis of IDF releases are also provided at individual tank farm areas as additional information. To gain insight on how the WIF approach compares with other approaches for estimating groundwater concentrations from mass releases to the unconfined aquifer, groundwater concentrations were estimated with the WIF approach for two hypothetical release scenarios and compared with similar results using a calculational approach (the convolution approach). One release scenario evaluated with both approaches (WIF and convolution) involved a long-term source release from immobilized low-activity waste glass containing 25,550 Ci of technetium-99 near the IDF; another involved a hypothetical shorter-term release of {approx}0.7 Ci of technetium over 600 years from the S-SX tank farm area. In addition, direct simulation results for both release

  11. Hydrology of precipitation and groundwater in a plateau area, southward South Carpathians, Mehedinti district, Romania, identified from isotope and climate monitoring

    NASA Astrophysics Data System (ADS)

    Bojar, Ana-Voica; Halas, Stanislaw

    2014-05-01

    The investigated region of around 100 square km and is situated on a plateau between 270 and 350 m elevation, between the South Carpathians to the north and Danube to the south. The area is represented by a plateau crossed from north-west to south-east by dry valleys, which cut in the sandy and clayely deposits of Pliocene age. In the region, the primary sources of drinking and irrigation waters are related to natural springs or wells. Through the valleys, water is flowing only temporarily after strong storms or during rainy periods. Between July to September, due the hot summer continental climate, population and crops suffer of water shortage. The objectives of this study are: 1) to determine the Local Meteoric Water Line (LMWL) for the plateau area by measuring the isotopic composition of precipitation in the region; 2) to determine the position of various aquifers in the region; 3) to measure the isotopic composition of spring waters and compare it to precipitation waters, in order to evaluate the source of water. The data set consists of monthly monitoring of rain isotopic composition (for 2012 to 2013), locating the regional distribution of springs and their isotopic composition and measuring daily variations of air temperature and humidity. Water samples were analysed for hydrogen and oxygen isotopic composition at the centre of Environmental Research, Lublin, Poland. The hydrogen and oxygen isotopic composition of precipitation range from -119 to -23 permil and -14 to -4 permil, respectively. Regression of the data resulted in a meteoric water line which is highly significant (r square = 0.98). The monthly isotopic composition indicates temperature-dependent seasonality. The more negative values occur in the winter to early spring (November-April) and more positive values occur in the late spring to early fall (May-October). The deuterium excess (d-excess) value of precipitation range between 16.3 to 5.7 permil, with an amount weighted mean value of 10

  12. Status and understanding of groundwater quality in the Cascade Range and Modoc Plateau study unit, 2010: California GAMA Priority Basin Project

    USGS Publications Warehouse

    Fram, Miranda S.; Shelton, Jennifer L.

    2015-01-01

    Organic constituents were not detected at high or moderate RCs, and the occurrence of low organic constituents at low RCs ranged from 27 percent to 73 percent of the primary aquifers system in the six study areas. The Shasta Valley and Mount Shasta Volcanic study area had significantly greater occurrence of low RCs of herbicides compared to all of the other study areas, which could reflect the greater prevalence of modern groundwater in the Shasta Valley and Mount Shasta Volcanic study area and the presence of potential sources of herbicides, including applications to timberlands and roadside rights-of-way. The Eastside Sacramento Valley study area had the greatest occurrence of low concentrations of chloroform, and chloroform occurrence was most strongly associated with the combination of septic-tank density greater than two tanks per square kilometer and urban land use greater than 10 percent within a radius of 500 meters of the well. These conditions were most prevalent in the Eastside Sacramento Valley study area. The detection frequency of low concentrations of perchlorate was consistent with the probability of occurrence expected under natural conditions, except in the Eastside Sacramento Valley study area, where detection frequencies were much higher than expected and could not be explained by known anthropogenic sources of perchlorate.

  13. Cluster growth modeling of plateau erosion

    NASA Technical Reports Server (NTRS)

    Stark, Colin P.

    1994-01-01

    The pattern of erosion of a plateau along an escarpment may be modeled usng cluster growth techniques, recently popularized in models of drainage network evolution. If erosion on the scarp takes place in discrete events at rates subject to local substrate strength, the whole range of behavior is described by a combination of three cluster growth mechanisms: invasion percolation, Eden growth and diffusion-limited aggregation (DLA). These model the relative importance of preexisting substrate strength, background weathering, and seepage weathering and erosion respectively. The rate of seepage processes is determined by the efflux of groundwater at the plateau margin, which in turn is determined by the pressure field in the plateau aquifer. If this process acted alone, it would produce erosion patterns in the form of Laplacian fractals, with groundwater recharge from a distant source, or Poissionian fractals, with groundwater recharge uniform over the plateau. DLA is used to mimic the Laplacian or Poissonian potential field and the corresponding seepage growth process. The scaling structure of clusters grown by pure DLA, invasion percolation, or Eden growth is well known; this study presents a model which combines all three growth mechanisms for the first time. Mixed growth processes create clusters with different scaling properties and morphologies over distinct length scale ranges, and this is demonstrable in natural examples of plateau erosion.

  14. Hydrogeology of the Markagunt Plateau, Southwestern Utah

    USGS Publications Warehouse

    Spangler, Lawrence E.

    2010-01-01

    The Markagunt Plateau, in southwestern Utah, lies at an altitude of about 9,500 feet and is capped primarily by Quaternary-age basalt that overlies Eocene-age freshwater limestone of the Claron Formation. Over large parts of the Markagunt Plateau, dissolution of the Claron limestone and subsequent collapse of the overlying basalt have produced a terrain characterized by sinkholes as much as 1,000 feet across and 100 feet deep. Numerous large springs discharge from the basalt and underlying limestone on the plateau, including Mammoth Spring, one of the largest springs in Utah, with a discharge that can exceed 300 cubic feet per second. Discharge from Mammoth Spring is from the Claron Formation; however, recharge to the spring largely takes place by both focused and diffuse infiltration through the basalt that caps the limestone. Results of dye tracing to Mammoth Spring indicate that recharge originates largely southwest of the spring outside of the Mammoth Creek watershed, as well as from losing reaches along Mammoth Creek. Maximum groundwater travel time to the spring from dye-tracer tests during the snowmelt runoff period was about 1 week. Specific conductance and water temperature data from the spring show an inverse relation to discharge during snowmelt runoff and rainfall events, also indicating short groundwater residence times. Results of major-ion analyses for samples collected from Mammoth and other springs on the plateau indicate calcium-bicarbonate type water containing low (less than 200 mg/L) dissolved-solids concentrations. Investigations in the Navajo Lake area along the southern margin of the plateau have shown that water losing to sinkholes bifurcates and discharges to both Cascade and Duck Creek Springs, which subsequently flow into the Virgin and Sevier River basins, respectively. Groundwater travel times to these springs, on the basis of dye tracing, were about 8.5 and 53 hours, respectively. Similarly, groundwater travel time from Duck Creek

  15. Central Plateau Cleanup at DOE's Hanford Site - 12504

    SciTech Connect

    Dowell, Jonathan

    2012-07-01

    The discussion of Hanford's Central Plateau includes significant work in and around the center of the Hanford Site - located about 7 miles from the Columbia River. The Central Plateau is the area to which operations will be shrunk in 2015 when River Corridor cleanup is complete. This work includes retrieval and disposal of buried waste from miles of trenches; the cleanup and closure of massive processing canyons; the clean-out and demolition to 'slab on grade' of the high-hazard Plutonium Finishing Plant; installation of key groundwater treatment facilities to contain and shrink plumes of contaminated groundwater; demolition of all other unneeded facilities; and the completion of decisions about remaining Central Plateau waste sites. A stated goal of EM has been to shrink the footprint of active cleanup to less than 10 square miles by 2020. By the end of FY2011, Hanford will have reduced the active footprint of cleanup by 64 percent exceeding the goal of 49 percent. By 2015, Hanford will reduce the active footprint of cleanup by more than 90 percent. The remaining footprint reduction will occur between 2015 and 2020. The Central Plateau is a 75-square-mile region near the center of the Hanford Site including the area designated in the Hanford Comprehensive Land Use Plan Environmental Impact Statement (DOE 1999) and Record of Decision (64 FR 61615) as the Industrial-Exclusive Area, a rectangular area of about 20 square miles in the center of the Central Plateau. The Industrial-Exclusive Area contains the 200 East and 200 West Areas that have been used primarily for Hanford's nuclear fuel processing and waste management and disposal activities. The Central Plateau also encompasses the 200 Area CERCLA National Priorities List site. The Central Plateau has a large physical inventory of chemical processing and support facilities, tank systems, liquid and solid waste disposal and storage facilities, utility systems, administrative facilities, and groundwater monitoring

  16. Comparison of Two Surface Contamination Sampling Techniques Conducted for the Characterization of Two Pajarito Site Manhattan Project National Historic Park Properties

    SciTech Connect

    Lopez, Tammy Ann

    2016-07-29

    Technical Area-18 (TA-18), also known as Pajarito Site, is located on Los Alamos National Laboratory property and has historic buildings that will be included in the Manhattan Project National Historic Park. Characterization studies of metal contamination were needed in two of the four buildings that are on the historic registry in this area, a “battleship” bunker building (TA-18-0002) and the Pond cabin (TA-18-0029). However, these two buildings have been exposed to the elements, are decades old, and have porous and rough surfaces (wood and concrete). Due to these conditions, it was questioned whether standard wipe sampling would be adequate to detect surface dust metal contamination in these buildings. Thus, micro-vacuum and surface wet wipe sampling techniques were performed side-by-side at both buildings and results were compared statistically. A two-tail paired t-test revealed that the micro-vacuum and wet wipe techniques were statistically different for both buildings. Further mathematical analysis revealed that the wet wipe technique picked up more metals from the surface than the microvacuum technique. Wet wipes revealed concentrations of beryllium and lead above internal housekeeping limits; however, using an yttrium normalization method with linear regression analysis between beryllium and yttrium revealed a correlation indicating that the beryllium levels were likely due to background and not operational contamination. PPE and administrative controls were implemented for National Park Service (NPS) and Department of Energy (DOE) tours as a result of this study. Overall, this study indicates that the micro-vacuum technique may not be an efficient technique to sample for metal dust contamination.

  17. Radiative plateau inflation

    NASA Astrophysics Data System (ADS)

    Ballesteros, Guillermo; Tamarit, Carlos

    2016-02-01

    We describe how monomial chaotic inflation becomes compatible with the latest CMB data thanks to radiative corrections producing a plateau. The interactions of the inflaton with other fields, required for reheating, can flatten the potential and moderate the production of primordial gravitational waves, keeping these below the current upper bound. We show that the appearance of a plateau requires that the inflaton couples to fermions and to another scalar or a gauge group. We give concrete examples of minimal particle physics models leading to plateaus for quadratic and quartic chaotic inflation. We also provide a three-parameter model-independent description of radiatively corrected inflation that is amenable to CMB analyses.

  18. Snowmelt hydrograph interpretation: Revealing watershed scale hydrologic characteristics of the Yellowstone volcanic plateau

    NASA Astrophysics Data System (ADS)

    Payton Gardner, W.; Susong, David D.; Kip Solomon, D.; Heasler, Henry

    2010-03-01

    SummarySnowmelt hydrograph analysis and groundwater age dates of cool water springs on the Yellowstone volcanic plateau provide evidence of high volumes of groundwater circulation in watersheds comprised of quaternary Yellowstone volcanics. Ratios of maximum to minimum mean daily discharge and average recession indices are calculated for watersheds within and surrounding the Yellowstone volcanic plateau. A model for snowmelt recession is used to separate groundwater discharge from overland runoff, and compare groundwater systems. Hydrograph signal interpretation is corroborated with chlorofluorocarbon (CFC) and tritium concentrations in cool water springs on the Yellowstone volcanic plateau. Hydrograph parameters show a spatial pattern correlated with watershed geology. Watersheds comprised dominantly of quaternary Yellowstone volcanics are characterized by slow streamflow recession, low maximum to minimum flow ratios. Cool springs sampled within the Park contain CFC's and tritium and have apparent CFC age dates that range from about 50 years to modern. Watersheds comprised of quaternary Yellowstone volcanics have a large volume of active groundwater circulation. A large, advecting groundwater field would be the dominant mechanism for mass and energy transport in the shallow crust of the Yellowstone volcanic plateau, and thus control the Yellowstone hydrothermal system.

  19. Snowmelt hydrograph interpretation: Revealing watershed scale hydrologic characteristics of the Yellowstone volcanic plateau

    USGS Publications Warehouse

    Payton, Gardner W.; Susong, D.D.; Kip, Solomon D.; Heasler, H.

    2010-01-01

    Snowmelt hydrograph analysis and groundwater age dates of cool water springs on the Yellowstone volcanic plateau provide evidence of high volumes of groundwater circulation in watersheds comprised of quaternary Yellowstone volcanics. Ratios of maximum to minimum mean daily discharge and average recession indices are calculated for watersheds within and surrounding the Yellowstone volcanic plateau. A model for snowmelt recession is used to separate groundwater discharge from overland runoff, and compare groundwater systems. Hydrograph signal interpretation is corroborated with chlorofluorocarbon (CFC) and tritium concentrations in cool water springs on the Yellowstone volcanic plateau. Hydrograph parameters show a spatial pattern correlated with watershed geology. Watersheds comprised dominantly of quaternary Yellowstone volcanics are characterized by slow streamflow recession, low maximum to minimum flow ratios. Cool springs sampled within the Park contain CFC's and tritium and have apparent CFC age dates that range from about 50 years to modern. Watersheds comprised of quaternary Yellowstone volcanics have a large volume of active groundwater circulation. A large, advecting groundwater field would be the dominant mechanism for mass and energy transport in the shallow crust of the Yellowstone volcanic plateau, and thus control the Yellowstone hydrothermal system. ?? 2009 Elsevier B.V.

  20. Rapid loss of lakes on the Mongolian Plateau.

    PubMed

    Tao, Shengli; Fang, Jingyun; Zhao, Xia; Zhao, Shuqing; Shen, Haihua; Hu, Huifeng; Tang, Zhiyao; Wang, Zhiheng; Guo, Qinghua

    2015-02-17

    Lakes are widely distributed on the Mongolian Plateau and, as critical water sources, have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all of the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multitemporal Landsat images from the 1970s to 2000s, combined with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km(2) decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km(2) has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, and in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration.

  1. Rapid Loss of Lakes on the Mongolian Plateau

    NASA Astrophysics Data System (ADS)

    Tao, S.; Fang, J.; Zhao, X.; Zhao, S.; Shen, H.; Hu, H.; Tang, Z.; Wang, Z.; Guo, Q.

    2015-12-01

    Lakes are widely distributed on the Mongolian Plateau and as critical water sources have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multi-temporal Landsat images from the 1970s to 2000s, combining with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km2 decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km2 has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, while in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration.

  2. Groundwater quality

    SciTech Connect

    Ward, C.H.; Giger, W.; McCarty, P.L.

    1985-01-01

    This book is a collection of 28 selected papers presented at the First International Conference on Groundwater Quality Research, at Rice University in October 1981. Several studies provide an overview of chemical and microbial contamination. Local groundwater pollution problems in the Netherlands and metals motility in New Zealand are described. In addition, the effects to groundwater quality due to the discharge of treated wastewaters in the Netherlands, Great Britain, and Houston, Texas are described. Mathematical models are presented that can be used to simulate and predict the transport of contaminants in a saturated groundwater system. Studies describing the sorption of halogenated hydrocarbons, the survival and transport of pathogenic bacteria, the biodegradation of contaminants, and anaerobic transformation in subsurface environments are included. Other topics of discussion include methods for obtaining representative groundwater samples, methods for assessing groundwater problems, methods for designing and constructing microcosms and the microbial characterization of subsurface systems.

  3. Episodic karstification, Edwards Plateau, central Texas

    SciTech Connect

    Kastning, E.H.

    1985-01-01

    The Edwards Plateau and Llano Basin of central Texas form one of the largest contiguous regions of karst in North America (>80,000 km/sup 2/). Solutional phenomena show that several major episodes of karstification are documentable from late Cambrian to Holocene. Relict landforms representing intervals of solutional activity correlate well with the accepted geomorphic chronology for central Texas. Secondary porosity are vertically controlled by lithology, topographic incision of streams, position of the potentiometric surface, and attitude of bedding. Areally, development of karst is strongly influenced by the extent, density, and orientation of fractures and by hydrodynamic characteristics such as points of recharge and discharge, degree of integration of groundwater flow paths, and hydraulic gradients. Early episodes of karstification correspond to intervals of subaerial exposure of carbonate rocks during marine regression or following regional uplift. Paleokarst is prevalent in the Paleozoic and Mesozoic sequences. Infilled dolines and solution-collapse breccias have been exhumed by extensive regional denudation during the Cenozoic Era. Subaerial conditions during the middle Cretaceous account for infilled solutional cavities within lower Cretaceous carbonate beds. The most extensive karstification began with regional uplift in the early Miocene. Enhanced relief along the Balcones escarpment promoted incision of streams, lowering of water tables, steepened hydraulic gradients, and increases in discharge. Caves at various-elevations attest to sequential dissection of the plateau during the late Quaternary.

  4. Groundwater Science

    NASA Astrophysics Data System (ADS)

    McKenna, Sean A.

    A good introductory groundwater textbook must strike a delicate balance in presenting the basics of the physical, chemical, geological, mathematical, and engineering aspects of the groundwater field without being too lengthy or overly detailed. Charles Fitts states that his motivation for writing Groundwater Science was to be able to “…teach concepts and quantitative analyses with a clear, lean, but thorough book.” He has succeeded in striking this balance of having just the right amount of information, and has met his goals of producing a concise book that can be used to teach the concepts and analyses necessary for the study of groundwater.Overall, Groundwater Science would serve well as the text for an introductory groundwater course at the college senior or first-year graduate level. The author and the publisher have made excellent use of two-color, gray and blue-scale images throughout the book. The graphics are crisp and explanatory. Data sets needed to work some of the problems in the book are available as text files from its Web site (http://www.academicpress.com/groundwater). I found these files to be complete and easy to understand. The references are up to date and point the reader to additional information across a wide range of groundwater issues, and also provide a number of examples to illustrate different points made in the book.

  5. Tibetan Plateau and beyond

    NASA Astrophysics Data System (ADS)

    Joswiak, Meri; Yao, Tandong; Joswiak, Daniel

    2012-03-01

    Third Annual Third Pole Environment Workshop; Reykjavík, Iceland, 29 August to 1 September 2011 Recognizing the necessity of multinational, interdisciplinary environmental research on the Tibetan Plateau and surrounding mountain ranges—dubbed the "Third Pole" for its considerable ice mass and high elevation— the Third Pole Environment (TPE) program accepted an invitation from the president of Iceland and the University of Iceland to hold its third annual TPE workshop in Iceland. In accordance with TPE's mission to evaluate climate and environmental changes at both local and global scales, participants from 15 countries converged for 3 days of intensive discussions and presentations related to TPE research. The Third Pole glaciers are undergoing considerable retreat, which will likely affect more than 1.5 billion people living in the region

  6. Data Package for Past and Current Groundwater Flow and Contamination beneath Single-Shell Tank Waste Management Areas

    SciTech Connect

    Horton, Duane G.

    2007-03-16

    This appendix summarizes historic and recent groundwater data collected from the uppermost aquifer beneath the 200 East and 200 West Areas. Although the area of interest is the Hanford Site Central Plateau, most of the information discussed in this appendix is at the scale of individual single-shell tank waste management areas. This is because the geologic, and thus the hydraulic, properties and the geochemical properties (i.e., groundwater composition) are different in different parts of the Central Plateau.

  7. Groundwater contamination

    SciTech Connect

    Haimes, Y. . Dept. of Systems Engineering)

    1986-01-01

    The subject of these conference proceedings is the groundwater contamination. It is by nature multifarious - dealing with detection and monitoring, prevention, abatement and containment, and correction and restoration of contaminated groundwater - it intrinsically encompasses myriad disciplines, and it involves all levels of government. Also, the subject of groundwater contamination is complex because decisions concerning groundwater pollution control that are scientifically sound, technologically within the state of the art, economically feasible, politically tractable, legally sustainable, socially acceptable, morally accountable, and organizationally implementable must be grounded on appropriate information and intelligence bases in their respective areas - science, technology, economics, politics, the law, society, ethics, and management. Indeed, the human health effects (e.g., cancer, damage to the central nervous system, liver and kidney damage) and non-health effects (economic hardship to industry, agriculture, households, and municipalities; environmental impacts; social impacts) necessitate that we, as a society, address in a somber way the following variations of the same question: How safe is safe enough How clean is safe enough The enormous cost - in billions of dollars over the next decade - that various studies project for the prevention, detection and monitoring, abatement and containment, and correction and restoration of groundwater contamination make an answer to these questions even more urgent. There are sixteen papers in these proceedings.

  8. Surface electromagnetic geophysical exploration of the ground-water resources of Isla de Mona, Puerto Rico, a caribbean carbonate island

    USGS Publications Warehouse

    Martinez, M.I.; Troester, Joseph W.; Richards, Ronald T.

    1995-01-01

    Ground-water flow in the coastal plain appears to be radial from the center of the freshwater mound. At the intersection between the coastal plain and the plateau, the flow is parallel to the coastline. The direction of flow on the rest of the plateau could not be determined accurately with the available data.

  9. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    SciTech Connect

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  10. Rapid loss of lakes on the Mongolian Plateau

    PubMed Central

    Tao, Shengli; Fang, Jingyun; Zhao, Xia; Zhao, Shuqing; Shen, Haihua; Hu, Huifeng; Tang, Zhiyao; Wang, Zhiheng; Guo, Qinghua

    2015-01-01

    Lakes are widely distributed on the Mongolian Plateau and, as critical water sources, have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all of the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multitemporal Landsat images from the 1970s to 2000s, combined with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km2 decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km2 has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, and in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration. PMID:25646423

  11. AUTOMATING GROUNDWATER SAMPLING AT HANFORD

    SciTech Connect

    CONNELL CW; HILDEBRAND RD; CONLEY SF; CUNNINGHAM DE

    2009-01-16

    Until this past October, Fluor Hanford managed Hanford's integrated groundwater program for the U.S. Department of Energy (DOE). With the new contract awards at the Site, however, the CH2M HILL Plateau Remediation Company (CHPRC) has assumed responsibility for the groundwater-monitoring programs at the 586-square-mile reservation in southeastern Washington State. These programs are regulated by the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). The purpose of monitoring is to track existing groundwater contamination from past practices, as well as other potential contamination that might originate from RCRA treatment, storage, and disposal (TSD) facilities. An integral part of the groundwater-monitoring program involves taking samples of the groundwater and measuring the water levels in wells scattered across the site. More than 1,200 wells are sampled each year. Historically, field personnel or 'samplers' have been issued pre-printed forms that have information about the well(s) for a particular sampling evolution. This information is taken from the Hanford Well Information System (HWIS) and the Hanford Environmental Information System (HEIS)--official electronic databases. The samplers used these hardcopy forms to document the groundwater samples and well water-levels. After recording the entries in the field, the samplers turned the forms in at the end of the day and the collected information was posted onto a spreadsheet that was then printed and included in a log book. The log book was then used to make manual entries of the new information into the software application(s) for the HEIS and HWIS databases. This is a pilot project for automating this tedious process by providing an electronic tool for automating water-level measurements and groundwater field-sampling activities. The automation will eliminate the manual forms and associated data entry, improve the accuracy of the

  12. Disruption of Groundwater System by Earthquakes

    NASA Astrophysics Data System (ADS)

    Wang, C. Y.; Liao, X.

    2015-12-01

    Earthquakes can enhance permeability of groundwater systems at great distances. Here we use the tidal response of the water level in a deep well (~4 km) in the near field of the 2008 Mw 7.9 Wenchuan earthquake, western China, to investigate how large earthquakes may disrupt groundwater systems in the near field. The well is located near the eastern margin of the Qinghai-Tibet plateau and 21 km from the ruptured fault of the Wenchuan earthquake, and is the only well we have found that is in the near field of a large earthquake and showed clear tidal signals before and after the earthquake. The well is open to a Triassic medium-grained sandstone aquifer confined by thick layers of shales on both sides. We show from tidal analysis of the water level in the well that large earthquakes can change not only the permeability but also the poroelastic properties of a groundwater system in an unexpected way. Using the lithologic well logs and experimental data for rock physical properties we interpret this change to reflect the breaching of aquitards of the groundwater system to depths of several km. Such disruption may connect previously isolated groundwater domains to impact groundwater supply, safety of underground waste repository, and hydrocarbon production. The method demonstrated here holds promise for monitoring the breaching of aquitards by hydraulic fracturing of shales during hydrocarbon production and deep injection of waste water.

  13. Groundwater resource development

    SciTech Connect

    Hamill, L.

    1986-01-01

    This book provides engineers with a treatment of the steps involved in the exploration and evaluation of aquifers, the construction and testing of water supply boreholes, and the management of the resource. The important subjects of water quality criteria, pollution hazards and modeling techniques are also included. Contents: Development of Groundwater Resources; Groundwater: Fundamentals; Groundwater Exploration; Assessment of Aquifer Recharge and Potential Well Yield; Groundwater Quality; Well Design and Construction; Aquifer Hydraulics and Pumping Tests; Groundwater Pollution; Groundwater Management; Groundwater Modeling Techniques.

  14. The Colorado Plateau: High, Wide, and Windswept.

    ERIC Educational Resources Information Center

    Booth, Bibi; Brook, Richard; Fischman, Shelly; Jacobson, LouAnn; Smith, Shelley; Tisdale, Mary

    1999-01-01

    Explores the natural forces that created the Colorado Plateau, examines a few of the myriad plants and animals inhabiting the six life zones on the plateau, and provides an overview of the challenges faced by land managers seeking to care for the plateau's extraordinary life and land forms. Contains 17 references. (WRM)

  15. Will Career Plateauing Become a Bigger Problem?

    ERIC Educational Resources Information Center

    Dawson, Christopher M.

    1983-01-01

    Though career plateauing can be put off, it can seldom be entirely avoided. Distinction is made between plateauing of the job content type and plateauing of the structural or organizational type. Primary solutions involve job enrichment, performance goal adjustments, lateral transfers, or modified standards of appraisal. (SSH)

  16. Indians of the Lower Plateau.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Washington, DC.

    The history of the Lower Plateau Indians--those in the states of Nevada, Utah, and Colorado--is traced and briefly described from early tribes to the modern day Indian. The environmental transition undergone by these peoples and their cultural change, more pronounced when the United States acquired the West, are discussed. Emphasis is placed on…

  17. Crustal structure, geophysical models and contemporary tectonism of the Colorado Plateau

    NASA Technical Reports Server (NTRS)

    Keller, G. R.; Braile, L. W.; Morgan, P.

    1979-01-01

    A regional analysis of the crust and upper mantle of the Colorado Plateau is presented, using existing geophysical and geological data combined with new surface wave dispersion and groundwater geothermometry data; the tectonic implications of these models are also investigated. Surface wave and seismic refraction data indicate that the crust of the interior of the Colorado Plateau is 44 + or - 3 km thick, and its crustal structure is typical of stable continental areas. Pn velocities, however, appear to be lower (7.8 km/s) than would be expected in a stable region, while silica geothermometry indicates that the average heat flow for the plateau is 55 mW per sq m (1.3 HFU).

  18. Crustal structure, geophysical models and contemporary tectonism of the Colorado Plateau

    NASA Technical Reports Server (NTRS)

    Keller, G. R.; Braile, L. W.; Morgan, P.

    1979-01-01

    A regional analysis of the crust and upper mantle of the Colorado Plateau is presented, using existing geophysical and geological data combined with new surface wave dispersion and groundwater geothermometry data; the tectonic implications of these models are also investigated. Surface wave and seismic refraction data indicate that the crust of the interior of the Colorado Plateau is 44 + or - 3 km thick, and its crustal structure is typical of stable continental areas. Pn velocities, however, appear to be lower (7.8 km/s) than would be expected in a stable region, while silica geothermometry indicates that the average heat flow for the plateau is 55 mW per sq m (1.3 HFU).

  19. Evaluation of Soil Flushing for Application to the Deep Vadose Zone in the Hanford Central Plateau

    SciTech Connect

    Truex, Michael J.; Oostrom, Martinus; Zhang, Z. F.; Carroll, Kenneth C.; Schramke, Janet A.; Wietsma, Thomas W.; Tartakovsky, Guzel D.; Gordon, Kathryn A.; Last, George V.

    2010-11-01

    Soil flushing was included in the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau as a technology with the potential to remove contaminants from the vadose zone. Soil flushing operates through the addition of water, and if necessary an appropriate mobilizing agent, to mobilize contaminants and flush them from the vadose zone and into the groundwater where they are subsequently captured by a pump-and-treat system. There are uncertainties associated with applying soil flushing technology to contaminants in the deep vadose zone at the Hanford Central Plateau. The modeling and laboratory efforts reported herein are intended to provide a quantitative assessment of factors that impact water infiltration and contaminant flushing through the vadose zone and into the underlying groundwater. Once in the groundwater, capture of the contaminants would be necessary, but this aspect of implementing soil flushing was not evaluated in this effort. Soil flushing was evaluated primarily with respect to applications for technetium and uranium contaminants in the deep vadose zone of the Hanford Central Plateau.

  20. Magnetotelluric data, Taos Plateau Volcanic Field, New Mexico

    USGS Publications Warehouse

    Ailes, Chad E.; Rodriguez, Brian D.

    2010-01-01

    The population of the San Luis Basin region of northern New Mexico is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's groundwater resources. An important issue in managing the groundwater resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal groundwater aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey called magnetotellurics (MT), and hydrologic and lithologic data are being used to better understand the aquifers. This report describes a regional east-west MT sounding profile acquired in late July 2009 across the Taos Plateau Volcanic Field where drillhole data are sparse. Resistivity modeling of the MT data can be used to help map changes in electrical resistivity with depths that are related to differences in rock types. These various rock types help control the properties of aquifers. The purpose of this report is to release the MT sounding data collected along the east-west profile. No interpretation of the data is included.

  1. Geochemical controls on dissolved sodium in basalt aquifers of the Columbia Plateau, Washington

    USGS Publications Warehouse

    Hearn, P.P.; Steinkampf, W.C.; Bortleson, Gilbert C.; Drost, B.W.

    1985-01-01

    Miocene basaltic aquifers of the Columbia Plateau are the principal source of water for agricultural, domestic, and municipal use in Washington State. Irrigation with groundwaters with relatively high sodium concentrations has been cause for concern in recent years, because of the tendency of such waters to reduce soil permeability. Chemical reactions involving groundwater and the basalts are the primary mechanisms responsible for the input of sodium to groundwater in the plateau. This conclusion is supported by the sequence of secondary alteration products found and by progressive changes in groundwater chemistry with depth and position along regional flow paths. Upgradient and shallow groundwaters have low sodium concentrations and sodium-adsorption ratios (SAR's), and are predominantly calcium sodium bicarbonate waters. Groundwaters from deeper and downgradient locations have higher sodium concentrations and SAR 's and are predominantly sodium bicarbonate water. Volcanic glass and cryptocrystalline matrix are the major sources of groundwater sodium, and are dissolved by a combination of silicate hydrolysis and dissolution by carbonic acid. Magnesium, iron, and calcium are removed from solution by the formation of an iron magnesium smectite, calcite , and amorphous iron oxyhydroxide. The addition of sodium, silicon, and potassium by dissolution of basalt exceeds their removal by the precipitation of secondary minerals, and their concentrations increase in the initial stages of this process. In later stages, these continued increases produce a water saturated with clinoptilolite and silica phases, and these begin to precipitate. While the timing of these processes is unclear, the mineralogy of secondary alteration and estimated cooling rates of the basalt flows suggest that observed alteration products formed primarily at low temperature, under conditions similar to those existing at the present time. (USGS)

  2. Plateau uplift and climatic change

    SciTech Connect

    Ruddiman, W.F. ); Kutzbach, J.E. )

    1991-03-01

    The earth of 40 million years ago was a warm, wet place. Forests abounded; grasslands and deserts were rare. Then the planet began to cool. Regional climate extremes developed. Many causes have been postulated, including continental drift and diminishing atmospheric carbon dioxide. The authors offer a new theory: continental uplift created huge plateaus that altered circulation of the atmosphere. The two largest masses of high, rocky terrain in the Northern Hemisphere today are the area encompassing the Tibetan Plateau and Himalaya Mountains and the broad region of the American West centered on the Colorado Plateau. Geologic evidence indicates that these regions rose substantially during the past 40 million years. The authors focused their research on these plateaus.

  3. Introduction to the Antarctic plateau

    NASA Astrophysics Data System (ADS)

    Storey, J. W. V.

    2006-10-01

    Over the past decade there has been remarkable progress in the exploration of the Antarctic plateau for astronomy. Already, major astronomical facilities are in operation at the Amundsen-Scott Station at South Pole, and even more ambitious telescopes are planned or under construction there. However, for a number of important reasons the high plateau sites of Dome A and Dome C appear to offer even more favorable conditions than South Pole for many kinds of astronomy. The success of the Chinese expedition to Dome A in January 2005, plus the opening of the French/Italian Concordia Station at Dome C for year-round operation in 2005, have now created exciting new opportunities for Antarctic astronomy.

  4. Introduction to the Antarctic Plateau

    NASA Astrophysics Data System (ADS)

    Storey, J. W. V.

    2007-01-01

    Over the past decade there has been remarkable progress in the exploration of the Antarctic plateau for astronomy. Already, major astronomical facilities are in operation at the Amundsen-Scott Station at South Pole, and even more ambitious telescopes are planned or under construction there. However, for a number of important reasons the high plateau sites of Dome A and Dome C appear to offer even more favourable conditions than South Pole for many kinds of astronomy. The success of the Chinese expedition to Dome A in January 2005, plus the opening of the French/Italian Concordia Station at Dome C for year-round operation in 2005, have now created exciting new opportunities for Antarctic astronomy.

  5. Monuments of the Giza Plateau

    NASA Astrophysics Data System (ADS)

    Ruggles, Clive L. N.

    The colossal pyramids of the pharaohs Khufu (Cheops), Khafre (Chephren), and Menkaure (Mycerinus) have attracted a huge amount of astronomical interest over the years, both scholarly and popular. Less attention is usually given to the broader context of structures on the Giza Plateau. One of the most notorious ideas connecting the Giza Plateau with astronomy is that the three large pyramids are laid out on the ground so as to reflect the appearance of the three stars of Orion's Belt in the sky. This idea is unsupportable for several reasons but has succeeded in generating huge public interest. Of much greater serious interest is the fact that the three main pyramids were oriented cardinally to extraordinary precision, which raises the questions of why this was important and how it was achieved. Another idea that has attracted serious attention but also some confusion is that the orientations of some narrow shafts within Khufu's pyramid might have been deliberately aligned upon particular stars. The overall layout of monuments on the plateau may certainly have been designed so as to emphasize certain solar phenomena, for symbolic and ideological reasons relating to a dominant sun cult. It is also possible that it formed part of a wider cosmological "master plan" extending to other pyramids and temples up to 20 km distant.

  6. Electromagnetic analysis of groundwater on the Arizona-Utah border

    NASA Astrophysics Data System (ADS)

    Vander Vis, T.; Porter, R. C.; Macy, J. P.

    2016-12-01

    Understanding subsurface structure and groundwater flow is an essential part of managing groundwater resources, especially in southwestern United States where supply is limited and demand is increasing. This study describes the preliminary results of a transient electromagnetic survey conducted on the Arizona-Utah border to better understand the groundwater system which supplies water to many wells and springs in the region. Electromagnetic surveys are ideal for groundwater investigations because they can locate and characterize areas of high conductivity, which often are indicative of groundwater. The study area is on the southwestern margin of the Colorado Plateau and consists of uplifted, flat-lying sedimentary units. Regionally, groundwater is located within the Navajo Sandstone and underlying Kayenta Formation as an unconfined aquifer that extends from Pipe Springs National Monument north to the East Fork of the Virgin River. This area is characterized by step-like structural blocks that accommodate small amounts of extension and are bounded by long north-south-trending normal faults. The Sevier Fault runs through the sedimentary units near the study area and has been shown to influence groundwater movement by offsetting permeable units west of the fault adjacent to impermeable units east of the fault. Electromagnetic measurements were recorded with a Zonge GDP-32 receiver at 30 receiver locations at 16 and 32 Hz with a 100mx100m transmitter loop. These data were used to create a subsurface conductivity model. Water levels from local wells and local geologic data were utilized to relate the geophysical data to the groundwater system. Preliminary results define the depth to water table and the location of the groundwater divide between the groundwater that flows north towards the springs that feed the East Fork of the Virgin River and the groundwater that flows south towards Pipe Springs National Monument.

  7. Dilution of nonpoint-source nitrate in groundwater

    SciTech Connect

    Altman, S.J.; Parizek, R.R.

    1995-07-01

    Nonpoint-source pollution from agriculture can cause the degradation of groundwater and surface water. Some studies conducted in Coastal Plain aquifiers have shown NO{sub 3}{sup -} removal from groundwater due to assimilation by vegetation or denitrification before discharge to a stream is significant; relatively few have been conducted on other physiographic and geological regions within the Chesapeake Bay watershed. This study was conducted at the boundary of the Valley and Ridge and Appalachian Plateau physiographic provinces to understand how the hydrological and geochemical conditions in this region effect the transport and removal of NO{sub 3}{sup -}. 35 refs., 8 figs., 3 tabs.

  8. PLATEAU IRIS SYNDROME--CASE SERIES.

    PubMed

    Feraru, Crenguta Ioana; Pantalon, Anca Delia; Chiselita, Dorin; Branisteanu, Daniel

    2015-01-01

    Plateau iris is characterized by closing the anterior chamber angle due to a large ciliary body or due to its anterior insertion that alters the position of iris periphery in respect to the trabecular meshwork. There are two aspects that need to be differentiated: plateau iris configuration and plateau iris syndrome. The first describes a situation when the iris root is flat and the anterior chamber is not shallow, the latter refers to a post laser iridotomy condition in which a patent iridotomy has removed the relative pupillary block, but goniscopically confirmed angle closure recurs without central shallowing of the anterior chamber. Isolated plateau iris syndrome is rare compared to plateau iris configuration. We hereby present two case reports of plateau iris syndrome in young patients who came to an ophthalmologic consult by chance.

  9. The handbook of groundwater engineering

    SciTech Connect

    Delleur, J.W.

    1998-12-31

    From an engineering perspective, this book provides a practical treatment of groundwater flow; substance transport, well construction, groundwater production, site characterization, and remediation of groundwater pollution.

  10. Determination of groundwater recharge mechanism in the deep loessial unsaturated zone by environmental tracers.

    PubMed

    Li, Zhi; Chen, Xi; Liu, Wenzhao; Si, Bingcheng

    2017-05-15

    Studying the groundwater recharge mechanism in regions with thick unsaturated zone can greatly improve our understanding of hydrological processes since these regions have complex groundwater processes. This study attempted to discuss the groundwater recharge in a region covered by loess over 130m deep in China's Loess Plateau. The water stable isotope, tritium and chloride in precipitation, groundwater and soil water were determined and used as inputs of mass balance methods. The tracer technique is found to be applicable and effective this region with thick unsaturated zone. The groundwater originates from rapid precipitation infiltration through some fast flow paths. The total recharge is likely to be 107±55mmyr(-1) accounting for 19±10% of average annual precipitation, while the recharge from preferential flow accounts for 87±4% of the total recharge. The identified recharge mechanism has important implication to groundwater management and recharge modeling for regions covered by thick loess.

  11. Curiosity on the Naukluft Plateau

    NASA Image and Video Library

    2016-06-22

    This image from NASA Mars Reconnaissance Orbiter spacecraft shows the Curiosity rover currently located on the Naukluft Plateau just north of the Bagnold Dune field. Its position was captured by HiRISE on 25 March 2016 (MSL Sol 1291. Views from the surface at this location are available here and here.) The rover is within sandstone outcrops informally named the "Stimson Formation." There are no obvious rover tracks in the HiRISE views indicating that this bedrock contains little dust that otherwise could be disturbed by the rover wheels as has been seen earlier in Curiosity's traverse. http://photojournal.jpl.nasa.gov/catalog/PIA20738

  12. Vertical tectonics of the High Plateau region, Manihiki Plateau, Western Pacific, from seismic stratigraphy

    NASA Astrophysics Data System (ADS)

    Ai, Huirong-Anita; Stock, Joann M.; Clayton, Robert; Luyendyk, Bruce

    2008-01-01

    The Manihiki Plateau is an elevated oceanic volcanic plateau that was formed mostly in Early Cretaceous time by hotspot activity. We analyze new seismic reflection data acquired on cruise KIWI 12 over the High Plateau region in the southeast of the plateau, to look for direct evidence of the location of the heat source and the timing of uplift, subsidence and faulting. These data are correlated with previous seismic reflection lines from cruise CATO 3, and with the results at DSDP Site 317 at the northern edge of the High Plateau. Seven key reflectors are identified from the seismic reflection profiles and the resulting isopach maps show local variations in thickness in the southeastern part of the High Plateau, suggesting a subsidence (cooling) event in this region during Late Cretaceous and up to Early Eocene time. We model this as a hotspot, active and centered on the High Plateau area during Early Cretaceous time in a near-ridge environment. The basement and Early Cretaceous volcaniclastic layers were formed by subaerial and shallow-water eruption due to the volcanic activity. After that, the plateau experienced erosion. The cessation of hotspot activity and subsequent heat loss by Late Cretaceous time caused the plateau to subside rapidly. The eastern and southern portions of the High Plateau were rifted away following the cessation of hot spot activity. As the southeastern portion of the High Plateau was originally higher and above the calcium carbonate compensation depth, it accumulated more sediments than the surrounding plateau regions. Apparently coeval with the rapid subsidence of the plateau are normal faults found at the SE edge of the plateau. Since Early Eocene time, the plateau subsided to its present depth without significant deformation.

  13. Groundwater Recharge in Juniper Woodlands: Insights from Long-Term Monitoring of Cave Drip Rates

    NASA Astrophysics Data System (ADS)

    Wilcox, B. P.; Sun, Z.; Munster, C.; Owens, K.

    2011-12-01

    The Edwards Plateau in Central Texas covers some 230,000 square kilometers. It is underlain by limestone and dolomite, and these karst parent materials give the region its distinct hydrologic character. Although the climate is semiarid, springs are abundant and support many perennial rivers. In particular, the Edwards Plateau is the source area for the prolific and regionally important Edwards Aquifer, the main water source for much of central Texas. Compared with other semiarid regions, the Edwards Plateau has abundant water resources; but an expanding population is now taxing those resources, and ways are being sought to increase groundwater recharge. Over the past 150 years, the expansion of juniper and oak have turned the Plateau into a shrub-dominated semiarid rangeland-a legacy of the historical overgrazing that took place from around 1880 to 1950. Many believe that reducing this woodland cover would lead to higher groundwater recharge. We undertook our study to try to understand the influence of juniper on groundwater recharge. For six years, we monitored drip rates in caves underlying juniper forests (these rates are surrogate measurements for groundwater recharge). After four years of monitoring, we removed the juniper from the study site and continued monitoring. Surprisingly, our results indicate that removing the trees had a negative effect on recharge. Several mechanisms may contribute to the reduction in recharge: for example, surface runoff increased following removal of the trees; and it is possible that the trees assist recharge by funneling water to their roots, hastening its movement through the substrate.

  14. Experiences with groundwater contamination

    SciTech Connect

    Not Available

    1984-01-01

    This book discusses developments in combating groundwater contamination. The papers include: Regulation of Groundwater; Utility Experiences Related to Existing and Proposed Drinking Water Regulations; Point-of-Use Treatment Technology to Control Organic and Inorganic Contamination; Hazardous Waste Disposal Practices and Groundwater Contamination; Reverse Osmosis Treatment to Control Inorganic and Volatile Organic Contamination; The Dilemma of New Wells Versus Treatment; Characteristics and Handling of Wastes From Groundwater Treatment Systems; and Removing Solvents to Restore Drinking Water at Darien, Connecticut.

  15. Future of groundwater modeling

    USGS Publications Warehouse

    Langevin, Christian D.; Panday, Sorab

    2012-01-01

    With an increasing need to better manage water resources, the future of groundwater modeling is bright and exciting. However, while the past can be described and the present is known, the future of groundwater modeling, just like a groundwater model result, is highly uncertain and any prediction is probably not going to be entirely representative. Thus we acknowledge this as we present our vision of where groundwater modeling may be headed.

  16. Prehistoric human settling on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Chen, Fahu; Zhang, Dongju; Dong, Guanghui

    2017-04-01

    When and where did human first settle down on the Tibetan Plateau is under hot debate among archaeologist, anthropologists, geneticist and paleo-geographers. Based on systematic archaeological, chronological and archaeo-botanical studies of 53 sites in Northeastern Tibetan Plateau, we propose that agriculture facilitated human permanent settlement on the Tibetan Plateau initially since 5200 years ago below 2500 masl and since 3600 years ago up to around 4000 masl, possibly assisted by domesticated animals (Chen et al. 2015). By studying hand- and footprints in Chusang, Meyer et al. (2016) argue that hunter-gatherers permanently occupied central Tibetan Plateau in early Holocene without the help of agriculture. However, we think the limited hand- and footprints evidence found in Chusang could indicate no more than prehistoric hunter-gatherers presence on the remote central Tibetan Plateau in the early Holocene. In addition, by reviewing all the published archaeological data, we propose that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in the Northeastern Tibetan Plateau (NETP). This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) when human adapted to the high altitude environment and climate change with different strategies and techniques. Particularly, the prevail of microlithic technology in North China provoked hunter-gatherers' first visit to the NETP in relatively ameliorated last Deglacial period, and the the quick development of millet farming and subsequent mixed barley-wheat farming and sheep herding facilitated farmers and herders permanently settled in Tibetan Plateau, even above 3000 masl, during mid- and late Holocene. References: Chen et al., 2015. Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 BP. Science, 347: 248-250. Meyer et al., 2016

  17. Evaluating Adult Groundwater Education.

    ERIC Educational Resources Information Center

    Gerakis, Argyrios

    1998-01-01

    One-day groundwater education workshops held to educate soil conservation personnel were assessed for effect on participant knowledge using a quasiexperimental design. Participants were tested on their groundwater knowledge and attitude toward groundwater conservation before and after the training. Participant scores improved significantly in only…

  18. Evaluating Adult Groundwater Education.

    ERIC Educational Resources Information Center

    Gerakis, Argyrios

    1998-01-01

    One-day groundwater education workshops held to educate soil conservation personnel were assessed for effect on participant knowledge using a quasiexperimental design. Participants were tested on their groundwater knowledge and attitude toward groundwater conservation before and after the training. Participant scores improved significantly in only…

  19. ALTERNATIVE REMEDIATION TECHNOLOGY STUDY FOR GROUNDWATER TREATMENT AT 200-PO-1 OPERABLE UNIT AT HANFORD SITE

    SciTech Connect

    DADO MA

    2008-07-31

    This study focuses on the remediation methods and technologies applicable for use at 200-PO-I Groundwater Operable Unit (OU) at the Hanford Site. The 200-PO-I Groundwater au requires groundwater remediation because of the existence of contaminants of potential concern (COPC). A screening was conducted on alternative technologies and methods of remediation to determine which show the most potential for remediation of groundwater contaminants. The possible technologies were screened to determine which would be suggested for further study and which were not applicable for groundwater remediation. COPCs determined by the Hanford Site groundwater monitoring were grouped into categories based on properties linking them by remediation methods applicable to each COPC group. The screening considered the following criteria. (1) Determine if the suggested method or technology can be used for the specific contaminants found in groundwater and if the technology can be applied at the 200-PO-I Groundwater au, based on physical characteristics such as geology and depth to groundwater. (2) Evaluate screened technologies based on testing and development stages, effectiveness, implementability, cost, and time. This report documents the results of an intern research project conducted by Mathew Dado for Central Plateau Remediation in the Soil and Groundwater Remediation Project. The study was conducted under the technical supervision of Gloria Cummins and management supervision of Theresa Bergman and Becky Austin.

  20. Groundwater sapping processes, Western Desert, Egypt.

    SciTech Connect

    Luo, W.; Arvidson, R.E.; Sultan, M.; Becker, R.; Crombie, M.K.; Sturchio, N.; El Alfy, Z.; Environmental Research; Washington Univ.; Egyptian Geological Survey and Mining Authority

    1997-01-01

    Depressions of the Western Desert of Egypt (specifically, Kharga, Farafra, and Kurkur regions) are mainly occupied by shales that are impermeable, but easily erodible by rainfall and runoff, whereas the surrounding plateaus are composed of limestones that are permeable and more resistant to fluvial erosion under semiarid to arid conditions. Scallop-shaped escarpment edges and stubby-looking channels that cut into the plateau units are suggestive of slumping of limestones by ground-water sapping at the limestone-shale interfaces, removal of slump blocks by weathering and fluvial erosion, and consequent scarp retreat. Spring-derived tufa deposits found near the limestone escarpments provide additional evidence for possible ground-water sapping during previous wet periods. A computer simulation model was developed to quantify the ground-water sapping processes, using a cellular automata algorithm with coupled surface runoff and ground-water flow for a permeable, resistant layer over an impermeable, friable unit. Erosion, deposition, slumping, and generation of spring-derived tufas were parametrically modeled. Simulations using geologically reasonable parameters demonstrate that relatively rapid erosion of the shales by surface runoff, ground-water sapping, and slumping of the limestones, and detailed control by hydraulic conductivity inhomogeneities associated with structures explain the depressions, escarpments, and associated landforms and deposits. Using episodic wet pulses, keyed by {delta}{sup 18}O deep-sea core record, the model produced tufa ages that are statistically consistent with the observed U/Th tufa ages. This result supports the hypothesis that northeastern African wet periods occurred during interglacial maxima. The {delta}{sup 18}O-forced model also replicates the decrease in fluvial and sapping activity over the past million years, as northeastern Africa became hyperarid. The model thus provides a promising predictive tool for studying long

  1. Expediting Groundwater Sampling at Hanford and Making It Safer

    SciTech Connect

    Connell, Carl W. Jr.; Carr, Jennifer S.; Hildebrand, R. Douglas; Schatz, Aaron L.; Conley, S. F.; Brown, W. L.

    2013-01-22

    The CH2M HILL Plateau Remediation Company (CHPRC) manages the groundwatermonitoring programs at the Department of Energy's 586-square-mile Hanford site in southeastern Washington state. These programs are regulated by the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), and the Atomic Energy Act (AEA). The purpose of monitoring is to track existing groundwater contamination from past practices, as well as other potential contamination that might originate from RCRA treatment, storage, and disposal (TSD) facilities. An integral part of the groundwater-monitoring program involves taking samples of the groundwater and measuring the water levels in wells scattered across the site. Each year, more than 1,500 wells are accessed for a variety of reasons.

  2. FINAL FRONTIER AT HANFORD TACKLING THE CENTRAL PLATEAU

    SciTech Connect

    GERBER MS

    2008-03-04

    The large land area in the center of the vast Department of Energy (DOE) Hanford Site in southeast Washington State is known as 'the plateau'--aptly named because its surface elevations are 250-300 feet above the groundwater table. By contrast, areas on the 585-square mile Site that border the Columbia River sit just 30-80 feet above the water table. The Central Plateau, which covers an ellipse of approximately 70 square miles, contains Hanford's radiochemical reprocessing areas--the 200 East and 200 West Areas--and includes the most highly radioactive waste and contaminated facilities on the Site. Five 'canyons' where chemical processes were used to separate out plutonium (Pu), 884 identified soil waste sites (including approximately 50 miles of solid waste burial trenches), more than 900 structures, and all of Hanford's liquid waste storage tanks reside in the Central Plateau. (Notes: Canyons is a nickname given by Hanford workers to the chemical reprocessing facilities. The 177, underground waste tanks at Hanford comprise a separate work scope and are not under Fluor's management). Fluor Hanford, a DOE prime cleanup contractor at the Site for the past 12 years, has moved aggressively to investigate Central Plateau waste sites in the last few years, digging more than 500 boreholes, test pits, direct soil 'pushes' or drive points; logging geophysical data sets; and performing electrical-resistivity scans (a non-intrusive technique that maps patterns of sub-surface soil conductivity). The goal is to identify areas of contamination areas in soil and solid waste sites, so that cost-effective and appropriate decisions on remediation can be made. In 2007, Fluor developed a new work plan for DOE that added 238 soil waste-site characterization activities in the Central Plateau during fiscal years (FYs) 2007-2010. This number represents a 50 percent increase over similar work previously done in central Hanford. Work Plans are among the required steps in the Comprehensive

  3. Plateau effects on diurnal circulation patterns

    SciTech Connect

    Reiter, E.R.; Tang, M.

    1984-04-01

    The diurnal variation of 850 mb heights, the detailed distribution of which could be assessed by the inclusion of surface data, and of resultant winds over, and in the vicinity of, the Great Basin reveals clearly a plateau-wind circulation during summer. This circulation reverses between day and night and appears to include the low-level jet stream over Texas and Oklahoma, as well as the time of occurrence of thunderstorms. This plateau circulation system interacts with local mountain-valley breeze systems. The thickness of the daytime inflow and nighttime outflow layer over the plateau is approximately 2 km. 19 references, 11 figures, 1 table.

  4. Compartment syndrome after tibial plateau fracture.

    PubMed

    Pitta, Guilherme Benjamin Brandão; Dos Santos, Thays Fernanda Avelino; Dos Santos, Fernanda Thaysa Avelino; da Costa Filho, Edelson Moreira

    2014-01-01

    Fractures of the tibial plateau are relatively rare, representing around 1.2% of all fractures. The tibia, due to its subcutaneous location and poor muscle coverage, is exposed and suffers large numbers of traumas, not only fractures, but also crush injuries and severe bruising, among others, which at any given moment, could lead compartment syndrome in the patient. The case is reported of a 58-year-old patient who, following a tibial plateau fracture, presented compartment syndrome of the leg and was submitted to decompressive fasciotomy of the four right compartments. After osteosynthesis with internal fixation of the tibial plateau using an L-plate, the patient again developed compartment syndrome.

  5. Plateau borders of smectic liquid crystalline films

    NASA Astrophysics Data System (ADS)

    Trittel, Torsten; Aldred, Ruth; Stannarius, Ralf

    2011-06-01

    We investigate the geometrical properties of Plateau borders in an arrangement of connected smectic A free standing films. The geometry is chosen such that a circular Plateau border surrounds a planar smectic film and connects it with two smectic catenoids. It is demonstrated that, similar to soap films, the smectic film geometry can be described by a negative line tension of the circular contact region. Thus, the equilibrium angle between the films depends upon the liquid content in this region, and with increasing liquid content, deviations from Plateau's rule are observed. The experimental results are qualitatively comparable to soap films. A possible origin of slight quantitative differences is discussed.

  6. [Hypoxic adaptation of the hearts of plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae)].

    PubMed

    Qi, Xin-Zhang; Wang, Xiao-Jun; Zhu, Shi-Hai; Rao, Xin-Feng; Wei, Lian; Wei, Deng-Bang

    2008-06-25

    Plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzniae) are native to the Qinghai-Tibet plateau. To study their adaptive mechanisms, the ratios of heart weight to body weight (HW/BW) and right to left ventricular plus septum weights [RV/(LV+S)] were determined; the microvessel density (MVD) of cardiac muscle were measured by immunohistochemical staining; the numerical density on area (N(A)), volume density (V(V)), specific surface (δ), and surface density (S(V)) of mitochondria were obtained by microscopy and stereology; the contents of myoglobin (Mb) and lactic acid (LD), and the activity of lactate dehydrogenase (LDH) in cardiac muscle were analyzed by spectrophotometer. The results showed that the HW/BW of plateau zokor [(4.55±0.26)%] and plateau pika [(4.41±0.38)%] was significantly greater than that of Sprague-Dawley (SD) rat [(3.44±0.41)%] (P<0.05), but the RV/(LV+S) [(22.04±1.98)%, (25.53±3.41)%] was smaller than that of SD rats [(44.23±3.87)%] (P<0.05). The MVD and N(A) of cardiac muscle were 1688.631±250.253 and 0.768±0.123 in SD rat, 2002.888±367.466 and 0.868±0.159 in plateau pika and 2 990.643±389.888 and 1.012±0.133 in plateau zokor. The V(V) of mitochondria in plateau zokor (0.272±0.045) was significantly lower than that in plateau pika (0.343±0.039) and SD rat (0.321±0.048) (P<0.05), while the δ of mitochondria in plateau zokor (9.409±1.238) was higher than that in plateau pika (6.772±0.892) and SD rat (7.287±1.373) (P<0.05). The S(V) of mitochondria in plateau pika (2.322±0.347) was not obviously different from that in plateau zokor (2.468±0.380) and SD rat (2.227±0.377), but that in plateau zokor was significantly higher than that in SD rat (P<0.05). The contents of Mb in cardiac muscle of plateau zokor [(763.33±88.73) nmol/g] and plateau pika [(765.96±28.47) nmol/g] were significantly higher than that of SD rat [(492.38±72.14) nmol/g] (P<0.05), the content of LD in plateau zokor [(0.57±0.06) mmol/L] was

  7. Increased Water Storage in the Qaidam Basin, the North Tibet Plateau from GRACE Gravity Data

    PubMed Central

    Jiao, Jiu Jimmy; Zhang, Xiaotao; Liu, Yi; Kuang, Xingxing

    2015-01-01

    Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan Plateau (NTP) using Gravity Recovery and Climate Experiment (GRACE) data. Our study confirms long-term (2003–2012) TWS increases in the NTP. Between 2003 and 2012 the TWS increased by 88.4 and 20.6 km3 in the NTP and the QB, respectively, which is 225% and 52% of the capacity of the Three Gorges Reservoir, respectively. Soil and water changes from the Global Land Data Assimilation System (GLDAS) were also used to identify groundwater storage in the TWS and to demonstrate a long-term increase in groundwater storage in the QB. We demonstrate that increases in groundwater, not lake water, are dominant in the QB, as observed by groundwater levels. Our study suggests that the TWS increase was likely caused by a regional increase in precipitation and a decrease in evaporation. Degradation of the permafrost increases the thickness of the active layers providing increased storage for infiltrated precipitation and snow and ice melt water, which may also contribute to the increased TWS. The huge increase of water storage in the NTP will have profound effects, not only on local ecology and environment, but also on global water storage and sea level changes. PMID:26506230

  8. Increased Water Storage in the Qaidam Basin, the North Tibet Plateau from GRACE Gravity Data.

    PubMed

    Jiao, Jiu Jimmy; Zhang, Xiaotao; Liu, Yi; Kuang, Xingxing

    2015-01-01

    Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan Plateau (NTP) using Gravity Recovery and Climate Experiment (GRACE) data. Our study confirms long-term (2003-2012) TWS increases in the NTP. Between 2003 and 2012 the TWS increased by 88.4 and 20.6 km3 in the NTP and the QB, respectively, which is 225% and 52% of the capacity of the Three Gorges Reservoir, respectively. Soil and water changes from the Global Land Data Assimilation System (GLDAS) were also used to identify groundwater storage in the TWS and to demonstrate a long-term increase in groundwater storage in the QB. We demonstrate that increases in groundwater, not lake water, are dominant in the QB, as observed by groundwater levels. Our study suggests that the TWS increase was likely caused by a regional increase in precipitation and a decrease in evaporation. Degradation of the permafrost increases the thickness of the active layers providing increased storage for infiltrated precipitation and snow and ice melt water, which may also contribute to the increased TWS. The huge increase of water storage in the NTP will have profound effects, not only on local ecology and environment, but also on global water storage and sea level changes.

  9. Western USA groundwater drilling

    NASA Astrophysics Data System (ADS)

    Jasechko, S.; Perrone, D.

    2016-12-01

    Groundwater in the western US supplies 40% of the water used for irrigated agriculture, and provides drinking water to individuals living in rural regions distal to perennial rivers. Unfortunately, current groundwater use is not sustainable in a number of key food producing regions. While substantial attention has been devoted to mapping groundwater depletion rates across the western US, the response of groundwater users via well drilling to changing land uses, water demands, pump and drilling technologies, pollution vulnerabilities, and economic conditions remains unknown. Here we analyze millions of recorded groundwater drilling events in the western US that span years 1850 to 2015. We show that groundwater wells are being drilled deeper in some, but not all, regions where groundwater levels are declining. Groundwater wells are generally deeper in arid and mountainous regions characterized by deep water tables (e.g., unconfined alluvial and fractured bedrock aquifers), and in regions that have productive aquifers with high water quality deep under the ground (e.g., confined sedimentary aquifers). Further, we relate water quality and groundwater drilling depths in 40 major aquifer systems across the western US. We show that there is substantial room for improvement to the existing 2-D continental-scale assessments of domestic well water vulnerability to pollution if one considers the depth that the domestic well is screened in addition to pollutant loading, surficial geology, and vertical groundwater flow rates. These new continental-scale maps can be used to (i) better assess economic, water quality, and water balance limitations to groundwater usage, (ii) steer domestic well drilling into productive strata bearing clean and protected groundwater resources, and (iii) assess groundwater management schemes across the western US.

  10. Groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010

    USGS Publications Warehouse

    Knierim, Katherine J.; Nottmeier, Anna M.; Worland, Scott C.; Westerman, Drew A.; Clark, Brian R.

    2016-01-01

    Groundwater is an often overlooked freshwater resource compared to surface water, but groundwater is used widely across the United States, especially during periods of drought. If groundwater models can successfully simulate past conditions, they may be used to evaluate potential future pumping scenarios or climate conditions, thus providing a valuable planning tool for water-resource managers. Quantifying the groundwater-use component for a groundwater model is a vital but often challenging endeavor. This dataset includes groundwater withdrawal rates modeled for the Ozark Plateaus aquifer system (Ozark system) from 1900 to 2010 by groundwater model cell (2.6 square kilometers) for five water-use divisions—agriculture (including irrigation and aquaculture), livestock, public supply (including municipal and rural water districts), and non-agriculture (including thermoelectric power generation, mining, commercial, and industrial)—and by country for domestic (self-supplied) use. Two child items are included with the dataset: “Domestic groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010” and “Public supply, non-agriculture, livestock, and agriculture groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010”. The Ozark system is located in the central United States and is composed of interbedded Cambrian to Pennsylvanian clastic and carbonate lithologies. In stratigraphic order, the Ozark system includes the Basement confining unit, St. Francois aquifer, St. Francois confining unit, Ozark aquifer, Ozark confining unit, Springfield Plateau aquifer, and Western Interior Plains confining system. Generally, the lower portion of the Ozark aquifer is the primary source of groundwater across much of Missouri and the Springfield Plateau aquifer is used across northern Arkansas. A full description of the methods used to model groundwater withdrawal rates from the Ozark system are available in Knierim et al., IN

  11. Inherent agricultural constraints in Allegheny Plateau soils

    USDA-ARS?s Scientific Manuscript database

    World population increases demand increased agricultural production. This can be accomplished through improved cultivars and production techniques or increased use of previously marginal agricultural regions. In the Allegheny Plateau (AP) region of the Appalachian Mountains, acid soils with toxic ...

  12. Career Plateauing: Implications for Career Development Specialists.

    ERIC Educational Resources Information Center

    Weiner, Andrew; And Others

    1992-01-01

    Reaction to career plateaus depends on the employee's resources as well as the organization's response. Counseling, training and development, job enrichment, and other activities can minimize the stressful effects of involuntary plateauing. (SK)

  13. Using multiple environmental methods to estimate groundwater discharge into an arid lake (Dakebo Lake, Inner Mongolia, China)

    NASA Astrophysics Data System (ADS)

    Su, Xiaosi; Cui, Geng; Du, Shanghai; Yuan, Wenzhen; Wang, Huang

    2016-11-01

    It is important to have both a qualitative and quantitative understanding of the hydraulic exchange between groundwater and surface water to support the development of effective management plans for sustainable use of water resources. Groundwater is a major source of surface-water recharge and plays an important role in maintaining the integrity of ecosystems, especially within wetlands in semi-arid regions. The Ordos Desert Plateau of Inner Mongolia (China) is a vulnerable ecosystem that suffers from an extreme lack of water. The hydraulic exchange between groundwater and lake water in Dakebo Lake (the largest of hundreds of lakes on the Ordos Desert Plateau) was evaluated using multiple environmental methods. Continuous monitoring of the groundwater and lake-water levels indicated that the lake was recharged vertically by groundwater. Application of hydrodynamic and temperature tracing methods to the western side of the lake indicated that the rate of groundwater discharge to the lake was about 2 × 10-6 to 3 × 10-6 m/s in spring, summer, and autumn, but that there was no recharge in winter because the hypolentic zone (HZ) was frozen. Mixing ratios of groundwater and lake water in the HZ, estimated from the 18O and 2H ratios, showed that there were spatial variations in the hydrodynamic exchange between groundwater and lake water within the HZ.

  14. Groundwater sustainability strategies

    USGS Publications Warehouse

    Gleeson, Tom; VanderSteen, Jonathan; Sophocleous, Marios A.; Taniguchi, Makoto; Alley, William M.; Allen, Diana M.; Zhou, Yangxiao

    2010-01-01

    Groundwater extraction has facilitated significant social development and economic growth, enhanced food security and alleviated drought in many farming regions. But groundwater development has also depressed water tables, degraded ecosystems and led to the deterioration of groundwater quality, as well as to conflict among water users. The effects are not evenly spread. In some areas of India, for example, groundwater depletion has preferentially affected the poor. Importantly, groundwater in some aquifers is renewed slowly, over decades to millennia, and coupled climate–aquifer models predict that the flux and/or timing of recharge to many aquifers will change under future climate scenarios. Here we argue that communities need to set multigenerational goals if groundwater is to be managed sustainably.

  15. Artificial recharge of groundwater

    SciTech Connect

    Asano, T.

    1985-01-01

    The vast underground reservoirs formed by aquifers constitute invaluable water supply sources as well as water storage facilities. Because natural replenishment of the supply occurs very slowly, continued excessive exploitation of it causes groundwater levels to decline with time. If not corrected this leads to an eventual depletion of a valuable natural resource. To prevent mining and groundwater pollution, the artificial recharge of groundwater basins is becoming increasingly important in groundwater management as a way to increase this natural supply of water. Artificial recharge can reduce, stop, and even reverse declining levels of groundwater. In addition, it can protect underground freshwater in coastal aquifers against salt-water intrusion from the ocean, and can be used to store surface and reclaimed water for future use. This book is a treatise of the artificial recharge of groundwater, with particular emphasis on recharge with reclaimed municipal wastewater.

  16. U.S. Geological Survey ground-water studies in Oregon

    USGS Publications Warehouse

    Bolke, E.L.

    1988-01-01

    The use of groundwater in Oregon is expected to increase owing to continued population growth and to surface water supplies that are inadequate to meet present or future demand. The major groundwater issues in Oregon are: conjunctive use of surface and groundwater; contamination from hazardous wastes, leakage from underground gasoline and diesel tanks, naturally occurring brackish water, and high concentrations of dissolved iron; groundwater availability; and Indian water rights. Before 1987, the Oregon Water Resources Department, in cooperation with the U.S. Geological Survey (USGS), maintained a network of about 400 observation wells in Oregon to monitor fluctuations in groundwater levels. Water levels currently are measured cooperatively only in active project areas. The USGS has conducted more than 120 hydrologic investigations in Oregon. During fiscal year 1987, the USGS entered into cooperative agreements with 23 local, State, and Federal agencies to conduct hydrologic investigations in Oregon; six investigations included quantitative studies of groundwater. Examples of these groundwater studies are: groundwater hydrology of the Portland basin; groundwater hydrology in the Umatilla Plateau; and iron geochemistry of a sand dune aquifer near Coos Bay. (Lantz-PTT)

  17. Geophysical Detection of Groundwater.

    DTIC Science & Technology

    1982-04-01

    was also given to deriving a method that would be both innovative and would directly detect groundwater. Currently, there is no " black box" that uses...either the refraction method or the resistivity method to deter- mine the depth to this interface. Unless a " black box" is developed in the near...and software to be developed for groundwater exploration. Unless a " black box" is developed in the near future, the best hope for locating groundwater

  18. Viability of the ground of Shithatha, western Iraqi plateau, for industrial and commercial uses via hydrochemistry analysis

    NASA Astrophysics Data System (ADS)

    Al-Qaraghuli, S. A.

    2017-08-01

    Iraqi western plateau is considered as one of the most resourceful areas of the middle east, that is not yet well explored, due to the many political disturbances and security issues. The viability of underground water for the various industrial, municipal, commercial and agricultural uses is examined for Shithatha, Karbala governorates as a representative for the western plateau via chemical and physical analysis of water samples that are taken from 9 wells and 3 springs all-around the study area during the wet and dry periods. Hydro chemical and statistical analysis for the field samples have proved that groundwater of the studied area is classified as slightly-brackish water and water hardness is very high. Also, the results of the analyses of trace elements in the groundwater of the study area have confirmed the contamination of groundwater with some elements such as (Fe, Cd, Pb, Ni) in concentrations that have exceeded the WHO and Iraqi national standards IQS, permissible limits. The application of Hydro-chemical formulae of Kurlouv and Piper, Schoeller, Stiff classifications have demonstrated that most samples of the study area have water type of (Na2SO4) while other samples have ranged between (MgSO4), and (NaCl) water type. The quality of groundwater is unsuitable for drinking and industrial purposes and it is almost suitable for irrigation purposes, but it is suitable for livestock, building and agricultural purposes because the salinity of the water is within the permissible limits when considering the nature of the soil.

  19. Geologic Setting and Hydrogeologic Units of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    USGS Publications Warehouse

    Kahle, Sue C.; Olsen, Theresa D.; Morgan, David S.

    2009-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers approximately 44,000 square miles of northeastern Oregon, southeastern Washington, and western Idaho. The area supports a $6 billion per year agricultural industry, leading the Nation in production of apples and nine other commodities (State of Washington Office of Financial Management, 2007; U.S. Department of Agriculture, 2007). Groundwater availability in the aquifers of the area is a critical water-resource management issue because the water demand for agriculture, economic development, and ecological needs is high. The primary aquifers of the CPRAS are basalts of the Columbia River Basalt Group (CRBG) and overlying basin-fill sediments. Water-resources issues that have implications for future groundwater availability in the region include (1) widespread water-level declines associated with development of groundwater resources for irrigation and other uses, (2) reduction in base flow to rivers and associated effects on temperature and water quality, and (3) current and anticipated effects of global climate change on recharge, base flow, and ultimately, groundwater availability. As part of a National Groundwater Resources Program, the U.S. Geological Survey began a study of the CPRAS in 2007 with the broad goals of (1) characterizing the hydrologic status of the system, (2) identifying trends in groundwater storage and use, and (3) quantifying groundwater availability. The study approach includes documenting changes in the status of the system, quantifying the hydrologic budget for the system, updating the regional hydrogeologic framework, and developing a groundwater-flow simulation model for the system. The simulation model will be used to evaluate and test the conceptual model of the system and later to evaluate groundwater availability under alternative development and climate scenarios. The objectives of this study were to update the hydrogeologic framework for the CPRAS using the available

  20. Evaluating geothermal and hydrogeologic controls on regional groundwater temperature distribution

    NASA Astrophysics Data System (ADS)

    Burns, Erick R.; Ingebritsen, Steven E.; Manga, Michael; Williams, Colin F.

    2016-02-01

    A one-dimensional (1-D) analytic solution is developed for heat transport through an aquifer system where the vertical temperature profile in the aquifer is nearly uniform. The general anisotropic form of the viscous heat generation term is developed for use in groundwater flow simulations. The 1-D solution is extended to more complex geometries by solving the equation for piece-wise linear or uniform properties and boundary conditions. A moderately complex example, the Eastern Snake River Plain (ESRP), is analyzed to demonstrate the use of the analytic solution for identifying important physical processes. For example, it is shown that viscous heating is variably important and that heat conduction to the land surface is a primary control on the distribution of aquifer and spring temperatures. Use of published values for all aquifer and thermal properties results in a reasonable match between simulated and measured groundwater temperatures over most of the 300 km length of the ESRP, except for geothermal heat flow into the base of the aquifer within 20 km of the Yellowstone hotspot. Previous basal heat flow measurements (˜110 mW/m2) made beneath the ESRP aquifer were collected at distances of >50 km from the Yellowstone Plateau, but a higher basal heat flow of 150 mW/m2 is required to match groundwater temperatures near the Plateau. The ESRP example demonstrates how the new tool can be used during preliminary analysis of a groundwater system, allowing efficient identification of the important physical processes that must be represented during more-complex 2-D and 3-D simulations of combined groundwater and heat flow.

  1. Evaluating geothermal and hydrogeologic controls on regional groundwater temperature distribution

    USGS Publications Warehouse

    Burns, Erick R.; Ingebritsen, Steven E.; Manga, Michael; Williams, Colin F.

    2016-01-01

    A one-dimensional (1-D) analytic solution is developed for heat transport through an aquifer system where the vertical temperature profile in the aquifer is nearly uniform. The general anisotropic form of the viscous heat generation term is developed for use in groundwater flow simulations. The 1-D solution is extended to more complex geometries by solving the equation for piece-wise linear or uniform properties and boundary conditions. A moderately complex example, the Eastern Snake River Plain (ESRP), is analyzed to demonstrate the use of the analytic solution for identifying important physical processes. For example, it is shown that viscous heating is variably important and that heat conduction to the land surface is a primary control on the distribution of aquifer and spring temperatures. Use of published values for all aquifer and thermal properties results in a reasonable match between simulated and measured groundwater temperatures over most of the 300 km length of the ESRP, except for geothermal heat flow into the base of the aquifer within 20 km of the Yellowstone hotspot. Previous basal heat flow measurements (∼110 mW/m2) made beneath the ESRP aquifer were collected at distances of >50 km from the Yellowstone Plateau, but a higher basal heat flow of 150 mW/m2 is required to match groundwater temperatures near the Plateau. The ESRP example demonstrates how the new tool can be used during preliminary analysis of a groundwater system, allowing efficient identification of the important physical processes that must be represented during more-complex 2-D and 3-D simulations of combined groundwater and heat flow.

  2. Patterns of groundwater salinity changes in a deep continental-oceanic transect off the southeastern Atlantic coast of the U.S.A.

    USGS Publications Warehouse

    Manheim, F. T.; Paull, C.K.

    1981-01-01

    Investigations of formation-fluid salinities in a transect from western Georgia to the edge of the Blake Plateau off the coast of Georgia show surprisingly similar hydrochemical features offshore and onshore. A fresh-brackish wedge of groundwater ( 100 g/kg) occur in Lower Cretaceous (?) strata. These strata have a pronounced evaporitic (anhydritic) character in the offshore segment. Strong salinity gradients in interstitial waters signify buried evaporite deposits at drill sites beneath the Blake Plateau. ?? 1981.

  3. Lithospheric structure across the northeastern margin of the Tibetan Plateau: Implications for the plateau's lateral growth

    NASA Astrophysics Data System (ADS)

    Shen, Xuzhang; Liu, Mian; Gao, Yuan; Wang, Weijun; Shi, Yutao; An, Meijian; Zhang, Yuansheng; Liu, Xuzhou

    2017-02-01

    Variations of lithospheric structure across the northeastern Tibetan Plateau and its bounding Asian blocks, the Alxa block to the north and the Ordos block to the east, are crucial for understanding the rise and lateral growth of the Tibetan Plateau. Using waveforms from high-density seismic arrays in northeastern Tibetan Plateau and the surrounding regions, we investigated the lithospheric structure with S- and P-wave receiver functions. The results show strong and relatively simple negative velocity gradients in the depth range of mantle lithosphere (∼70-150 km) under the Ordos and Alxa blocks, similar to those under typical stable continental lithosphere. In contrast, under northeastern Tibetan Plateau including its marginal regions, the velocity gradients are weak and diffusive for the mantle lithosphere, which may be explained by elevated temperature and presence of partial melts. The changes of lithospheric structures are sharp between the Tibetan Plateau and the bounding Ordos and Alxa blocks, suggesting that these two blocks have restricted the lateral growth of the Tibetan Plateau as rigid boundaries. However, across the northeastern corner of the Tibetan Plateau to the Yinchuan rift, the lithospheric mantle structures are similar, suggesting a lateral mantle flow from the Tibetan Plateau to the gap between the Ordos and the Alxa blocks. The crustal structures along this transition show evidence of lateral growth of the Tibetan Plateau. In particular, the edge of thickened crust and evidence of Moho superposition are found between the Haiyuan Fault and the Tianjin-shan Fault, which may have replaced the Haiyuan Fault as the front boundary of the laterally growing Tibetan Plateau in its northeastern corner.

  4. Groundwater in Science Education

    ERIC Educational Resources Information Center

    Dickerson, Daniel L.; Penick, John E.; Dawkins, Karen R.; Van Sickle, Meta

    2007-01-01

    Although clean, potable groundwater constitutes one of our most valuable resources, few students or science educators hold complete and appropriate understandings regarding the concept. Recent studies that focus on secondary students' and preservice science teachers' understandings of groundwater found little difference between the groups'…

  5. Human health and groundwater

    USDA-ARS?s Scientific Manuscript database

    The high quality of most groundwaters, consequent upon the self-purification capacity of subsurface strata, has long been a key factor in human health and wellbeing. More than 50% of the world’s population now rely on groundwater for their supply of drinking water – and in most circumstances a prope...

  6. Groundwater and Distribution Workbook.

    ERIC Educational Resources Information Center

    Ekman, John E.

    Presented is a student manual designed for the Wisconsin Vocational, Technical and Adult Education Groundwater and Distribution Training Course. This program introduces waterworks operators-in-training to basic skills and knowledge required for the operation of a groundwater distribution waterworks facility. Arranged according to the general order…

  7. Groundwater pollution microbiology

    SciTech Connect

    Bitton, G.; Gerba, C.P.

    1984-01-01

    This book provides a survey of available information on groundwater pollution microbiology. It is useful as a starting point for students and professionals investigating this topic. Subjects discussed include bacteria and virus movement through soils, carcinogenicity of some organic chemicals detected in groundwater, sampling techniques, and land treatment systems. Include references to the journal literature and a subject index.

  8. Groundwater in Science Education

    ERIC Educational Resources Information Center

    Dickerson, Daniel L.; Penick, John E.; Dawkins, Karen R.; Van Sickle, Meta

    2007-01-01

    Although clean, potable groundwater constitutes one of our most valuable resources, few students or science educators hold complete and appropriate understandings regarding the concept. Recent studies that focus on secondary students' and preservice science teachers' understandings of groundwater found little difference between the groups'…

  9. Groundwater and Distribution Workbook.

    ERIC Educational Resources Information Center

    Ekman, John E.

    Presented is a student manual designed for the Wisconsin Vocational, Technical and Adult Education Groundwater and Distribution Training Course. This program introduces waterworks operators-in-training to basic skills and knowledge required for the operation of a groundwater distribution waterworks facility. Arranged according to the general order…

  10. Groundwater and organic chemicals

    SciTech Connect

    Dawson, H.E.

    1995-12-01

    Groundwater is a major source of drinking water for many communities. Unfortunately, organic chemicals such as dry cleaning fluids, solvent, fuels, and pesticides have contaminated groundwater in many areas, rendering the groundwater useless as a drinking water resource. In many cases, the groundwater cannot be cleaned up with current technologies, particularly if the groundwater has been contaminated with immiscible (low solubility) organic liquids. In this talk, I will describe the path I have followed from geologist to geochemist and finally to environmental engineer. As a geologist, I studied the chemistry of rock metamorphosis. As a geochemist, I explored for gold and other metals. Now as an environmental engineer, I investigate the behavior of organic liquids in the subsurface. While these fields all appear very different, in reality I have always focused on the interaction of rocks or sediments with the fluids with which they come in contact.

  11. Estimating groundwater recharge

    USGS Publications Warehouse

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    Understanding groundwater recharge is essential for successful management of water resources and modeling fluid and contaminant transport within the subsurface. This book provides a critical evaluation of the theory and assumptions that underlie methods for estimating rates of groundwater recharge. Detailed explanations of the methods are provided - allowing readers to apply many of the techniques themselves without needing to consult additional references. Numerous practical examples highlight benefits and limitations of each method. Approximately 900 references allow advanced practitioners to pursue additional information on any method. For the first time, theoretical and practical considerations for selecting and applying methods for estimating groundwater recharge are covered in a single volume with uniform presentation. Hydrogeologists, water-resource specialists, civil and agricultural engineers, earth and environmental scientists and agronomists will benefit from this informative and practical book. It can serve as the primary text for a graduate-level course on groundwater recharge or as an adjunct text for courses on groundwater hydrology or hydrogeology.

  12. Compartment syndrome after tibial plateau fracture☆

    PubMed Central

    Pitta, Guilherme Benjamin Brandão; dos Santos, Thays Fernanda Avelino; dos Santos, Fernanda Thaysa Avelino; da Costa Filho, Edelson Moreira

    2014-01-01

    Fractures of the tibial plateau are relatively rare, representing around 1.2% of all fractures. The tibia, due to its subcutaneous location and poor muscle coverage, is exposed and suffers large numbers of traumas, not only fractures, but also crush injuries and severe bruising, among others, which at any given moment, could lead compartment syndrome in the patient. The case is reported of a 58-year-old patient who, following a tibial plateau fracture, presented compartment syndrome of the leg and was submitted to decompressive fasciotomy of the four right compartments. After osteosynthesis with internal fixation of the tibial plateau using an L-plate, the patient again developed compartment syndrome. PMID:26229779

  13. The Hikurangi Plateau: Tectonic Ricochet and Accretion

    NASA Astrophysics Data System (ADS)

    Willis, David; Moresi, Louis; Betts, Peter; Whittaker, Joanne

    2015-04-01

    80 million years between interactions with different subduction systems provided time for the Hikurangi Plateau and Pacific Ocean lithosphere to cool, densify and strengthen. Neogene subduction of the Hikurangi Plateau occurring orthogonal to its Cretaceous predecessor, provides a unique opportunity to explore how changes to the physical properties of oceanic lithosphere affect subduction dynamics. We used Underworld to build mechanically consistent collision models to understand the dynamics of the two Hikurangi collisions. The Hikurangi Plateau is a ~112 Ma, 15km thick oceanic plateau that has been entrained by subduction zones immediately preceding the final break-up of Eastern Gondwana and currently within the active Hikurangi Margin. We explore why attempted subduction of the plateau has resulted in vastly different dynamics on two separate occasions. Slab break-off occured during the collision with Gondwana, currently there is apparent subduction of the plateau underneath New Zealand. At ~100Ma the young, hot Hikurangi Plateau, positively buoyant with respect to the underlying mantle, impacted a Gondwana Margin under rapid extension after the subduction of an mid-ocean ridge 10-15Ma earlier. Modelling of plateaus within young oceanic crust indicates that subduction of the thickened crust was unlikely to occur. Frontal accretion of the plateau and accompanying slab break-off is expected to have occured rapidly after its arrival. The weak, young slab was susceptible to lateral propagation of the ~1500 km window opened by the collision, and break-off would have progressed along the subduction zone inhibiting the "step-back" of the trench seen in older plates. Slab break-off coincided with a world-wide reorganisation of plate velocites, and orogenic collapse along the Gondwana margin characterised by rapid extension and thinning of the over-riding continental plate from ~60 to 30km. Following extension, Zealandia migrated to the NW until the Miocene allowing the

  14. Evolutionary History and Conservation Status of Cave Crayfishes Along the Cumberland Plateau

    NASA Astrophysics Data System (ADS)

    Buhay, J. E.; Crandall, K. A.

    2005-05-01

    Obligate cave-dwelling crayfish species are found only in southeastern United States, Mexico, and Cuba. Most species are considered to be endangered because of surface pollution threats to groundwater and small geographic distributions. There are currently three subterranean species of the genus Orconectes found along the Cumberland Plateau, a worldwide hotspot of cave biodiversity. The objectives of my dissertation research are to: 1) delineate species' boundaries using molecular genetic data in a phylogenetic framework, 2) examine evolutionary history of each species using Nested Clade Analysis, and 3) assess conservation status of each species using measures of effective population size and genetic diversity. This research project has uncovered a new species of cave crayfish along the border of Tennessee and Kentucky, an area previously thought to have "intergrades" between two subspecies of O. australis. It appears that Cambarus gentryi, a surface-dwelling burrowing species, is the closest living ancestor to the cave Orconectes assemblage on the Plateau. The origin appears to be Eastern Kentucky, with range expansions occuring southward down the Plateau. Although controversial, these cave species exhibit high levels of genetic diversity, especially in comparison to surface-dwellers. Conservation efforts should focus on protecting `high-traffic' areas to maintain gene flow and prevent isolation.

  15. Tectonomagmatic Associations on the Central Andean Plateau

    NASA Astrophysics Data System (ADS)

    de Silva, S. L.; Viramonte, J. G.

    2012-12-01

    The Neogene evolution of the Central Andes is characterized by a strong association between plate convergence, mountain building and plateau formation, and magmatism. Plateau uplift by crustal shortening and thickening in the lower crust is broadly coincident with large scale silicic magmatism defined by the Neogene Central Andean ignimbrite province. Of particular interest here are the spatiotemporal correlations between silicic magmatism and tectonic evolution of the Altiplano-Puna plateau. Although magmatism is driven by the subduction-related flux from mantle to crust, the shift to "crustal" magmatism as indicated by elevated crustal isotopic indices after ~10Ma suggests a link between crustal thickening, plateau formation and silicic magmatism. In particular, elevated geotherms associated with crustal thickening and enhanced mantle flux associated with lithospheric delamination may have played a role in thermally preparing the Central Andean crust for enhanced silicic magma production during the extensive Neogene ignimbrite flare-up. Emplacement of these magmas in the upper crust throughout the Neogene may have fuelled a period of significant interaction between magmatism and tectonism on the plateau. With particular reference to the 21° to 24°S segment of the Central Andes, spatial and structural coincidence of calderas of the Altiplano Puna Volcanic Complex with the NW-SE striking Calama-Olacapata-El Toro fault zone suggests significant tectonomagmatic interaction. Location of calderas suggest that these regional faults focused magma intrusion and storage, while spatially and temporally correlated eruption pulses connote a tectonic control. Indeed, current thermomechanical models of magma chamber development and eruption triggering promote a role for external triggering of "perched" upper crustal magma chambers. This might have been achieved by melt-enhanced deformation, or alternatively, significant uplift (~1km) associated with the development of large

  16. HANFORD SITE CENTRAL PLATEAU CLEANUP COMPLETION STRATEGY

    SciTech Connect

    BERGMAN TB

    2011-01-14

    Cleanup of the Hanford Site is a complex and challenging undertaking. The U.S. Department of Energy (DOE) has developed a comprehensive vision for completing Hanford's cleanup mission including transition to post-cleanup activities. This vision includes 3 principle components of cleanup: the {approx}200 square miles ofland adjacent to the Columbia River, known as the River Corridor; the 75 square miles of land in the center of the Hanford Site, where the majority of the reprocessing and waste management activities have occurred, known as the Central Plateau; and the stored reprocessing wastes in the Central Plateau, the Tank Wastes. Cleanup of the River Corridor is well underway and is progressing towards completion of most cleanup actions by 2015. Tank waste cleanup is progressing on a longer schedule due to the complexity of the mission, with construction of the largest nuclear construction project in the United States, the Waste Treatment Plant, over 50% complete. With the progress on the River Corridor and Tank Waste, it is time to place increased emphasis on moving forward with cleanup of the Central Plateau. Cleanup of the Hanford Site has been proceeding under a framework defmed in the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement). In early 2009, the DOE, the State of Washington Department of Ecology, and the U.S. Environmental Protection Agency signed an Agreement in Principle in which the parties recognized the need to develop a more comprehensive strategy for cleanup of the Central Plateau. DOE agreed to develop a Central Plateau Cleanup Completion Strategy as a starting point for discussions. This DOE Strategy was the basis for negotiations between the Parties, discussions with the State of Oregon, the Hanford Advisory Board, and other Stakeholder groups (including open public meetings), and consultation with the Tribal Nations. The change packages to incorporate the Central Plateau Cleanup Completion Strategy were signed by

  17. Peopling the Tibetan plateau: insights from archaeology.

    PubMed

    Aldenderfer, Mark

    2011-01-01

    Recent studies of the genome of modern Tibetans have revealed the existence of genes thought to provide an adaptive advantage for life at high elevation. Extrapolating from this discovery, some researchers now argue that a Tibetan-Han split occurred no more than 2750 yr ago. This date is implausible, and in this paper I review the archaeological data from the Tibetan plateau as one means by which to examine the veracity of this assertion. Following a review of the general state of knowledge of Tibetan prehistory, which is unfortunately only at its beginnings, I first examine the data that speak to the initial peopling of the plateau and assess the evidence that traces of their presence can be seen in modern Tibetans today. Although the data are sparse, both archaeology and genetics suggest that the plateau was occupied in the Late Pleistocene, perhaps as early as 30,000 yr ago, and that these early peoples have left a genetic signature in modern Tibetans. I then turn to the evidence for later migrations and focus on the question of the timing of the establishment of permanent settled villages on the plateau. Three areas of the plateau-northeastern Qinghai, extreme eastern Tibet, and the Yarlung Tsangpo valley-have evidence of permanent settlements dating from ca. 6500, 5900, and 3750 yr ago, respectively. These data are not consonant with the 2750 yr ago date for the split and suggest at a minimum that the plateau has been occupied substantially longer and, further, that multiple migrations at different times and from different places have created a complex mosaic of population history.

  18. Projected impacts of climate change on farmers' extraction of groundwater from crystalline aquifers in South India

    NASA Astrophysics Data System (ADS)

    Ferrant, Sylvain; Caballero, Yvan; Perrin, Jérome; Gascoin, Simon; Dewandel, Benoit; Aulong, Stéphanie; Dazin, Fabrice; Ahmed, Shakeel; Maréchal, Jean-Christophe

    2014-01-01

    Local groundwater levels in South India are falling alarmingly. In the semi-arid crystalline Deccan plateau area, agricultural production relies on groundwater resources. Downscaled Global Climate Model (GCM) data are used to force a spatially distributed agro-hydrological model in order to evaluate Climate Change (CC) effects on local groundwater extraction (GWE). The slight increase of precipitation may alleviate current groundwater depletion on average, despite the increased evaporation due to warming. Nevertheless, projected climatic extremes create worse GWE shortages than for present climate. Local conditions may lead to opposing impacts on GWE, from increases to decreases (+/-20 mm/year), for a given spatially homogeneous CC forcing. Areas vulnerable to CC in terms of irrigation apportionment are thus identified. Our results emphasize the importance of accounting for local characteristics (water harvesting systems and maximal aquifer capacity versus GWE) in developing measures to cope with CC impacts in the South Indian region.

  19. Projected impacts of climate change on farmers' extraction of groundwater from crystalline aquifers in South India

    PubMed Central

    Ferrant, Sylvain; Caballero, Yvan; Perrin, Jérome; Gascoin, Simon; Dewandel, Benoit; Aulong, Stéphanie; Dazin, Fabrice; Ahmed, Shakeel; Maréchal, Jean-Christophe

    2014-01-01

    Local groundwater levels in South India are falling alarmingly. In the semi-arid crystalline Deccan plateau area, agricultural production relies on groundwater resources. Downscaled Global Climate Model (GCM) data are used to force a spatially distributed agro-hydrological model in order to evaluate Climate Change (CC) effects on local groundwater extraction (GWE). The slight increase of precipitation may alleviate current groundwater depletion on average, despite the increased evaporation due to warming. Nevertheless, projected climatic extremes create worse GWE shortages than for present climate. Local conditions may lead to opposing impacts on GWE, from increases to decreases (+/−20 mm/year), for a given spatially homogeneous CC forcing. Areas vulnerable to CC in terms of irrigation apportionment are thus identified. Our results emphasize the importance of accounting for local characteristics (water harvesting systems and maximal aquifer capacity versus GWE) in developing measures to cope with CC impacts in the South Indian region. PMID:24424295

  20. The CHPRC Groundwater and Technical Integration Support (Master Project) Quality Assurance Management Plan

    SciTech Connect

    Fix, N. J.

    2009-04-03

    The scope of the CH2M Hill Plateau Remediation Company, LLC (CHPRC) Groundwater and Technical Integration Support (Master Project) is for Pacific Northwest National Laboratory staff to provide technical and integration support to CHPRC. This work includes conducting investigations at the 300-FF-5 Operable Unit and other groundwater operable units, and providing strategic integration, technical integration and assessments, remediation decision support, and science and technology. The projects under this Master Project will be defined and included within the Master Project throughout the fiscal year, and will be incorporated into the Master Project Plan. This Quality Assurance Management Plan provides the quality assurance requirements and processes that will be followed by the CHPRC Groundwater and Technical Integration Support (Master Project) and all releases associated with the CHPRC Soil and Groundwater Remediation Project. The plan is designed to be used exclusively by project staff.

  1. Insufficiency fractures of the tibial plateau

    SciTech Connect

    Manco, L.G.; Schneider, R.; Pavlov, H.

    1983-06-01

    An insufficiency fracture of the tibial plateau may be the cause of knee pain in patients with osteoporosis. The diagnosis is usually not suspected until a bone scan is done, as initial radiographs are often negative or inconclusive and clinical findings are nonspecific and may simulate osteoarthritis or spontaneous osteonecrosis. In five of 165 patients referred for bone scans due to nontraumatic knee pain, a characteristic pattern of intense augmented uptake of radionuclide confined to the tibial plateau led to a presumptive diagnosis of insufficiency fracture, later confirmed on radiographs.

  2. Outcome of Posterior Tibial Plateau Fixation.

    PubMed

    Jiwanlal, Aneel; Jeray, Kyle James

    2016-01-01

    Isolated posterior tibial plateau fractures are rare injuries that encompass a wide variety of fracture patterns. Based on the variation in fracture pattern, the surgical approach varies, with both anterior and posterior approaches described for surgical fixation. Postoperative protocol also varies among studies. The aim of this article is to summarize the outcomes related to posterior column tibial plateau fractures. The papers reviewed, primarily small retrospective case series, showed functional knee range of motion is preserved, a low incidence of wound complications, and patient outcome scores comparable to other reported lower extremity injury outcome scores. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. Groundwater quality in the San Francisco Bay groundwater basins, California

    USGS Publications Warehouse

    Parsons, Mary C.; Kulongoski, Justin T.; 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 groundwater quality and increases public access to groundwater-quality information. Selected groundwater basins of the San Francisco Bay area constitute one of the study units being evaluated.

  4. Groundwater contamination in Japan

    NASA Astrophysics Data System (ADS)

    Tase, Norio

    1992-07-01

    Problems on groundwater contamination in Japan are briefly summarized in this paper. Although normal physical conditions in Japan restrict the possibilities of groundwater contamination, human activities are threatening groundwater resources. A survey by the Environment Agency of Japan showed nationwide spreading of organic substances, such as trichloroethylene as well as nitrogen compounds. Synthetic detergents have also been detected even in rural areas and in deep confined aquifers, although their concentrations are not as high. Public awareness of agrichemical or pesticides abuse, especially from golf courses, is apparent. Other problems such as nitrate-nitrogen, leachate from landfills, and the leaking of underground storage tanks are also discussed.

  5. Groundwater data network interoperability

    USGS Publications Warehouse

    Brodaric, Boyan; Booth, Nathaniel; Boisvert, Eric; Lucido, Jessica M.

    2016-01-01

    Water data networks are increasingly being integrated to answer complex scientific questions that often span large geographical areas and cross political borders. Data heterogeneity is a major obstacle that impedes interoperability within and between such networks. It is resolved here for groundwater data at five levels of interoperability, within a Spatial Data Infrastructure architecture. The result is a pair of distinct national groundwater data networks for the United States and Canada, and a combined data network in which they are interoperable. This combined data network enables, for the first time, transparent public access to harmonized groundwater data from both sides of the shared international border.

  6. [Groundwater pollution risk mapping method].

    PubMed

    Shen, Li-na; Li, Guang-he

    2010-04-01

    Based on methods for groundwater vulnerability assessment not involving in contamination source elements, and lack of the systemic and effective techniques and parameter system on groundwater pollution risk mapping in present, through analyzing the structure of groundwater system and characteristics of contaminant sources, and coupling groundwater intrinsic vulnerability with contaminant sources, the integrated multi-index models were developed to evaluate the risk sources of groundwater contaminant and form the groundwater pollution risk mapping in this paper. The models had been used to a large-scale karst groundwater source of northern China as a case study. The results indicated that vulnerability assessment overlaid risk pollution sources of groundwater could effectively confirm the high risk regions of groundwater pollution, and the methods might provide necessary support for the supervision of groundwater pollution.

  7. Evaluating the coupling effects of climate aridity and vegetation restoration on soil erosion over the Loess Plateau in China.

    PubMed

    Zhang, Baoqing; He, Chansheng; Burnham, Morey; Zhang, Lanhui

    2016-01-01

    In this study, the coupling effects of climate aridity and vegetation restoration on runoff and sediment yield over the Loess Plateau were examined and characterized. To take into consideration the complexity of drought, as well as the varied strengths and weaknesses of different drought measures, two drought indices are selected to identify and evaluate drought variability. The Normalized Difference Vegetation Index (NDVI) data were obtained to monitor and express spatiotemporal variations in vegetation cover. The results show that most regions of the Loess Plateau experienced increasingly severe droughts over the past 40years, and these regions comprise the major source of the Yellow River sediment. Climatic drying initially occurred in the 1990s, and became statistically significant in 2000s. The increasingly severe droughts could negatively impact surface and groundwater supplies as well as soil water storage, but may also minimize surface runoff yield, which is one of the major causes of soil erosion on the Loess Plateau. Vegetation cover on the Loess Plateau was significantly improved after the implementation of "Grain for Green" project, which were helpful for controlling severe soil erosion. With the impacts of the construction of check dams, terraces and large reservoirs, runoff and sediment yield over the Loess Plateau initially exhibited downward trends between 1970 and 1990. After 1990, with the effects of the climate warming and drying, a second sharp reduction in runoff and sediment yield occurred. The coupling effects of climate aridity and vegetation restoration have led to a third significant decrease in runoff and sediment yield over the Loess Plateau after 2000. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Central Tibetan Meso-Tethyan oceanic plateau

    NASA Astrophysics Data System (ADS)

    Zhang, Kai-Jun; Xia, Bin; Zhang, Yu-Xiu; Liu, Wei-Liang; Zeng, Lu; Li, Jian-Feng; Xu, Li-Feng

    2014-12-01

    We report the occurrences of the remnants of a Meso-Tethyan oceanic plateau, encompassing an area of ~ 2 × 105 km2 in central Tibet. The plateau remnants include large volumes of pillow basalt formed largely by emergent to subaerial eruption, minor ultramafic intrusives and cumulates, exotic blocks of limestone, radiolarian chert, graywacke, and shale. Isotopic and paleontological dating suggest two major plateau eruptive events at 193-173 Ma and at 128-104 Ma, respectively. The basalts are characterized by enrichment of incompatible elements and a wide range of Sr-Nd isotope composition (initial εNd from -3.71 to + 7.9, initial 87Sr/86Sr from 0.703927 to 0.707618). The trace element and Sr-Nd isotopic data suggest that these basalts are of affinity with those from the Kerguelen and Tethyan plumes, indicative of a plume mantle upwelling origin with involvement of continental material. The wholesale obduction of the Meso-Tethyan oceanic plateau, along with the dismembered normal oceanic crustal fragments, over the Tibetan continental crust could have given rise to perhaps 2 km elevation of central Tibet during the Late Cretaceous.

  9. Structure and sedimentary history of Exmouth Plateau

    SciTech Connect

    Exon, N.F.; Williamson, P.E.; Von Rad, U.

    1989-03-01

    The large, deep-water Exmouth Plateau off northwestern Australia has been actively explored for petroleum, and a giant gas accumulation has been found. Data from industry and research institutions have established its geological framework. The plateau has a basement of continental crust that was thinned and extended in the Permian. This is overlain by 10 km of Phanerozoic strata, with an average of more than 3 km of Triassic, about 1 km of Jurassic/Cretaceous, and 0.5 km of Cenozoic strata. The plateau separated from other parts of the northern margin of Gondwanaland in the Mesozoic. Latest Triassic and Jurassic rifting formed large north-northeast-trending fault blocks; in the Oxfordian a microcontinent drifted away to the northwest, forming the plateau's northern margin. The other margins developed in the Neocomian as Greater India separated from Australia - the western margin by rifting and the southern by shearing. Terrigenous input declined greatly at that time. This old continental margin, with its relatively thin Mesozoic and Cenozoic sediments, was selected by the Ocean Drilling Program (ODP) for comprehensive and fully integrated sedimentologic, biostratigraphic, paleobathymetric, and subsidence studies.

  10. Forest statistics for plateau Tennessee counties

    Treesearch

    Renewable Resources Evaluation Research Work Unit

    1982-01-01

    These tables were derived from data obtained during a 1980 inventory of 16 counties comprising the Plateau Unit of Tennessee (fib. 1). The data on forest acreage and timber volume were secured by a systematic sampling method involving a forest-nonforest classification on aerial photographs and on-the-ground measurements of trees at sample locations. The sample...

  11. A Standard Atmosphere of the Antarctic Plateau

    NASA Technical Reports Server (NTRS)

    Mahesh, Ashwin; Lubin, Dan

    2004-01-01

    Climate models often rely on standard atmospheres to represent various regions; these broadly capture the important physical and radiative characteristics of regional atmospheres, and become benchmarks for simulations by researchers. The high Antarctic plateau is a significant region of the earth for which such standard atmospheres are as yet unavailable. Moreover, representative profiles from atmospheres over other regions of the planet, including &om the northern high latitudes, are not comparable to the atmosphere over the Antarctic plateau, and are therefore only of limited value as substitutes in climate models. Using data from radiosondes, ozonesondes and satellites along with other observations from South Pole station, typical seasonal atmospheric profiles for the high plateau are compiled. Proper representations of rapidly changing ozone concentrations (during the ozone hole) and the effect of surface elevation on tropospheric temperatures are discussed. The differences between standard profiles developed here and the most similar standard atmosphere that already exists - namely, the Arctic Winter profile - suggest that these new profiles will be extremely useful to make accurate representations of the atmosphere over the high plateau.

  12. Estimating groundwater recharge

    USGS Publications Warehouse

    Stonestrom, David A.

    2011-01-01

    Groundwater recharge is the entry of fresh water into the saturated portion of the subsurface part of the hydrologic cycle, the modifier "saturated" indicating that the pressure of the pore water is greater than atmospheric.

  13. Bioremediation of contaminated groundwater

    SciTech Connect

    Hazen, T.C.; Fliermans, C.B.

    1992-12-31

    The present invention relates to a method for in situ bioremediation of contaminated soil and groundwater. In particular, the invention relates to remediation of contaminated soil and groundwater by the injection of nutrients to stimulate growth of pollutant-degrading microorganisms. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.

  14. Bioremediation of groundwater pollution.

    PubMed

    Crawford, R L

    1991-06-01

    Significant progress has been made in the past year towards an understanding of the microbial processes in subsurface environments that may allow natural microbial populations to be employed for bioremediation of groundwater pollution. Among the highlights were: the discovery of several previously unknown xenobiotic-degrading abilities in groundwater microorganisms; progress in using the unique abilities of methanotrophs to oxidize halogenated solvents; and characterizations of microbial populations from subsurface soils.

  15. High-fluoride groundwater.

    PubMed

    Rao, N Subba

    2011-05-01

    Fluoride (F(-)) is essential for normal bone growth, but its higher concentration in the drinking water poses great health problems and fluorosis is common in many parts of India. The present paper deals with the aim of establishment of facts of the chemical characteristics responsible for the higher concentration of F(-) in the groundwater, after understanding the chemical behavior of F(-) in relation to pH, total alkalinity (TA), total hardness (TH), carbonate hardness (CH), non-carbonate hardness (NCH), and excess alkalinity (EA) in the groundwater observed from the known areas of endemic fluorosis zones of Andhra Pradesh that have abundant sources of F(-)-bearing minerals of the Precambrians. The chemical data of the groundwater shows that the pH increases with increase F(-); the concentration of TH is more than the concentration of TA at low F(-) groundwater, the resulting water is represented by NCH; the TH has less concentration compared to TA at high F(-) groundwater, causing the water that is characterized by EA; and the water of both low and high concentrations of F(-) has CH. As a result, the F(-) has a positive relation with pH and TA, and a negative relation with TH. The operating mechanism derived from these observations is that the F(-) is released from the source into the groundwater by geochemical reactions and that the groundwater in its flowpath is subjected to evapotranspiration due to the influence of dry climate, which accelerates a precipitation of CaCO(3) and a reduction of TH, and thereby a dissolution of F(-). Furthermore, the EA in the water activates the alkalinity in the areas of alkaline soils, leading to enrichment of F(-). Therefore, the alkaline condition, with high pH and EA, and low TH, is a more conducive environment for the higher concentration of F(-) in the groundwater.

  16. Tectonostratigraphic evolution of Falkland (Malvinas) Plateau

    SciTech Connect

    Snavely, P.D. III

    1987-05-01

    The Falkland (a.k.a. Malvinas) Plateau, offshore southern Argentina, came into being as the result of the Late Jurassic-Early Cretaceous breakup of west Gondwanaland and the opening of the South Atlantic. As the trailing edge of the South American plate, this continental salient has periodically interacted with the African, Antarctic, Scotia, and Nazca plates, recording the complex history of Mesozoic and Cenozoic plate reorganization in the Southern Hemisphere. The pelagic depositional setting of the plateau following its separation from Africa has resulted in the accumulation of a relatively thin post-rift sedimentary section. This has allowed not only local penetration of the lower Mesozoic section by borehole but also seismic resolution of the pre- and syn-rift strata beyond that generally obtainable from the thick marine basins of the Argentine or South African continental shelves. These subsurface data have been used to compile a relatively complete depositional and tectonic history for the Falkland Plateau which may be applied, by analogy, to sedimentary basins of similar age along the circum-Gondwana perimeter. Three principal tectonic events appear to have influenced the type and orientation of structures and the distribution of stratal patterns presently observed on the Falkland Plateau. These are (1) a Permo-Triassic compressional event (Cape orogeny) that resulted in the formation of a fold-belt running from northwest Argentina through South Africa and across the Falkland Plateau to Antarctica, (2) the two-stage breakup of the Gondwana supercontinent from Late Triassic to Early Cretaceous time, and (3) the Tertiary opening of the Drake Passage and the formation of the Scotia Sea.

  17. Regional Seismotectonics in the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Zhao, Z.; Xu, J.; Zhao, Z.

    2009-12-01

    The relationships among the depth of lithosphere brittle fracture, seismotectonics and geothermal anomalous active in Tibetan plateau were investigated using the seismic dada from ISC and Chinese seismic net and geothermal data. The results suggest that the region of anomalously geothermal activity almost coincides that of the normal faulting type earthquake. The geothermal anomaly activity region coincides spatially with that of the events deeper than 60 km as well as. The normal faulting earthquakes may be mainly tectonic activity regimes until 110 km deep in the thermal anomaly region. The strike directions of events are likely the N-S direction, coinciding with the strike of the thermal anomaly active belts. The earthquakes align along the normal faults and faulted-depression zone with the N-S direction. The thermal anomaly activity also distributes along the faulted-depression zone. Many events deeper than 60 km exist in the anomalously geothermal activity region in the plateau. Events extend to bottom of the lithosphere of 110km from the surface, like columnar seismic crowd. The lithosphere extends along the E-W direction due to the E-W extensional stress in the central and southern Tibetan plateau, altitude of the plateau. The tensional stress in the E-W results in the lithosphere fractures and the normal faults striking N-S direction, grabens and faulted-depression zones. Thermal material from the asthenosphere wells upward to the surface along deep seismic fractures and faults through the thick crust. The anomalously thermal activities are attributable to the upwelling thermal material from the mantle in the altitude of Tibetan plateau.

  18. Applications of Groundwater Helium

    USGS Publications Warehouse

    Kulongoski, Justin T.; Hilton, David R.

    2011-01-01

    Helium abundance and isotope variations have widespread application in groundwater-related studies. This stems from the inert nature of this noble gas and the fact that its two isotopes ? helium-3 and helium-4 ? have distinct origins and vary widely in different terrestrial reservoirs. These attributes allow He concentrations and 3He/4He isotope ratios to be used to recognize and quantify the influence of a number of potential contributors to the total He budget of a groundwater sample. These are atmospheric components, such as air-equilibrated and air-entrained He, as well as terrigenic components, including in situ (aquifer) He, deep crustal and/or mantle He and tritiogenic 3He. Each of these components can be exploited to reveal information on a number of topics, from groundwater chronology, through degassing of the Earth?s crust to the role of faults in the transfer of mantle-derived volatiles to the surface. In this review, we present a guide to how groundwater He is collected from aquifer systems and quantitatively measured in the laboratory. We then illustrate the approach of resolving the measured He characteristics into its component structures using assumptions of endmember compositions. This is followed by a discussion of the application of groundwater He to the types of topics mentioned above using case studies from aquifers in California and Australia. Finally, we present possible future research directions involving dissolved He in groundwater.

  19. Integrated groundwater data management

    USGS Publications Warehouse

    Fitch, Peter; Brodaric, Boyan; Stenson, Matt; Booth, Nathaniel; Jakeman, Anthony J.; Barreteau, Olivier; Hunt, Randall J.; Rinaudo, Jean-Daniel; Ross, Andrew

    2016-01-01

    The goal of a data manager is to ensure that data is safely stored, adequately described, discoverable and easily accessible. However, to keep pace with the evolution of groundwater studies in the last decade, the associated data and data management requirements have changed significantly. In particular, there is a growing recognition that management questions cannot be adequately answered by single discipline studies. This has led a push towards the paradigm of integrated modeling, where diverse parts of the hydrological cycle and its human connections are included. This chapter describes groundwater data management practices, and reviews the current state of the art with enterprise groundwater database management systems. It also includes discussion on commonly used data management models, detailing typical data management lifecycles. We discuss the growing use of web services and open standards such as GWML and WaterML2.0 to exchange groundwater information and knowledge, and the need for national data networks. We also discuss cross-jurisdictional interoperability issues, based on our experience sharing groundwater data across the US/Canadian border. Lastly, we present some future trends relating to groundwater data management.

  20. Availability and chemistry of ground water on the Bruneau Plateau and adjacent eastern plain in Twin Falls County, south-central Idaho

    USGS Publications Warehouse

    Moffatt, R.L.; Jones, M.L.

    1984-01-01

    The Bruneau plateau in south-central Idaho consists of about 889 ,600 acres of potentially irrigable land. About 112,200 of these acres have been developed for agriculture; 11,200 acres are irrigated with ground water, and the remaining acreage is irrigated with water from the Snake and Bruneau rivers and Salmon Falls Creek. On the basis of present usage, about 158,000 acre-feet of water per year are needed to develop an additional 63,000 acres. About 438,000 acre-feet per year are needed to irrigate existing and newly developed lands in dry years when streamflow in the Snake River at Milner Dam is inadequate to meet appropriated needs. Pumping lifts of about 400-600 feet and low well yields on the Bruneau plateau probably preclude large-scale irrigation development solely from local ground-water resources. However, supplemental sources of irrigation water are available from a perched-water aquifer, a thermal aquifer, and the regional aquifer adjacent to the plateau. About 100,000-115,000 acre-feet per year of water probably could be withdrawn from the perched and regional aquifers and conveyed to the plateau without serious impact on local ground-water resources. The amount of water that could be safely withdrawn from the thermal aquifer was not determined. (USGS)

  1. Exchange of groundwater and surface-water mediated by permafrost response to seasonal and long term air temperature variation

    USGS Publications Warehouse

    Ge, S.; McKenzie, J.; Voss, C.; Wu, Q.

    2011-01-01

    Permafrost dynamics impact hydrologic cycle processes by promoting or impeding groundwater and surface water exchange. Under seasonal and decadal air temperature variations, permafrost temperature changes control the exchanges between groundwater and surface water. A coupled heat transport and groundwater flow model, SUTRA, was modified to simulate groundwater flow and heat transport in the subsurface containing permafrost. The northern central Tibet Plateau was used as an example of model application. Modeling results show that in a yearly cycle, groundwater flow occurs in the active layer from May to October. Maximum groundwater discharge to the surface lags the maximum subsurface temperature by two months. Under an increasing air temperature scenario of 3C per 100 years, over the initial 40-year period, the active layer thickness can increase by three-fold. Annual groundwater discharge to the surface can experience a similar three-fold increase in the same period. An implication of these modeling results is that with increased warming there will be more groundwater flow in the active layer and therefore increased groundwater discharge to rivers. However, this finding only holds if sufficient upgradient water is available to replenish the increased discharge. Otherwise, there will be an overall lowering of the water table in the recharge portion of the catchment. Copyright 2011 by the American Geophysical Union.

  2. Exchange of Groundwater and Surface-Water Mediated by Permafrost Response to Seasonal and Long Term Air Temperature Variation

    USGS Publications Warehouse

    Ge, Shemin; McKenzie, Jeffrey; Voss, Clifford; Wu, Qingbai

    2011-01-01

    Permafrost dynamics impact hydrologic cycle processes by promoting or impeding groundwater and surface water exchange. Under seasonal and decadal air temperature variations, permafrost temperature changes control the exchanges between groundwater and surface water. A coupled heat transport and groundwater flow model, SUTRA, was modified to simulate groundwater flow and heat transport in the subsurface containing permafrost. The northern central Tibet Plateau was used as an example of model application. Modeling results show that in a yearly cycle, groundwater flow occurs in the active layer from May to October. Maximum groundwater discharge to the surface lags the maximum subsurface temperature by two months. Under an increasing air temperature scenario of 3?C per 100 years, over the initial 40-year period, the active layer thickness can increase by three-fold. Annual groundwater discharge to the surface can experience a similar three-fold increase in the same period. An implication of these modeling results is that with increased warming there will be more groundwater flow in the active layer and therefore increased groundwater discharge to rivers. However, this finding only holds if sufficient upgradient water is available to replenish the increased discharge. Otherwise, there will be an overall lowering of the water table in the recharge portion of the catchment.

  3. Water supply at Los Alamos during 1994. Progress report

    SciTech Connect

    McLin, S.G.; Purtymun, W.D.; Stoker, A.K.; Maes, M.N.

    1996-10-01

    Production of potable municipal water supplies during 1994 totaled about 1,426.6 million gallons of wells in the Guaje, Pajarito, and Otowi Fields. The non-potable water supply for industrial use was about 11.6 million gallons from the spring gallery in Water Canyon. There was no water used for irrigation from Guaje or Los Alamos Reservoirs; thus, the total water usage in 1994 was about 1,438.2 million gallons. Pumps in Guaje Well 5 and Otowi Well 4 failed during the year and were not operational by the end of 1994. Water production resumed in Pajarito Well 3 in June. Wells in the Los Alamos Field, on Pueblo Land, were plugged and abandoned in 1992, or were transferred to San Ildefonso Pueblo. This report fulfills requirements which require the Laboratory to monitor and document groundwater conditions below Pajarito Plateau, and to protect the main aquifer from contamination associated with Laboratory operations by providing information on hydrologic characteristics of the main aquifer, including operating conditions of the municipal water supply system.

  4. Limits to global groundwater consumption

    NASA Astrophysics Data System (ADS)

    de Graaf, I.; Van Beek, L. P.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

    2016-12-01

    Groundwater is the largest accessible freshwater resource worldwide and is of critical importance for irrigation, and so for global food security. For many regions of the world where groundwater abstraction exceeds groundwater recharge, persistent groundwater depletion occurs. A direct consequence of depletion is falling groundwater levels, reducing baseflows to rivers, harming ecosystems. Also, pumping costs increase, wells dry up and land subsidence can occur. Water demands are expected to increase further due to growing population, economic development and climate change, posing the urgent question how sustainable current water abstractions are worldwide and where and when these abstractions approach conceivable limits with all the associated problems. Here, we estimated past and future trends (1960-2050) in groundwater levels resulting from changes in abstractions and climate and predicted when limits of groundwater consumption are reached. We explored these limits by predicting where and when groundwater levels drop that low that groundwater becomes unattainable for abstractions and how river flows are affected. Water availabilities, abstractions, and lateral groundwater flows are simulated (5 arcmin. resolution) using a coupled version of the global hydrological model PCR-GLOBWB and a groundwater model based on MODFLOW. The groundwater model includes a parameterization of the worlds confined and unconfined aquifer systems, needed for a realistic simulation of groundwater head dynamics. Results show that, next to the existing regions experiencing groundwater depletion (like India, Pakistan, Central Valley) new regions will develop, e.g. Southern Europe, the Middle East, and Africa. Using a limit that reflects present-day feasibility of groundwater abstraction, we estimate that in 2050 groundwater becomes unattainable for 20% of the global population, mainly in the developing countries and pumping cost will increase significantly. Largest impacts are found

  5. Occurrence of dissolved sodium ground waters in basalts underlying the Columbia Plateau, Washington

    USGS Publications Warehouse

    Bortleson, Gilbert C.; Cox, S.E.

    1986-01-01

    Basalt aquifers of the Columbia River Basalt Group are a principal source of water for agricultural, domestic, and municipal use. Concern has been expressed in this agriculture-dependent region about problems associated with the use of groundwaters with a high sodium concentration relative to the calcium and magnesium content (high sodium-adsorption ratio). Continued irrigation with such waters can reduce soil permeability to the degree that water cannot effectively reach plant roots. Groundwaters within a flow path evolved from a calcium magnesium bicarbonate type in shallow and upgradient locations to a sodium potassium bicarbonate type in deeper and downgradient locations. Most of the intermediate and high sodium adsorption ratio values were observed in discharge areas near major streams and in pumping centers within the central part of the plateau. Ninety-six percent of the groundwaters sampled had a low sodium absorption ratio, indicating that, for irrigation purposes, there is probably little danger of harmful levels of exchangeable sodium occurring on soil. However, water from 18 of 418 wells sampled had a sodium absorption ratio grater than 8.0 and were classified as having a medium, high, or very high sodium hazard. (USGS)

  6. A secondary origin for the central plateau of Hebes Chasma

    NASA Technical Reports Server (NTRS)

    Peterson, C.

    1982-01-01

    Hebes Chasma, one of the northern members of the Valles Marineris, can be divided into three physiographic provinces; chasma walls, chasma floor, and central plateau. Theories of origin of the 5-kilometer-high central plateau include (1) the plateau is an eroded remnant of the surrounding plains, and (2) the plateau is a secondary feature deposited after formation of the chasma. A secondary eolian or pyroclastic origin best explains the morphology of the plateau. The chasma probably formed by collapse of a pre-existing graben that was widened by landslides and subsequently filled with eolian or pyroclastic material. Continued mass wasting isolated the plateau from the chasma walls. The enclosed nature of Hebes Chasma may have inhibited eolian erosion and transport within the trough, so that the relatively fresh appearance of the plateau has been preserved.

  7. PLATEAUING COSMIC RAY DETECTORS TO ACHIEVE OPTIMUM OPERATING VOLTAGE

    SciTech Connect

    Knoff, E.N.; Peterson, R.S.

    2008-01-01

    Through QuarkNet, students across the country have access to cosmic ray detectors in their high school classrooms. These detectors operate using a scintillator material and a photomultiplier tube (PMT). A data acquisition (DAQ) board counts cosmic ray hits from the counters. Through an online e-Lab, students can analyze and share their data. In order to collect viable data, the PMTs should operate at their plateau voltages. In these plateau ranges, the number of counts per minute remains relatively constant with small changes in PMT voltage. We sought to plateau the counters in the test array and to clarify the plateauing procedure itself. In order to most effectively plateau the counters, the counters should be stacked and programmed to record the number of coincident hits as well as their singles rates. We also changed the threshold value that a signal must exceed in order to record a hit and replateaued the counters. For counter 1, counter 2, and counter 3, we found plateau voltages around 1V. The singles rate plateau was very small, while the coincidence plateau was very long. The plateau voltages corresponded to a singles rate of 700–850 counts per minute. We found very little effect of changing the threshold voltages. Our chosen plateau voltages produced good performance studies on the e-Lab. Keeping in mind the nature of the experiments conducted by the high school students, we recommend a streamlined plateauing process. Because changing the threshold did not drastically affect the plateau voltage or the performance study, students should choose a threshold value, construct plateau graphs, and analyze their data using a performance study. Even if the counters operate slightly off their plateau voltage, they should deliver good performance studies and return reliable results.

  8. Limits to Global Groundwater Consumption

    NASA Astrophysics Data System (ADS)

    Graaf, I. D.; Van Beek, R.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

    2015-12-01

    In regions with frequent water stress and large aquifer systems, groundwater is often used as an additional fresh water source. For many regions of the world groundwater abstraction exceeds groundwater recharge and persistent groundwater depletion occurs. The most direct effect of groundwater depletion is declining of water tables, leading to reduced groundwater discharge needed to sustain base-flow to e.g. rivers. Next to that, pumping costs increase, wells dry up and land subsidence occurs. These problems are expected to increase in the near future due to growing population and climate changes. This poses the urgent question of what the limits are of groundwater consumption worldwide. We simulate global water availability (5 arc-minute resolution, for 1960-2050) using the hydrological model PCR-GLOBWB (van Beek et al. 2011), coupled to a groundwater model based on MODFLOW (de Graaf et al. 2015), allowing for groundwater - surface water interactions. The groundwater model includes a parameterization of world's confined and unconfined aquifer systems needed for a realistic simulation of groundwater head dynamics. Water demands are included (from Wada et al. 2014). We study the limits to water consumption, focusing on locally attainable groundwater and groundwater levels critical to rivers to sustain low flows. We show an increasing trend (1960-2050) in groundwater head declines, due to increase in groundwater demand. Also, stream flow will decrease and low flow conditions will occur more frequent and will be longer in duration in the near future, especially for irrigated areas. Next to that, we provide a global overview of the years it takes until groundwater gets unattainable for e.g. a local farmer (100 m below land-surface used as a proxy), and estimate the increase in pumping cost for the near future. The results show where and when limits of groundwater consumption are reached globally.

  9. Age Distribution of Groundwater

    NASA Astrophysics Data System (ADS)

    Morgenstern, U.; Daughney, C. J.

    2012-04-01

    Groundwater at the discharge point comprises a mixture of water from different flow lines with different travel time and therefore has no discrete age but an age distribution. The age distribution can be assessed by measuring how a pulse shaped tracer moves through the groundwater system. Detection of the time delay and the dispersion of the peak in the groundwater compared to the tracer input reveals the mean residence time and the mixing parameter. Tritium from nuclear weapons testing in the early 1960s resulted in a peak-shaped tritium input to the whole hydrologic system on earth. Tritium is the ideal tracer for groundwater because it is an isotope of hydrogen and therefore is part of the water molecule. Tritium time series data that encompass the passage of the bomb tritium pulse through the groundwater system in all common hydrogeologic situations in New Zealand demonstrate a semi-systematic pattern between age distribution parameters and hydrologic situation. The data in general indicate high fraction of mixing, but in some cases also indicate high piston flow. We will show that still, 45 years after the peak of the bomb tritium, it is possible to assess accurately the parameters of age distributions by measuring the tail of the bomb tritium.

  10. PLAN FOR CLOSURE OF HANFORDS CENTRAL PLATEAU

    SciTech Connect

    AUSTIN, B.A.

    2004-12-15

    This paper summarizes an approach to reduce risk to the public and environment through accelerated closure of Hanford's Central Plateau, based on a plan developed by Fluor Hanford and submitted to the Department of Energy (DOE)-Richland Office, for consideration, in September, 2004. This plan provides a framework and starting point for discussions with regulators and further planning for closure activities on the Plateau. The closure strategy and approach required developing a full inventory of items needing closure as well as identifying and defining technical and regulatory approaches that were compatible with current regulatory processes, reduce risks, and met DOE objectives. This effort, and the paper that follows, integrates closure activities among several contractors and two DOE field offices.

  11. Simulation of groundwater withdrawal scenarios for the Redwall-Muav and Coconino Aquifer Systems of northern and central Arizona

    USGS Publications Warehouse

    Pool, D.R.

    2016-09-23

    The Northern Arizona Regional Groundwater Flow Model was used to estimate the hydrologic changes, including water-level change and groundwater discharge to streams and springs, that may result from future changes in groundwater withdrawals in and near the Coconino Plateau Water Advisory Council study area, Coconino and Navajo Counties, Arizona. Three future groundwater withdrawal scenarios for tribal and nontribal uses were developed by the Coconino Plateau Water Advisory Council and were simulated for the period representing the years from 2006 through 2105. Scenario 1 assumes no major changes in groundwater use except for increased demand based on population projections. Scenario 2 assumes that a pipeline will provide a source of surface water from Lake Powell to areas near Cameron and Moenkopi that would replace local groundwater withdrawals. Scenario 3 assumes that the pipeline extends to the Flagstaff and Williams areas, and would replace groundwater demands for water in the area.The Coconino Plateau Water Advisory Council withdrawal scenarios primarily influence water levels and groundwater discharge in the Coconino Plateau basin, near the western margin of the Little Colorado River Plateau basin, and the Verde Valley subbasin. Simulated effects of the withdrawal scenarios are superimposed on effects of previous variations in groundwater withdrawals and artificial and incidental recharge. Pre-scenario variations include changes in water-levels in wells; groundwater storage; discharge to streams and springs; and evapotranspiration by plants that use groundwater. Future variations in groundwater discharge and water-levels in wells will continue to occur as a result of both the past and any future changes.Water-level variations resulting from post-2005 stresses, including groundwater withdrawals and incidental and artificial recharge, in the area of the withdrawal scenarios are primarily localized and superimposed on the regional changes caused by variations in

  12. Ennedi Plateau, Chad/Sudan Border, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This view of the Ennedi Plateau (18.0N, 24.0E) shows the effects of severe wind erosion on this desert landscape in the far eastern portion of the Sahara Desert. The dark areas are lava flows, the calderas have long ago been eroded by the desert winds. The red toned surrounding surfaces are thick tropical soils, remnants of much earlier times when this region was a much greener savanna landscape that have also been severly eroded.

  13. Electron transport fluxes in potato plateau regime

    SciTech Connect

    Shaing, K.C.; Hazeltine, R.D.

    1997-12-01

    Electron transport fluxes in the potato plateau regime are calculated from the solutions of the drift kinetic equation and fluid equations. It is found that the bootstrap current density remains finite in the region close to the magnetic axis, although it decreases with increasing collision frequency. This finite amount of the bootstrap current in the relatively collisional regime is important in modeling tokamak startup with 100{percent} bootstrap current. {copyright} {ital 1997 American Institute of Physics.}

  14. Freshwater Biogeography and Limnological Evolution of the Tibetan Plateau - Insights from a Plateau-Wide Distributed Gastropod Taxon (Radix spp.)

    PubMed Central

    von Oheimb, Parm Viktor; Albrecht, Christian; Riedel, Frank; Du, Lina; Yang, Junxing; Aldridge, David C.; Bößneck, Ulrich; Zhang, Hucai; Wilke, Thomas

    2011-01-01

    Background The Tibetan Plateau is not only the highest and largest plateau on earth; it is also home to numerous freshwater lakes potentially harbouring endemic faunal elements. As it remains largely unknown whether these lakes have continuously existed during the Last Glacial Maximum (LGM), questions arise as to whether taxa have been able to exist on the plateau since before the latest Pleistocene, from where and how often the plateau was colonized, and by which mechanisms organisms conquered remote high altitude lentic freshwater systems. In this study, species of the plateau-wide distributed freshwater gastropod genus Radix are used to answer these biogeographical questions. Methodology/Principal Findings Based on a broad spatial sampling of Radix spp. on the Tibetan Plateau, and phylogenetic analyses of mtDNA sequence data, three probably endemic and one widespread major Radix clade could be identified on the plateau. Two of the endemic clades show a remarkably high genetic diversity, indicating a relatively great phylogenetic age. Phylogeographical analyses of individuals belonging to the most widely distributed clade indicate that intra-plateau distribution cannot be explained by drainage-related dispersal alone. Conclusions/Significance Our study reveals that Radix spp. persisted throughout the LGM on the Tibetan Plateau. Therefore, we assume the continuous existence of suitable water bodies during that time. The extant Radix diversity on the plateau might have been caused by multiple colonization events combined with a relatively long intra-plateau evolution. At least one colonization event has a Palaearctic origin. In contrast to freshwater fishes, passive dispersal, probably by water birds, might be an important mechanism for conquering remote areas on the plateau. Patterns found in Radix spp. are shared with some terrestrial plateau taxa, indicating that Radix may be a suitable model taxon for inferring general patterns of biotic origin, dispersal and

  15. Groundwater: Climate-induced pumping

    NASA Astrophysics Data System (ADS)

    Gurdak, Jason J.

    2017-01-01

    Groundwater resources are directly affected by climate variability via precipitation, evapotranspiration and recharge. Analyses of US and India trends reveal that climate-induced pumping indirectly influences groundwater depletion as well.

  16. Hikurangi Plateau: Crustal structure, rifted formation, and Gondwana subduction history

    NASA Astrophysics Data System (ADS)

    Davy, Bryan; Hoernle, Kaj; Werner, Reinhard

    2008-07-01

    Seismic reflection profiles across the Hikurangi Plateau Large Igneous Province and adjacent margins reveal the faulted volcanic basement and overlying Mesozoic-Cenozoic sedimentary units as well as the structure of the paleoconvergent Gondwana margin at the southern plateau limit. The Hikurangi Plateau crust can be traced 50-100 km southward beneath the Chatham Rise where subduction cessation timing and geometry are interpreted to be variable along the margin. A model fit of the Hikurangi Plateau back against the Manihiki Plateau aligns the Manihiki Scarp with the eastern margin of the Rekohu Embayment. Extensional and rotated block faults which formed during the breakup of the combined Manihiki-Hikurangi plateau are interpreted in seismic sections of the Hikurangi Plateau basement. Guyots and ridge-like seamounts which are widely scattered across the Hikurangi Plateau are interpreted to have formed at 99-89 Ma immediately following Hikurangi Plateau jamming of the Gondwana convergent margin at ˜100 Ma. Volcanism from this period cannot be separately resolved in the seismic reflection data from basement volcanism; hence seamount formation during Manihiki-Hikurangi Plateau emplacement and breakup (125-120 Ma) cannot be ruled out. Seismic reflection data and gravity modeling suggest the 20-Ma-old Hikurangi Plateau choked the Cretaceous Gondwana convergent margin within 5 Ma of entry. Subsequent uplift of the Chatham Rise and slab detachment has led to the deposition of a Mesozoic sedimentary unit that thins from ˜1 km thickness northward across the plateau. The contrast with the present Hikurangi Plateau subduction beneath North Island, New Zealand, suggests a possible buoyancy cutoff range for LIP subduction consistent with earlier modeling.

  17. Groundwater-Seepage Meter

    NASA Technical Reports Server (NTRS)

    Walthall, Harry G.; Reay, William G.

    1993-01-01

    Instrument measures seepage of groundwater into inland or coastal body of water. Positioned at depth as great as 40 meters, and measures flow at low rate and low pressure differential. Auxiliary pressure meter provides data for correlation of flow of groundwater with tides and sea states. Seepage meter operates independently for several weeks. Its sampling rate adjusted to suit hydrologic conditions; to measure more frequently when conditions changing rapidly. Used in water-quality management and for biological and geological research. Potential industrial uses include measurement of seepage of caustic and corrosive liquids.

  18. Groundwater-Seepage Meter

    NASA Technical Reports Server (NTRS)

    Walthall, Harry G.; Reay, William G.

    1993-01-01

    Instrument measures seepage of groundwater into inland or coastal body of water. Positioned at depth as great as 40 meters, and measures flow at low rate and low pressure differential. Auxiliary pressure meter provides data for correlation of flow of groundwater with tides and sea states. Seepage meter operates independently for several weeks. Its sampling rate adjusted to suit hydrologic conditions; to measure more frequently when conditions changing rapidly. Used in water-quality management and for biological and geological research. Potential industrial uses include measurement of seepage of caustic and corrosive liquids.

  19. In situ groundwater bioremediation

    SciTech Connect

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  20. Subpermafrost groundwater systems

    NASA Astrophysics Data System (ADS)

    van der Ploeg, Martine; Bense, Victor; Haldorsen, Sylvi

    2017-04-01

    Groundwater basins in polar areas are probably among the least studied systems in the World. Foremost, this is because such systems are mainly situated in sparsely populated areas. Also, where the permafrost is thick and continuous over large areas, the recharge is very limited and terrestrial discharge takes place only in some few springs. A now completed study of polar groundwater was carried out in Svalbard, the arctic archipelago north of Norway. Based on field observations and simulation models it was concluded that major discharge conduits only formed during extensive global glacial phases, beneath the parts of the glaciers were the ice was temperate. During most of the interglacial periods, when the glaciers retreat, the number of discharge springs will decrease gradually as long as continuous permafrost covers the area. However, the amount of recharge and thereby discharge in each individual groundwater spring is today highly dependent on short-time fluctuations in precipitation and air temperature. This situation may also be applicable in other polar areas where glaciers are abundant and parts of them are temperate. Such conditions occur in e.g. Greenland and on islands north of the North American mainland, as well as in parts of Antarctica. However, we cannot use the glacial-interglacial boundary conditions in all polar regions. Subpermafrost groundwater systems also exist in permafrost areas where few or no glaciers occur today and where the recharge has taken and takes place under e.g. larger lakes or snowfields. In many areas the groundwater systems may be much older than assumed in Svalbard. Their cycles may relate to several glaciations or to true non-glacial periods in the past. The development and melting of thick continuous permafrost are slow processes and the dynamic of the related groundwater systems will be dependent on cold/mild climate episodes lasting for many thousand years. The polar systems thereby have many of the same characteristics

  1. The crustal composition of the Falkland Plateau

    NASA Astrophysics Data System (ADS)

    Klemt, Claudia; Jokat, Wilfried

    2015-04-01

    The Falkland Islands are situated in the South Atlantic Ocean 500 km east of Patagonia, South America. The islands are part of the Falkland Plateau, which stretches eastward for more than 1500 km. A bathymetric high, the Maurice Ewing Bank, terminates the plateau in the east. Until Late Jurassic the Falkland Islands were part of Gondwana and were located adjacent to the east coast of South Africa. While the Falkland Islands and Maurice Ewing Bank are proved to be of continental composition, the nature and structure of the Falkland Plateau's basement in between is debatable. The first crustal model derived from sonobuoy data contradicts an only recently published 3D-gravity model. To enhance the understanding of Gondwana break-up considering timing, geometry and amount of volcanism, further knowledge about the structure and thickness of the crust is inevitable. During the ANT-XXIX/5 Polarstern cruise seismic refraction measurements were conducted using Ocean Bottom Seismometers (OBS) and Reftek land stations onshore of East Falkland. The OBS were deployed at 78 locations along an approximately 1500 km east-west stretching profile. For the western transect a P-wave velocity model is calculated using 2D-raytracing techniques. The results are presented in combination with potential field data showing the extension of the Falkland Islands basement, the continent-ocean transition zone and the crustal structure of the plateau. On the Falkland Plateau Basin sediment thickness is about 6 km with velocities ranging from 1.7 to 4.1 km/s in the upper part and about 4.7 km/s above basement. The crust is of oceanic composition with an igneous section that is considerably thicker than average oceanic crust (up to 17 km). The velocity structure in the upper crustal part is typical for layer 2 with a velocity gradient ranging from 5.4 km/s to 6.5 km/s and thicknesses between 1.5 km and 4 km. Layer 3 is about 14 km thick with a velocity gradient from 6.6 km/s to 7.6 km/s, which is

  2. Groundwater: A Community Action Guide.

    ERIC Educational Resources Information Center

    Boyd, Susan, Ed.; And Others

    Designed to be a guide for community action, this booklet examines issues and trends related to groundwater contamination. Basic concepts about groundwater and information about problems affecting it are covered under the categories of (1) what is groundwater? (2) availability and depletion; (3) quality and contamination; (4) public health…

  3. Groundwater: A Community Action Guide.

    ERIC Educational Resources Information Center

    Boyd, Susan, Ed.; And Others

    Designed to be a guide for community action, this booklet examines issues and trends related to groundwater contamination. Basic concepts about groundwater and information about problems affecting it are covered under the categories of (1) what is groundwater? (2) availability and depletion; (3) quality and contamination; (4) public health…

  4. Scenario modelling of drainage impact of a groundwater-dependent heath ecosystem, Belgium

    NASA Astrophysics Data System (ADS)

    Batelaan, Okke; El-Rawy, Mustafa; Schneidewind, Uwe; De Becker, Piet

    2013-04-01

    Groundwater dependent heathlands are valuable ecosystems in need of protection (Habitats Directive, 92/43/EEC). Over the last 15 years the groundwater table below a military area near Houthalen-Helchteren in the North-East of Belgium has been lowered by a network of drainage ditches to improve on-site military operability and to intensify nearby agriculture. Dewatering has lead to a gradual deterioration of the local NATURA 2000 ecosystem that includes wet and dry heathlands, transition mires and depression bogs. The studied area is located on the Campine Plateau about 70-80 m above sea level and covers an area of roughly 2200 ha. The local unconfined aquifer has a thickness of about 200 m and consists of several layers of Quaternary and Tertiary sands and fine gravels and occasional local clay lenses. To analyze the impact of the presence of the system of drainage ditches on the groundwater table, percentage of time of open water in the area, and occurrence of valuable ecosystems a multi-layer transient (1990-2010) groundwater model and coupled simple vegetation prediction model has been set-up. The MODFLOW 2005 groundwater model combined geological and hydrogeological data from regional groundwater models with local time-series of water level observations, groundwater abstraction data and monthly recharge estimates from the WetSpass model. Satisfying model calibration was achieved using UCODE-2005 and the Double Constrained Method. Simulated time series maps of the groundwater table were used to calculated for depressions the percentage of time that open water was present. The time series were also summarized in indicator maps as 'average groundwater level', 'average spring groundwater level', 'average highest groundwater level' and 'average lowest groundwater level', the last one was used to drive a decision rule for the occurrence 4 different habitat types. 19 scenarios considering varying options for adjustment of the drainage network were simulated and

  5. Insights into the crustal structure and magmatic evolution of the High and Western Plateau of the Manihiki Plateau, Central Pacific

    NASA Astrophysics Data System (ADS)

    Hochmuth, Katharina; Gohl, Karsten; Uenzelmann-Neben, Gabriele

    2014-05-01

    The Manihiki Plateau is a Large Igneous Province (LIP) located in the Central Pacific. It is assumed, that the formation of the Manihiki Plateau took place during the early Cretaceous in multiple volcanic stages as part of the "Super-LIP" Ontong-Java-Nui. The plateau consists of several sub-plateaus of which the Western Plateau und High Plateau are the largest. In addressing the plateau's magmatic evolutionary history, one of the key questions is whether all sub-plateaus experienced the same magmatic history or if distinct phases of igneous or tectonic processes led to its fragmentation. During the RV Sonne cruise SO-224 in 2012; we collected two deep crustal seismic refraction/wide-angle reflection lines, crossing the two main sub-plateaus. Modeling of P- and S-wave phases reveals the different crustal nature of both sub-plateaus. On the High Plateau, the 20 km thick crust is divided into four seismic units, interpreted to range from basaltic composition in the uppermost crust to peridotitic composition in the middle and lower crust. The Western Plateau on the other hand shows multiple rift structures and no indications of basalt flows. With a maximum of 17 km crustal thickness, the Western Plateau is also thinner than the High Plateau. The upper basement layers show relatively low P-wave velocities (3.0 - 5.0 km/s), which infers that on the Western Plateau these layers consist of volcanoclastic and carbonatic rocks rather than basaltic flow units. Later volcanic stages may be restricted to the High Plateau with a possible eastward trend in the center of volcanic activity. Extensive secondary volcanism does not seem to have occurred on the Western Plateau, and its later deformation is mainly caused by tectonic extension and rifting.

  6. Biogeographical study of plateau pikas Ochotona curzoniae (Lagomorpha, Ochotonidae).

    PubMed

    Yu, Fahong; Li, Shiping; Kilpatrick, William C; McGuire, Peter M; He, Kai; Wei, Wanhong

    2012-08-01

    We reconstructed the demographic history of the plateau pika (Ochotona curzoniae) on the Qinghai-Tibetan plateau by using genetic variation data obtained from spatially distributed populations across much of the plateau. We obtained sequence data, including cob (1,140 bp) and D-loop sequences (732 bp), from 144 individuals at sites ranging from the high-altitude interior to the relatively low-altitude northeastern plateau, and identified 37 and 42 unique haplotypes, respectively. Phylogenetic analysis and haplotype networks based on the individual and the combined datasets of cob and D-loop sequences clustered all populations into four well-supported major groups, and the interaction between vicariance, dispersal, and habitat fragmentation resulted in the current geographical distribution and genetic diversity of O. curzoniae on the plateau. Analysis of molecular variance (AMOVA) and mismatch distribution suggested that the recent continuous uplifts of the plateau contributed to the radiation and diversification of the O. curzoniae populations occurring there.

  7. Hydrologic reconnaissance of the Kolob, Alton, and Kaiparowits Plateau coal fields, south-central Utah

    USGS Publications Warehouse

    Plantz, Gerald G.

    1985-01-01

    The study area in south-central Utah (fig. 1) is noted for its large coal reserves in the Alton, Kolob, and Kaiparowits Plateau coal fields. The area also is noted for its scenic beauty and general scarcity of water. Although there has been very little development of the coal resources through 1983, there is a potential for large-scale development with both surface- and underground-mining methods. Mining of coal could have significant effects on the quantity and quality of the water resources. The purpose of this atlas is to define the surface- and ground-water resources of the area and to identify the potential effects on these resources by coal mining.

  8. Gas-Phase Treatment of Technetium in the Vadose Zone at the Hanford Site Central Plateau

    SciTech Connect

    Truex, Michael J.; Szecsody, James E.; Zhong, Lirong; Qafoku, Nikolla

    2014-09-01

    Technetium-99 (Tc-99) is present in the vadose zone of the Hanford Central Plateau and is a concern with respect to the protection of groundwater. The persistence, limited natural attenuation mechanisms, and geochemical behavior of Tc-99 in oxic vadose zone environments must be considered in developing effective alternatives for remediation. This report describes a new in situ geochemical manipulation technique for decreasing Tc-99 mobility using a combination of geochemical Tc-99 reduction with hydrogen sulfide gas and induced sediment mineral dissolution with ammonia vapor, which create conditions for deposition of stable precipitates that decrease the mobility of Tc-99. Laboratory experiments were conducted to examine changes in Tc-99 mobility in vadose zone sediment samples to evaluate the effectiveness of the treatment under a variety of operational and sediment conditions.

  9. Hydrogeology of the Hanford Site Central Plateau – A Status Report for the 200 West Area

    SciTech Connect

    Last, George V.; Thorne, Paul D.; Horner, Jacob A.; Parker, Kyle R.; Bjornstad, Bruce N.; Mackley, Rob D.; Lanigan, David C.; Williams, Bruce A.

    2009-08-27

    The Remediation Decisions Support (RDS) function of the Soil and Groundwater Remediation Project (managed by CH2M HILL Plateau Remediation Company [CHPRC]) is responsible for facilitating the development of consistent data, parameters, and conceptual models to resolve technical issues and support efforts to estimate contaminant migration and impacts (i.e., the assessment process). In particular, the RDS function is working to update electronic data sources and conceptual models of the geologic framework and associated hydraulic and geochemical parameters to facilitate traceability, transparency, defensibility, and consistency in support of environmental assessments. This report summarizes the efforts conducted by Pacific Northwest National Laboratory (PNNL) scientists in fiscal year 2008 (FY08) that focused primarily on the 200 West Area, as well as a secondary effort initiated on the 200 East Area.

  10. What controls the partitioning between baseflow and mountain block recharge in the Qinghai-Tibet Plateau?

    NASA Astrophysics Data System (ADS)

    Yao, Yingying; Zheng, Chunmiao; Andrews, Charles; Zheng, Yi; Zhang, Aijing; Liu, Jie

    2017-08-01

    Mountainous areas are referred to as "water towers" since they are the source of water for many low-lying communities. The hydrologic budgets of these areas, which are particularly susceptible to climate change, are typically poorly constrained. To address this, we analyzed the partitioning between baseflow and mountain block recharge (MBR) using a regional groundwater model of the northern Qinghai-Tibet Plateau run with multiple scenarios. We found that 19% of precipitation is recharged, approximately 35% of which becomes MBR, while 65% discharges as baseflow. This partitioning is relatively independent of the recharge rate but is sensitive to exponential depth decrease of hydraulic conductivity (K). The MBR is more sensitive to this exponential decrease in K than baseflow. The proportion of MBR varies from twice to half of baseflow as the decay exponent increases by more than fivefold. Thus, the depth dependence of K is critical for quantifying hydrologic partitioning in these sensitive areas.

  11. GROUNDWATER RECHARGE AND CHEMICAL ...

    EPA Pesticide Factsheets

    The existing knowledge base regarding the presence and significance of chemicals foreign to the subsurface environment is large and growing -the papers in this volume serving as recent testament. But complex questions with few answers surround the unknowns regarding the potential for environmental or human health effects from trace levels of xenobiotics in groundwater, especially groundwater augmented with treated wastewater. Public acceptance for direct or indirect groundwater recharge using treated municipal wastewater ( especially sewage) spans the spectrum from unquestioned embrace to outright rejection. In this article, I detour around the issues most commonly discussed for groundwater recharge and instead focus on some of the less-recognized issues- those that emanate from the mysteries created at the many literal and virtual interfaces involved with the subsurface world. My major objective is to catalyze discussion that advances our understanding of the barriers to public acceptance of wastewater reuse -with its ultimate culmination in direct reuse for drinking. I pose what could be a key question as to whether much of the public's frustration or ambivalence in its decision making process for accepting or rejecting water reuse (for various purposes including personal use) emanates from fundamental inaccuracies, misrepresentation, or oversimplification of what water 'is' and how it functions in the environment -just what exactly is the 'water cyc

  12. PATHS groundwater hydrologic model

    SciTech Connect

    Nelson, R.W.; Schur, J.A.

    1980-04-01

    A preliminary evaluation capability for two-dimensional groundwater pollution problems was developed as part of the Transport Modeling Task for the Waste Isolation Safety Assessment Program (WISAP). Our approach was to use the data limitations as a guide in setting the level of modeling detail. PATHS Groundwater Hydrologic Model is the first level (simplest) idealized hybrid analytical/numerical model for two-dimensional, saturated groundwater flow and single component transport; homogeneous geology. This document consists of the description of the PATHS groundwater hydrologic model. The preliminary evaluation capability prepared for WISAP, including the enhancements that were made because of the authors' experience using the earlier capability is described. Appendixes A through D supplement the report as follows: complete derivations of the background equations are provided in Appendix A. Appendix B is a comprehensive set of instructions for users of PATHS. It is written for users who have little or no experience with computers. Appendix C is for the programmer. It contains information on how input parameters are passed between programs in the system. It also contains program listings and test case listing. Appendix D is a definition of terms.

  13. Automated Groundwater Screening

    SciTech Connect

    Taylor, Glenn A.; Collard, Leonard, B.

    2005-10-31

    The Automated Intruder Analysis has been extended to include an Automated Ground Water Screening option. This option screens 825 radionuclides while rigorously applying the National Council on Radiation Protection (NCRP) methodology. An extension to that methodology is presented to give a more realistic screening factor for those radionuclides which have significant daughters. The extension has the promise of reducing the number of radionuclides which must be tracked by the customer. By combining the Automated Intruder Analysis with the Automated Groundwater Screening a consistent set of assumptions and databases is used. A method is proposed to eliminate trigger values by performing rigorous calculation of the screening factor thereby reducing the number of radionuclides sent to further analysis. Using the same problem definitions as in previous groundwater screenings, the automated groundwater screening found one additional nuclide, Ge-68, which failed the screening. It also found that 18 of the 57 radionuclides contained in NCRP Table 3.1 failed the screening. This report describes the automated groundwater screening computer application.

  14. Hanford Groundwater Remediation

    SciTech Connect

    Charboneau, B.; Thompson, K. M.; Wilde, R.; Ford, B.; Gerber, M.

    2006-07-01

    By 1990 nearly 50 years of producing plutonium put approximately 1.70 E+12 liters (450 billion gallons) of liquid wastes into the soil of the 1,518-square kilometer (586-square mile) Hanford Site in southeast Washington State. The liquid releases consisted of chemicals used in laboratory experiments, manufacturing and rinsing uranium fuel, dissolving that fuel after irradiation in Hanford's nuclear reactors, and in liquefying plutonium scraps needed to feed other plutonium-processing operations. Chemicals were also added to the water used to cool Hanford's reactors to prevent corrosion in the reactor tubes. In addition, water and acid rinses were used to clean plutonium deposits from piping in Hanford's large radiochemical facilities. All of these chemicals became contaminated with radionuclides. As Hanford raced to help win World War II, and then raced to produce materials for the Cold War, these radioactive liquid wastes were released to the Site's sandy soils. Early scientific experiments seemed to show that the most highly radioactive components of these liquids would bind to the soil just below the surface of the land, thus posing no threat to groundwater. Other experiments predicted that the water containing most radionuclides would take hundreds of years to seep into groundwater, decaying (or losing) most of its radioactivity before reaching the groundwater or subsequently flowing into the Columbia River, although it was known that some contaminants like tritium would move quickly. Evidence today, however, shows that many contaminants have reached the Site's groundwater and the Columbia River, with more on its way. Over 259 square kilometers (100 square miles) of groundwater at Hanford have contaminant levels above drinking-water standards. Also key to successfully cleaning up the Site is providing information resources and public-involvement opportunities to Hanford's stakeholders. This large, passionate, diverse, and geographically dispersed community is

  15. HANFORD GROUNDWATER REMEDIATION

    SciTech Connect

    CHARBONEAU, B; THOMPSON, M; WILDE, R.; FORD, B.; GERBER, M.S.

    2006-02-01

    By 1990 nearly 50 years of producing plutonium put approximately 1.70E + 12 liters (450 billion gallons) of liquid wastes into the soil of the 1,518-square kilometer (586-square mile) Hanford Site in southeast Washington State. The liquid releases consisted of chemicals used in laboratory experiments, manufacturing and rinsing uranium fuel, dissolving that fuel after irradiation in Hanford's nuclear reactors, and in liquefying plutonium scraps needed to feed other plutonium-processing operations. Chemicals were also added to the water used to cool Hanford's reactors to prevent corrosion in the reactor tubes. In addition, water and acid rinses were used to clean plutonium deposits from piping in Hanford's large radiochemical facilities. All of these chemicals became contaminated with radionuclides. As Hanford raced to help win World War II, and then raced to produce materials for the Cold War, these radioactive liquid wastes were released to the Site's sandy soils. Early scientific experiments seemed to show that the most highly radioactive components of these liquids would bind to the soil just below the surface of the land, thus posing no threat to groundwater. Other experiments predicted that the water containing most radionuclides would take hundreds of years to seep into groundwater, decaying (or losing) most of its radioactivity before reaching the groundwater or subsequently flowing into the Columbia River, although it was known that some contaminants like tritium would move quickly. Evidence today, however, shows that many contaminants have reached the Site's groundwater and the Columbia River, with more on its way. Over 259 square kilometers (100 square miles) of groundwater at Hanford have contaminant levels above drinking-water standards. Also key to successfully cleaning up the Site is providing information resources and public-involvement opportunities to Hanford's stakeholders. This large, passionate, diverse, and geographically dispersed community is

  16. Colorado Plateau magmatism and uplift by warming of heterogeneous lithosphere.

    PubMed

    Roy, Mousumi; Jordan, Thomas H; Pederson, Joel

    2009-06-18

    The forces that drove rock uplift of the low-relief, high-elevation, tectonically stable Colorado Plateau are the subject of long-standing debate. While the adjacent Basin and Range province and Rio Grande rift province underwent Cenozoic shortening followed by extension, the plateau experienced approximately 2 km of rock uplift without significant internal deformation. Here we propose that warming of the thicker, more iron-depleted Colorado Plateau lithosphere over 35-40 Myr following mid-Cenozoic removal of the Farallon plate from beneath North America is the primary mechanism driving rock uplift. In our model, conductive re-equilibration not only explains the rock uplift of the plateau, but also provides a robust geodynamic interpretation of observed contrasts between the Colorado Plateau margins and the plateau interior. In particular, the model matches the encroachment of Cenozoic magmatism from the margins towards the plateau interior at rates of 3-6 km Myr(-1) and is consistent with lower seismic velocities and more negative Bouguer gravity at the margins than in the plateau interior. We suggest that warming of heterogeneous lithosphere is a powerful mechanism for driving epeirogenic rock uplift of the Colorado Plateau and may be of general importance in plate-interior settings.

  17. Groundwater quality mapping in urban groundwater using GIS.

    PubMed

    Nas, Bilgehan; Berktay, Ali

    2010-01-01

    Konya City, located in the central part of Turkey, has grown and urbanized rapidly. A large amount of the water requirement of Konya City is supplied from groundwater. The quality of this groundwater was determined by taking samples from 177 of the wells within the study area. The purposes of this investigation were (1) to provide an overview of present groundwater quality and (2) to determine spatial distribution of groundwater quality parameters such as pH, electrical conductivity, Cl-, SO4(-2), hardness, and NO3- concentrations, and (3) to map groundwater quality in the study area by using GIS and Geostatistics techniques. ArcGIS 9.0 and ArcGIS Geostatistical Analyst were used for generation of various thematic maps and ArcGIS Spatial Analyst to produce the final groundwater quality map. An interpolation technique, ordinary kriging, was used to obtain the spatial distribution of groundwater quality parameters. The final map shows that the southwest of the city has optimum groundwater quality, and, in general, the groundwater quality decreases south to north of the city; 5.03% (21.51 km2) of the total study area is classified to be at the optimum groundwater quality level.

  18. Evaluation of groundwater dynamic regime with groundwater depth evaluation indexes.

    PubMed

    Genxu, Wang; Jian, Zhou; Kubota, Jumpei; Jianping, Su

    2008-06-01

    An accurate quantitative evaluation of anthropogenic effects on regional groundwater dynamics is critical to the rational planning, management, and use of such resources and in maintaining the sustainability of groundwater-dependent ecosystems. Based on groundwater dynamics, a series of groundwater depth evaluation indexes were created to quantitatively evaluate the effects of anthropogenic activities on the groundwater system. These indexes were based on mathematical relationships relating groundwater depth to surface runoff (gammat), precipitation (rhot), and extraction (deltat). The anthropogenic effects on these relationships were evaluated statistically, with respect to both temporal and spatial variation. The anthropogenic effects on groundwater dynamics within the arid Zhangye Basin, located in the middle reaches of northwest China's Heihe River, were investigated. River valley plains in the western portion of the basin excepted, anthropogenic activities have, since 1995, dramatically altered the basin's groundwater dynamics; in particular, in the mid-upper and lower portions of alluvial-diluvial fans and in localized northerly fine-soil plains regions, the relationship of groundwater to surface runoff and atmospheric precipitation has shifted. This and other changes indicate that anthropogenic effects on groundwater systems in this region show clear spatiotemporal variation.

  19. Oceanic Plateau Overview and Look Ahead

    NASA Astrophysics Data System (ADS)

    Coffin, M. F.

    2011-12-01

    Oceanic plateaus result from fundamental processes in the Earth's interior, and have been implicated as instigators of major worldwide environmental changes. Although the plate tectonics paradigm successfully explains volcanic activity on the Earth's surface associated with seafloor spreading and plate subduction, it does not elucidate the massive flood volcanism that produces oceanic plateaus. Temporal correlations between flood basalts and environmental phenomena such as mass extinctions and oceanic anoxic events (OAEs) are well documented, yet the underlying mechanisms causing these global catastrophes are only beginning to be grasped. Focused investigations of oceanic plateaus have targeted the two largest features globally, the ~120 Ma Ontong Java Plateau (Pacific Ocean) and ~120-95 Ma Kerguelen Plateau/Broken Ridge (Indian Ocean), and the ~145-130 Ma Shatsky Rise (Pacific Ocean). These three features constitute the only oceanic plateaus where igneous basement has been drilled at more than one site. Multiple models - plume, bolide impact, and upwelling eclogite - have been proposed for Ontong Java's origin. The feature correlates temporally with OAE-1a, and interpretation of Sr, Os, and Pb isotopic systems during the time of OAE-1a points to a close linkage between the two, with CO2, Fe, and trace metal emissions from the massive magmatism potentially triggering the event. The Kerguelen Plateau/Broken Ridge is a composite feature that includes flood basalts, depleted mid-ocean ridge basalt (MORB)-related asthenosphere, and continental lithosphere. Models for the Shatsky Rise include mantle plume and fast seafloor spreading. Future studies of oceanic plateaus have the potential to transform our understanding of the Earth system through investigating: 1) magma (and hence mantle source) variability through times; 2) the nature of melting anomalies, i.e., compositional vs. thermal, that produce oceanic plateaus; 3) the precise durations of oceanic plateau events

  20. [Functional difference of malate-aspartate shuttle system in liver between plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae)].

    PubMed

    Zhu, Rui-Juan; Rao, Xin-Feng; Wei, Deng-Bang; Wang, Duo-Wei; Wei, Lian; Sun, Sheng-Zhen

    2012-04-25

    To explore the adaptive mechanisms of plateau zokor (Myospalax baileyi) to the enduring digging activity in the hypoxic environment and of plateau pika (Ochotona curzoniae) to the sprint running activity, the functional differences of malate-aspartate shuttle system (MA) in liver of plateau zokor and plateau pika were studied. The ratio of liver weight to body weight, the parameters of mitochondria in hepatocyte and the contents of lactic acid in serum were measured; the open reading frame of cytoplasmic malate dehydrogenase (MDH1), mitochondrial malate dehydrogenase (MDH2), and the partial sequence of aspartate glutamate carrier (AGC) and oxoglutarate malate carrier (OMC) genes were cloned and sequenced; MDH1, MDH2, AGC and OMC mRNA levels were determined by real-time PCR; the specific activities of MDH1 and MDH2 in liver of plateau zokor and plateau pika were measured using enzymatic methods. The results showed that, (1) the ratio of liver weight to body weight, the number and the specific surface of mitochondria in hepatocyte of plateau zokor were markedly higher than those of plateau pika (P < 0.01 or P < 0.05), but the content of lactic acid in serum of plateau pika was significantly higher than that of plateau zokor (P < 0.01); (2) MDH1 and MDH2 mRNA levels as well as their enzymatic activities in liver of plateau zokor were significantly higher than those of plateau pika (P < 0.01 or 0.05), AGC mRNA level of the zokor was significantly higher than that of the pika (P < 0.01), while no difference was found at OMC mRNA level between them (P > 0.05); (3) mRNA level and enzymatic activity of MDH1 was significantly lower than those of MDH2 in the pika liver (P < 0.01), MDH1 mRNA level of plateau zokor was markedly higher than that of MDH2 (P < 0.01), but the activities had no difference between MDH1 and MDH2 in liver of the zokor (P > 0.05). These results indicate that the plateau zokor obtains ATP in the enduring digging activity by enhancing the function of MA

  1. The noble gas geochemistry of natural CO 2 gas reservoirs from the Colorado Plateau and Rocky Mountain provinces, USA

    NASA Astrophysics Data System (ADS)

    Gilfillan, Stuart M. V.; Ballentine, Chris J.; Holland, Greg; Blagburn, Dave; Lollar, Barbara Sherwood; Stevens, Scott; Schoell, Martin; Cassidy, Martin

    2008-02-01

    Identification of the source of CO 2 in natural reservoirs and development of physical models to account for the migration and interaction of this CO 2 with the groundwater is essential for developing a quantitative understanding of the long term storage potential of CO 2 in the subsurface. We present the results of 57 noble gas determinations in CO 2 rich fields (>82%) from three natural reservoirs to the east of the Colorado Plateau uplift province, USA (Bravo Dome, NM., Sheep Mountain, CO. and McCallum Dome, CO.), and from two reservoirs from within the uplift area (St. John's Dome, AZ., and McElmo Dome, CO.). We demonstrate that all fields have CO 2/ 3He ratios consistent with a dominantly magmatic source. The most recent volcanics in the province date from 8 to 10 ka and are associated with the Bravo Dome field. The oldest magmatic activity dates from 42 to 70 Ma and is associated with the McElmo Dome field, located in the tectonically stable centre of the Colorado Plateau: CO 2 can be stored within the subsurface on a millennia timescale. The manner and extent of contact of the CO 2 phase with the groundwater system is a critical parameter in using these systems as natural analogues for geological storage of anthropogenic CO 2. We show that coherent fractionation of groundwater 20Ne/ 36Ar with crustal radiogenic noble gases ( 4He, 21Ne, 40Ar) is explained by a two stage re-dissolution model: Stage 1: Magmatic CO 2 injection into the groundwater system strips dissolved air-derived noble gases (ASW) and accumulated crustal/radiogenic noble gas by CO 2/water phase partitioning. The CO 2 containing the groundwater stripped gases provides the first reservoir fluid charge. Subsequent charges of CO 2 provide no more ASW or crustal noble gases, and serve only to dilute the original ASW and crustal noble gas rich CO 2. Reservoir scale preservation of concentration gradients in ASW-derived noble gases thus provide CO 2 filling direction. This is seen in the Bravo Dome

  2. Abnormally high formation pressures, Potwar Plateau, Pakistan

    USGS Publications Warehouse

    Law, B.E.; Shah, S.H.A.; Malik, M.A.

    1998-01-01

    Abnormally high formation pressures in the Potwar Plateau of north-central Pakistan are major obstacles to oil and gas exploration. Severe drilling problems associated with high pressures have, in some cases, prevented adequate evaluation of reservoirs and significantly increased drilling costs. Previous investigations of abnormal pressure in the Potwar Plateau have only identified abnormal pressures in Neogene rocks. We have identified two distinct pressure regimes in this Himalayan foreland fold and thrust belt basin: one in Neogene rocks and another in pre-Neogene rocks. Pore pressures in Neogene rocks are as high as lithostatic and are interpreted to be due to tectonic compression and compaction disequilibrium associated with high rates of sedimentation. Pore pressure gradients in pre-Neogene rocks are generally less than those in Neogene rocks, commonly ranging from 0.5 to 0.7 psi/ft (11.3 to 15.8 kPa/m) and are most likely due to a combination of tectonic compression and hydrocarbon generation. The top of abnormally high pressure is highly variable and doesn't appear to be related to any specific lithologic seal. Consequently, attempts to predict the depth to the top of overpressure prior to drilling are precluded.

  3. Biological stability of groundwater

    SciTech Connect

    Noble, P.A.; Clark, D.L.; Olson, B.H.

    1996-05-01

    Conventional (e.g., coagulation, flocculation, and filtration) or membrane filtration treatment trains were used to remove organic compounds from groundwater. For the conventional train with sand-anthracite columns, the assimilable organic carbon (AOC) of the groundwater was reduced from 349 {+-} 127 {micro}g/L C to 54 {+-} 51 {micro}g/L C. For the membrane filtration train, there was no statistical difference between the AOC of the raw water influent (388 {+-} 126 {micro}g C) and that of the membrane permeate (334 {+-} 156 {micro}g/L C), suggesting that this treatment produced biologically unstable water. Similar results were obtained using the heterotrophic growth response (HGR) method. Comparison of the biostability methods showed that HGR was positively correlated with AOC (r = 0.52; P < 0.0001; n = 156), indicating that AOC only partially explains the ability of heterotrophic bacteria to grow in water samples.

  4. Groundwater monitoring system

    DOEpatents

    Ames, Kenneth R.; Doesburg, James M.; Eschbach, Eugene A.; Kelley, Roy C.; Myers, David A.

    1987-01-01

    A groundwater monitoring system includes a bore, a well casing within and spaced from the bore, and a pump within the casing. A water impermeable seal between the bore and the well casing prevents surface contamination from entering the pump. Above the ground surface is a removable operating means which is connected to the pump piston by a flexible cord. A protective casing extends above ground and has a removable cover. After a groundwater sample has been taken, the cord is disconnected from the operating means. The operating means is removed for taking away, the cord is placed within the protective casing, and the cover closed and locked. The system is thus protected from contamination, as well as from damage by accident or vandalism.

  5. Monitoring and remediating groundwater

    SciTech Connect

    Vedder, M.

    1995-03-01

    Choosing the optimum groundwater remediation process is a site-specific task. A variety of factors--including soil type, water type, water flow, water table levels and contaminant type--influence sampling and treatment techniques. Because underground contaminant plumes must first be characterized and mapped, initial sampling often is a hit or miss proposition. Historical geophysical data can be obtained from many local water boards to supplement the process. Equipment used in sampling includes drilling rigs, depth probes, bailers, sample tubing and well pumps. Once samples are collected, they are preserved with ice and transported to an environmental laboratory for analysis. Common groundwater contaminants include hydrocarbons, solvents, metals and volatile organic compounds. Typical lab analysis methods include gas chromatography and spectrometry. Remediation options include air stripping, carbon adsorption, the use of bacterial cultures, chemical precipitation, ion exchange, reverse osmosis and ultrafiltration.

  6. Oahu Groundwater Flow Model

    DOE Data Explorer

    Nicole Lautze

    2015-01-01

    Groundwater flow model for the island of Oahu. Data is from the following sources: Rotzoll, K., A.I. El-Kadi. 2007. Numerical Ground-Water Flow Simulation for Red Hill Fuel Storage Facilities, NAVFAC Pacific, Oahu, Hawaii - Prepared TEC, Inc. Water Resources Research Center, University of Hawaii, Honolulu.; Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume VII – Island of Oahu Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008.; and Whittier, R. and A.I. El-Kadi. 2009. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. December 2009.

  7. Effects of urbanization on groundwater evolution in an urbanizing watershed

    NASA Astrophysics Data System (ADS)

    Reyes, D.; Banner, J. L.; Bendik, N.

    2011-12-01

    The Jollyville Plateau Salamander (Eurycea tonkawae), a candidate species for listing under the Endangered Species Act, is endemic to springs and caves within the Bull Creek Watershed of Austin, Texas. Rapid urbanization endangers known populations of this salamander. Conservation strategies lack information on the extent of groundwater contamination from anthropogenic sources in this karst watershed. Spring water was analyzed for strontium (Sr) isotopes and major ions from sites classified as "urban" or "rural" based on impervious cover estimates. Previous studies have shown that the 87Sr/86Sr value of municipal water is significantly higher than values for natural streamwater, which are similar to those for the Cretaceous limestone bedrock of the region's watersheds. We investigate the application of this relationship to understanding the effects of urbanization on groundwater quality. The use of Sr isotopes as hydrochemical tracers is complemented by major ion concentrations, specifically the dominant ions in natural groundwater (Ca and HCO3) and the ions associated with the addition of wastewater (Na and Cl). To identify high priority salamander-inhabited springs for water quality remediation, we explore the processes controlling the chemical evolution of groundwater such as municipal water inputs, groundwater-soil interactions, and solution/dissolution reactions. 87Sr/86Sr values for water samples from within the watershed range from 0.70760 to 0.70875, the highest values corresponding to sites located in the urbanized areas of the watershed. Analyses of the covariation of Sr isotopes with major ion concentrations help elucidate controls on spring water evolution. Springs located in rural portions of the watershed have low 87Sr/86Sr, high concentrations of Ca and HCO3, and low concentrations of Na and Cl. This is consistent with small inputs of municipal water. Three springs located in urban portions of the watershed have high 87Sr/86Sr, low Ca and HCO3, and

  8. Groundwater pollution abatement

    SciTech Connect

    Fenton, D.M.; Holm, L.W.; Saunders, D.L.

    1987-05-12

    A method is described for for pollution abatement in groundwaters, comprising the steps of: drilling a series of wells into an aquifer, ahead of an advancing front of water which contains one or more contaminants. The wells are disposed along a line approximately parallel to the advancing front; and introducing, through the wells and into the aquifer, a particulate adsorbent material which can adsorb at least one contaminant.

  9. SSCL groundwater model

    SciTech Connect

    Romero, V.; Bull, J.; Stapleton, G.; Baker, S.; Goss, D.; Coulson, L.

    1994-02-01

    Activation of groundwater due to accelerator operations has been a consideration since the conceptual stages of the SSC. Prior to site selection, an elementary hydrological model assuming a porous medium with a shallow well in proximity to the tunnel was used to determine the radionuclide concentrations in the water pumped from a well. The model assumed that radionuclides produced within a few feet of the tunnel would migrate to the shallow well and be diluted as the well drew water from a conically symmetric region. After the Ellis County site was selected, the compatibility of this model with the site specific geology was evaluated. The host geology at the selected site is low permeability rock, Austin chalk, shale, and marl, however, vertical fractures do exist. Since the host rock has a low permeability, groundwater in proximity to the tunnel would have to travel primarily through fractures. This hydrology is not compatible with the above mentioned model since water does not percolate uniformly from the surrounding rock into local wells. The amount of dilution of activated water will vary significantly depending on the specific relationship of the well to the activation zone. A further complication in the original model is that it assumes the high energy particles escaping from the accelerator enclosure are localized. The model does not provide for particles being lost over a large area as will happen with routine operational losses. These losses will be distributed along the accelerator over the life of the project. The SSCL groundwater model has been recast to account for the site specific hydrology and both point and distributed losses. Using the new groundwater model, the SSC accelerators are designed to limit the activation concentration in the water located one meter outside the accelerator enclosure to meet the federal drinking water standards. This technical note provides the details of this model.

  10. Groundwater in civil engineering

    SciTech Connect

    Rethati, L.

    1983-01-01

    This book is based on the fundamentals of geotechnics and hydrology, with chapters on hydraulics, hydrogeology, pedology, hydrochemistry, meteorology and mathematical statistics also included. In the first part of the book, theoretical and methodological problems are dealt with, and mathematical - primarily probabilistic - methods are also discussed. The second part presents methods of obtaining solutions to practical problems. Through numerous examples and statistical relationships, the author demonstrates that there are considerable temporal changes in the soil properties due to changes in the groundwater level.

  11. Estimating Vertical Groundwater Velocities Using Groundwater Thermal Gradients

    NASA Astrophysics Data System (ADS)

    Arriaga, M. A.; Leap, D. I.; Petruccione, J. L.

    2007-05-01

    An understanding of vertical groundwater flow through unconsolidated deposits is a component for predicting fate and transport of contaminants in the saturated zone. Groundwater movement through heterogeneous glacial deposits common to northern Indiana (USA) provided a test setting for determining if measured vertical groundwater thermal gradients could aid in calculating vertical groundwater velocity estimates. Field procedure was conducted by collecting stratified groundwater temperatures from a series of cased monitoring wells previously advanced through glacial till and outwash sedimentary sequences. Groundwater thermal gradients (temperature-depth profiles) were plotted and matched using automated computer modeling software (Microsoft Excel Solver) with published type curves to derive a dimensionless parameter for estimating vertical groundwater velocities. Data results matched predictions, to include an increase in vertical groundwater velocities during the seasonally wetter Spring; and, higher calculated vertical groundwater velocities for the finer-grained till aquitards when compared to aquifers comprised of coarser-grained outwash deposits. This study shows promise and has gathered interest both in the scientific community and environmental consulting practice for estimating vertical migration rates of contaminants (specifically those affected by advection) within the saturated zone. Government agencies or consultants, for instance, could also potentially apply this estimation technique to measure and map localized recharge rates for developing more accurate wellhead protection zones.

  12. Composite analysis for low-level waste disposal in the 200 area plateau of the Hanford Site

    SciTech Connect

    Kincaid, C.T.; Bergeron, M.P.; Cole, C.R.

    1998-03-01

    This report presents the first iteration of the Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site (Composite Analysis) prepared in response to the U.S. Department of Energy Implementation Plan for the Defense Nuclear Facility Safety Board Recommendation 94-2. The Composite Analysis is a companion document to published analyses of four active or planned low-level waste disposal actions: the solid waste burial grounds in the 200 West Area, the solid waste burial grounds in the 200 East Area, the Environmental Restoration Disposal Facility, and the disposal facilities for immobilized low-activity waste. A single Composite Analysis was prepared for the Hanford Site considering only sources on the 200 Area Plateau. The performance objectives prescribed in U.S. Department of Energy guidance for the Composite Analysis were 100 mrem in a year and examination of a lower dose (30 mrem in a year) to ensure the {open_quotes}as low as reasonably achievable{close_quotes} concept is followed. The 100 mrem in a year limit was the maximum allowable all-pathways dose for 1000 years following Hanford Site closure, which is assumed to occur in 2050. These performance objectives apply to an accessible environment defined as the area between a buffer zone surrounding an exclusive waste management area on the 200 Area Plateau, and the Columbia River. Estimating doses to hypothetical future members of the public for the Composite Analysis was a multistep process involving the estimation or simulation of inventories; waste release to the environment; migration through the vadose zone, groundwater, and atmospheric pathways; and exposure and dose. Doses were estimated for scenarios based on agriculture, residential, industrial, and recreational land use. The radionuclides included in the vadose zone and groundwater pathway analyses of future releases were carbon-14, chlorine-36, selenium-79, technetium-99, iodine-129, and uranium isotopes.

  13. The Manihiki Plateau, Hikurangi Plateau, Wishbone Scarp, and Osbourn Trough: A Review and Analysis

    NASA Astrophysics Data System (ADS)

    Henig, A.; Luyendyk, B. P.

    2007-12-01

    The extinct Osbourn Trough spreading system in the southwestern Pacific played a key role in separating the once joined Hikurangi and Manihiki Plateaus in Cretaceous time. Recent studies by Downey et al. [2007] and Taylor [20006] have provided new data and concepts on that history. Studies by Larson et al. [2002] describe Cretaceous histories adjacent and east of the Osbourn system and Eagles et al. [2004] describe a history for the southwest Pacific just after the Osbourn system became extinct. The lack of identifiable magnetic anomalies allows tectonic events during separation of the plateaus and spreading on the Osbourn Trough to occur between about 124.6 and 84 Ma (Chron 34). Satellite gravity maps of the region identify what are interpreted as Cretaceous fracture zone trends. Swath bathymetry data reveal at least four provinces of abyssal hill trends. What is known are the following: Minimum age of the Manihiki High Plateau at 123.4 Ma from DSDP Site 317, the age of seafloor, 115 Ma, from a dredge sample from the southern segment of the West Wishbone Scarp 300 km northeast of the Hikurangi Plateau, the east-west trend and extent of the extinct Osbourn spreading center at latitude 26° S, the trends (NNE-SSW to NE-SW) and extent of portions of the West Wishbone Scarp east of the Hikurangi Plateau, the N-S trend of the East Wishbone Scarp that appears to truncate the West Wishbone Scarp, the NNE- SSW trend and extent of the prominent Manihiki (Eastern) Scarp at the eastern boundary of the Manihiki High Plateau, the NW-SE trend and extent of the Rapuhia Scarp on the northwestern Hikurangi Plateau, and trends in abyssal hills; E-W near the Osbourn Trough and WNW-ESE closer to the plateaus. Differences in abyssal hill morphology suggest one or more changes in spreading rates. The Osbourn Trough began rifting apart a Large Igneous Province formed at 123.5 +/- 1.5 Ma, into the separate Ontong-Java, Manihiki, and Hikurangi Plateaus by 121 Ma. After an initial 6 Myr

  14. [Difference in oxygen uptake in skeletal muscles between plateau zokor (Myospalax rufescens baileyi) and plateau pika (Ochotona curzoniac)].

    PubMed

    Zhu, Shi-Hai; Qi, Xin-Zhang; Wang, Xiao-Jun; Rao, Xin-Feng; Wei, Lian; Wei, Deng-Bang

    2009-08-25

    To investigate the difference between the functions of oxygen uptake in skeletal muscle and living habits of plateau zokor (Myospalax rufescens baileyi) and plateau pika (Ochotona curzoniac), the microvessel densities (MVD) of skeletal muscle of plateau zokor, plateau pika and Sprague-Dawley (SD) rat were measured by immunohistochemical staining; the numerical density on area (N(A)) of mitochondria, and surface density (S(V), external surface area density of mitochondria per unit volume of skeletal muscle fiber) were obtained by stereo microscope technique; mRNA levels of myoglobin (Mb) in skeletal muscle were determined by real-time PCR, and the contents of Mb protein in skeletal muscle were determined by spectro-photometer. The results showed that MVD, N(A) and S(V) of mitochondria in skeletal muscle of plateau pika were significantly lower than those of plateau zokor and SD rat (P<0.05). The mRNA levels of Mb gene in skeletal muscle of plateau zokor and plateau pika were notably higher than that of SD rat (P<0.05). There were significant differences in the contents of Mb among these three species, and plateau zokor and SD rat presented the highest and the lowest value, respectively (P<0.05). The results suggest that even though plateau zokor inhabits in the hypoxia environment, most of its skeletal muscle fiber are red muscle fiber. While most of skeletal muscle fibers of plateau pika are white muscle fibers. This kind of white muscle has low MVD, N(A) and S(V) of mitochondria and less content of Mb compared with the red one, suggesting it obtains most energy from aerobic oxidation. The above-mentioned differences in skeletal muscles may be related to not only the different species, but also the different living habits of these two high altitude species.

  15. Plateau Waves of Intracranial Pressure and Multimodal Brain Monitoring.

    PubMed

    Dias, Celeste; Maia, Isabel; Cerejo, Antonio; Smielewski, Peter; Paiva, José-Artur; Czosnyka, Marek

    2016-01-01

    The aim of this study was to describe multimodal brain monitoring characteristics during plateau waves of intracranial pressure (ICP) in patients with head injury, using ICM+ software for continuous recording. Plateau waves consist of an abrupt elevation of ICP above 40 mmHg for 5-20 min. This is a prospective observational study of patients with head injury who were admitted to a neurocritical care unit and who developed plateau waves. We analyzed 59 plateau waves that occurred in 8 of 18 patients (44 %). At the top of plateau waves arterial blood pressure remained almost constant, but cerebral perfusion pressure, cerebral blood flow, brain tissue oxygenation, and cerebral oximetry decreased. After plateau waves, patients with a previously better autoregulation status developed hyperemia, demonstrated by an increase in cerebral blood flow and brain oxygenation. Pressure and oxygen cerebrovascular reactivity indexes (pressure reactivity index and ORxshort) increased significantly during the plateau wave as a sign of disruption of autoregulation. Bedside multimodal brain monitoring is important to characterize increases in ICP and give differential diagnoses of plateau waves, as management of this phenomenon differs from that of regular ICP.

  16. An introduction to the Colorado Plateau Native Plant Initiative

    Treesearch

    Wayne Padgett; Peggy Olwell; Scott Lambert

    2010-01-01

    The Colorado Plateau Ecoregion is occupied by a variety of ecosystems requiring restoration activities following natural and human-caused disturbances. The Colorado Plateau Native Plant Initiative, included in the BLM Native Plant Materials Development Program, was established as a part of the Seeds of Success program. This program is a partnership between USDI Bureau...

  17. Removal of pinyon-juniper woodlands on the Colorado Plateau

    Treesearch

    Michael Peters; Neil S. Cobb

    2008-01-01

    (Please note, this is an abstract only) Pinyon-Juniper (PJ) woodland is the 3rd largest vegetation type in the United States, covering 35.5% of the Colorado Plateau, it is the largest vegetation type administered by the Bureau of Land Management (BLM) on the Colorado Plateau. These woodlands have been increasing dramatically in density and extent over the last 100...

  18. The Properties of Groundwater

    NASA Astrophysics Data System (ADS)

    Caruccio, Frank T.

    Scientists and engineers concerned with the environmental aspects of groundwater frequently require a comprehensive reference text that provides an overview of the pertinent problem, appropriate decision making criteria and a guide to relevant references. The Properties of Groundwater, translated from the German by John C. Harvey, is a welcome addition to the select books currently available in this field. The book occupies the niche that lies between Hem's classic Study and Interpretation of the Chemical Characteristics of Natural Water (U.S.G.S., Water Supply Pap. 1473, 363, pp., 1970), Stumm and Morgan's Aquatic Chemistry (John Wiley, New York, 780 pp., 1970), and Freeze and Cherry's Groundwater (Prentice-Hall, Englewood Cliffs, N.J., 604 pp., 1979). The level of presentation, coupled with the cost, may limit the use of the book to advanced seminar courses and, more appropriately, as a solid reference text for scientists and researchers concerned with water and water quality. The table of contents is well indexed and is structured to allow the reader to review effectively the subject matter.

  19. Changing land management practices and vegetation on the Central Plateau of Burkina Faso (1968-2002)

    USGS Publications Warehouse

    Reij, C.; Tappan, G.; Belemvire, A.

    2005-01-01

    In the early 1980s, the situation on the northern part of the Central Plateau of Burkina Faso was characterized by expanding cultivation on lands marginal to agriculture, declining rainfall, low and declining cereal yields, disappearing and impoverishing vegetation, falling ground-water levels and strong outmigration. This crisis situation provoked two reactions. Farmers, as well as technicians working for non-governmental organizations, started to experiment in improving soil and water conservation (SWC) techniques. When these experiments proved successful, donor agencies rapidly designed SWC projects based on simple, effective techniques acceptable to farmers. A study looked at the impact of SWC investments in nine villages and identified a number of major impacts, including: significant increases in millet and sorghum yields since the mid-1980s, cultivated fields treated with SWC techniques have more trees than 10-15 years ago, but the vegetation on most of the non-cultivated areas continues to degrade, greater availability of forage for livestock, increased investment in livestock by men and women and a beginning change in livestock management from extensive to semi-intensive methods, improved soil fertility management by farmers, locally rising ground-water tables, a decrease in outmigration and a significant reduction in rural poverty. Finally, data are presented on the evolution of land use in three villages between 1968 and 2002. ?? 2005 Elsevier Ltd. All rights reserved.

  20. TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD SITE CENTRAL PLATEAU

    SciTech Connect

    PETERSEN SW; MORSE JG; TRUEX MJ; LAST GV

    2007-11-29

    A treatability test plan has been prepared to address options for remediating portions of the deep vadose zone beneath a portion of the U.S. Department of Energy's (DOE's) Hanford Site. The vadose zone is the region of the subsurface that extends from the ground surface to the water table. The overriding objective of the treatability test plan is to recommend specific remediation technologies and laboratory and field tests to support the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and Resource Conservation and Recovery Act of 1976 remedial decision-making process in the Central Plateau of the Hanford Site. Most of the technologies considered involve removing water from the vadose zone or immobilizing the contaminants to reduce the risk of contaminating groundwater. A multi-element approach to initial treatability testing is recommended, with the goal of providing the information needed to evaluate candidate technologies. The proposed tests focus on mitigating two contaminants--uranium and technetium. Specific technologies are recommended for testing at areas that may affect groundwater in the future, but a strategy to test other technologies is also presented.

  1. Simulation of reactive transport of injected CO2 on the Colorado Plateau, Utah, USA

    USGS Publications Warehouse

    White, S.P.; Allis, R.G.; Moore, J.; Chidsey, T.; Morgan, C.; Gwynn, W.; Adams, M.

    2005-01-01

    This paper investigates injection of CO2 into non-dome-shaped geological structures that do not provide the traps traditionally deemed necessary for the development of artificial CO2 reservoirs. We have developed a conceptual and two numerical models of the geology and groundwater along a cross-section lying approximately NW-SE and in the vicinity of the Hunter power station on the Colorado Plateau, Central Utah and identified a number of potential sequestration sites on this cross-section. Preliminary modeling identified the White Rim Sandstone as appearing to offer the properties required of a successful sequestration site. Detailed modeling of injection of CO2 into the White Rim Sandstone using the reactive chemical simulator ChemTOUGH found that 1000 years after the 30 year injection period began approximately 21% of the injected CO2 was permanently sequestered as a mineral, 52% was beneath the ground surface as a gas or dissolved in the groundwater and 17% had leaked to the surface and leakage to the surface was continuing. ?? 2005 Elsevier B.V. All rights reserved.

  2. Defining groundwater age: Chapter 3

    USGS Publications Warehouse

    Torgersen, T.; Purtschert, R.; Phillips, F.M.; Plummer, L.N.; Sanford, W.E.; Suckow, A.

    2013-01-01

    This book investigates applications of selected chemical and isotopic substances that can be used to recognize and interpret age information pertaining to ‘old’ groundwater (defined as water that was recharged on a timescale from approximately 1000 to more than 1 000 000 a). However, as discussed below, only estimates of the ‘age’ of water extracted from wells can be inferred. These groundwater age estimates are interpreted from measured concentrations of chemical and isotopic substances in the groundwater. Even then, there are many complicating factors, as discussed in this book. In spite of these limitations, much can be learned about the physics of groundwater flow and about the temporal aspects of groundwater systems from age interpretations of measured concentrations of environmental tracers in groundwater systems. This chapter puts the concept of ‘age’ into context, including its meaning and interpretation, and attempts to provide a unifying usage for the rest of the book.

  3. Groundwater hydrology and estimation of horizontal groundwater flux from the Rio Grande at selected locations in Albuquerque, New Mexico, 2009–10

    USGS Publications Warehouse

    Rankin, Dale R.; Oelsner, Gretchen P.; McCoy, Kurt J.; Goeff J.M. Moret,; Jeffery A. Worthington,; Kimberly M. Bandy-Baldwin,

    2016-03-17

    The Albuquerque area of New Mexico has two principal sources of water: (1) groundwater from the Santa Fe Group aquifer system, and (2) surface water from the Rio Grande. From 1960 to 2002, pumping from the Santa Fe Group aquifer system caused groundwater levels to decline more than 120 feet while water-level declines along the Rio Grande in Albuquerque were generally less than 40 feet. These differences in water-level declines in the Albuquerque area have resulted in a great deal of interest in quantifying the river-aquifer interaction associated with the Rio Grande.In 2003, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, acting as fiscal agent for the Middle Rio Grande Endangered Species Collaborative Program, and the U.S. Army Corps of Engineers, began a study to characterize the hydrogeology of the Rio Grande inner valley alluvial aquifer in the Albuquerque area of New Mexico. The study provides hydrologic data in order to enhance the understanding of rates of water leakage from the Rio Grande to the alluvial aquifer, groundwater flow through the aquifer, and discharge of water from the aquifer to riverside drains. The study area extends about 20 miles along the Rio Grande in the Albuquerque area. Piezometers and surface-water gages were installed in paired transects at eight locations. Nested piezometers, completed at various depths in the alluvial aquifer, and surface-water gages, installed in the Rio Grande and riverside drains, were instrumented with pressure transducers. Water-level and water-temperature data were collected from 2009 to 2010.Water levels from the piezometers indicated that groundwater movement was usually away from the river towards the riverside drains. Annual mean horizontal groundwater gradients in the inner valley alluvial aquifer ranged from 0.0024 (I-25 East) to 0.0144 (Pajarito East). The median hydraulic conductivity values of the inner valley alluvial aquifer, determined from slug tests, ranged from 30

  4. Tower mast of precipitation over the central Tibetan Plateau summer

    NASA Astrophysics Data System (ADS)

    Fu, Yunfei; Liu, Guosheng; Wu, Guoxiong; Yu, Rucong; Xu, Youping; Wang, Yu; Li, Rui; Liu, Qi

    2006-03-01

    Over the Tibetan Plateau, solar heating often produces strong convective instability in the atmosphere. Using 3 years (1998-2000) of Tropical Rainfall Measuring Mission (TRMM) precipitation radar data, our investigations revealed a tower mast shape of precipitation over the Plateau in both height-longitude and height-latitude cross-sections. High rain rate center over the Plateau is located above 6km as a tower penetrating into the mid-troposphere against the nearby background, implying a unique latent heating source injecting directly to the middle atmosphere. Results indicate that there are more isolated rain cells over the Plateau than its nearby regions, and the strongest diurnal cycle of rainfall existing over the Plateau with a peak around 1600 and a valley around 0500 local time, indicating the dominance of convective clouds caused by solar heating. It is also found that the TRMM algorithm might have misclassified weak convections as stratiform rains.

  5. Prehistoric vegetation on the Loess Plateau: steppe or forest?

    NASA Astrophysics Data System (ADS)

    Tungsheng, Liu; Zhengtang, Guo; Wu Naiqin; Lu Houyuan

    The paper aims to assess the Holocene natural vegetation on the Loess Plateau before human reclamation, a contentious point in paleo-environmental studies. Coordinated analyses on the soils, phytolith assemblage, organic carbon isotope composition and pollen data from selected sites suggest that the Holocene vegetation on the Loess Plateau was dominated by steppe. During the mid-Holocene, corresponding to the climatic optimum, the southernmost part of the Plateau (Weinan and Xian) was covered by an open meadow steppe with the presence of some coniferous species, while the middle part of the plateau (Luochuan) was covered by steppe. Our results do not support the notion that dense forest cover had developed on the Loess Plateau during the Holocene.

  6. GROUNDWATER PROTECTION MANAGEMENT PROGRAM DESCRIPTION.

    SciTech Connect

    PAQUETTE,D.E.; BENNETT,D.B.; DORSCH,W.R.; GOODE,G.A.; LEE,R.J.; KLAUS,K.; HOWE,R.F.; GEIGER,K.

    2002-05-31

    THE DEPARTMENT OF ENERGY ORDER 5400.1, GENERAL ENVIRONMENTAL PROTECTION PROGRAM, REQUIRES THE DEVELOPMENT AND IMPLEMENTATION OF A GROUNDWATER PROTECTION PROGRAM. THE BNL GROUNDWATER PROTECTION MANAGEMENT PROGRAM DESCRIPTION PROVIDES AN OVERVIEW OF HOW THE LABORATORY ENSURES THAT PLANS FOR GROUNDWATER PROTECTION, MONITORING, AND RESTORATION ARE FULLY DEFINED, INTEGRATED, AND MANAGED IN A COST EFFECTIVE MANNER THAT IS CONSISTENT WITH FEDERAL, STATE, AND LOCAL REGULATIONS.

  7. Water supply at Los Alamos during 1996. Progress report

    SciTech Connect

    McLin, S.G.; Purtymun, W.D.; Maes, M.N.; Longmire, P.A.

    1997-12-01

    Production of potable municipal water supplies during 1996 totaled about 1,368.1 million gallons from wells in the Guaje, Pajarito, and Otowi well fields. There was no water used from either the spring gallery in Water Canyon or from Guaje Reservoir during 1996. About 2.6 million gallons of water from Los Alamos Reservoir was used for lawn irrigation. The total water usage in 1996 was about 1,370.7 million gallons, or about 131 gallons per day per person living in Los Alamos County. Groundwater pumpage was up about 12.0 million gallons in 1996 compared with the pumpage in 1995. This report fulfills requirements specified in US Department of Energy (DOE) Order 5400.1 (Groundwater Protection Management Program), which requires the Los Alamos National Laboratory (LANL) to monitor and document groundwater conditions below Pajarito Plateau and to protect the regional aquifer from contamination associated with Laboratory operations. Furthermore, this report also fulfills special conditions by providing information on hydrologic characteristics of the regional aquifer, including operating conditions of the municipal water supply system.

  8. Satellite precipitation estimation over the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Porcu, F.; Gjoka, U.

    2012-04-01

    Precipitation characteristics over the Tibetan Plateau are very little known, given the scarcity of reliable and widely distributed ground observation, thus the satellite approach is a valuable choice for large scale precipitation analysis and hydrological cycle studies. However,the satellite perspective undergoes various shortcomings at the different wavelengths used in atmospheric remote sensing. In the microwave spectrum often the high soil emissivity masks or hides the atmospheric signal upwelling from light-moderate precipitation layers, while low and relatively thin precipitating clouds are not well detected in the visible-infrared, because of their low contrast with cold and bright (if snow covered) background. In this work an IR-based, statistical rainfall estimation technique is trained and applied over the Tibetan Plateau hydrological basin to retrive precipitation intensity at different spatial and temporal scales. The technique is based on a simple artificial neural network scheme trained with two supervised training sets assembled for monsoon season and for the rest of the year. For the monsoon season (estimated from June to September), the ground radar precipitation data for few case studies are used to build the training set: four days in summer 2009 are considered. For the rest of the year, CloudSat-CPR derived snowfall rate has been used as reference precipitation data, following the Kulie and Bennartz (2009) algorithm. METEOSAT-7 infrared channels radiance (at 6.7 and 11 micometers) and derived local variability features (such as local standard deviation and local average) are used as input and the actual rainrate is obtained as output for each satellite slot, every 30 minutes on the satellite grid. The satellite rainrate maps for three years (2008-2010) are computed and compared with available global precipitation products (such as C-MORPH and TMPA products) and with other techniques applied to the Plateau area: similarities and differences are

  9. Arkansas Groundwater-Quality Network

    USGS Publications Warehouse

    Pugh, Aaron L.; Jackson, Barry T.; Miller, Roger

    2014-01-01

    Arkansas is the fourth largest user of groundwater in the United States, where groundwater accounts for two-thirds of the total water use. Groundwater use in the State increased by 510 percent between 1965 and 2005 (Holland, 2007). The Arkansas Groundwater-Quality Network is a Web map interface (http://ar.water.usgs.gov/wqx) that provides rapid access to the U.S. Geological Survey’s (USGS) National Water Information System (NWIS) and the U.S. Environmental Protection Agency’s (USEPA) STOrage and RETrieval (STORET) databases of ambient water information. The interface enables users to perform simple graphical analysis and download selected water-quality data.

  10. Intensive rainfall recharges tropical groundwaters

    NASA Astrophysics Data System (ADS)

    Jasechko, Scott; Taylor, Richard G.

    2015-12-01

    Dependence upon groundwater to meet rising agricultural and domestic water needs is expected to increase substantially across the tropics where, by 2050, over half of the world’s population is projected to live. Rare, long-term groundwater-level records in the tropics indicate that groundwater recharge occurs disproportionately from heavy rainfalls exceeding a threshold. The ubiquity of this bias in tropical groundwater recharge to intensive precipitation is, however, unknown. By relating available long-term records of stable-isotope ratios of O and H in tropical precipitation (15 sites) to those of local groundwater, we reveal that groundwater recharge in the tropics is near-uniformly (14/15 sites) biased to intensive monthly rainfall, commonly exceeding the ∼70th intensity decile. Our results suggest that the intensification of precipitation brought about by global warming favours groundwater replenishment in the tropics. Nevertheless, the processes that transmit intensive rainfall to groundwater systems and enhance the resilience of tropical groundwater storage in a warming world, remain unclear.

  11. Groundwater contamination and emergency response guide

    SciTech Connect

    Guswa, J.H.; Donigian, A.S.

    1984-01-01

    This book provides a review of equipment, methods, and field techniques; an overview of groundwater hydrology; and a methodology for estimating groundwater contamination under emergency response conditions. It describes techniques used to identify, quantify, and respond to groundwater pollution incidents.

  12. Large contrast observed in crustal composition and structure between the Ordos plateau and the northeastern margin of the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Pan, S.; Niu, F.

    2010-12-01

    The Ordos plateau located in the western side of the North China craton is a distinct aseismic block. The plateau is bounded on the south and east, respectively, by the Paleozoic-Mesozoic Qinling orogenic belt and the Taihangshan mountain range. A series of graben systems were developed late in Cenozoic around the southern and eastern margins of the plateau. The Ordos is also bordered on the southwest by the northeastern margin of the Tibetan Plateau formed by the Cenozoic India-Eurasia collision. The gentle topographic slope together with the moderately thickened crust along the northeastern margin of the Tibetan Plateau was modeled by an injection of lower crustal material into a relatively weak foreland. We have analyzed thousands of receiver-function data recorded by 182 national and regional stations of the broadband seismic network operated by the China Earthquake Administration to study the crustal structure beneath the Ordos plateau and the northeastern margin of the Tibetan plateau. Crustal thickness and average crustal Vp/Vs ratio were measured at each station. The Ordos plateau is underlain by a moderate thick crust with an average Moho depth ~40 km. The Trans-North China Orogen east to the Ordos is featured by a thin crust varying from 25-35 km. The Weihe Graben at the southern border of the Ordos plateau is lying above a ~30-km thin crust, while its southern neighbor, the Qinling organic belt has a thick root extending to as much as 45 km deep. Crust beneath the northeastern margin of the Tibetan plateau varies from 55 to 65 km. We found a remarkable contrast between the Tibetan and Ordos plateaus in the measured Poisson’s ratio: the Ordos plateau is featured by a high Poisson’s ratio while the Tibetan margin has a very low Poisson’s ratio. In general, lower crustal rocks are more mafic with a higher Poisson’s ratio than those found in the upper crust and mafic rocks are mechanically stronger than the felsic ones. The measured lower ratio thus

  13. Hydrology of coal-resource areas in the southern Wasatch Plateau, central Utah

    USGS Publications Warehouse

    Danielson, T.W.; Sylla, D.A.

    1982-01-01

    The study defines the surface and groundwater hydrology of coal-resources areas in the Southern Wasatch Plateau in Central Utah and, where possible, predicts the hydrologic impacts of underground mining. Discharge data at four streamflow gaging stations indicated that from 5 to 29% of the average annual precipitation on a drainage runs off streams, mainly during the snowmelt period (spring and summer). Most of the base flow of streams originates as spring discharge in the higher altitudes of drainages. Peak flows, average 7-day flood flows, and flood depths were related to basin characteristics in order to develop flood equations for ungaged sites. Chemical quality of surface water was suitable for most uses. Dissolved-solids concentrations ranged from 97 to 835 milligrams per liter in 61 samples collected throughout the area. Data from wells and coal-test holes, and a comprehensive spring inventory indicate that groundwater occurs in all geologic units exposed in the study area. The coal-bearing Blackhawk Formation and underlying Star Point Sandstone are saturated in most areas. Some future mining operations would require dewatering of the Star Point-Blackhawk aquifer. Most of the springs issue from the Flagstaff Limestone and North Horn Formation above the Star Point-Blackhawk aquifer. It is not known whether water in the Flagstaff and North Horn is perched. Dissolved-solids concentrations in groundwater ranged from 105 to 1,080 milligrams per liter in 87 analyzed samples. Water levels in wells, the discharge of springs, benthic invertebrates in streams, and quantity and quality of mine effluents all need to be monitored in order to detect changes in the hydrologic system caused by coal mining. (USGS)

  14. Extension of the Yellowstone plateau, eastern Snake River Plain, and Owyhee plateau

    NASA Astrophysics Data System (ADS)

    Rodgers, David W.; Hackett, William R.; Ore, H. Thomas

    1990-11-01

    Formation of the late Cenozoic volcanic province comprising the Owyhee plateau, eastern Snake River Plain, and Yellowstone plateau has been accompanied by east-northeast-directed crustal extension. A new vector of 45 mm/yr, N56°E for the migration of silicic volcanism across the volcanic province is calculated. If migration of volcanism reflects west-southwest continental drift over a mantle plume, a zone of crustal extension must separate the volcanic province from the more slowly moving North American craton. Space-time relations of basin fill in the adjacent Basin and Range province provide evidence for a zone of extension, about 125 km wide, coincident with and east of coeval silicic volcanism. Since 16 Ma, the zone of extension has migrated along with silicic volcanism, maintaining its position between the province and the unextended craton.

  15. Extension of the Yellowstone plateau, eastern Snake River Plain, and Owyhee plateau

    SciTech Connect

    Rodgers, D.W.; Hackett, W.R.; Ore, H.T. )

    1990-11-01

    Formation of the late Cenozoic volcanic province comprising the Owyhee plateau, eastern Snake River Plain, and Yellowstone plateau has been accompanied by east-northeast-directed crustal extension. A new vector of 45 mm/yr, N56{degree}E for the migration of silicic volcanism across the volcanic province is calculated. If migration of volcanism reflects west-southwest continental drift over a mantle plume, a zone of crustal extension must separate the volcanic province from the more slowly moving North American craton. Space-time relations of basin fill in the adjacent Basin and Range province provide evidence for a zone of extension, about 125 km wide, coincident with and east of coeval silicic volcanism. Since 16 Ma, the zone of extension has migrated along with silicic volcanism, maintaining its position between the province and the unextended craton.

  16. Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment

    PubMed Central

    Nie, Junsheng; Stevens, Thomas; Rittner, Martin; Stockli, Daniel; Garzanti, Eduardo; Limonta, Mara; Bird, Anna; Andò, Sergio; Vermeesch, Pieter; Saylor, Joel; Lu, Huayu; Breecker, Daniel; Hu, Xiaofei; Liu, Shanpin; Resentini, Alberto; Vezzoli, Giovanni; Peng, Wenbin; Carter, Andrew; Ji, Shunchuan; Pan, Baotian

    2015-01-01

    Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records. PMID:26449321

  17. Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment.

    PubMed

    Nie, Junsheng; Stevens, Thomas; Rittner, Martin; Stockli, Daniel; Garzanti, Eduardo; Limonta, Mara; Bird, Anna; Andò, Sergio; Vermeesch, Pieter; Saylor, Joel; Lu, Huayu; Breecker, Daniel; Hu, Xiaofei; Liu, Shanpin; Resentini, Alberto; Vezzoli, Giovanni; Peng, Wenbin; Carter, Andrew; Ji, Shunchuan; Pan, Baotian

    2015-10-09

    Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records.

  18. Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment

    NASA Astrophysics Data System (ADS)

    Nie, Junsheng; Stevens, Thomas; Rittner, Martin; Stockli, Daniel; Garzanti, Eduardo; Limonta, Mara; Bird, Anna; Andò, Sergio; Vermeesch, Pieter; Saylor, Joel; Lu, Huayu; Breecker, Daniel; Hu, Xiaofei; Liu, Shanpin; Resentini, Alberto; Vezzoli, Giovanni; Peng, Wenbin; Carter, Andrew; Ji, Shunchuan; Pan, Baotian

    2015-10-01

    Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records.

  19. The Hubble flow of plateau inflation

    SciTech Connect

    Coone, Dries; Roest, Diederik; Vennin, Vincent E-mail: d.roest@rug.nl

    2015-11-01

    In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard ''horizon flow'' procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau inflation, which suggests the use of Padé approximants instead. We propose a novel method that provides analytic solutions of the flow equations for a given parametrization of the Hubble function. This method is illustrated in the Taylor and Padé cases, for low order expansions. We then present the results of a full numerical treatment scanning larger order expansions, and compare these parametrizations in terms of convergence, prior dependence, predictivity and compatibility with the data. Finally, we highlight the implications for potential reconstruction methods.

  20. Plateau inflation in SUGRA-MSSM

    NASA Astrophysics Data System (ADS)

    Chakravarty, Girish Kumar; Gupta, Gaveshna; Lambiase, Gaetano; Mohanty, Subhendra

    2016-09-01

    We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the SU (2) Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the D-flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a successful Higgs inflation scenario in the context of Supergravity and it is compatible with Minimal Supersymmetric extension of the Standard Model.

  1. Rapid increase of lakes in Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ren, H.; Fan, W.; Yao, Y., Sr.; Tian, D.; MA, B.; LIU, R.; Qin, Q.

    2016-12-01

    The Tibetan Plateau, covered with a huge area of snow, glaciers and lakes, feeds several large rivers, incluidng Yangtze River, Yellow River, Yarlung Tsangpo River and Lancang River. Climate change can cause lakes to expand and bring floods and mudflows, and the response of lakes in this plateau to global climate change is very crucial. Using time-series Landsats clear-sky images in summer from the late 1980s to 2015, we established a new finer-resolution (30m) database of lakes in the plateau among five stages (1980s, 1995, 2000, 2005 and 2015), analyzed lake changes in the past three decades, and explored the possible driving forces. Results and discussions(1) Changes in lakes > 1km2 between 1980s and 2015The changes of lake numbers and surface areas were investigated between 1980s and 2015. The lakes were identified by visual interpretation and classified to several different sizes: small (1-10km2), medium (10-50km2), large (50-100km2) and huge (>100km2) lakes. A total of 1375 lakes (>1km2) were detected in 2015, in which the small, medium, large and huge lakes respectively account for 97, 74, 262 and 942 (Fig.1 and Table 1). The numbers of lakes (> 1km2 ) has increased by 384 from 991 in 1980s (Fig.2 a, b). Meanwhile, a rapid increase of lake surface area also occurred: increased by 28.2% from 37711.0km2 in 1980s to 48335.2km2 in 2015 (Fig.2c and Table 1). (2) Temporal changes in lakes > 10km2 between 1980s and 2015Temporal variation in all lakes > 10km2 were investigated at the five stages. Most lakes have expanded (Fig.3). The water surface area of large and huge lakes increased by 13.7% from a total area of 32056.7km2 in 1980s to 36437.0km2 in 2015. For example, Siling Co, which is the largest lake in Tibet region and second largest lake in Tibetan Plateau, has increased by 702.1 km2 (41.0%) to 2416.08 km2 since 1980s with an rate about 28 km2 /a. Some new lakes or water bodies appeared due to melting glaciers or anthropogenic intervention. A few of small

  2. Logarithmic correlations in quantum Hall plateau transitions

    NASA Astrophysics Data System (ADS)

    Vasseur, Romain

    2015-07-01

    The critical behavior of quantum Hall transitions in two-dimensional disordered electronic systems can be described by a class of complicated, nonunitary conformal field theories with logarithmic correlations. The nature and the physical origin of these logarithmic correlation functions remain, however, mysterious. Using the replica trick and the underlying symmetries of these quantum critical points, we show here how to construct nonperturbatively disorder-averaged observables in terms of Green's functions that scale logarithmically at criticality. In the case of the spin quantum Hall transition, which may occur in disordered superconductors with spin-rotation symmetry and broken time reversal invariance, we argue that our results are compatible with an alternative approach based on supersymmetry. The generalization to the integer quantum Hall plateau transition is also discussed.

  3. Geochemical Evolution of the Hikurangi Oceanic Plateau, New Zealand

    NASA Astrophysics Data System (ADS)

    Hoernle, K.; Hauff, F.; Werner, R.; Mortimer, N.; van den Bogaard, P.; Geldmacher, J.; Garbe-Schoenberg, D.

    2004-12-01

    The Hikurangi oceanic plateau or large igneous province (LIP), located east of the North Island of New Zealand, covers an area of 350,000 km3 and is located at a depth of 2,500-3,500 b.s.l. The Hikurangi plateau was possibly connected to the Manihiki LIP (now located 3000 km to the north) but may have been separated by Cretaceous seafloor spreading at the Osbourn Trough (Billen and Stock, 2000, J. Geophys. Res., 106, 13481-13489). Therefore it may have formed part of the "greater Ontong Java Plateau event" (Coffin and Eldholm, Geology, 21, 515-51), the largest magmatic event preserved on Earth. During the R/V Sonne SO168 ZEALANDIA cruise, 77 dredge hauls containing igneous samples were recovered from the Hikurangi Plateau. Volcanic rocks were obtained from 1) the plateau basement along the 1 km high Rapuhia Scarp, 2) large guyot-type seamounts within the plateau, and 3) ridge-type seamounts associated with rifting of the NE plateau margin (Hoernle et al., 2004, EOS). The recovered plateau rocks range from basalts, dolerites and gabbros with tholeiitic and alkali basaltic to trachybasaltic compositions. The seamount volcanic rocks have more Si-undersaturated compositions than the plateau rocks and range from alkali basalts through mugearites to basanites through tephrites to nephelinites. The plateau basement rocks have flat rare earth element (REE) patterns similar to enriched mid-ocean-ridge basalt (MORB) and basement rocks from other oceanic LIPs, such as Manihiki, Ontong-Java and the Caribbean. The late-stage seamount lavas show enrichment in the light REE and all strongly to moderately incompatible elements, having incompatible element characteristics similar to the HIMU (high time-integrated U/Pb) component in ocean island basalts (OIB). Although the Pb isotopic composition has been extensively effected by seawater alteration, the freshest samples have enriched (EM-type) Sr-Nd-Pb isotopic compositions similar to Ontong-Java and Manihiki basement rocks

  4. Overview of Ground-Water Recharge Study Sites

    USGS Publications Warehouse

    Constantz, Jim; Adams, Kelsey S.; Stonestrom, David A.

    2007-01-01

    Multiyear studies were done to examine meteorologic and hydrogeologic controls on ephemeral streamflow and focused ground-water recharge at eight sites across the arid and semiarid southwestern United States. Campaigns of intensive data collection were conducted in the Great Basin, Mojave Desert, Sonoran Desert, Rio Grande Rift, and Colorado Plateau physiographic areas. During the study period (1997 to 2002), the southwestern region went from wetter than normal conditions associated with a strong El Ni?o climatic pattern (1997?1998) to drier than normal conditions associated with a La Ni?a climatic pattern marked by unprecedented warmth in the western tropical Pacific and Indian Oceans (1998?2002). The strong El Ni?o conditions roughly doubled precipitation at the Great Basin, Mojave Desert, and Colorado Plateau study sites. Precipitation at all sites trended generally lower, producing moderate- to severe-drought conditions by the end of the study. Streamflow in regional rivers indicated diminishing ground-water recharge conditions, with annual-flow volumes declining to 10?46 percent of their respective long-term averages by 2002. Local streamflows showed higher variability, reflecting smaller scales of integration (in time and space) of the study-site watersheds. By the end of the study, extended periods (9?15 months) of zero or negligible flow were observed at half the sites. Summer monsoonal rains generated the majority of streamflow and associated recharge in the Sonoran Desert sites and the more southerly Rio Grande Rift site, whereas winter storms and spring snowmelt dominated the northern and westernmost sites. Proximity to moisture sources (primarily the Pacific Ocean and Gulf of California) and meteorologic fluctuations, in concert with orography, largely control the generation of focused ground-water recharge from ephemeral streamflow, although other factors (geology, soil, and vegetation) also are important. Watershed area correlated weakly with focused

  5. Management of Egypt's Surface and Groundwater Resources: Present and Future

    NASA Astrophysics Data System (ADS)

    Sultan, M.; Ahmed, M.; Yan, E.; Milewski, A.; Mohamed, L.; Farag, A. Z. A.

    2014-12-01

    The River Nile is the main source of fresh water in Egypt. Most of Egypt's River Nile water (>85%) originates as precipitation over the Ethiopian highlands and is channeled by the Blue Nile. The construction (years: 2011 to 2017) of the Renaissance Dam (reservoir capacity: 70 x 109m3) on the Blue Nile poses an extreme threat to Egypt's population. If the reservoir was to be filled in 7 years, Egypt will lose (during each of 7 years following dam completion) a minimum of 15 x 109m3 of its annual allocation (55 x 109m3) to reservoir filling (10 x 109m3), evaporation (3.5 x 109m3), and infiltration (1.5 x 109m3). Three solutions are proposed: Solution I takes advantage of the cyclicity of Nile floods and is based on findings from a calibrated (against temporal head data) unconfined 2-dimensional transient groundwater flow model for Lake Nasser and surroundings and a calibrated (against lake levels) surface water model. Models show with time: (1) losses to infiltration will decrease (1975-193: 58.4 109m3; 1993-2001: 43.6 x 109m3) due to silting of Lake bottom and encroachment of excess Lake Nasser water will increase (e.g., 1975-1993: none; 1993-2001: 17 x 109m3). We propose to develop sustainable agricultural in the Western Desert: (1) In high flood years, excess Lake Nasser water (e.g., 1993-2001: 17 x 109m3) is channeled across the plateau bounding (from west) the River Nile valley to artificially recharge the Nubian Sandstone Aquifer System (NSAS) that crops out west of the plateau and, (2) in low flood years, we extract the recharged groundwater. Solution II calls on mining the NSAS at reasonable rates. Using temporal (January 2003 - September 2012) Gravity Recovery and Climate Experiment (GRACE) data we estimate the annual depletion rates at 2 x 109m3 due to artificial extraction (1.5 x 109m3) and natural discharge (0.5 x 109m3). Assuming current GRACE depletion rates, the recoverable groundwater (5,180 x 109m3) will last for 2500 years; if we were to quadruple

  6. Analysis of links between groundwater recharge and discharge areas and wetland plant communities distribution in Middle Biebrza Basin, Poland

    NASA Astrophysics Data System (ADS)

    Grygoruk, Mateusz; Batelaan, Okke; Okruszko, Tomasz; Kotowski, Wiktor; Rycharski, Marek; Chormanski, Jaroslaw; Miroslaw-Swiatek, Dorota

    2010-05-01

    Natural evolution of wetlands is strongly dependent on groundwater dynamics, soil aeration and climate. These environmental factors determine the constant development of wetland plant communities and peat forming processes. Depending on spatial distribution of groundwater flow systems and recharge and discharge conditions, shallow groundwater can also be influenced by phreatophytic plants. Such feedback plays an important role in wetland development, especially when landuse or climate changes occur. Thus, understanding the links between dynamics of biotopic and biocenotic relations is crucial for wetland management aimed at the comprehensive set of conservation strategies. Main aim of this study was to review links between valuable wetland plant communities and the groundwater recharge/discharge conditions of particular habitats of Middle Biebrza Basin, Poland. The study area consists of various types of wetland landscapes, of which the dominant are fens. Organogenic top layer is intersected locally by sandy dunes and glaci-fluvial residual plateaus. The northern boundary of the study area is covered with an outwash plateau. A three-dimensional regional groundwater flow model was set up to quantify groundwater system and flow paths. Model calibration involved measured heads of the unconfined organogenic top layer and the underlaying, confined sandy aquifer. Measured thickness of unsaturated zone as well as physical parameters of organogenic layer were taken into account in interpretation of shallow groundwater dynamics. Recharge to groundwater was spatially distributed in accordance to analysis of measured precipitation-groundwater level relationships. Cell-by-cell flow analysis and groundwater exfiltration analysis were applied to map groundwater recharge and discharge areas within the modelled area. Results of groundwater modelling were validated with phytosociologic research combined with remote-sensing based spatial analysis of wetland habitats distribution

  7. Groundwater inventory and monitoring technical guide: Remote sensing of groundwater

    USDA-ARS?s Scientific Manuscript database

    The application of remotely sensed data in conjunction with in situ data greatly enhances the ability of the USDA Forest Service to meet the demands of field staff, customers, and others for groundwater information. Generally, the use of remotely sensed data to inventory and monitor groundwater reso...

  8. Groundwater Unmasked: Combining Techniques to Trace Groundwater in Lowland Streams

    NASA Astrophysics Data System (ADS)

    Kaandorp, Vince; de Hilster, Stèphanie; Doornenbal, Pieter; de Louw, Perry

    2017-04-01

    Seepage of groundwater produces a significant part of stream discharge. This base flow component is of vital important for stream functioning as it prevents streams from falling dry and provides a specific water chemistry and temperature. The interaction between groundwater and surface water is complex and highly heterogeneous both in space and time. The location of groundwater seepage can be found using several techniques which we combined to reduce uncertainties. We applied the different techniques in two lowland streams in the Netherlands, which have different geological and hydrological settings. Two glass fibre cables with a length of 1.5 km were placed in the streams for the application of Distributed Temperature Sensing (DTS). The high-frequent spatially distributed stream temperature measurements revealed local hotspots of groundwater/surface water interaction. These were compared with measurements from the groundwater tracer Radon-222, vertical flux measurements using seepage meters, vertical temperature profile measurements and visual seepage indicators. Groundwater/surface water interaction was found to vary spatially in a spectacular way: whereas seepage occurred on one side of the stream, no seepage was found on the opposite side at only meter distance. It is essential to include these small scale differences as they can result in contrasting ecological habitats. Although combining groundwater tracing methods proved to be valuable, capturing the heterogeneity and quantifying the amounts of water exchange stay the most challenging problem facing research on groundwater/surface water interaction.

  9. The groundwater subsidy to vegetation: groundwater exchanges between landcover patches

    NASA Astrophysics Data System (ADS)

    Steven, L. I.; Gimenez, R.; Jobbagy, E. G.

    2015-12-01

    The Gran Chaco is a hot, dry plain, that spans over 60 million hectares across Bolivia, Paraguay, Brazil and Argentina. It supports high biodiversity in its dry forest and savannahs, but is rapidly being converted to agriculture in response to growing soy demand and technology including genetic modification and zero-till, that has made cultivation in drier landscapes more viable. Under natural conditions, the deep-rooted, native vegetation of the Chaco effectively captured all rainfall for evapotranspiration resulting in near zero groundwater recharge under the dry forest. Conversion to shallower rooted soy and corn, combined with the fallow period prior to the growing season, reduces evapotranspiration and allows some water to percolate through the root zone and recharge the groundwater system. When this groundwater recharge occurs, it creates groundwater mounding and a hydraulic gradient that drives flow to adjacent landcover patches where recharge does not occur. As the watertable rises, groundwater becomes available to the deep-rooted, dry forest vegetation. We develop a soil and groundwater flow model to simulate infiltration, percolation, evaporation, rootwater uptake, groundwater recharge and the lateral transfer of water between adjacent landcover patches to quantify this groundwater subsidy from converted agricultural lands to remnant patches of dry forest.

  10. Lake level changes on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Zhang, G.; Xie, H.; Kang, S.; Ackley, S. F.

    2010-12-01

    The Tibetan Plateau (TP) in central Asia has an average elevation of more than 4000 m, covers an area of about 2.5 million km2, and is now called “the Third Pole” of the Earth with the largest ice mass outside the north and south polar regions. It is also considered as “the Water Tower” of Asia since glaciers and seasonal snow melt provide the primary water source for billions of people. The TP, as a whole, has undergone warming in the past three decades; the temperature rise of 0.3 °C per decade is twice the global warming rate. It is currently difficult, if not impossible, to monitor elevation and its change of all lakes in Tibetan Plateau (TP) using field observations. Here we use ICESat altimetry data to provide precise lake elevations and their changes during the period of 2003-2008. We find that in the 68 lakes (51 salt lakes) examined, 53 (78%) of all lakes and 44 (86%) of the salt lakes show trends of lake level increase. The mean lake level increase rate is 0.29 m/year for the 53 lakes, and 0.30 m/year for the 44 salt lakes. The largest lake level increase (0.95 m/year) we found is the lake Cedo Caka. Three of the four subregions of the TP show increased lake levels. The increase in lake level, particularly for a high percentage of salt lakes, supports the accelerated glacier melting in the TP due to global warming.

  11. Behavioral mechanisms of male sterilization on plateau pika in the Qinghai-Tibet plateau.

    PubMed

    Liu, Ming; Qu, Jiapeng; Wang, Zengli; Wang, Yan-Ling; Zhang, Yanming; Zhang, Zhibin

    2012-03-01

    Fertility control is an alternative non-lethal method in the management of rodents. Previous modeling suggests that the efficacy of male sterilization depends on mating systems of animals, but behavioral mechanisms of male sterilization have not been investigated. Here we investigated the behavioral mechanism of the sterilant quinestrol in reducing the fertility of plateau pika (Ochotona curzoniae) inhabiting the Qinghai-Tibet plateau. Male pikas treated with quinestrol showed reduced aggression compared to control males, but they showed significantly higher levels of territorial behavior such as long-calls and long-chases. Levels of long-call and long-chase were negatively correlated with the number of newborn pikas in the family. Single-baiting of quinestrol effectively sterilized male pikas and reduced the pregnancy rate of female pikas; this was likely achieved by increased territorial behavior of sterilized pikas which resulted in unsuccessful invasions by fertile adult male pikas. Our study reveals a novel behavioral mechanism, increased territoriality in sterilized males, in the fertility control of plateau pikas. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Assessing Groundwater Resources Sustainability Using Groundwater Footprint Concept

    NASA Astrophysics Data System (ADS)

    Charchousi, Despoina; Spanoudaki, Katerina; Papadopoulou, Maria P.

    2017-04-01

    Over-pumping, water table depletion and climate change impacts require effective groundwater management. The Groundwater Footprint (GWF), introduced by Gleeson et al. in 2012 expresses the area required to sustain groundwater use and groundwater dependent ecosystem services. GWF represents a water balance between aquifer inflows and outflows, focusing on environmental flow requirements. Developing the water balance, precipitation recharge and additional recharge from irrigation are considered as inflows, whereas outflows are considered the groundwater abstraction from the aquifer of interest and the quantity of groundwater that is needed to sustain ecosystem services. The parameters required for GWF calculation can be estimated through in-situ measurements, observations and models outputs. The actual groundwater abstraction is often difficult to be estimated with a high accuracy. Environmental flow requirements can be calculated through different approaches; the most accurate of which are considered the ones that focus on hydro-ecological data analysis. As the GWF is a tool recently introduced in groundwater assessment and management, only a few studies have been reported in the literature to use it as groundwater monitoring and management tool. The present study emphasizes on a case study in Southern Europe, where awareness should be raised about rivers' environmental flow. GWF concept will be applied for the first time to a pilot area in Greece, where the flow of the perennial river that crosses the area of interest is dependent on baseflow. Recharge and abstraction of the pilot area are estimated based on historical data and previous reports and a groundwater flow model is developed using Visual Modflow so as to diminish the uncertainty of the input parameters through model calibration. The groundwater quantity that should be allocated on surface water body in order to sustain satisfactory biological conditions is estimated under the assumption that surface

  13. Solutions Remediate Contaminated Groundwater

    NASA Technical Reports Server (NTRS)

    2010-01-01

    During the Apollo Program, NASA workers used chlorinated solvents to clean rocket engine components at launch sites. These solvents, known as dense non-aqueous phase liquids, had contaminated launch facilities to the point of near-irreparability. Dr. Jacqueline Quinn and Dr. Kathleen Brooks Loftin of Kennedy Space Center partnered with researchers from the University of Central Florida's chemistry and engineering programs to develop technology capable of remediating the area without great cost or further environmental damage. They called the new invention Emulsified Zero-Valent Iron (EZVI). The groundwater remediation compound is cleaning up polluted areas all around the world and is, to date, NASA's most licensed technology.

  14. Tracer attenuation in groundwater

    NASA Astrophysics Data System (ADS)

    Cvetkovic, Vladimir

    2011-12-01

    The self-purifying capacity of aquifers strongly depends on the attenuation of waterborne contaminants, i.e., irreversible loss of contaminant mass on a given scale as a result of coupled transport and transformation processes. A general formulation of tracer attenuation in groundwater is presented. Basic sensitivities of attenuation to macrodispersion and retention are illustrated for a few typical retention mechanisms. Tracer recovery is suggested as an experimental proxy for attenuation. Unique experimental data of tracer recovery in crystalline rock compare favorably with the theoretical model that is based on diffusion-controlled retention. Non-Fickian hydrodynamic transport has potentially a large impact on field-scale attenuation of dissolved contaminants.

  15. Groundwater pollution control

    SciTech Connect

    Steele, J.L.

    1984-05-03

    Chlorinated organic compounds (trichloroethylene, tetrachloroethylene, and 1, 1, 1 trichloroethane) were discovered in the groundwater beneath the reactor fuel and target fabrication area at the Savannah River Plant in June 1981 during routine RCRA monitoring. Principal sources and contaminant location were identified along with air stripping as the remedial action technology. A pilot air stripping column with one recovery well was installed to evaluate air stripping and a 50 gpm production unit with two recovery wells was installed to expedite contaminant recovery. A 400 gpm air stripping column and eleven recovery wells are in the design stage and will be operational in the first quarter of 1985.

  16. EDITORIAL: Integrated assessments of environmental change on the Tibetan Plateau Integrated assessments of environmental change on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Sheng, Yongwei; Yao, Tandong

    2009-12-01

    The Tibetan Plateau is one of the Earth's most sensitive regions in responding to climate change due to its extremely high altitude and the presence of permafrost and glaciers. The cryosphere, biosphere and hydrosphere of the plateau have been undergoing significant changes. Due to the low human population density, environmental changes on the plateau are largely driven by natural processes. Thus, the plateau provides a unique and comprehensive site for global change studies. This focus issue on Climate Change on the Tibetan Plateau aims to address both paleo and recent environmental changes across the plateau to facilitate our understanding of this remote and under-studied area. We invited a wide spectrum of contributions to address climate change, permafrost degradation, glacier/snow/ice dynamics, lake dynamics, land- cover/land-use changes, and their interactions on the plateau. Collectively, the diverse contributions in this special issue are expected to present the recent advancement of the above topics and beyond. See the PDF for the full text of the editorial. Focus on Climate Change on the Tibetan Plateau Contents Does a weekend effect in diurnal temperature range exist in the eastern and central Tibetan Plateau? Qinglong You, Shichang Kang, Wolfgang-Albert Flügel, Arturo Sanchez-Lorenzo, Yuping Yan, Yanwei Xu and Jie Huang Diurnal variations of summertime precipitation over the Tibetan Plateau in relation to orographically-induced regional circulations Xiaodong Liu, Aijuan Bai and Changhai Liu Lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, investigated using optically stimulated luminescence dating of beach ridges Dewen Li, Yingkui Li, Baoqi Ma, Guocheng Dong, Liqiang Wang and Junxiang Zhao Recent changes in Imja Glacial Lake and its damming moraine in the Nepal Himalaya revealed by in situ surveys and multi-temporal ASTER imagery Koji Fujita, Akiko Sakai, Takayuki Nuimura, Satoru Yamaguchi and Rishi R Sharma Changes

  17. Sagittal plane deformity in bicondylar tibial plateau fractures.

    PubMed

    Streubel, Philipp N; Glasgow, Donald; Wong, Ambrose; Barei, David P; Ricci, William M; Gardner, Michael J

    2011-09-01

    To evaluate the prevalence and magnitude of sagittal plane deformity in bicondylar tibial plateau fractures. Retrospective radiographic review. Two Level I trauma centers. Sagittal inclination of the medial and lateral plateau measured in relation to the longitudinal axis of the tibia using computed tomographic reconstruction images. Seventy-four patients (mean age, 49 years; range, 16-82 years; 64% male) with acute bicondylar tibial plateau fractures (Orthopaedic Trauma Association 41C, Schatzker VI) treated from October 2006 to July 2009. The average sagittal plane angulation of the lateral plateau was 9.8° posteriorly (range, 17° anteriorly to 37° posteriorly). The medial plateau was angulated 4.1° posteriorly on average (range, 16° anteriorly to 31° posteriorly). Forty-two lateral plateaus were angulated more than 5° from the "normal" anatomic slope (defined as 5° of posterior tibial slope). Of these, 76% were angulated posteriorly. Forty-three (58%) of the medial plateaus were angulated greater than 5° from normal, of which only 47% were inclined posteriorly (P = 0.019 compared with lateral plateaus). In 68% of patients, the difference between medial and lateral plateaus was greater than 5°; the average intercondylar slope difference was 9° (range, 0°-31°; P < 0.001). Spanning external fixation did not affect the slope of either the medial or lateral tibial plateau. Intraobserver and interobserver correlations were high for both the medial and lateral plateaus (r > 0.81, P < 0.01). Considerable sagittal plane deformity exists in the majority of bicondylar tibial plateau fractures. The lateral plateau has a higher propensity for sagittal angulation and tends to have increased posterior slope. Most patients have a substantial difference between the lateral and medial plateau slopes. The identification of this deformity allows for accurate preoperative planning and specific reduction maneuvers to restore anatomic alignment.

  18. Groundwater hydrology--coastal flow

    USGS Publications Warehouse

    Sanford, Ward E.

    2010-01-01

    How groundwater flow varies when long-term external conditions change is little documented. Geochemical evidence shows that sea-level rise at the end of the last glacial period led to a shift in the flow patterns of coastal groundwater beneath Florida.

  19. SUPERFUND GROUNDWATER ISSUE - FACILITATED TRANSPORT

    EPA Science Inventory

    The Regional Superfund Ground Water Forum is a group of ground-water scientists representing EPA's Regional Superfund Offices, organized to exchange up to date information related to ground-water remediation at Superfund sites. Facilitated transport is an issue identified by the ...

  20. Linking climate change and groundwater

    USDA-ARS?s Scientific Manuscript database

    Projected global change includes groundwater systems, which are linked with changes in climate over space and time. Consequently, global change affects key aspects of subsurface hydrology (including soil water, deeper vadose zone water, and unconfined and confined aquifer waters), surface-groundwat...

  1. SUPERFUND GROUNDWATER ISSUE - FACILITATED TRANSPORT

    EPA Science Inventory

    The Regional Superfund Ground Water Forum is a group of ground-water scientists representing EPA's Regional Superfund Offices, organized to exchange up to date information related to ground-water remediation at Superfund sites. Facilitated transport is an issue identified by the ...

  2. Sustainable groundwater management in California

    USGS Publications Warehouse

    Phillips, Steven P.; Rogers, Laurel Lynn; Faunt, Claudia

    2015-12-01

    The U.S. Geological Survey (USGS) uses data collection, modeling tools, and scientific analysis to help water managers plan for, and assess, hydrologic issues that can cause “undesirable results” associated with groundwater use. This information helps managers understand trends and investigate and predict effects of different groundwater-management strategies.

  3. Promoting local management in groundwater

    NASA Astrophysics Data System (ADS)

    van Steenbergen, Frank

    2006-03-01

    There is a strong case for making greater effort to promote local groundwater management—in addition to other measures that regulate groundwater use. Though scattered, there are several examples—from India, Pakistan, Yemen and Egypt—where groundwater users effectively self-imposed restrictions on the use of groundwater. There are a number of recurrent themes in such spontaneously-developed examples of local regulation: the importance of not excluding potential users; the importance of simple, low transaction cost rules; the power of correct and accessible hydrogeological information; the possibility of making more use of demand and supply management strategies; and the important supportive role of local governments. The case is made, using examples, for actively promoting local groundwater management as an important element in balancing groundwater uses. Two programmes for promoting local groundwater management in South India are described—one focussing on participatory hydrological monitoring, and one focussing on micro-resource planning and training. In both cases the response was very positive and the conclusion is that promoting local groundwater regulation is not difficult, costly or sensitive and can reach the necessary scale quickly.

  4. Hydrogeology of the Coconino Plateau and adjacent areas, Coconino and Yavapai Counties, Arizona

    USGS Publications Warehouse

    Bills, Donald J.; Flynn, Marilyn E.; Monroe, Stephen A.

    2007-01-01

    Two large, regional ground-water flow systems occur in the Coconino Plateau and adjacent areas: the C aquifer and the Redwall-Muav aquifer. The C aquifer occurs mainly in the eastern and southern parts of the 10,300-square-mile Coconino Plateau study area, and the Redwall-Muav aquifer underlies the entire study area. The C aquifer is a water-table aquifer for most of its occurrence with depths to water that range from a few hundred feet to more than 1,500 feet. In the western part of the Coconino Plateau study area, the C aquifer is dry except for small localized perched water-bearing zones decoupled from the C aquifer to the east. The Redwall-Muav aquifer underlies the C aquifer and ranges from at least 3,000 feet below land surface in the western part of the Coconino Plateau study area to more than 3,200 feet below land surface in the eastern part of the study area. The Redwall-Muav aquifer is a confined aquifer for most of its occurrence with hydraulic heads of several hundred to more than 500 feet above the top of the aquifer in the western part of the study area and more than 2,000 feet above the top of the aquifer in the eastern part of the study area near Flagstaff. In the eastern and northeast parts of the area, the C aquifer and the Redwall-Muav aquifer are in partial hydraulic connection through faults and other fractures. The water discharging from the two aquifers on the Coconino Plateau study area is generally of good quality for most intended uses. Water from sites in the lower Little Colorado River Canyon had high concentrations of most trace elements relative to other springs, rivers, and streams in the study area. Concentrations of barium, arsenic, uranium, and lead, and gross alpha radioactivity were greater than U.S. Environmental Protection Agency Maximum Contaminant Levels for drinking water at some sites. Ground water discharging to most springs, streams, and wells on the Coconino Plateau and in adjacent areas is a calcium magnesium

  5. Monitoring probe for groundwater flow

    DOEpatents

    Looney, Brian B.; Ballard, Sanford

    1994-01-01

    A monitoring probe for detecting groundwater migration. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow.

  6. Monitoring probe for groundwater flow

    DOEpatents

    Looney, B.B.; Ballard, S.

    1994-08-23

    A monitoring probe for detecting groundwater migration is disclosed. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow. 4 figs.

  7. 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

    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

  8. Tectonic geomorphology of the Qilian Shan in the northeastern Tibetan Plateau: Insights into the plateau formation processes

    NASA Astrophysics Data System (ADS)

    Zhang, Huiping; Zhang, Peizhen; Prush, Veronica; Zheng, Dewen; Zheng, Wenjun; Wang, Weitao; Liu, Caicai; Ren, Zhikun

    2017-06-01

    We examined the regional scale topography of the Qilian Shan on the northeastern margin of the Tibetan plateau. Longitudinal profiles and geomorphometric indices, such as slope, local relief and channel steepness reveal that the Qilian Shan was developed as a local plateau with high-relief steep marginal ranges, and interior low-relief topography. Landscape mapping across this local plateau revealed spatially varied origins of the low-relief landscape in the Qilian Shan. North of the Haiyuan fault, universal massive intermontane aggradation was identified. However, the low-relief plateau to the south of the Haiyuan fault was dominated by relict erosional surfaces, even though accompany basin-filling still contributes. The geomorphologic contrasts led us to integrate both the basin-filling processes and antecedent low-relief erosional surfaces into a new insight into the development of the Qilian Shan plateau in the northeastern Tibet. Our present study highlights that explanation for the low-relief plateau formation needs to consider the complex geological evolution of the Qilian Shan, and the Tibetan Plateau itself.

  9. In vitro comparison of tibial plateau leveling osteotomy with and without use of a tibial plateau leveling jig.

    PubMed

    Schmerbach, Kay Ingo; Boeltzig, Christian Konrad Matthias; Reif, Ullrich; Wieser, Jan Carsten; Keller, Thomas; Grevel, Vera

    2007-02-01

    To evaluate the influence of a tibial plateau leveling jig on osteotomy orientation, fragment reduction, and postoperative tibial plateau angle (TPA) during tibial plateau leveling osteotomy (TPLO). In vitro experimental study. Large-breed canine cadavers (n=20). TPLO was performed on 40 hindlimbs using 4 methods. Group 1: Jig; dogs in dorsal recumbency with the osteotomy parallel to the distal jig pin. Groups 2-4: No jig; dogs in lateral recumbency with the osteotomy in a vertical orientation (group 2: tibia parallel to the table top; group 3: controlled superimposition of the femoral condyles; group 4: internal rotation of the tibia). Postoperative TPA, fragment reduction, and osteotomy orientation relative to the tibial plateau were compared. Positive or negative values denoted deviation from parallel relative to the tibial plateau. Postoperative TPA, fragment reduction, and proximodistal osteotomy orientation were not significantly different between groups. Craniocaudal osteotomy orientation was significantly different (P<.005) from the tibial plateau. Median deviations were -4.0 degrees (group 1), 11.8 degrees (group 2), 11.2 degrees (group 3), and 0.2 degrees (group 4). Group 1 was not significantly different from group 4. A jig is not essential for osteotomy orientation, tibial plateau rotation, or fragment reduction. Comparable results were achieved performing a vertical osteotomy with the tibia slightly internally rotated (10 degrees -15 degrees) and parallel to the table surface. TPLO without use of a jig reduces surgical trauma, is less time consuming, and reduces cost.

  10. Artificial recharge of groundwater

    NASA Astrophysics Data System (ADS)

    The Task Committee on Guidelines for Artificial Recharge of Groundwater, of the American Society of Civil Engineers' (ASCE) Irrigation and Drainage Division, sponsored an International Symposium on Artificial Recharge of Groundwater at the Inn-at-the-Park Hotel in Anaheim, Calif., August 23-27, 1988. Cosponsors were the U.S. Geological Survey, California Department of Water Resources, University of California Water Resources Center, Metropolitan Water District of Southern California, with cooperation from the U.S. Bureau of Reclamation, International Association of Hydrological Sciences, American Water Resources Association, U.S. Agency for International Development, World Bank, United Nations Department of Technical Cooperation for Development, and a number of local and state organizations.Because of the worldwide interest in artificial recharge and the need to develop efficient recharge facilities, the Anaheim symposium brought together an interdisciplinary group of engineers and scientists to provide a forum for many professional disciplines to exchange experiences and findings related to various types of artificial recharge; learn from both successful and unsuccessful case histories; promote technology transfer between the various disciplines; provide an education resource for communication with those who are not water scientists, such as planners, lawyers, regulators, and the public in general; and indicate directions by which cities or other entities can save funds by having reasonable technical guidelines for implementation of a recharge project.

  11. 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.

  12. Ground-Water Recharge in the Arid and Semiarid Southwestern United States - Climatic and Geologic Framework

    USGS Publications Warehouse

    Stonestrom, David A.; Harrill, James R.

    2007-01-01

    Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Ni?o and Pacific Decadal Oscillations strongly but irregularly control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of multidecadal droughts unlike any in the modern instrumental record. Anthropogenically induced climate change likely will reduce ground-water recharge through diminished snowpack at higher elevations, and perhaps through increased drought. Future changes in El Ni?o and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Land-use modifications influence ground-water recharge directly through vegetation, irrigation, and impermeable area, and indirectly through climate change. High ranges bounding the study area?the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east?provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive

  13. Potentiometric Surfaces in the Springfield Plateau and Ozark Aquifers of Northwestern Arkansas, Southeastern Kansas, Southwestern Missouri, and Northeastern Oklahoma, 2006

    USGS Publications Warehouse

    Gillip, Jonathan A.; Czarnecki, John B.; Mugel, Douglas N.

    2008-01-01

    The Springfield Plateau and Ozark aquifers are important sources of ground water in the Ozark Plateaus aquifer system. Water from these aquifers is used for agricultural, domestic, industrial, and municipal water sources. Changing water use over time in these aquifers presents a need for updated potentiometric-surface maps of the Springfield Plateau and Ozark aquifers. The Springfield Plateau aquifer consists of water-bearing Mississippian-age limestone and chert. The Ozark aquifer consists of Late Cambrian to Middle Devonian age water-bearing rocks consisting of dolostone, limestone, and sandstone. Both aquifers are complex with areally varying lithologies, discrete hydrologic units, varying permeabilities, and secondary permeabilities related to fractures and karst features. During the spring of 2006, ground-water levels were measured in 285 wells. These data, and water levels from selected lakes, rivers, and springs, were used to create potentiometric-surface maps for the Springfield Plateau and Ozark aquifers. Linear kriging was used initially to construct the water-level contours on the maps; the contours were subsequently modified using hydrologic judgment. The potentiometric-surface maps presented in this report represent ground-water conditions during the spring of 2006. During the spring of 2006, the region received less than average rainfall. Dry conditions prior to the spring of 2006 could have contributed to the observed water levels as well. The potentiometric-surface map of the Springfield Plateau aquifer shows a maximum measured water-level altitude within the study area of about 1,450 feet at a spring in Barry County, Missouri, and a minimum measured water-level altitude of 579 feet at a well in Ottawa County, Oklahoma. Cones of depression occur in Dade, Lawrence and Newton Counties in Missouri and Delaware and Ottawa Counties in Oklahoma. These cones of depression are associated with private wells. Ground water in the Springfield Plateau aquifer

  14. Reconstruction of Groundwater Depletion Using a Global Scale Groundwater Model

    NASA Astrophysics Data System (ADS)

    de Graaf, I. E. M.; Van Beek, L. P.; Bierkens, M. F.

    2014-12-01

    Groundwater is a crucial part of the global water cycle. It is the world's largest accessible source of fresh water to satisfy human water needs. During times of droughts it sustains river flows and evaporation in areas with shallow water tables. However, most global scale hydrological models do not include a lateral groundwater flow component due to a lack of consistent global-scale hydrogeological information. Such data is needed to arrive at a more realistic physical representation of the groundwater system allowing for the simulation of groundwater head dynamics and lateral flows including abstractions in confined and unconfined aquifers. This improved process description is indispensable to understand the effects of past and future climate variations and human dependence on global water resources. In this study we developed a high resolution (5 arc-minutes) global scale transient groundwater model presenting confined and unconfined aquifers. This model is based on MODFLOW (McDonald and Harbaugh, 1988) and coupled with the land-surface model PCR-GLOBWB (van Beek et al. 2011) via recharge and surface water levels. The aquifer parameterization is based on available global data-sets on lithology (Hartmann and Moosdorf 2011) and permeability (Gleeson et al. 2011) and newly derived estimates of aquifer depth and thickness of confining layers from an integration of lithological and topographical information. In a sensitivity analysis the model is run with various hydrogeological parameter settings, under natural recharge only. Scenarios of past groundwater abstractions and recharge (Wada et al 2012) are evaluated. Trends and fluctuations of groundwater head and streamflow are studied in response to human groundwater use and climate variability, as well as revealing hotspots and magnitude of global groundwater depletion.

  15. End member models for Andean Plateau uplift

    NASA Astrophysics Data System (ADS)

    Barnes, J. B.; Ehlers, T. A.

    2009-12-01

    Diverse techniques have been applied over the past decade to quantify the uplift history of the central Andean Plateau (AP). In this study, opposing models for surface uplift are evaluated including: a rapid rise of ˜ 2.5 km ˜ 10-6 Ma and a slow and steady rise since ˜ 40 Ma. These end member models are evaluated by synthesizing observations of the AP lithosphere and the history of deformation, sedimentation, exhumation, magmatism, uplift, and fluvial incision. Structural and geophysical studies estimate variable shortening magnitudes (˜ 530-150 km) involving cover-to-basement rocks, an isostatically-compensated thick crust (˜ 80-65 km), high heat flow, and zones of variable velocity and attenuation in the crust and mantle. These observations have invoked interpretations such as a hot/weak lithosphere, partial melt, crustal flow, and perhaps current, localized delamination, but do not provide strong support for massive delamination required by the rapid uplift model. Deformation and associated exhumation began ˜ 60-40 Ma and generally migrated eastward with consistent long-term average shortening rates (˜ 12-8 mm/yr) in Bolivia, favoring the slow uplift model. Volcanic and helium isotope evidence show an AP-wide zone of shallow mantle melting and thin lithosphere that has existed since ˜ 25 Ma, which is inconsistent with the rapid rise model that suggests lithospheric thinning occurred 10-6 Ma. Paleoaltimetry data suggest a rapid ˜ 2.5 km elevation gain 10 to 6 Ma, but are equally consistent within error with a linear rise since ≥ 25 Ma. Widespread fluvial incision (2.5-1 km) occurred along the western flank since ˜ 11-8 Ma and may be associated with surface uplift as proposed by the rapid rise model. However, the paleoaltimetry and incision data can also be explained by regional climate change associated with plateau uplift. Implications of these results for reconstructions of AP evolution are that: (1) substantial deformation of a weak lithosphere is

  16. Colorado Plateau Uplift Through Deep Crustal Hydration?

    NASA Astrophysics Data System (ADS)

    Butcher, L. A.; Mahan, K. H.; Jones, C. H.; Farmer, G.

    2013-12-01

    The conventional view of plate tectonics restricts deformation to plate boundaries and does not account for regionally elevated topography in continental interiors. Thermal, mechanical or chemical alteration of ancient continental lithosphere is a mechanism sometimes invoked to explain intracratonic uplift in the western U.S. although the timing, extent and effects of this modification are poorly understood. Here we present new petrological and in situ geochronological data for a hydrated deep crustal xenolith from the Colorado Plateau and investigate the effects of deep crustal hydration on topography. Two distinct mineral assemblages recorded in a garnet biotite schist xenolith from the Navajo Volcanic Field, Four Corners region document hydration subsequent to peak metamorphism in the deep crust whereby the primary metamorphic assemblage (Gt + Bt + Ms + Pl + Kfs + Qtz) is variably replaced by a lower-density, hydrated assemblage (Ab + Ph + Cc + Rt). Results from forward petrological modeling constrain hydration at ≥ 20 km (0.65 GPa, 450 °C) prior to exhumation in the ˜20 Ma volcanic host. In situ Th/Pb dating of secondary monazite grains spatially associated with fluid-related plagioclase and allanite breakdown reveals a significant majority of Late Cretaceous dates from 91 to 58 Ma. These dates are interpreted to reflect a finite period of deep crustal hydration, possibly by fluids sourced from a shallowly subducting Farallon slab. Xenolith data additionally supports crustal hydration as a mechanism for producing regionally elevated topography. Fluid-related reactions in the deep crust may lead to a net density decrease as low-density hydrous phases (e.g. Ms + Amp + Cc) replace high-density, anhydrous minerals (e.g. Gt + Fsp + Opx + Cpx) abundant in high-pressure, high-temperature assemblages preserved in Proterozoic North American lithosphere. If these reactions are sufficiently pervasive and widespread, reductions in lower crustal density would provide a

  17. Reconstruction of groundwater depletion using a global scale groundwater model

    NASA Astrophysics Data System (ADS)

    de Graaf, Inge; van Beek, Rens; Sutanudjaja, Edwin; Wada, Yoshi; Bierkens, Marc

    2015-04-01

    Groundwater forms an integral part of the global hydrological cycle and is the world's largest accessible source of fresh water to satisfy human water needs. It buffers variable recharge rates over time, thereby effectively sustaining river flows in times of drought as well as evaporation in areas with shallow water tables. Moreover, although lateral groundwater flows are often slow, they cross topographic and administrative boundaries at appreciable rates. Despite the importance of groundwater, most global scale hydrological models do not consider surface water-groundwater interactions or include a lateral groundwater flow component. The main reason of this omission is the lack of consistent global-scale hydrogeological information needed to arrive at a more realistic representation of the groundwater system, i.e. including information on aquifer depths and the presence of confining layers. The latter holds vital information on the accessibility and quality of the global groundwater resource. In this study we developed a high resolution (5 arc-minutes) global scale transient groundwater model comprising confined and unconfined aquifers. This model is based on MODFLOW (McDonald and Harbaugh, 1988) and coupled with the land-surface model PCR GLOBWB (van Beek et al., 2011) via recharge and surface water levels. Aquifers properties were based on newly derived estimates of aquifer depths (de Graaf et al., 2014b) and thickness of confining layers from an integration of lithological and topographical information. They were further parameterized using available global datasets on lithology (Hartmann and Moosdorf, 2011) and permeability (Gleeson et al., 2014). In a sensitivity analysis the model was run with various hydrogeological parameter settings, under natural recharge only. Scenarios of past groundwater abstractions and corresponding recharge (Wada et al., 2012, de Graaf et al. 2014a) were evaluated. The resulting estimates of groundwater depletion are lower than

  18. Incision into the eastern Andean Plateau during Pliocene cooling.

    PubMed

    Lease, Richard O; Ehlers, Todd A

    2013-08-16

    Canyon incision into mountain topography is commonly used as a proxy for surface uplift driven by tectonic or geodynamic processes, but climatic changes can also instigate incision. The ~1250-kilometer (km)-long eastern margin of the Andean Plateau hosts a series of 1.5- to 2.5-km-deep canyons that cross major deformation zones. Using (U-Th)/He thermochronology, we document a transition from Miocene faulting to Pliocene canyon incision across the northeastern plateau margin. Regionally, widespread Pliocene incision into the eastern plateau margin is concurrent with a shift in global climate from early Pliocene warmth to late Pliocene cooling. Enhanced moisture transport onto the Andean Plateau driven by sea surface temperature changes during cooling is the likely pacemaker for canyon incision.

  19. Quaternary geochronology and distribution of Mammuthus on the Colorado Plateau

    SciTech Connect

    Agenbroad, L.D.; Mead, J.I. )

    1989-09-01

    There are 41 known localities containing mammoth remains from the Colorado Plateau: 24 in Arizona, 12 in Utah, 3 in New Mexico, and 2 in Colorado. Of the 41 localities, 13 (32%; Arizona and Utah only) have yielded radiometric dates ({sup 14}C and U/Th); 10 (77%) of these have been the result of the authors' investigations. The four youngest radiocarbon dates produce a weighted average date of approximately 11,270 {plus minus}65 yr B.P., the youngest directly aged mammoth remains on the Colorado Plateau. Mammoth remains are recovered predominantly in alluvial regimes, in addition to alcove, cave, and spring deposits. No direct association of Mammuthus and the Clovis hunters has been reported from the Colorado Plateau. Dietary intake, recorded in dung remains, included predominantly graminoids, in addition to various woody shrubs and trees that currently grow at higher elevations on the Colorado Plateau.

  20. Total knee arthroplasty and fractures of the tibial plateau

    PubMed Central

    Softness, Kenneth A; Murray, Ryan S; Evans, Brian G

    2017-01-01

    Tibial plateau fractures are common injuries that occur in a bimodal age distribution. While there are various treatment options for displaced tibial plateau fractures, the standard of care is open reduction and internal fixation (ORIF). In physiologically young patients with higher demand and better bone quality, ORIF is the preferred method of treating these fractures. However, future total knee arthroplasty (TKA) is a consideration in these patients as post-traumatic osteoarthritis is a common long-term complication of tibial plateau fractures. In older, lower demand patients, ORIF is potentially less favorable for a variety of reasons, namely fixation failure and the need for delayed weight bearing. In some of these patients, TKA can be considered as primary mode of treatment. This paper will review the literature surrounding TKA as both primary treatment and as a salvage measure in patients with fractures of the tibial plateau. The outcomes, complications, techniques and surgical challenges are also discussed. PMID:28251061

  1. Deep mantle forces and the uplift of the Colorado Plateau

    NASA Astrophysics Data System (ADS)

    Moucha, Robert; Forte, Alessandro M.; Rowley, David B.; Mitrovica, Jerry X.; Simmons, Nathan A.; Grand, Stephen P.

    2009-10-01

    We introduce a quantitative model of global mantle convection that reconstructs the detailed motion of a warm mantle upwelling over the last 30 Ma towards the interior of the southwestern USA from observed present-day mantle heterogeneity. The onset and evolution of uplift in the central Basin and Range province and Colorado Plateau during this time is determined by tracking the topographic swell due to this mantle upwelling. We show that: (1) the extension and basaltic volcanism (post 25 Ma) in the central Basin and Range coincides with the arrival and eastward progression of this upwelling, and (2) dynamic uplift of the southern Colorado Plateau, totaling about 1 km, transpired in the last 20 Ma. Since 10 Ma, the center of uplift continued northeastward from the southwestern rim of the plateau consistent with a young Grand Canyon model and eastward sweep of magmatism in the western Colorado Plateau.

  2. Groundwater at Mayon, Volcano

    NASA Astrophysics Data System (ADS)

    Albano, S. E.; Sandoval, T.; Toledo, R.

    2001-12-01

    Around Mayon Volcano, Philippines, anecdotal evidence and rainfall normalized spring discharge data suggest that the water table 8 km from the summit of the volcano drops prior to eruptions. Residents report that they had to deepen their shallow wells in 1993 (some before and others following the eruption). In some cases they had to dig as far as 5 meters deeper to reach the water table. Significant decreases in spring discharge were recorded prior to the 1999 phreatic explosions and explosive eruption in 2000. A lesser decrease in spring discharge was recorded prior to the 2001 explosive eruptions. The cause of the observed correlation is not yet understood. Mechanisms consider include decrease in rainfall and boiling away of groundwater due to magmatic intrusion. Dilatation of the volcano may cause an increase in pore pressure, opening of cracks, and inflation of the ground surface that would all result in lower water table levels and decreases in spring discharges. Lack of significant hydraulic precursors prior to the 2001 eruptions may be due to a sustained state of inflation following the eruption of 2000. To better understand the relationship between changes in the volcanic system and changes in the groundwater system surrounding Mayon, instruments were installed about eight kilometers from the summit immediately following the explosive eruption of 26 July 2001. Parameters monitored include rainfall data, water levels in four shallow wells, discharge in the main river basin, and spring discharge. The aquifers at eight kilometers are predominantly poorly sorted lahar flow deposits. Characterization of these highly permeable aquifers has been conducted. Preliminary data include porosity ranges, hydraulic conductivity estimates, and response to rainfall. Water samples have been collected that are intended for geo-chemical analysis to determine if the water is predominantly meteoric or magmatic in origin. Numerical modeling of the system using the above mentioned

  3. Groundwater Pollution and Vulnerability Assessment.

    PubMed

    Kurwadkar, Sudarshan

    2017-10-01

    Groundwater is a critical resource that serve as a source of drinking water to large human population and, provide long-term water for irrigation purposes. In recent years; however, this precious resource being increasingly threatened, due to natural and anthropogenic activities. A variety of contaminants of emerging concern such as pharmaceuticals and personal care products, perfluorinated compounds, endocrine disruptors, and biological agents detected in the groundwater sources of both developing and developed nations. In this review paper, various studies have been included that documented instances of groundwater pollution and vulnerability to emerging contaminants of concern, pesticides, heavy metals, and leaching potential of various organic and inorganic contaminants from poorly managed residual waste products (biosolids, landfills, latrines, and septic tanks etc.). Understanding vulnerability of groundwater to pollution is critical to maintain the integrity of groundwater. A section on managed artificial recharge studies is included to highlight the sustainable approaches to groundwater conservation, replenishment and sustainability. This review paper is the synthesis of studies published in last one year that either documented the pollution problems or evaluated the vulnerability of groundwater pollution.

  4. Impact of geology and geomorphology on fluoride contaminated groundwater in hard rock terrain of India using geoinformatics approach

    NASA Astrophysics Data System (ADS)

    Shekhar, Shashank; Ghosh, Mili; Pandey, A. C.; Tirkey, Anamika Shalini

    2017-08-01

    The present study demonstrates a GIS-based spatial evaluation of fluoride contamination (FC) in groundwater vis-a-vis geology and geomorphology of the area using analytical hierarchy process and weighted sum method in Palamu district of Jharkhand. The integration and analyses of the various thematic databases along with the field sampled fluoride data proved useful in delineating the FC zones. The FC index ranged between 141 and 707, and was classified into four zones, viz., low, moderate, high, and very high zones of FC. The FC index map showed that a total of 49.75% of the study area lies between high to very high FC zone. The very high FC zone is found in the moderately weathered plateau with granitic terrain, whereas the high and moderately FC zones covering 49.31 and 36.41% of the study area are dominated by plateau weathered shallow, pediment-inselberg complex, pediplain moderately weathered, pediplain shallow weathered, and inselberg which have high fluoride. The lowest FC zone covers an area of 193.27 sq. km (13.84%). The spatial analysis of geology with fluoride showed that groundwater within granitic gneiss exhibits high FC followed by granitoid gneiss and alluvium. Geomorphologically highest FC was recorded in plateau weathered moderate (91.67%) followed by plateau weathered shallow (71.43%), flood plain (41.76%), inselberg (27.27%), and pediment (25%). The spatial analysis of groundwater yield with fluoride showed that regions having good yield exhibit maximum FC thereby accelerating the vulnerability of the population to fluorosis.

  5. Solution of the Kirchhoff-Plateau Problem.

    PubMed

    Giusteri, Giulio G; Lussardi, Luca; Fried, Eliot

    2017-01-01

    The Kirchhoff-Plateau problem concerns the equilibrium shapes of a system in which a flexible filament in the form of a closed loop is spanned by a liquid film, with the filament being modeled as a Kirchhoff rod and the action of the spanning surface being solely due to surface tension. We establish the existence of an equilibrium shape that minimizes the total energy of the system under the physical constraint of noninterpenetration of matter, but allowing for points on the surface of the bounding loop to come into contact. In our treatment, the bounding loop retains a finite cross-sectional thickness and a nonvanishing volume, while the liquid film is represented by a set with finite two-dimensional Hausdorff measure. Moreover, the region where the liquid film touches the surface of the bounding loop is not prescribed a priori. Our mathematical results substantiate the physical relevance of the chosen model. Indeed, no matter how strong is the competition between surface tension and the elastic response of the filament, the system is always able to adjust to achieve a configuration that complies with the physical constraints encountered in experiments.

  6. Dendroclimatic reconstructions for the southern Colorado plateau

    SciTech Connect

    Dean, J.S.; Funkhouser, G.S.

    1995-09-01

    A geographical network of climate sensitive tree-ring chronologies consisting of 25 archaeological sequences and two bristlecone pine series provides the basis for high resolution reconstructions of low and high frequency climatic variability on the southern Colorado Plateau over the last 1,500 years. Qualitative and quantitative dendroclimatic analyses of these data produce annual retrodictions of yearly and seasonal precipitation and summer Palmer Drought Severity Indices for each station and reconstructions of regional scale patterns in climatic variability. These reconstructions provide detailed information on climatic fluctuations that affected biotic and human populations as well as long-term baseline data for evaluating present-day climate and estimating future climatic trends. When integrated with other measures of past environmental variability, these reconstructions specify periods of favorable and unfavorable environmental conditions that would have affected past human populations of the region. The severest degradation, which occurred between A.D. 1250 and 1450, probably was causally related to numerous cultural changes that occurred at the end of the l3th century including the Anasazi abandonment of the Four Comers area. Projecting environmental patterns that characterized the last two millennia into the future indicates potential hazards to long term uranium mill waste disposal and containment and the potential and limitations of environmental restoration.

  7. Solution of the Kirchhoff-Plateau Problem

    NASA Astrophysics Data System (ADS)

    Giusteri, Giulio G.; Lussardi, Luca; Fried, Eliot

    2017-06-01

    The Kirchhoff-Plateau problem concerns the equilibrium shapes of a system in which a flexible filament in the form of a closed loop is spanned by a liquid film, with the filament being modeled as a Kirchhoff rod and the action of the spanning surface being solely due to surface tension. We establish the existence of an equilibrium shape that minimizes the total energy of the system under the physical constraint of noninterpenetration of matter, but allowing for points on the surface of the bounding loop to come into contact. In our treatment, the bounding loop retains a finite cross-sectional thickness and a nonvanishing volume, while the liquid film is represented by a set with finite two-dimensional Hausdorff measure. Moreover, the region where the liquid film touches the surface of the bounding loop is not prescribed a priori. Our mathematical results substantiate the physical relevance of the chosen model. Indeed, no matter how strong is the competition between surface tension and the elastic response of the filament, the system is always able to adjust to achieve a configuration that complies with the physical constraints encountered in experiments.

  8. Composition of Syrtis Major volcanic plateau

    NASA Technical Reports Server (NTRS)

    Mustard, John F.; Erard, S.; Bibring, Jean-Pierre; Langevin, Yves; Head, James W.; Pieters, Carle M.

    1991-01-01

    Syrtis Major, a low-relief volcanic shield centered near 295 degrees 10 degrees N, is an old, well-preserved and exposed volcanic region on Mars which formed at the end of the heavy bombardment period. The composition of these volcanic materials has importance for understanding the thermal and chemical history of Mars. Imaging spectrometer data of the Syrtis Major volcanic plateau are used in this analysis to identify major compositional components. First and second order even channel reflectance spectra between 0.77 and 2.55 microns from four broad classes of materials on Syrtis Major are given. For the volcanic materials, there are three primary classes characterized by albedo, slope, and shape of the 10 micron band. To emphasize the latter, straight line continua were removed from each spectral segment and replotted in another figure. Each spectrum shows a band minima near 0.96 microns and 2.15 microns indicative of pyroxene mineral absorptions. Comparison of these band minima with studies of pyroxene reflectance spectra suggests that the pyroxenes in the volcanics of Syrtis Major are high calcium pyroxene with a Ca/(Mg+Fe+Ca) ratio of 0.2 to 0.3. The most likely pyroxene is an augite.

  9. Solution of the Kirchhoff-Plateau Problem

    NASA Astrophysics Data System (ADS)

    Giusteri, Giulio G.; Lussardi, Luca; Fried, Eliot

    2017-01-01

    The Kirchhoff-Plateau problem concerns the equilibrium shapes of a system in which a flexible filament in the form of a closed loop is spanned by a liquid film, with the filament being modeled as a Kirchhoff rod and the action of the spanning surface being solely due to surface tension. We establish the existence of an equilibrium shape that minimizes the total energy of the system under the physical constraint of noninterpenetration of matter, but allowing for points on the surface of the bounding loop to come into contact. In our treatment, the bounding loop retains a finite cross-sectional thickness and a nonvanishing volume, while the liquid film is represented by a set with finite two-dimensional Hausdorff measure. Moreover, the region where the liquid film touches the surface of the bounding loop is not prescribed a priori. Our mathematical results substantiate the physical relevance of the chosen model. Indeed, no matter how strong is the competition between surface tension and the elastic response of the filament, the system is always able to adjust to achieve a configuration that complies with the physical constraints encountered in experiments.

  10. Blowing Snow Over the Antarctic Plateau

    NASA Technical Reports Server (NTRS)

    Mahesh, Ashwin; Eager, Rebecca; Campbell, James R.; Spinhirne, James D.

    2002-01-01

    Studies of blowing snow over Antarctica have been limited greatly by the remoteness and harsh conditions of the region. Space-based observations are also of lesser value than elsewhere, given the similarities between ice clouds and snow-covered surfaces, both at infrared and visible wavelengths. It is only in recent years that routine ground-based observation programs have acquired sufficient data to overcome the gap in our understanding of surface blowing snow. In this paper, observations of blowing snow from visual observers' records as well as ground-based spectral and lidar programs at South Pole station are analyzed to obtain the first climatology of blowing snow over the Antarctic plateau. Occurrence frequencies, correlation with wind direction and speed, typical layer heights, as well as optical depths are determined. Blowing snow is seen in roughly one third of the visual observations and occurs under a narrow range of wind directions. The near-surface layers typically a few hundred meters thick emit radiances similar to those from thin clouds. Because blowing snow remains close to the surface and is frequently present, it will produce small biases in space-borne altimetry; these must be properly estimated and corrected.

  11. Global scale groundwater flow model

    NASA Astrophysics Data System (ADS)

    Sutanudjaja, Edwin; de Graaf, Inge; van Beek, Ludovicus; Bierkens, Marc

    2013-04-01

    As the world's largest accessible source of freshwater, groundwater plays vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and supplies water for agricultural and industrial activities. During times of drought, groundwater sustains water flows in streams, rivers, lakes and wetlands, and thus supports ecosystem habitat and biodiversity, while its large natural storage provides a buffer against water shortages. Yet, the current generation of global scale hydrological models does not include a groundwater flow component that is a crucial part of the hydrological cycle and allows the simulation of groundwater head dynamics. In this study we present a steady-state MODFLOW (McDonald and Harbaugh, 1988) groundwater model on the global scale at 5 arc-minutes resolution. Aquifer schematization and properties of this groundwater model were developed from available global lithological model (e.g. Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moorsdorff, in press). We force the groundwtaer model with the output from the large-scale hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the long term net groundwater recharge and average surface water levels derived from routed channel discharge. We validated calculated groundwater heads and depths with available head observations, from different regions, including the North and South America and Western Europe. Our results show that it is feasible to build a relatively simple global scale groundwater model using existing information, and estimate water table depths within acceptable accuracy in many parts of the world.

  12. Does the climate warming hiatus exist over the Tibetan Plateau?

    PubMed Central

    Duan, Anmin; Xiao, Zhixiang

    2015-01-01

    The surface air temperature change over the Tibetan Plateau is determined based on historical observations from 1980 to 2013. In contrast to the cooling trend in the rest of China, and the global warming hiatus post-1990s, an accelerated warming trend has appeared over the Tibetan Plateau during 1998–2013 (0.25 °C decade−1), compared with that during 1980–1997 (0.21 °C decade−1). Further results indicate that, to some degree, such an accelerated warming trend might be attributable to cloud–radiation feedback. The increased nocturnal cloud over the northern Tibetan Plateau would warm the nighttime temperature via enhanced atmospheric back-radiation, while the decreased daytime cloud over the southern Tibetan Plateau would induce the daytime sunshine duration to increase, resulting in surface air temperature warming. Meanwhile, the in situ surface wind speed has recovered gradually since 1998, and thus the energy concentration cannot explain the accelerated warming trend over the Tibetan Plateau after the 1990s. It is suggested that cloud–radiation feedback may play an important role in modulating the recent accelerated warming trend over the Tibetan Plateau. PMID:26329678

  13. Permafrost and Railroad Construction on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Cheng, G.; Zhang, T.

    2004-12-01

    The Qinghai-Xizang railroad is under construction on "The Roof of the World" --- the Tibetan Plateau, to be completed in 2007. The railroad will cross 550 km of permafrost region over the Tibetan Plateau, 50% of which is high-temperature permafrost and 37% of which is ice-rich permafrost. Predicted climate warming over the Tibetan Plateau in the coming decades would accelerate permafrost degradation. Surface disturbance due to the railroad construction would further destabilize permafrost conditions and seriously damage the ecosystem in the permafrost region. Thawing of warm permafrost over the Tibetan Plateau becomes one of the key issues in the cross-Plateau railroad construction. In this presentation, we will discuss techniques used to prevent permafrost from thawing due both to the climate warming and the surface disturbance of engineering construction. Although several techniques have been used over the Tibetan Plateau, application of crushed rock layer to cool permafrost and maintain permafrost stability is very successful at current stage although further observations are needed. We will also further demonstrate the principles of using the crushed rock layer to maintain permafrost based on data from field investigation, laboratory experiments, and numerical simulations.

  14. Miocene high-elevation landscape of the eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Xu, Qiang; Liu, Xiaohui; Ding, Lin

    2016-10-01

    The high topography of central Asia is the most distinctive expression of the India-Asia collision, yet a broad understanding of the timing and processes involved in the development of the Tibetan Plateau remains elusive. Here we investigate the Neogene Songpan Basin located on the eastern margin of the plateau using oxygen isotope paleoaltimetry to determine when the steep Longmen Shan margin obtained its present elevations. Hydrologically open lacustrine and fluvial-alluvial authigenic carbonates from the basin record the paleoelevations of the eastern Tibetan Plateau and suggest that the area has attained near-present elevations of ˜3000 m by the late Miocene. This reconstruction is consistent with the results from the comparison of pollen fossils to their nearest living relatives in this area (2750-3050 m). We propose that the eastern Tibetan Plateau may have attained significant elevations prior to the late Miocene through an uplift scenario involving eastward growth of the plateau between the Eocene and the Miocene. Two tectonic processes, either crustal shortening in the Oligocene-Miocene or eastward propagation of weakened lower crust starting in the Eocene, most likely thickened the crust and raised the surface of the eastern Tibetan Plateau to its present elevation by the late Miocene.

  15. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, T.C.; Fliermans, C.B.

    1994-01-01

    Disclosed is an apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid (NF) is selected to simulated the growth and reproduction of indigenous subsurface microorganisms capable of degrading the contaminants; an oxygenated fluid (OF) is selected to create an aerobic environment with anaerobic pockets. NF is injected periodically while OF is injected continuously and both are extracted so that both are drawn across the plume. NF stimulates microbial colony growth; withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is acceptable. NF can be methane and OF be air, for stimulating production of methanotrophs to break down chlorohydrocarbons, especially TCE and tetrachloroethylene.

  16. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, Terry C.; Fliermans, Carl B.

    1995-01-01

    An apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants; an oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth; withholding it periodicially forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene.

  17. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, T.C.; Fliermans, C.B.

    1995-01-24

    An apparatus and method are described for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants. An oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth. Withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene. 3 figures.

  18. Kauai Groundwater Flow Model

    SciTech Connect

    Nicole Lautze

    2015-01-01

    Groundwater flow model for Kauai. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014.; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume IV – Island of Kauai Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2015.

  19. Groundwater chemicals desk reference

    SciTech Connect

    Montgomery, J.H.; Welkom, L.M.

    1990-01-01

    Information is compiled on more than 135 compounds that may be groundwater pollutants. The compounds profiled include all the Priority Pollutants promulgated by the US EPA under the Clean Water Act (CWA) of 1977. Many of these priority pollutants were included among the Target Compounds promulgated by the EPA under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in 1980 and the Superfund Amendments and Reauthorization Act (SARA) of 1986. All chemicals described in the book are classified as priority pollutants and/or target compounds. For each chemical, the following information is given: (1) synonyms; (2) structural formula; (3) CAS Registry number; (4) DOT designation; (5) empirical formula; (6) formula weight; (7) RETCS number; (8) physical and chemical properties; (9) fire hazards; (10) health hazard data; and (11) manufacturing data and/or selected manufacturers.

  20. Modelling the effects of climate and land cover change on groundwater recharge in south-west Western Australia

    NASA Astrophysics Data System (ADS)

    Dawes, W.; Ali, R.; Varma, S.; Emelyanova, I.; Hodgson, G.; McFarlane, D.

    2012-05-01

    The groundwater resource contained within the sandy aquifers of the Swan Coastal Plain, south west Western Australia, provides approximately 60% of the drinking water for the metropolitan population of Perth. Rainfall decline over the past three decades coupled with increasing water demand from a growing population has resulted in falling dam storage and groundwater levels. Projected future changes in climate across south-west Western Australia consistently show a decline in annual rainfall of between 5 and 15%. There is expected to be a continuing reduction of diffuse recharge across the Swan Coastal Plain. This study aims to quantify the change in groundwater recharge in response to a range of future climate and land cover patterns across south-west Western Australia. Modelling the impact on the groundwater resource of potential climate change was achieved with a dynamically linked unsaturated/saturated groundwater model. A Vertical Flux Manager was used in the unsaturated zone to estimate groundwater recharge using a variety of simple and complex models based on land cover type (e.g. native trees, plantation, cropping, urban, wetland), soil type, and taking into account the groundwater depth. These recharge estimates were accumulated on a daily basis for both observed and projected climate scenarios and used in a MODFLOW simulation with monthly stress periods. In the area centred on the city of Perth, Western Australia, the patterns of recharge change and groundwater level change are not consistent spatially, or consistently downward. In the Dandaragan Plateau to the north-east of Perth there has been groundwater level rise since the 1970s associated with land clearing, and with rainfall projected to reduce the least in this area the groundwater levels are estimated to continue to rise. Along the coastal zone north of Perth there is an interaction between projected rainfall decline and legislated removal to pine forests. This results in areas of increasing

  1. Groundwater and Terrestrial Water Storage

    NASA Technical Reports Server (NTRS)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2012-01-01

    Groundwater is a vital resource and also a dynamic component of the water cycle. Unconfined aquifer storage is less responsive to short term weather conditions than the near surface terrestrial water storage (TWS) components (soil moisture, surface water, and snow). However, save for the permanently frozen regions, it typically exhibits a larger range of variability over multi-annual periods than the other components. Groundwater is poorly monitored at the global scale, but terrestrial water storage (TWS) change data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission are a reasonable proxy for unconfined groundwater at climatic scales.

  2. Mining's impact on groundwater assessed

    NASA Astrophysics Data System (ADS)

    Detailed studies have indicated that groundwater is contaminated in the immediate vicinity of many mines in the eastern United States. However, no underground mines and very few refuse disposal areas have monitoring systems that can provide adequate warning of impending threats to groundwater quality.This was one of the conclusions of a 3-year study by Geraghty & Miller, Inc., a firm of consulting groundwater geologists and hydrologists based in Syosset, New York. The study focused on mines east of the 100th meridian. These mines will produce an estimated 1.1 billion tons of coal and 200 million tons of waste by 1985.

  3. Assessment of effectiveness of geologic isolation systems. Geologic-simulation model for a hypothetical site in the Columbia Plateau. Volume 2: results

    SciTech Connect

    Foley, M.G.; Petrie, G.M.; Baldwin, A.J.; Craig, R.G.

    1982-06-01

    This report contains the input data and computer results for the Geologic Simulation Model. This model is described in detail in the following report: Petrie, G.M., et. al. 1981. Geologic Simulation Model for a Hypothetical Site in the Columbia Plateau, Pacific Northwest Laboratory, Richland, Washington. The Geologic Simulation Model is a quasi-deterministic process-response model which simulates, for a million years into the future, the development of the geologic and hydrologic systems of the ground-water basin containing the Pasco Basin. Effects of natural processes on the ground-water hydrologic system are modeled principally by rate equations. The combined effects and synergistic interactions of different processes are approximated by linear superposition of their effects during discrete time intervals in a stepwise-integration approach.

  4. Eocene Tibetan Plateau remnants preserved in the Northwest Himalaya

    NASA Astrophysics Data System (ADS)

    van der Beek, P. A.; van Melle, J.; Guillot, S.; Pêcher, A.; Reiners, P. W.; Nicolescu, S.; Latif, M.

    2009-04-01

    The northwest Himalaya shows strongly contrasting relief, opposing deeply incised mountain ranges characterized by extremely rapid exhumation and some of the highest peaks in the world (i.e., the Karakorum range and Nanga Parbat massif) to high-elevation, low-relief areas such as the 4000-m high Deosai plateau in northern Pakistan and the 5000-m high Tso Morari in Indian Ladakh. The origin and evolution of such plateau regions in the syntaxis of the most active continental collision in the world remain elusive. Here, we report the first low-temperature thermochronology (apatite fission-track, apatite and zircon (U-Th)/He) data from the Deosai plateau and use thermal history modelling to show that it has undergone continuous slow (≤ 200 m/Myr) denudation and has thus remained tectonically stable for the last 35 Myr at least. The inferred history of constant slow denudation of the plateau contradicts the hypothesis that widespread low-relief surfaces in the northwest Himalaya result from efficient, km-scale glacial erosion during Quaternary times; such erosion would have been recorded as a phase of rapid recent denudation that is not observed in the data. Slow continuous denudation since Eocene times, i.e. only 15-20 Myr after the onset of India-Asia collision implies that the Deosai plateau surface developed early in the Himalayan history and limits the phase of orogenic relief growth in the Ladakh-Kohistan arc to the early Paleogene. Although thermochronology data do not directly record surface uplift, the simplest explanation for the inferred constant denudation rates is that the plateau had reached its present-day elevation already during the Eocene, as a later phase of surface uplift would have triggered an erosional response that would have been recorded by the thermochronology data. We use morphological analyses to characterise such plateaux and identify them at the scale of the entire northwest Himalaya and compare our thermochronological data with

  5. Chiral topological superconductor and half-integer conductance plateau from quantum anomalous Hall plateau transition

    DOE PAGES

    Wang, Jing; Zhou, Quan; Lian, Biao; ...

    2015-08-31

    Here, we propose to realize a two-dimensional chiral topological superconducting (TSC) state from the quantum anomalous Hall plateau transition in a magnetic topological insulator thin film through the proximity effect to a conventional s -wave superconductor. This state has a full pairing gap in the bulk and a single chiral Majorana mode at the edge. The optimal condition for realizing such chiral TSC is to have inequivalent superconducting pairing amplitudes on top and bottom surfaces of the doped magnetic topological insulator. We further propose several transport experiments to detect the chiral TSC. One unique signature is that the conductance willmore » be quantized into a half-integer plateau at the coercive field in this hybrid system. In particular, with the point contact formed by a superconducting junction, the conductance oscillates between e2 /2h and e2 /h with the frequency determined by the voltage across the junction. We close by discussing the feasibility of these experimental proposals.« less

  6. Chiral topological superconductor and half-integer conductance plateau from quantum anomalous Hall plateau transition

    SciTech Connect

    Wang, Jing; Zhou, Quan; Lian, Biao; Zhang, Shou -Cheng

    2015-08-31

    Here, we propose to realize a two-dimensional chiral topological superconducting (TSC) state from the quantum anomalous Hall plateau transition in a magnetic topological insulator thin film through the proximity effect to a conventional s -wave superconductor. This state has a full pairing gap in the bulk and a single chiral Majorana mode at the edge. The optimal condition for realizing such chiral TSC is to have inequivalent superconducting pairing amplitudes on top and bottom surfaces of the doped magnetic topological insulator. We further propose several transport experiments to detect the chiral TSC. One unique signature is that the conductance will be quantized into a half-integer plateau at the coercive field in this hybrid system. In particular, with the point contact formed by a superconducting junction, the conductance oscillates between e2 /2h and e2 /h with the frequency determined by the voltage across the junction. We close by discussing the feasibility of these experimental proposals.

  7. Integrated groundwater quality management in urban areas

    NASA Astrophysics Data System (ADS)

    Swartjes, F. A.; Otte, P. F.

    2012-04-01

    Traditionally, groundwater assessments and remediations are approached at the scale of individual groundwater plumes. In urban areas, however, this management of individual groundwater plumes is often problematic for technical, practical or financial reasons, since the groundwater quality is often affected by a combination of sources, including (former) industrial activities, spills and leachate from uncontrolled landfills and building materials. As a result, often a whole series of intermingling contamination plumes is found in large volumes of groundwater. In several countries in the world, this led to stagnation of groundwater remediation in urban areas. Therefore, in the Netherlands there is a tendency managing groundwater in urban areas from an integrated perspective and on a larger scale. This so-called integrated groundwater quality management is often more efficient and hence, cheaper, since the organisation of the management of a cluster of groundwater plumes is much easier than it would be if all individual groundwater plumes were managed at different points in time. Integrated groundwater quality management should follow a tailor-made approach. However, to facilitate practical guidance was developed. This guidance relates to the delineation of the domain, the management of sources for groundwater contamination, procedures for monitoring, and (risk-based) assessment of the groundwater quality. Function-specific risk-based groundwater quality criteria were derived to support the assessment of the groundwater quality.

  8. Paleomagnetic Data From Ontong Java Plateau are Anomalous ˜ Did the Plateau Form on Another Plate?

    NASA Astrophysics Data System (ADS)

    Sager, W. W.

    2004-12-01

    A recent study of Ocean Drilling Program basalt core paleomagnetic data from Ontong Java Plateau (OJP) found paleolatitudes that disagree with previous estimates of the Early Cretaceous Pacific APWP, a result attributed to poor quality of data used in prior pole calculations [Riisager, P., S. Hall, M. Antretter, X. Zhao, Earth Planet. Sci. Lett., 208, p. 235, 2003]. My compilation of paleomagnetic data from Cretaceous Pacific basalt cores drilled by the Deep Sea Drilling Project and Ocean Drilling Program shows that paleocolatitude data in of ages 118-129 Ma display greater scatter than other age bins. The only factor that allows this data group to be coherently subdivided is whether or not the coring site is located on OJP. Without OJP data, paleocolatitude scatter is much less and gives a similar pole position (48.9° N, 327.1° E, N=40) to data in the 110-118 Ma interval. Data from the plateau give a pole that is 15° farther north (64.9° N, 323.4° E; N=37), indistinguishable from late Jurassic and earliest Cretaceous skewness poles. The OJP and non-OJP poles are distinct at the 95% confidence level despite having indistinguishable mean ages of 121.6 ±1.1 Ma (OJP) and 123.4 ±4.1 (non-OJP). Because Ontong Java Plateau data come from 6 different sites spread over the northern plateau, tectonic tilting is not a likely explanation for the difference. Also unlikely are systematic errors such as incomplete averaging of secular variation (large number of independent magnetic units sampled), inaccurate radiometric dates (many high quality dates), or inadequate paleomagnetic techniques (detailed studies by several different investigators). Rapid true polar wander does not seem a plausible explanation because global true polar wander curves have a different trend. Perhaps the simplest explanation is the one often used when anomalous data are found within a plate: the anomalous region had a different history of tectonic drift. In this scenario, OJP formed on a separate

  9. Glycol Ethers As Groundwater Contaminants

    NASA Astrophysics Data System (ADS)

    Ross, Benjamin; Johannson, Gunnar; Foster, Gregory D.; Eckel, William P.

    1992-01-01

    Ether derivatives of dihydroxy alcohols, which are formed from ethylene or propylene, comprise an important group of groundwater contaminants known as glycol ethers. Compounds in this group are used as solvents, cleaning agents, and emulsifiers in many chemical products and manufacturing operations. Glycol ethers have been associated with a variety of toxic effects, and some compounds in the group are relatively potent teratogens. The limited information available suggests that glycol ethers are contaminants in groundwater, especially in anaerobic plumes emanating from disposal of mixed industrial and household waste. Most methods used to analyze groundwater samples cannot adequately detect μg/? (ppb) concentrations of glycol ethers, and the existing methods perform worst for the most widely used and toxic species. A new method capable of analyzing μg/? concentrations of glycol ethers was recently developed, and its use is recommended for groundwater samples where glycol ethers are likely to be present.

  10. Holocene climate controls on water isotopic variations on thenortheastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Zhao, C.; He, Y.; Liu, Z.; Wang, H.; Liu, W.; Yu, Z.; Zhao, Y.; Ito, E.

    2016-12-01

    Oxygen and hydrogen isotopes derived from geological archives have been widely used to reconstruct past climate change. On the Tibetan Plateau, however, applications of stable-isotope proxies in paleoclimate studies tend to be complicated due to multiple processes influencing isotopic compositions in paleoclimatic archives. In this study, we systematically analyze isotopic compositions of modern waters in the eastern Qaidam Basin on the northeastern Tibetan Plateau, and hydrogen isotope values of n-fatty acids (n-FA δD) from a sediment core at Hurleg Lake to infer hydroclimate controls during the Holocene. The modern water isotopic results show a major contribution of snowmelt water originating from high-elevation mountains to the north of the Qaidam Basin via river and groundwater discharge, and the importance of evaporation in affecting lake hydrology in this region. n-C26 FA δD values tend to be more negative at millennial-scale warm-dry periods during the Holocene, and vice versa, opposite to what is commonly expected. Assisted with modern water isotopic results, we infer amplified contribution of snowmelt water to the soil water around this open lake system at warm-dry periods. Meanwhile, changes in n-C16 FA δD values at Hurleg Lake reflect the evolution of isotopic compositions of lake water, thus we use the isotopic difference between n-C26 and n-C16 FA (ΔDC16-C26) to infer hydroclimate and evaporation variations in this region. Based on our data, relatively low n-C26 FA δD and n-C16 FA δD values at 10-6 cal ka BP probably indicate large contribution of snowmelt water input into the lake under the Holocene climate optimum. After 6 cal ka BP, evaporation became the major control on lake hydrology changes, probably resulting from intensified millennial-scale climate variability after the mid-Holocene, caused by an increase in climate sensitivity of the Qaidam Basin. Our study highlights the importance of systematic analysis before using stable isotopes

  11. The controversial age of Kilimanjaro's plateau glaciers

    NASA Astrophysics Data System (ADS)

    Uglietti, Chiara; Zapf, Alexander; Szidat, Sönke; Salazar, Gary; Hardy, Doug; Schwikowski, Margit

    2015-04-01

    Interpreting climate signals contained in natural archives requires a precise chronology. Radiocarbon analysis can be a powerful tool for dating high-altitude ice cores, especially for the lowermost segments for which ice flow-induced thinning limits the counting of annual layers. Radiocarbon dating has been applied to ice cores containing sufficient organic material, which is a limiting factor to the wider application of this technique. We present a novel radiocarbon dating approach using carbonaceous aerosols enclosed in the ice to help resolve the debate about the age of the Kilimanjaro's plateau glaciers. Paleoclimate reconstructions based on six ice cores drilled in 2000 assigned a basal age of 11'700 years. A recent study claims recurring cycles of waxing and waning controlled primarily by atmospheric moisture and an absence of the ice bodies was suggested for 1200 AD. The Kilimanjaro ice fields are subject to rapid areal shrinkage and thinning and are expected to disappear within several decades. Resolving the controversy of the time frame for the extinction of the Kilimanjaro ice might have wide implications for the understanding of the natural climate variability in the tropics. A stratigraphic sequence of samples from the exposed vertical ice cliffs at the margins of the Northern Ice Field (NIF) was collected in 2011. A total of 45 horizontal short cores (50 cm length) were extracted from 22 horizons characterized by varying micro-particle concentrations. Additionally, 3 samples were taken from the glacier surface to investigate a potential age offset. All samples were shipped frozen to Paul Scherrer Institute, decontaminated in a cold room by removing the outer layer (0.3 mm) and by rinsing the samples with ultra-pure water. The insoluble carbonaceous particles were filtrated by using freshly preheated quartz fibre filters. Procedural blanks were estimated using artificial ice blocks of frozen ultra-pure water treated as real ice samples and were

  12. Manganese concentrations in Scottish groundwater.

    PubMed

    Homoncik, Sally C; Macdonald, Alan M; Heal, Kate V; Dochartaigh, Brighid E O; Ngwenya, Bryne T

    2010-05-15

    Groundwater is increasingly being used for public and private water supplies in Scotland, but there is growing evidence that manganese (Mn) concentrations in many groundwater supplies exceed the national drinking water limit of 0.05 mg l(-1). This study examines the extent and magnitude of high Mn concentrations in groundwater in Scotland and investigates the factors controlling Mn concentrations. A dataset containing 475 high quality groundwater samples was compiled using new data from Baseline Scotland supplemented with additional high quality data where available. Concentrations ranged up to 1.9 mg l(-1); median Mn concentration was 0.013 mg l(-1) with 25th and 75th percentiles 0.0014 and 0.072 mg l(-1) respectively. The Scottish drinking water limit (0.05 mg l(-1)) was exceeded for 30% of samples and the WHO health guideline (0.4 mg l(-1)) by 9%; concentrations were highest in the Carboniferous sedimentary aquifer in central Scotland, the Devonian sedimentary aquifer of Morayshire, and superficial aquifers. Further analysis using 137 samples from the Devonian aquifers indicated strong redox and pH controls (pH, Eh and dissolved oxygen accounted for 58% of variance in Mn concentrations). In addition, an independent relationship between Fe and Mn was observed, suggesting that Fe behaviour in groundwater may affect Mn solubility. Given the redox status and pH of Scottish groundwaters the most likely explanation is sorption of Mn to Fe oxides, which are released into solution when Fe is reduced. Since the occurrence of elevated Mn concentrations is widespread in groundwaters from all aquifer types, consideration should be given to monitoring Mn more widely in both public and private groundwater supplies in Scotland and by implication elsewhere. Copyright 2010 NERC. Published by Elsevier B.V. All rights reserved.

  13. Irrigation and groundwater in Pakistan

    NASA Astrophysics Data System (ADS)

    Ertsen, Maurits; Iftikhar Kazmi, Syed

    2010-05-01

    Introduction of large gravity irrigation system in the Indus Basin in late nineteenth century without a drainage system resulted in water table rise consequently giving rise to water logging and salinity problems over large areas. In order to cope with the salinity and water logging problem government initiated salinity control and reclamation project (SCARP) in 1960. Initially 10,000 tube wells were installed in different areas, which not only resulted in the lowering of water table, but also supplemented irrigation. Resulting benefits from the full irrigation motivated framers to install private tube wells. Present estimate of private tube wells in Punjab alone is around 0.6 million and 48 billion cubic meter of groundwater is used for irrigation, contributing is 1.3 billion to the economy. The Punjab meets 40% of its irrigation needs from groundwater abstraction. Today, farmers apply both surface water flows and groundwater from tubewells, creating a pattern of private and public water control. As the importance of groundwater in sustaining human life and ecology is evident so are the threats to its sustainability due to overexploitation, but sufficient information for its sustainable management especially in developing countries is still required. Sustainable use of groundwater needs proper quantification of the resource and information on processes involved in its recharge and discharge. Groundwater recharge is broadly defined as water that reaches the aquifer from any direction (Lerner 1997). Sustainability and proper management of groundwater resource requires reliable quantification of the resource. In order to protect the resource from contamination and over exploitation, identification of recharge sources and their contribution to resource is a basic requirement. Physiochemical properties of some pesticides and their behavior in soil and water can make them potential tracers of subsurface moisture movement. Pesticides are intensively used in the area to

  14. Aftershock Decay Rates in the Iranian Plateau

    NASA Astrophysics Data System (ADS)

    Ommi, S.; Zafarani, H.; Zare, M.

    2016-07-01

    Motivated by the desire to have more information following the occurrence of damaging events, the main purpose of this article is to study aftershock sequence parameters in the Iranian plateau. To this end, the catalogue of the Iranian earthquakes between 2002 to the end of 2013 has been collected and homogenized among which 15 earthquakes have been selected to study their aftershock decay rates. For different tectonic provinces, the completeness magnitudes ( M c) of the earthquake catalogue have been calculated in different time intervals. Also, the M c variability in spatial and temporal windows has been determined for each selected event. For major Iranian earthquakes, catalogue of aftershocks has been collected thanks to three declustering methods: first, the classical windowing method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974); second, a modified version of this using spatial windowing based on the Wells and Coppersmith (Bull Seismol Soc Am 84:974-1002, 1994) relations; and third, the Burkhard and Grünthal (Swiss J Geosci 102:149-188, 2009) scheme. Effects of the temporal windows also have been investigated using the time periods of 1 month, 100 days, and 1 year in the declustering method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974). In the next step, the modified Omori law coefficients have been calculated for the 15 selected earthquakes. The calibrated regional generic model describing the temporal and magnitude distribution of aftershocks is of interest for time-dependent seismic hazard forecasts. The regional characteristics of the aftershock decay rates have been studied for the selected Iranian earthquakes in the Alborz, Zagros and Central Iran regions considering their different seismotectonics regimes. However, due to the lack of sufficient data, no results have been reported for the Kopeh-Dagh and Makran seismotectonic regions.

  15. The Colorado Plateau II: biophysical, socioeconomic, and cultural research

    USGS Publications Warehouse

    Mattson, David J.; van Riper, Charles

    2005-01-01

    The publication of The Colorado Plateau: Cultural, Biological, and Physical Research in 2004 marked a timely summation of current research in the Four Corners states. This new volume, derived from the seventh Biennial Conference on the Colorado Plateau in 2003, complements the previous book by focusing on the integration of science into resource management issues. The 32 chapters range in content from measuring human impacts on cultural resources, through grazing and the wildland-urban interface issues, to parameters of climate change on the Plateau. The book also introduces economic perspectives by considering shifting patterns and regional disparities in the Colorado Plateau economy. A series of chapters on mountain lions explores the human-wildland interface. These chapters deal with the entire spectrum of challenges associated with managing this large mammal species in Arizona and on the Colorado Plateau, conveying a wealth of timely information of interest to wildlife managers and enthusiasts. Another provocative set of chapters on biophysical resources explores the management of forest restoration, from the micro scale all the way up to large-scale GIS analyses of ponderosa pine ecosystems on the Colorado Plateau. Given recent concerns for forest health in the wake of fires, severe drought, and bark-beetle infestation, these chapters will prove enlightening for forest service, park service, and land management professionals at both the federal and state level, as well as general readers interested in how forest management practices will ultimately affect their recreation activities. With broad coverage that touches on topics as diverse as movement patterns of rattlesnakes, calculating watersheds, and rescuing looted rockshelters, this volume stands as a compendium of cutting-edge research on the Colorado Plateau that offers a wealth of insights for many scholars.

  16. High Tibetan Plateau: a Nature Reserve of C3 Flora

    NASA Astrophysics Data System (ADS)

    Zhuang, G.; Pagani, M.; Brandon, M. T.

    2015-12-01

    Uplift of the Tibetan Plateau and associated climate changes leading to enhanced seasonality in precipitation and drying, are argued to have induced a global ecological shift from C3-frorest to C4-grassland between 8 and 5 million years ago. However, both tectonic and climatic changes predate the timing of the C3-C4 transition, with paleoaltimetry studies pointing to a high Tibetan Plateau no later than 10 Ma and the existence of an intense monsoon since ca. 11 Ma. To better understand the role of the Tibetan Plateau, we present results of a paleoecology study based on the carbon isotope compositions of leaf-wax n-alkanes (δ13Calk) from Qaidam basin, an intermontane basin on the youngest and the northernmost portion of Tibetan Plateau. Samples were collected from a 5-km thick, fluvial-lacustrine sequence dated 15 Ma to 1.8 Ma. Organic geochemical indices and detrital thermochronological studies preclude post-depositional thermal alteration of the studied materials. Our results, which show persistently low δ13Calk values, are consistent with the dominance of C3 flora on the Tibetan Plateau, in contrast to the prominent C4 rise surrounding the Tibetan Plateau and around the globe. We argue that a high Tibetan Plateau, established prior to the global ecological C3-C4 shift, served as a shelter of C3 flora since the Miocene. High-elevation and cold environments provided a competitive advantage for C3 by damping/counteracting the physiological advantage of C4 which outperforms C3 plants under warm, high-irradiance, water-stress and low pCO2 conditions.

  17. Surface currents and upwelling in Kerguelen Plateau regions

    NASA Astrophysics Data System (ADS)

    Zhou, M.; Zhu, Y.; d'Ovidio, F.; Park, Y.-H.; Durand, I.; Kestenare, E.; Sanial, V.; Van-Beek, P.; Queguiner, B.; Carlotti, F.; Blain, S.

    2014-05-01

    Mean currents, horizontal diffusivity and upwelling on the Kerguelen Plateau and the deep basin east of the Kerguelen Islands were studied using 48 World Ocean Circulation Experiment (WOCE) Standard Surface Velocity Program (SVP) drifters deployed during the 2011 austral spring KEOPS II (KErguelen Ocean Plateau compared Study II) cruise. These drifter data were analyzed based on autocovariances for temporal scales, least-squares fitted streamfunctions for estimating mesoscale mean currents, wind stress fields and Ekman pumping, and Taylor's single particle diffusivity for estimating horizontal dispersion of surface waters. The results have revealed the shelfbreak current on the southern and eastern shelf slopes of the Kerguelen Islands, transport of surface waters from the Kerguelen-Heard shelf basin crossing the shelf slope into the deep basin off the plateau east of the Kerguelen Islands, and upwelling driven by wind stress curl in both the plateau and deep basin regions. The estimated volume transports off the Plateau in the upper 50 m based on surface drifters and below the mixed layer based on wind stress curl are 0.5 and 1.7 Sv, respectively, the mean and standard deviation of vertical velocities driven by wind stress curl averaged in the plateau and deep basin regions up to 3.2 ± 7.4 m d-1, and the upwelling fluxes in the surveyed plateau and deep basin regions are approximately 0.7 and 1.1 Sv, respectively. These physical transport processes can have significant effects on balances between biogeochemical elements and their recycling processes.

  18. Hoe Creek groundwater restoration, 1989

    SciTech Connect

    Renk, R.R.; Crader, S.E.; Lindblom, S.R.; Covell, J.R.

    1990-01-01

    During the summer of 1989, approximately 6.5 million gallons of contaminated groundwater were pumped from 23 wells at the Hoe Creek underground coal gasification site, near Gillette, Wyoming. The organic contaminants were removed using activated carbon before the water was sprayed on 15.4 acres at the sites. Approximately 2647 g (5.8 lb) of phenols and 10,714 g (23.6 lb) of benzene were removed from the site aquifers. Phenols, benzene, toluene, ethylbenzene, and naphthalene concentrations were measured in 43 wells. Benzene is the only contaminant at the site exceeds the federal standard for drinking water (5 {mu}g/L). Benzene leaches into the groundwater and is slow to biologically degrade; therefore, the benzene concentration has remained high in the groundwater at the site. The pumping operation affected groundwater elevations across the entire 80-acre site. The water levels rebounded quickly when the pumping operation was stopped on October 1, 1989. Removing contaminated groundwater by pumping is not an effective way to clean up the site because the continuous release of benzene from coal tars is slow. Benzene will continue to leach of the tars for a long time unless its source is removed or the leaching rate retarded through mitigation techniques. The application of the treated groundwater to the surface stimulated plant growth. No adverse effects were noted or recorded from some 60 soil samples taken from twenty locations in the spray field area. 20 refs., 52 figs., 8 tabs.

  19. Groundwater pumping by heterogeneous users

    NASA Astrophysics Data System (ADS)

    Saak, Alexander E.; Peterson, Jeffrey M.

    2012-08-01

    Farm size is a significant determinant of both groundwater-irrigated farm acreage and groundwater-irrigation-application rates per unit land area. This paper analyzes the patterns of groundwater exploitation when resource users in the area overlying a common aquifer are heterogeneous. In the presence of user heterogeneity, the common resource problem consists of inefficient dynamic and spatial allocation of groundwater because it impacts income distribution not only across periods but also across farmers. Under competitive allocation, smaller farmers pump groundwater faster if farmers have a constant marginal periodic utility of income. However, it is possible that larger farmers pump faster if the Arrow-Pratt coefficient of relative risk-aversion is sufficiently decreasing in income. A greater farm-size inequality may either moderate or amplify income inequality among farmers. Its effect on welfare depends on the curvature properties of the agricultural output function and the farmer utility of income. Also, it is shown that a flat-rate quota policy that limits the quantity of groundwater extraction per unit land area may have unintended consequences for the income distribution among farmers.

  20. Tracking groundwater with fluoride tracers

    SciTech Connect

    Goldberg, S.P.; Carey, P.J.; Fitzsimmons, J.H.

    1995-10-01

    A municipality on Long Island, NY, owns and operates a solid waste landfill that is currently affecting groundwater quality. Specifically, groundwater monitoring in wells downgradient from the facility indicates the presence of organic and inorganic constituents in excess of New York state groundwater quality standards and guidance values. The municipality wishes to expand its existing facility by constructing a new cell adjacent to the old unlined facility. The new cell will incorporate state-of-the-art landfill design. A double-composite baseliner system--mandated by the New York State Department of Environmental Conservation (NYSDEC)--will be constructed to minimize the potential for leakage of leachate into the groundwater system. The downgradient groundwater flow paths from the existing and the proposed facility will overlap. As such, using conventional monitoring approaches, differentiating known groundwater quality impacts from the existing facility with potential impacts from the new cell could be extremely difficult. To consider the application for the landfill expansion, NYSDEC requested that a study be conducted to determine whether the incorporation of a tracer into the liner design for the new cell could help to differentiate potential future water quality impacts from those impacts presently exerted by the existing landfill.

  1. Groundwater Model Validation

    SciTech Connect

    Ahmed E. Hassan

    2006-01-24

    Models have an inherent uncertainty. The difficulty in fully characterizing the subsurface environment makes uncertainty an integral component of groundwater flow and transport models, which dictates the need for continuous monitoring and improvement. Building and sustaining confidence in closure decisions and monitoring networks based on models of subsurface conditions require developing confidence in the models through an iterative process. The definition of model validation is postulated as a confidence building and long-term iterative process (Hassan, 2004a). Model validation should be viewed as a process not an end result. Following Hassan (2004b), an approach is proposed for the validation process of stochastic groundwater models. The approach is briefly summarized herein and detailed analyses of acceptance criteria for stochastic realizations and of using validation data to reduce input parameter uncertainty are presented and applied to two case studies. During the validation process for stochastic models, a question arises as to the sufficiency of the number of acceptable model realizations (in terms of conformity with validation data). Using a hierarchical approach to make this determination is proposed. This approach is based on computing five measures or metrics and following a decision tree to determine if a sufficient number of realizations attain satisfactory scores regarding how they represent the field data used for calibration (old) and used for validation (new). The first two of these measures are applied to hypothetical scenarios using the first case study and assuming field data consistent with the model or significantly different from the model results. In both cases it is shown how the two measures would lead to the appropriate decision about the model performance. Standard statistical tests are used to evaluate these measures with the results indicating they are appropriate measures for evaluating model realizations. The use of validation

  2. Potential impacts to perennial springs from tar sand mining, processing, and disposal on the Tavaputs Plateau, Utah, USA.

    PubMed

    Johnson, William P; Frederick, Logan E; Millington, Mallory R; Vala, David; Reese, Barbara K; Freedman, Dina R; Stenten, Christina J; Trauscht, Jacob S; Tingey, Christopher E; Kip Solomon, D; Fernandez, Diego P; Bowen, Gabriel J

    2015-11-01

    Similar to fracking, the development of tar sand mining in the U.S. has moved faster than understanding of potential water quality impacts. Potential water quality impacts of tar sand mining, processing, and disposal to springs in canyons incised approximately 200 m into the Tavaputs Plateau, at the Uinta Basin southern rim, Utah, USA, were evaluated by hydrogeochemical sampling to determine potential sources of recharge, and chemical thermodynamic estimations to determine potential changes in transfer of bitumen compounds to water. Because the ridgetops in an area of the Tavaputs Plateau named PR Spring are starting to be developed for their tar sand resource, there is concern for potential hydrologic connection between these ridgetops and perennial springs in adjacent canyons on which depend ranching families, livestock, wildlife and recreationalists. Samples were collected from perennial springs to examine possible progression with elevation of parameters such as temperature, specific conductance, pH, dissolved oxygen, isotopic tracers of phase change, water-rock interaction, and age since recharge. The groundwater age dates indicate that the springs are recharged locally. The progression of hydrogeochemical parameters with elevation, in combination with the relatively short groundwater residence times, indicate that the recharge zone for these springs includes the surrounding ridges, and thereby suggests a hydrologic connection between the mining, processing, disposal area and the springs. Estimations based on chemical thermodynamic approaches indicate that bitumen compounds will have greatly enhanced solubility in water that comes into contact with the residual bitumen-solvent mixture in disposed tailings relative to water that currently comes into contact with natural tar.

  3. Prokaryotic Community Structure Driven by Salinity and Ionic Concentrations in Plateau Lakes of the Tibetan Plateau.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Miao, Li-Li; Wang, Fang; Chu, Li-Min; Wang, Jia-Li; Liu, Zhi-Pei

    2016-01-08

    The prokaryotic community composition and diversity and the distribution patterns at various taxonomic levels across gradients of salinity and physiochemical properties in the surface waters of seven plateau lakes in the Qaidam Basin, Tibetan Plateau, were evaluated using Illumina MiSeq sequencing. These lakes included Lakes Keluke (salinity, <1 g/liter), Qing (salinity, 5.5 to 6.6 g/liter), Tuosu (salinity, 24 to 35 g/liter), Dasugan (salinity, 30 to 33 g/liter), Gahai (salinity, 92 to 96 g/liter), Xiaochaidan (salinity, 94 to 99 g/liter), and Gasikule (salinity, 317 to 344 g/liter). The communities were dominated by Bacteria in lakes with salinities of <100 g/liter and by Archaea in Lake Gasikule. The clades At12OctB3 and Salinibacter, previously reported only in hypersaline environments, were found in a hyposaline lake (salinity, 5.5 to 6.6 g/liter) at an abundance of ∼1.0%, indicating their ecological plasticity. Salinity and the concentrations of the chemical ions whose concentrations covary with salinity (Mg(2+), K(+), Cl(-), Na(+), SO4 (2-), and Ca(2+)) were found to be the primary environmental factors that directly or indirectly determined the composition and diversity at the level of individual clades as well as entire prokaryotic communities. The distribution patterns of two phyla, five classes, five orders, five families, and three genera were well predicted by salinity. The variation of the prokaryotic community structure also significantly correlated with the dissolved oxygen concentration, pH, the total nitrogen concentration, and the PO4 (3-) concentration. Such correlations varied depending on the taxonomic level, demonstrating the importance of comprehensive correlation analyses at various taxonomic levels in evaluating the effects of environmental variable factors on prokaryotic community structures. Our findings clarify the distribution patterns of the prokaryotic community composition in plateau lakes at the levels of individual clades as

  4. Prokaryotic Community Structure Driven by Salinity and Ionic Concentrations in Plateau Lakes of the Tibetan Plateau

    PubMed Central

    Zhong, Zhi-Ping; Liu, Ying; Miao, Li-Li; Wang, Fang; Chu, Li-Min; Wang, Jia-Li

    2016-01-01

    The prokaryotic community composition and diversity and the distribution patterns at various taxonomic levels across gradients of salinity and physiochemical properties in the surface waters of seven plateau lakes in the Qaidam Basin, Tibetan Plateau, were evaluated using Illumina MiSeq sequencing. These lakes included Lakes Keluke (salinity, <1 g/liter), Qing (salinity, 5.5 to 6.6 g/liter), Tuosu (salinity, 24 to 35 g/liter), Dasugan (salinity, 30 to 33 g/liter), Gahai (salinity, 92 to 96 g/liter), Xiaochaidan (salinity, 94 to 99 g/liter), and Gasikule (salinity, 317 to 344 g/liter). The communities were dominated by Bacteria in lakes with salinities of <100 g/liter and by Archaea in Lake Gasikule. The clades At12OctB3 and Salinibacter, previously reported only in hypersaline environments, were found in a hyposaline lake (salinity, 5.5 to 6.6 g/liter) at an abundance of ∼1.0%, indicating their ecological plasticity. Salinity and the concentrations of the chemical ions whose concentrations covary with salinity (Mg2+, K+, Cl−, Na+, SO42−, and Ca2+) were found to be the primary environmental factors that directly or indirectly determined the composition and diversity at the level of individual clades as well as entire prokaryotic communities. The distribution patterns of two phyla, five classes, five orders, five families, and three genera were well predicted by salinity. The variation of the prokaryotic community structure also significantly correlated with the dissolved oxygen concentration, pH, the total nitrogen concentration, and the PO43− concentration. Such correlations varied depending on the taxonomic level, demonstrating the importance of comprehensive correlation analyses at various taxonomic levels in evaluating the effects of environmental variable factors on prokaryotic community structures. Our findings clarify the distribution patterns of the prokaryotic community composition in plateau lakes at the levels of individual clades as well as whole

  5. Gravitational salt tectonics above a rising basement plateau offshore Algeria

    NASA Astrophysics Data System (ADS)

    Gaullier, Virginie; Vendeville, Bruno C.; Besème, Grégoire; Legoux, Gaetan; Déverchère, Jacques; Lymer, Gaël

    2017-04-01

    Seismic data (survey "MARADJA 1", 2003) offshore the Algerian coast have imaged an unexpected deformation pattern of the Messinian salt (Mobile Unit; MU) and its sedimentary overburden (Messinian Upper Unit and Plio-Quaternary) above an actively rising plateau in the subsalt basement. From a geodynamic point of view, the region is undergoing crustal convergence, as attested by the Boumerdes earthquake (2003, magnitude 6.8). The rise of this plateau, forming a 3D promontory restricted to the area offshore Algiers, is associated with that geodynamic setting. The seismic profiles show several subsalt thrusts (Domzig et al. 2006). The data provided additional information on the deformation of the Messinian mobile evaporitic unit and its Plio-Quaternary overburden. Margin-perpendicular profiles show mostly compressional features (anticlines and synclines) that had little activity during Messinian times, then grew more during Plio-Quaternary times. A few normal faults are also present, but are not accompanied by salt rise. By contrast, margin-parallel profiles clearly show that extensional, reactive salt diapiric ridges (symptomatic with their triangular shape in cross section) formed early, as early as the time of deposition of the Messinian Upper Unit, as recorded by fan-shaped strata. These ridges have recorded E-W, thin-skinned gravity gliding above the Messinian salt, as a response to the rise of the basement plateau. We tested this hypothesis using two analogue models, one where we assumed that the rise of the plateau started after Messinian times (initially tabular salt across the entire region), the second model assumed that the plateau had already risen partially as the Messininan Mobile Unit was deposited (salt initially thinner above the plateau than in the adjacent regions). In both experiments, the rise of the plateau generated preferential E-W extension above the salt, combined with N-S shortening. Extension was caused by gravity gliding of the salt from

  6. Conceptual Model of Uranium in the Vadose Zone for Acidic and Alkaline Wastes Discharged at the Hanford Site Central Plateau

    SciTech Connect

    Truex, Michael J.; Szecsody, James E.; Qafoku, Nikolla; Serne, R. Jeffrey

    2014-09-01

    Historically, uranium was disposed in waste solutions of varying waste chemistry at the Hanford Site Central Plateau. The character of how uranium was distributed in the vadose zone during disposal, how it has continued to migrate through the vadose zone, and the magnitude of potential impacts on groundwater are strongly influenced by geochemical reactions in the vadose zone. These geochemical reactions can be significantly influenced by the disposed-waste chemistry near the disposal location. This report provides conceptual models and supporting information to describe uranium fate and transport in the vadose zone for both acidic and alkaline wastes discharged at a substantial number of waste sites in the Hanford Site Central Plateau. The conceptual models include consideration of how co-disposed acidic or alkaline fluids influence uranium mobility in terms of induced dissolution/precipitation reactions and changes in uranium sorption with a focus on the conditions near the disposal site. This information, when combined with the extensive information describing uranium fate and transport at near background pH conditions, enables focused characterization to support effective fate and transport estimates for uranium in the subsurface.

  7. Seismic wave speed structure of the Ontong Java Plateau

    NASA Astrophysics Data System (ADS)

    Covellone, Brian M.; Savage, Brian; Shen, Yang

    2015-06-01

    The Ontong Java Plateau (OJP) represents the result of a significant event in the Earth's geologic history. Limited geophysical and geochemical data, as well as the plateau's relative isolation in the Pacific ocean, have made interpretation of the modern day geologic structure and its 120 Ma formation history difficult. Here we present the highest resolution image to date of the wave speed structure of the OJP region. We use a data set that combines Rayleigh waves extracted from both ambient noise and earthquake waveforms and an iterative finite-frequency tomography methodology. The combination of datasets allow us to best exploit the limited station distribution in the Pacific and image wave speed structures between 35 km and 300 km into the Earth. We image a region of fast shear wave speeds, greater than 4.75 km/s, that extends to greater than 100 km beneath the plateau. The wave speeds are similar to as observed in cratonic environments and are consistent with a compositional anomaly that resulted from the residuum of eclogite entrainment during the plateau's formation. The combination of our imaged wave speed structure and previous geochemical work suggest that a surfacing plume head entrained eclogite from the deep mantle and accounts for the anomalous buoyancy characteristics of the plateau and observed fast wave speeds.

  8. Peak or plateau maximal inspiratory mouth pressure: which is best?

    PubMed

    Windisch, W; Hennings, E; Sorichter, S; Hamm, H; Criée, C P

    2004-05-01

    There is no clear evidence as to how maximal inspiratory mouth pressure (PI,max) should be measured, although plateau pressures sustained for 1 s and measured at residual volume (RV) are usually recommended. Peak and plateau PI,max were measured at RV and at functional residual capacity (FRC) in 533 healthy subjects (aged 10-90 yrs) in order to comparably test all PI,max measurements for their predictors, reproducibility and normal values. Plateau pressures accounted for 82.0-86.3%, of peak pressures. Peak and plateau pressures measured at FRC accounted for 84.3-90.5% of pressures at RV, and were highly correlated. Age was negatively predictive and weight and body mass index positively predictive of PI,max, but regression parameters were low. All PI,max measurements were comparable when calculating regression parameters, between-subject variability and reproducibility. In conclusion, peak and plateau maximal inspiratory mouth pressure are comparably useful for the assessment of inspiratory muscle strength and can be reliably measured at functional residual capacity and at residual volume. Regression equations are of low impact in predicting normal values due to the weak influence of demographic and anthropometric factors and to the high unexplained between-subject-variability. Age-related 5th percentiles can indicate the lower limit of the normal range.

  9. Constraints on the early uplift history of the Tibetan Plateau

    PubMed Central

    Wang, Chengshan; Zhao, Xixi; Liu, Zhifei; Lippert, Peter C.; Graham, Stephan A.; Coe, Robert S.; Yi, Haisheng; Zhu, Lidong; Liu, Shun; Li, Yalin

    2008-01-01

    The surface uplift history of the Tibetan Plateau and Himalaya is among the most interesting topics in geosciences because of its effect on regional and global climate during Cenozoic time, its influence on monsoon intensity, and its reflection of the dynamics of continental plateaus. Models of plateau growth vary in time, from pre-India-Asia collision (e.g., ≈100 Ma ago) to gradual uplift after the India-Asia collision (e.g., ≈55 Ma ago) and to more recent abrupt uplift (<7 Ma ago), and vary in space, from northward stepwise growth of topography to simultaneous surface uplift across the plateau. Here, we improve that understanding by presenting geologic and geophysical data from north-central Tibet, including magnetostratigraphy, sedimentology, paleocurrent measurements, and 40Ar/39Ar and fission-track studies, to show that the central plateau was elevated by 40 Ma ago. Regions south and north of the central plateau gained elevation significantly later. During Eocene time, the northern boundary of the protoplateau was in the region of the Tanggula Shan. Elevation gain started in pre-Eocene time in the Lhasa and Qiangtang terranes and expanded throughout the Neogene toward its present southern and northern margins in the Himalaya and Qilian Shan. PMID:18362353

  10. Constraints on the early uplift history of the Tibetan Plateau.

    PubMed

    Wang, Chengshan; Zhao, Xixi; Liu, Zhifei; Lippert, Peter C; Graham, Stephan A; Coe, Robert S; Yi, Haisheng; Zhu, Lidong; Liu, Shun; Li, Yalin

    2008-04-01

    The surface uplift history of the Tibetan Plateau and Himalaya is among the most interesting topics in geosciences because of its effect on regional and global climate during Cenozoic time, its influence on monsoon intensity, and its reflection of the dynamics of continental plateaus. Models of plateau growth vary in time, from pre-India-Asia collision (e.g., approximately 100 Ma ago) to gradual uplift after the India-Asia collision (e.g., approximately 55 Ma ago) and to more recent abrupt uplift (<7 Ma ago), and vary in space, from northward stepwise growth of topography to simultaneous surface uplift across the plateau. Here, we improve that understanding by presenting geologic and geophysical data from north-central Tibet, including magnetostratigraphy, sedimentology, paleocurrent measurements, and (40)Ar/(39)Ar and fission-track studies, to show that the central plateau was elevated by 40 Ma ago. Regions south and north of the central plateau gained elevation significantly later. During Eocene time, the northern boundary of the protoplateau was in the region of the Tanggula Shan. Elevation gain started in pre-Eocene time in the Lhasa and Qiangtang terranes and expanded throughout the Neogene toward its present southern and northern margins in the Himalaya and Qilian Shan.

  11. More evidence of the plateau effect: a social perspective.

    PubMed

    Pinto-Prades, J L; Lopez-Nicolás, A

    1998-01-01

    The purpose of this study was to test the existence of the plateau effect at the social level. The authors tried to confirm the preliminary conclusion that people may not be willing to trade off any longevity to improve the health state of a large number of people if the health states are mild enough. They tested this assumption using the person-tradeoff technique. They also used a parametric approach and a nonparametric approach to study the relationship between individual and social values. Results show the existence of the plateau effect in the context of resource allocation. Furthermore, with the nonparametric approach, a plateau effect in the middle part of the scale was also observed, suggesting that social preference may not be directly predicted from individual utilities. The authors caution against the possible framing effects that may be present in these kinds of questions.

  12. Geologic applications of ERTS images on the Colorado Plateau, Arizona

    NASA Technical Reports Server (NTRS)

    Goetz, A. F. H.; Billingsley, F. C.; Elston, D. P.; Lucchitta, I.; Shoemaker, E. M.

    1974-01-01

    Three areas in central and northern Arizona centered on the (1) Verde Valley, (2) Coconino Plateau, and (3) Shivwits Plateau were studied using ERTS photography. Useful applications results include: (1) upgrading of the existing state geologic map of the Verde Valley region; (2) detection of long NW trending lineaments in the basalt cap SE of Flagstaff which may be favorable locations for drilling for new water supplies; (3) tracing of the Bright Angel and Butte faults to twice their previously known length and correlating the extensions with modern seismic events, showing these faults to be present-day earthquake hazards; (4) discovering and successfully drilling perched sandstone aquifers in the Kaibab Limestone on the Coconino Plateau; and (5) determining the relationship between the Shivwits lavas and the formation of the lower Grand Canyon and showing that the lavas should be an excellent aquifer, as yet untapped.

  13. State of tectonic stress in Shillong Plateau of northeast India

    NASA Astrophysics Data System (ADS)

    Baruah, Santanu; Baruah, Saurabh; Saikia, Sowrav; Shrivastava, Mahesh N.; Sharma, Antara; Reddy, C. D.; Kayal, J. R.

    2016-10-01

    Tectonic stress regime in the Shillong plateau, northeast region of India, is examined by stress tensor inversion. Some 97 reliable fault plane solutions are used for stress inversion by the Michael and Gauss methods. Although an overall NNW-SSE compressional stress is observed in the area, the stress regime varies from western part to eastern part of the plateau. The eastern part of the plateau is dominated by NNE-SSW compression and the western part by NNW-SSE compression. The NNW-SSE compression in the western part may be due to the tectonic loading induced by the Himalayan orogeny in the north, and the NNE-SSW compression in the eastern part may be attributed to the influence of oblique convergence of the Indian plate beneath the Indo-Burma ranges. Further, Gravitational Potential Energy (GPE) derived stress also indicates a variation from west to east.

  14. Spontaneous rupture of thinning liquid films with Plateau borders

    NASA Astrophysics Data System (ADS)

    Anderson, Anthony; Brush, Lucien; Davis, Stephen

    2009-11-01

    Spontaneous film rupture from van der Waals instability is investigated in 2D. A thin liquid film between adjacent bubbles in a foam has finite length, curved boundaries (Plateau borders), and a drainage flow from capillary suction that causes thinning. A full linear stability analysis of this thinning film shows that rupture occurs once the film has thinned to tens of nanometers. Whereas, in an unbounded, quiescent, flat free film, rupture occurs when the thickness is hundreds of nanometers. Finite length, Plateau borders and flow are all found to contribute to the stabilization. The drainage flow leads to several distinct qualitative features as well. In particular, unstable disturbances are advected by the flow to the edges of the thin film. As a result, the edges of the film close to the Plateau borders are more susceptible to rupture that the center of the film.

  15. Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits

    PubMed Central

    Wang, Ninglian; Wu, Xiaobo; Kehrwald, Natalie; Li, Zhen; Li, Quanlian; Jiang, Xi; Pu, Jianchen

    2015-01-01

    The β radioactivity of snow-pit samples collected in the spring of 2011 on four Tibetan Plateau glaciers demonstrate a remarkable peak in each snow pit profile, with peaks about ten to tens of times higher than background levels. The timing of these peaks suggests that the high radioactivity resulted from the Fukushima nuclear accident that occurred on March 11, 2011 in eastern Japan. Fallout monitoring studies demonstrate that this radioactive material was transported by the westerlies across the middle latitudes of the Northern Hemisphere. The depth of the peak β radioactivity in each snow pit compared with observational precipitation records, suggests that the radioactive fallout reached the Tibetan Plateau and was deposited on glacier surfaces in late March 2011, or approximately 20 days after the nuclear accident. The radioactive fallout existed in the atmosphere over the Tibetan Plateau for about one month. PMID:25658094

  16. Bedrock geology of the northern Columbia Plateau and adjacent areas

    NASA Technical Reports Server (NTRS)

    Swanson, D. A.; Wright, T. L.

    1978-01-01

    The Columbia Plateau is surrounded by a complex assemblage of highly deformed Precambrian to lower Tertiary continental and oceanic rocks that reflects numerous episodes of continental accretion. The plateau itself is comprised of the Columbia River basalt group formed between about 16.5 x 1 million years B.P. and 6 x 1 million years B.P. Eruptions were infrequent between about 14 and 6 x 1 million years B.P., allowing time for erosion and deformation between successive outpourings. The present-day courses of much of the Snake River, and parts of the Columbia River, across the plateau date from this time. Basalt produced during this waning activity is more heterogeneous chemically and isotopically than older flows, reflecting its prolonged period of volcanism.

  17. The impacts of the summer plateau monsoon over the Tibetan Plateau on the rainfall in the Tarim Basin, China

    NASA Astrophysics Data System (ADS)

    Zhao, Yong; Huang, Anning; Zhou, Yang; Yang, Qing

    2016-10-01

    The impacts of the summer plateau monsoon (PM) over the Tibetan Plateau on summer rainfall over the Tarim Basin in northwest China are investigated, based on the observed rainfall data at 34 stations and the NCEP/NCAR reanalysis data during 1961 to 2007. Results showed that the PM is well correlated to the summer rainfall over the Tarim Basin. Process analysis shows that strong PM corresponds to an anomalous cyclone over the Tibetan Plateau in the middle troposphere and an anomalous anticyclone in the upper troposphere over northwest part of Tibetan Plateau. They result in cold air moving from high latitudes into Central Asia over the western part of Tibetan Plateau. The concurrences of the cooling in the middle-upper troposphere over Central Asia leads to an anomalous cyclone over Central Asia at 500 hPa and the anomalous descending motions prevailing over the cooling region. Associated with this anomaly, there are enhanced southerly winds and corresponding ascending motion over the Tarim Basin located in the east of the cooling region. These processes lead to more summer rainfall over the Tarim Basin.

  18. A Multistage Volcanic and Tectonic Evolution History on the High Plateau, Part of the Manihiki Plateau, Central Pacific

    NASA Astrophysics Data System (ADS)

    Pietsch, R.; Uenzelmann-Neben, G.

    2014-12-01

    For the Manihiki Plateau, a Large Igneous Province (LIP), a multistage volcanic emplacement history is revealed in new, multi channel high resolution seismic reflection data. Gathered during cruise So224 the profiles are distributed to study the initial emplacement of the High Plateau (HP), part of the Manihiki Plateau, as well as tectonic related processes at its margins. Extension of a previously defined seismostratigraphic model has allowed an identification of an intra-basalt reflector which has been formed by volcanism prior to the major emplacement during the early Cretaceous. We suggest that it represents the nucleus of the HP's formation and conclude that the Manihiki Plateau is older than the proposed ~120 Ma. We have identified evidence that the plateau extended to the east and broke-up along the Manihiki Scarp prior to the second volcanic active phase. The south-western margin shows a stretched and rifted structure, which could be related to the separation of the Manihiki and Hikurangi Plateaus. Identification of extrusion centers associated with a third volcanic active period ending ~65 Ma ago and their spatial distribution hint on a shift of the emplacement mechanism from sources related to initial emplacement to tectonic induced volcanism at the margins. Later stage tectonic and volcanic reactivations occurred, which were concentrated in the south-western part of the HP.

  19. Groundwater and Terrestrial Water Storage

    NASA Technical Reports Server (NTRS)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2011-01-01

    Most people think of groundwater as a resource, but it is also a useful indicator of climate variability and human impacts on the environment. Groundwater storage varies slowly relative to other non-frozen components of the water cycle, encapsulating long period variations and trends in surface meteorology. On seasonal to interannual timescales, groundwater is as dynamic as soil moisture, and it has been shown that groundwater storage changes have contributed to sea level variations. Groundwater monitoring well measurements are too sporadic and poorly assembled outside of the United States and a few other nations to permit direct global assessment of groundwater variability. However, observational estimates of terrestrial water storage (TWS) variations from the GRACE satellites largely represent groundwater storage variations on an interannual basis, save for high latitude/altitude (dominated by snow and ice) and wet tropical (surface water) regions. A figure maps changes in mean annual TWS from 2009 to 2010, based on GRACE, reflecting hydroclimatic conditions in 2010. Severe droughts impacted Russia and the Amazon, and drier than normal weather also affected the Indochinese peninsula, parts of central and southern Africa, and western Australia. Groundwater depletion continued in northern India, while heavy rains in California helped to replenish aquifers that have been depleted by drought and withdrawals for irrigation, though they are still below normal levels. Droughts in northern Argentina and western China similarly abated. Wet weather raised aquifer levels broadly across western Europe. Rains in eastern Australia caused flooding to the north and helped to mitigate a decade long drought in the south. Significant reductions in TWS seen in the coast of Alaska and the Patagonian Andes represent ongoing glacier melt, not groundwater depletion. Figures plot time series of zonal mean and global GRACE derived non-seasonal TWS anomalies (deviation from the mean of

  20. Near-surface and deep groundwaters

    NASA Astrophysics Data System (ADS)

    Seiler, Klaus-Peter; Lindner, Wulf

    1995-02-01

    Groundwater occurs in all climatic zones and differs in hydrodynamic, isotopic and chemical terms according to its activity within the water cycle and its interaction with rocks. Among the many chemical components in groundwaters, tritium concentrations allow differentiation between groundwater of high and low mobility and thus permit the distinction between shallow and deep groundwaters. In Germany shallow groundwaters range in depth between 10 and 100 m and account for more than 85% of groundwater recharge. Deep groundwaters, in contrast, participate in the water cycle only at intervals of hundreds or thousands of years and reach depths of several hundred metres. Both types of groundwater overlie connate waters that have been isolated from the water cycle since the accumulation of the sediments in which they occur. The exploitation of deep groundwaters mostly causes long-term non-steady-state conditions, large-scale changes of flow patterns of the groundwaters and hydraulic short circuits to shallow aquifers. Thus, persistent contaminants may penetrate extraction wells in deep groundwaters even if the wells are believed to be well protected against pollution. In deep groundwaters it is difficult to apply the conventional use of groundwater protection zones to prevent this kind of intrusion of contaminants.

  1. Surficial geology, structure, and thickness of selected geohydrologic units in the Columbia Plateau, Washington

    USGS Publications Warehouse

    Drost, B.W.; Whiteman, K.J.

    1986-01-01

    A 2-1/2 year study of the Columbia Plateau in Washington was begun in March 1982 to define spatial and temporal variations in dissolved sodium in the Columbia River Basalt Group aquifers and to relate these variations to the groundwater system and its geologic framework. This report describes the geologic framework , including the vertical and areal extent of the major basalt units, interbeds, and overlying materials. Thickness and structure of the Grande Ronde, Wanapum, and Saddle Mountains Basalts, thickness of the interbeds between the Grande Ronde and Wanapum, and Wanapum and Saddle Mountains Basalts, and thickness of the overburden were mapped at a scale of 1:500,000. Information was compiled from 2,500 well records using chemical analyses of core or drill chips, geophysical logs, and driller 's logs, in decreasing order of reliability. Surficial geology and surficial expression of structural features were simplified from published maps to provide maps with this information at the 1:500,000 scale. This report is intended to serve as a base for evaluating the distribution of dissolved sodium in basalt aquifers and as a base for future water resource studies. (USGS)

  2. Modeling of Groundwater Flow in a Karst Aquifer in Northeast Iowa

    NASA Astrophysics Data System (ADS)

    Zhang, Y.

    2001-12-01

    Groundwater contamination has been a major environmental concern in northeast Iowa for many years. The Paleozoic Plateau region of northeast Iowa differs from most other parts of the state because the bedrocks are at or near the surface. Carbonates dominate the bedrock landscape of the region and are subject to karst development by groundwater movement. Only thin, isolated remnants of loess and glacial-drift deposits remain in the region. The open nature of the karst system makes the groundwater resource highly susceptible to chemical or biological contamination. The Williams Creek watershed is located within the Paleozoic Plateau region and was selected for this study. The creek originates near Postville, Iowa, flows northeast through the center of the watershed and discharges into the Yellow River. The Postville Wastewater Treatment Plant is located at the head of Williams Creek and consequently drains its wastewater effluent directly into this stretch of the creek. The rural population is concerned that water quality throughout the watershed has diminished in recent years. The purpose of this study was to collect water quality data and construct a groundwater flow model of the area in order to gain a better understanding of the contaminants and contaminant transport within the watershed. Groundwater Modeling Systems (GMS) version 3.0 software was used to construct a conceptual model based on the geologic and hydrogeologic data of the site. Fourteen private wells were selected for monthly water table measurements for ten months. A steady-state flow model was built and calibrated against the long-term average water table conditions of the watershed and spatially-varied recharge rates were obtained. The transient simulation was then carried out using monthly hydraulic head data and time-dependent recharge rates were obtained. Karst conditions coupled with contaminant sources such as pesticide applications, hog confinement lots, and wastewater treatment facilities

  3. Reduced convergence within the Tibetan Plateau by 26 Ma?

    NASA Astrophysics Data System (ADS)

    Meng, Jun; Coe, Robert S.; Wang, Chengshan; Gilder, Stuart A.; Zhao, Xixi; Liu, Hao; Li, Yalin; Ma, Pengfei; Shi, Kai; Li, Shuai

    2017-07-01

    Understanding the dynamics of double-thickening and uplifting of the Tibetan crust requires constraints on the magnitude and timing of crustal shortening. New elongation/inclination (E/I)-corrected paleomagnetic data from 26-22 Ma sediments indicate that the latitude of southern Tibet in the early Miocene was 31.1/-6.8/+5.2°N, not significantly different from today. This implies that the southern margin of Asia, which was at 21-24°N latitude from the Late Cretaceous to the early Eocene, advanced 8-10° northward between the early Eocene and the latest Oligocene. Our results therefore suggest that at least 900-1100 km of continental shortening and significant regional uplift of the plateau occurred between the early Eocene and late Oligocene. Our results suggest that N-S intra-Asian convergence was considerably reduced around 26 Ma, corresponding to a transition from compression to extension within the Tibetan Plateau.Plain Language SummaryTwo critical questions involving the geodynamic evolution of the Tibetan <span class="hlt">plateau</span> are (i) when did a compression-dominated tectonic regime change to an extension-dominated tectonic regime on the <span class="hlt">plateau</span> and (ii) how does this timing correlate with double thickening of the crust? Here we provide paleomagnetic evidence for the timing, magnitude, and partitioning of intra-Asian convergence. Our results imply a first-order constraint of 900-1100 km north-south shortening concentrated within the interval from 53 to 26 Ma. This suggests that a fundamental change at 26 Ma occurred in the geodynamics of the Tibetan <span class="hlt">Plateau</span> marked by a reduction in large-scale convergence and compressive deformation. The implication is that significant regional uplift of the proto-Tibetan <span class="hlt">Plateau</span> occurred within the 55-26 Ma interval. The paleolatitude, paleoclimate, and topography of south central Tibet seen at present were likely established around 26 Ma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22072575','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22072575"><span>Transport in the <span class="hlt">plateau</span> regime in a tokamak pedestal</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Seol, J.; Shaing, K. C.</p> <p>2012-07-15</p> <p>In a tokamak H-mode, a strong E Multiplication-Sign B flow shear is generated during the L-H transition. Turbulence in a pedestal is suppressed significantly by this E Multiplication-Sign B flow shear. In this case, neoclassical transport may become important. The neoclassical fluxes are calculated in the <span class="hlt">plateau</span> regime with the parallel plasma flow using their kinetic definitions. In an axisymmetric tokamak, the neoclassical particles fluxes can be decomposed into the banana-<span class="hlt">plateau</span> flux and the Pfirsch-Schlueter flux. The banana-<span class="hlt">plateau</span> particle flux is driven by the parallel viscous force and the Pfirsch-Schlueter flux by the poloidal variation of the friction force. The combined quantity of the radial electric field and the parallel flow is determined by the flux surface averaged parallel momentum balance equation rather than requiring the ambipolarity of the total particle fluxes. In this process, the Pfirsch-Schlueter flux does not appear in the flux surface averaged parallel momentum equation. Only the banana-<span class="hlt">plateau</span> flux is used to determine the parallel flow in the form of the flux surface averaged parallel viscosity. The heat flux, obtained using the solution of the parallel momentum balance equation, decreases exponentially in the presence of sonic M{sub p} without any enhancement over that in the standard neoclassical theory. Here, M{sub p} is a combination of the poloidal E Multiplication-Sign B flow and the parallel mass flow. The neoclassical bootstrap current in the <span class="hlt">plateau</span> regime is presented. It indicates that the neoclassical bootstrap current also is related only to the banana-<span class="hlt">plateau</span> fluxes. Finally, transport fluxes are calculated when M{sub p} is large enough to make the parallel electron viscosity comparable with the parallel ion viscosity. It is found that the bootstrap current has a finite value regardless of the magnitude of M{sub p}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.S21F..11B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.S21F..11B"><span>The Colorado <span class="hlt">Plateau</span> and its Role in the Laramide Orogeny</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bump, A. P.</p> <p>2001-12-01</p> <p>The Colorado <span class="hlt">Plateau</span> is a relatively undeformed region bordered on the south and west by the highly extended Basin and Range province and on the north and east by the towering Laramide uplifts of the Rocky Mountains. Tectonically, the <span class="hlt">Plateau</span> is a part of the Laramide orogen and contains basement-cored uplifts similar in style to those of the Rocky Mountains but with lower structural and topographic relief. Together, these observations have led some workers to hypothesize that the <span class="hlt">Plateau</span> is anomalously strong and behaved as a rigid microplate during the Laramide orogeny. Evidence for a fundamental difference between the <span class="hlt">Plateau</span> and the Rocky Mountains is largely circumstantial however, and is not supported by structural, topographic, geophysical or crustal assemblage data. The gradation in deformational intensity is better explained as the product of northeastward-increasing tectonic force, which is a predictable result of coupling between the North American crust and the flat, northeastward-subducting Farallon slab. Assuming that coupling-related stress and crustal strength are approximately constant, net force (and hence deformational intensity) grow with distance over which the coupling is active resulting in low tectonic force/minor deformation in the hinterland and high force/intense deformation in the foreland just before the subducting slab loses contact with the overriding plate. Minimal deformation of the Colorado <span class="hlt">Plateau</span> is thus a logical result of its location in the hinterland of the Laramide orogen. Interpreted northeastward translation and clockwise rotation of the <span class="hlt">Plateau</span> are consistent with a normal along-strike "bow and arrow" orogenic shortening profile and require no special explanation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1513236H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1513236H"><span>Climate sensitivity of Tibetan <span class="hlt">Plateau</span> glaciers - past and future implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heyman, Jakob; Hubbard, Alun; Stroeven, Arjen P.; Harbor, Jonathan M.</p> <p>2013-04-01</p> <p>The Tibetan <span class="hlt">Plateau</span> is one of the most extensively glaciated, non-Polar regions of the world, and its mountain glaciers are the primary source of melt water for several of the largest Asian rivers. During glacial cycles, Tibetan <span class="hlt">Plateau</span> glaciers advanced and retreated multiple times, but remained restricted to the highest mountain areas as valley glaciers and ice caps. Because glacier extent is dominantly controlled by climate, the past extent of Tibetan glaciers provide information on regional climate. Here we present a study analyzing the past maximum extents of glaciers on the Tibetan <span class="hlt">Plateau</span> with the output of a 3D glacier model, in an effort to quantify Tibetan <span class="hlt">Plateau</span> climate. We have mapped present-day glaciers and glacial landforms deposited by formerly more extensive glaciers in eight mountain regions across the Tibetan <span class="hlt">Plateau</span>, allowing us to define present-day and past maximum glacier outlines. Using a high-resolution (250 m) higher-order glacier model calibrated against present-day glacier extents, we have quantified the climate perturbations required to expand present-day glaciers to their past maximum extents. We find that a modest cooling of at most 6°C for a few thousand years is enough to attain past maximum extents, even with 25-75% precipitation reduction. This evidence for limited cooling indicates that the temperature of the Tibetan <span class="hlt">Plateau</span> remained relatively stable over Quaternary glacial cycles. Given the significant sensitivity to temperature change, the expectation is perhaps that a future warmer climate might result in intense glacier reduction. We have tested this hypothesis and modeled the future glacier development for the three mountain regions with the largest present-day glacier cover using a projected warming of 2.8 to 6.2°C within 100 years (envelope limits from IPCC). These scenarios result in dramatic glacier reductions, including 24-100% ice volume loss after 100 years and 77-100% ice volume loss after 300 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6395226','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6395226"><span>Sedimentary basin framework of Exmouth <span class="hlt">Plateau</span>, northwest Australia</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Boyd, R.; Exon, N.; Williamson, P.</p> <p>1987-05-01</p> <p>The Exmouth <span class="hlt">Plateau</span> is a marginal <span class="hlt">plateau</span> lying off northwest Australia. Water depths range between 800 m and 4000 m, and the area shallower than 2000 m covers approximately 150,000 km/sup 2/. The <span class="hlt">plateau</span> consists of rifted and deeply subsided continental crust, with a Phanerozoic sedimentary sequence around 10 km thick, deposited in the Canning and Carnarvon basins. The <span class="hlt">plateau</span> is separated from the Northwest Shelf by the Kangaroo syncline and is bounded to the north, west, and south by oceanic crust of Cretaceous and Jurassic age. The present structural configuration of Exmouth <span class="hlt">Plateau</span> was initiated by rifting in the Triassic to Middle Jurassic, followed by northwest-oriented sea floor spreading. The western margin has a normal rifted structure, while the southern margin structure was dominated by transform motion. The complex rifted and sheared northern margin contains at least one crustal block of post-breakup igneous origin. Below a rift onset unconformity of Neocomian age lies a thick Triassic paralic sequence to the south, while farther north the unconformity is of Callovian age and overlies a Jurassic sequence of Tethyan carbonates, coal measures, and volcanics. The post-breakup sequence consists of Late Jurassic-Cenomanian deltaic and shelf clastics, overlain by thin Late Cretaceous-Tertiary shallow marine to pelagic carbonates. Exmouth <span class="hlt">Plateau</span> therefore represents classic rift to mature ocean stage development of a sediment-starved passive margin. The large fault blocks in the rifted Triassic-Jurassic sequences and large areal closures in the Cretaceous deltas encouraged petroleum exploration over the last two decades. The rifted section was shown to be gas prone, while the overlying section proved to be largely immature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70025102','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70025102"><span><span class="hlt">Groundwater</span> recharge and agricultural contamination</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Böhlke, J.K.</p> <p>2002-01-01</p> <p>Agriculture has had direct and indirect effects on the rates and compositions of <span class="hlt">groundwater</span> recharge and aquifer biogeochemistry. Direct effects include dissolution and transport of excess quantities of fertilizers and associated materials and hydrologic alterations related to irrigation and drainage. Some indirect effects include changes in water-rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agrilcultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in <span class="hlt">groundwater</span>, for example NO3-, N2, Cl, SO42-, H+, P, C, K, Mg, Ca, Sr, Ba, Ra, and As, as well a wide variety of pesticides and other organic compounds. For reactive contaminants like NO3-, a combination of chemical, isotopic, and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in <span class="hlt">groundwater</span>. <span class="hlt">Groundwater</span> records derived from multi-component hydrostratigraphic data can be used to quantify recharge rates and residence times of water and dissolved contaminants, document past variations in recharging contaminant loads, and identify natural contaminant-remediation processes. These data indicate that many of the world's surficial aquifers contain transient records of changing agricultural contamination from the last half of the 20th century. The transient agricultural <span class="hlt">groundwater</span> signal has important implications for long-term trends and spatial heterogeneity in discharge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70045213','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70045213"><span>Review: <span class="hlt">groundwater</span> in Alaska (USA)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Callegary, J.B.; Kikuchi, C.P.; Koch, J.C.; Lilly, M.R.; Leake, S.A.</p> <p>2013-01-01</p> <p><span class="hlt">Groundwater</span> in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the <span class="hlt">groundwater</span> system. The climate ranges from maritime in the southern portion of the state to continental in the Interior, and arctic on the North Slope. During the Quaternary period, topography and rock type have combined with glacial and periglacial processes to develop the unconsolidated alluvial aquifers of Alaska and have resulted in highly heterogeneous hydrofacies. In addition, the long persistence of frozen ground, whether seasonal or permanent, greatly affects the distribution of aquifer recharge and discharge. Because of high runoff, a high proportion of <span class="hlt">groundwater</span> use, and highly variable permeability controlled in part by permafrost and seasonally frozen ground, understanding <span class="hlt">groundwater</span>/surface-water interactions and the effects of climate change is critical for understanding <span class="hlt">groundwater</span> availability and the movement of natural and anthropogenic contaminants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5672973','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5672973"><span>Composite multiphase <span class="hlt">groundwater</span> model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Joon Hyun.</p> <p>1989-01-01</p> <p>A general comprehensive mathematical model using the composite multi-phase approach to describe <span class="hlt">groundwater</span> flow and pollution was developed. The comprehensive governing equation was derived from the simple mass balance of chemical species over all the phases in schematic elementary volume, and traditional ground water governing equations are explained from it. An attempt was made to include the complicated aspects of physical chemical and biological processes such as mass fraction, compressibility, capillarity, dispersion, gravity, relative permeability, viscosity, sorption, interfacial mass change and chemical and biological reactions. To make the analysis possible, assumptions have been made for continuous flow of each phase and instantaneous equilibrium for partition. The resulting system of nonlinear governing and constitutive equations was solved numerically. To handle the irregular geometry, complex boundary conditions and many different governing equations with simple modifications, the upstream weighted finite element method was adopted. By using the dynamic allocation of arrays, the code is flexible to work on an IBM 3090 Vector Facility, workstations and PC's for one, two and three dimensional problems. To reduce the computation time and storage requirements, decoupling of the system equations, banded global matrix and vector and parallel processing were used. The program was structured to facilitate inclusion of additional future constitutive equations. To demonstrate the model's versatility, several hypothetical problems were simulated: unsaturated flow through an embankment; one and two dimensional solute transport; one, two, three dimensional multiphase flow; composite multiphase flow and contaminant migration. The instability and convergence criteria of the nonlinear problems were studied. Parameter dependency of the model was also studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2011/5124/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2011/5124/"><span>Hydrogeologic framework and hydrologic budget components of the Columbia <span class="hlt">Plateau</span> Regional Aquifer System, Washington, Oregon, and Idaho</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kahle, S.C.; Morgan, D.S.; Welch, W.B.; Ely, D.M.; Hinkle, S.R.; Vaccaro, J.J.; Orzol, L.L.</p> <p>2011-01-01</p> <p>The Columbia <span class="hlt">Plateau</span> Regional Aquifer System (CPRAS) covers an area of about 44,000 square miles in a structural and topographic basin within the drainage of the Columbia River in Washington, Oregon, and Idaho. The primary aquifers are basalts of the Columbia River Basalt Group (CRBG) and overlying sediment. Eighty percent of the <span class="hlt">groundwater</span> use in the study area is for irrigation, in support of a $6 billion per year agricultural economy. Water-resources issues in the Columbia <span class="hlt">Plateau</span> include competing agricultural, domestic, and environmental demands. <span class="hlt">Groundwater</span> levels were measured in 470 wells in 1984 and 2009; water levels declined in 83 percent of the wells, and declines greater than 25 feet were measured in 29 percent of the wells. Conceptually, the system is a series of productive basalt aquifers consisting of permeable interflow zones separated by less permeable flow interiors; in places, sedimentary aquifers overly the basalts. The aquifer system of the CPRAS includes seven hydrogeologic units-the overburden aquifer, three aquifer units in the permeable basalt rock, two confining units, and a basement confining unit. The overburden aquifer includes alluvial and colluvial valley-fill deposits; the three basalt units are the Saddle Mountains, Wanapum, and Grande Ronde Basalts and their intercalated sediments. The confining units are equivalent to the Saddle Mountains-Wanapum and Wanapum-Grande Ronde interbeds, referred to in this study as the Mabton and Vantage Interbeds, respectively. The basement confining unit, referred to as Older Bedrock, consists of pre-CRBG rocks that generally have much lower permeabilities than the basalts and are considered the base of the regional flow system. Based on specific-capacity data, median horizontal hydraulic conductivity (Kh) values for the overburden, basalt units, and bedrock are 161, 70, and 6 feet per day, respectively. Analysis of oxygen isotopes in water and carbon isotopes in dissolved inorganic carbon from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSAES..78..150B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSAES..78..150B"><span><span class="hlt">Groundwater</span> chemistry characterization using multi-criteria approach: The upper Samalá River basin (SW Guatemala)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bucci, Arianna; Franchino, Elisa; De Luca, Domenico Antonio; Lasagna, Manuela; Malandrino, Mery; Bianco Prevot, Alessandra; Hernández Sac, Humberto Osvaldo; Coyoy, Israel Macario; Sac Escobar, Edwin Osvaldo; Hernández, Ardany</p> <p>2017-10-01</p> <p>Improving understanding on <span class="hlt">groundwater</span> chemistry is a key priority for water supply from <span class="hlt">groundwater</span> resources, especially in developing countries. A hydrochemical study was performed in an area of SW Guatemala (Samalà River basin), where water supply to population is <span class="hlt">groundwater</span>-based and no systematic studies on its <span class="hlt">groundwater</span> resources have been performed so far. Traditional hydrochemical analyses on major ions and some trace elements metals coupled with chemometric approach were performed, including principal component analysis and hierarchical clustering analysis. Results evidence that chemical differentiation is linked to the spatial distribution of sampled waters. The most common hydrochemical facies, bicarbonate calcium and magnesium, is linked to infiltration of meteoric waters in recharge areas represented by highlands surrounding Xela caldera, a wide <span class="hlt">plateau</span> where most of population is concentrated. This trend undergoes chemical evolution in proximity of active volcanic complexes in the southern area, with enrichment in sulphate, chloride and magnesium. Chemical evolution also occurs towards the centre of Xela caldera due to slow circulation in aquifer and consequent sodium enrichment due to ion exchange with the porous medium. Water quality did not reveal severe concerns, even though some sources of contamination could be identified; in particular, agriculture and urban wastewater could be responsible for observed threshold exceedances in nitrate and lead. This integrated multi-approach to hydrochemical data interpretation yielded to the achievement of important information that poses the basis for future <span class="hlt">groundwater</span> protection in an area where main water features were almost unknown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10182295','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10182295"><span>Neoclassical kinetic theory near an X-point: <span class="hlt">Plateau</span> regime</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Solano, E.R.; Hazeltine, R.D.</p> <p>1993-08-01</p> <p>Traditionally, neoclassical transport calculations ignore poloidal variation of the poloidal magnetic field. Near an X-point of the confining field of a diverted plasma, the poloidal field is small, causing guiding centers to linger at that poloidal position. We study how neoclassical transport is affected by this differential shaping. The problem is solved in general in the <span class="hlt">plateau</span> regime, and a model poloidal flux function with an X-point is utilized as an analytic example to show that the <span class="hlt">plateau</span> diffusion coefficient can change considerably (factor of 2 reduction). Ion poloidal rotation is proportional to the local value of 8 poi, but otherwise it is not strongly affected by shaping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110002762','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110002762"><span>Geologic Mapping of the Aristarchus <span class="hlt">Plateau</span> Region on the Moon</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lough, T. A.; Gregg, T. K. P.; Yingst, Aileen R.</p> <p>2010-01-01</p> <p>Aristarchus <span class="hlt">plateau</span> (25 N, 40 W) is a volcanologically diverse region containing sinuous rilles, volcanic depressions, mare material of various ages - including a candidate for the youngest mare unit on the lunar surface - pyroclastic deposits, and material of possible highland origin [1-5]. Here, we present preliminary mapping of a 13deg x 10deg area around Aristarchus <span class="hlt">plateau</span> [6]. Interpretations of the region s volcanic evolution have implications for the global history of lunar volcanism, the crustal and mantle development of the Moon, and may ultimately help support successful lunar exploration [7].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/840684','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/840684"><span>COMPREHENSIVE CLOSURE PLAN FOR THE HANFORD CENTRAL <span class="hlt">PLATEAU</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>LACKEY, M.B.</p> <p>2005-05-31</p> <p>This paper describes a comprehensive and strategic plan that has been recently developed for the environmental closure of the Central <span class="hlt">Plateau</span> area of the Hanford Site, a former weapons-production complex managed by the U.S. Department of Energy (DOE). This approach was submitted to the DOE Richland Operations Office by Fluor Hanford to provide a framework and roadmap to integrate ongoing operations with closure of facilities that are no longer actively used--all with a view to closing the Central <span class="hlt">Plateau</span> by 2035. The plan is currently under consideration by the DOE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/625838','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/625838"><span>Ion <span class="hlt">plateau</span> transport near the tokamak magnetic axis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shaing, K.C.; Hazeltine, R.D.</p> <p>1998-04-01</p> <p>Conventional neoclassical transport theory does not pertain near the magnetic axis, where orbital variation of the minor radius and the poloidal field markedly change the nature of guiding-center trajectories. Instead of the conventional tokamak banana-shaped trajectories, near-axis orbits, called potato orbits, are radially wider and lead to distinctive kinetic considerations. Here it is shown that there is a <span class="hlt">plateau</span> regime for the near-axis case; the corresponding potato-<span class="hlt">plateau</span> ion thermal conductivity is computed. {copyright} {ital 1998 American Institute of Physics.}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2010/5227/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2010/5227/"><span><span class="hlt">Groundwater</span>-flow model and effects of projected <span class="hlt">groundwater</span> use in the Ozark Plateaus Aquifer System in the vicinity of Greene County, Missouri - 1907-2030</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Richards, Joseph M.</p> <p>2010-01-01</p> <p>Recent and historical periods of rapid growth have increased the stress on the <span class="hlt">groundwater</span> resources in the Ozark aquifer in the Greene County, Missouri area. Historical pumpage from the Ozark aquifer has caused a cone of depression beneath Springfield, Missouri. In an effort to ease its dependence on <span class="hlt">groundwater</span> for supply, the city of Springfield built a pipeline in 1996 to bring water from Stockton Lake to the city. Rapid population growth in the area coupled with the expanding cone of depression raised concern about the sustainability of <span class="hlt">groundwater</span> as a resource for future use. A <span class="hlt">groundwater</span>-flow model was developed by the U.S. Geological Survey in cooperation with Greene County, Missouri, the U. S. Army Corps of Engineers, and the Missouri Department of Natural Resources to assess the effect that increased <span class="hlt">groundwater</span> demand is having on the long-term availability of <span class="hlt">groundwater</span> in and around Greene County, Missouri. Three hydrogeologic units were represented in the <span class="hlt">groundwater</span>-flow model: the Springfield <span class="hlt">Plateau</span> aquifer, the Ozark confining unit, and the Ozark aquifer. The Springfield <span class="hlt">Plateau</span> aquifer is less than 350 feet thick in the model area and generally is a low yield aquifer suitable only for domestic use. The Ozark aquifer is composed of a more than 900-foot thick sequence of dolomite and sandstone in the model area and is the primary aquifer throughout most of southern Missouri. Wells open to the entire thickness of the Ozark aquifer typically yield 1,000 gallons per minute or more. Between the two aquifers is the Ozark confining unit composed of as much as 98 feet of shale and limestone. Karst features such as sinkholes, springs, caves, and losing streams are present in both aquifers, but the majority of these features occur in the Springfield <span class="hlt">Plateau</span> aquifer. The solution-enlarged fracture and bedding plane conduits in the karst system, particularly in the Springfield <span class="hlt">Plateau</span> aquifer, are capable of moving large quantities of <span class="hlt">groundwater</span> through</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=328822','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=328822"><span>Future research needs involving pathogens in <span class="hlt">groundwater</span></span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Contamination of <span class="hlt">groundwater</span> by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important barriers to preventing <span class="hlt">groundwater</span> contamination. However, non-point sources of pathogen contamination are frequently difficult to ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=87238&keyword=water+AND+pump+AND+maintenance&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78761525&CFTOKEN=61772028','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=87238&keyword=water+AND+pump+AND+maintenance&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78761525&CFTOKEN=61772028"><span>PERMEABLE REACTIVE BARRIERS FOR <span class="hlt">GROUNDWATER</span> REMEDIATION</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Permeable reactive barriers (PRB's) are an emerging, alternative in-situ approach for remediating <span class="hlt">groundwater</span> contamination that combine subsurface fluid flow management with a passive chemical treatment zone. Removal of contaminants from the <span class="hlt">groundwater</span> plume is achieved by alt...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1985/4151/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1985/4151/report.pdf"><span>Plan of study for the Regional Aquifer-System Analysis, Columbia <span class="hlt">Plateau</span>, Washington, northern Oregon, and northwestern Idaho</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Vaccaro, J.J.</p> <p>1986-01-01</p> <p>The U.S. Geological Survey began a 4-year study of the regional aquifer system underlying the Columbia <span class="hlt">Plateau</span>, in central and eastern Washington, northern Oregon, and northwestern Idaho in October 1983, as part of the Regional Aquifer System Analysis program. The study will describe the geohydrology, geochemistry, and quality of water in the Columbia River Basalt Group, the Miocene rocks that underlie 70,000 square miles in three States. Water from the basalts is used for municipal and industrial purposes, and most importantly, for agriculture. As more land is brought under cultivation and surface water becomes totally allocated, the <span class="hlt">groundwater</span> is an increasingly important supply for agriculture and related activities. In addition, the basalts are being considered as a repository site for high-level nuclear wastes. For management agencies to make the best decisions regarding the future development of this area, the regional <span class="hlt">groundwater</span> flow system, its relation to the surfacewater system , and the quality of the water need to be quantified. This report describes the geohydrologic setting, hydrologic problems, objectives, and approach for the region. (USGS)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/910310','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/910310"><span>INTEC <span class="hlt">Groundwater</span> Monitoring Report 2006</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>J. R. Forbes S. L. Ansley M. Leecaster</p> <p>2007-02-01</p> <p>This report summarizes 2006 perched water and <span class="hlt">groundwater</span> monitoring activities at the Idaho Nuclear Technology and Engineering Center (INTEC) located at the Idaho National Laboratory (INL). During 2006, <span class="hlt">groundwater</span> samples were collected from a total of 22 Snake River Plain Aquifer (SRPA) monitoring wells, plus six aquifer wells sampled for the Idaho CERCLA Disposal Facility (ICDF) monitoring program. In addition, perched water samples were collected from 21 perched wells and 19 suction lysimeters. <span class="hlt">Groundwater</span> and perched water samples were analyzed for a suite of radionuclides and inorganic constituents. Laboratory results in this report are compared to drinking water maximum contaminant levels (MCLs). Such comparison is for reference only and it should be noted that the Operable Unit 3-13 Record of Decision does not require that perched water comply with drinking water standards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2011/3106/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2011/3106/"><span><span class="hlt">Groundwater</span> quality of southeastern Wyoming</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Eddy-Miller, Cheryl A.; Blain, Liberty</p> <p>2011-01-01</p> <p><span class="hlt">Groundwater</span> is an important resource for domestic, municipal, stock, and irrigation uses in southeastern Wyoming. Thirty-seven percent of water used in the tri-County area, which includes Laramie, Platte, and Goshen Counties, is from <span class="hlt">groundwater</span>. Most <span class="hlt">groundwater</span> use in the tri-County area is withdrawn from three primary aquifer groups: Quaternary-age unconsolidated-deposit aquifers, Tertiary-age units of the High Plains aquifer system, and Upper Cretaceous bedrock aquifers (Lance Formation and Fox Hills Sandstone). Authors include selected physical properties and chemicals found in water samples, describe sources and importance, and report maximum levels established by the U.S. Environmental Protection Agency. They also show concentration ranges for selected physical properties and chemicals in samples collected from the three primary aquifer groups in the tri-County area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6574025','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6574025"><span>Sanitary landfill <span class="hlt">groundwater</span> monitoring report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1993-02-01</p> <p>The Sanitary Landfill at the Savannah River Site (SRS) is composed of the original 32-acre landfill, plus expansion areas to the north and south that added 16 and 22 acres, respectively, to the facility. The landfill is subject to the requirements of the Resource Conservation and Recovery Act and currently operates under South Carolina Department of Health and Environmental Control (SCDHEC) Domestic Waste Permit 87A. Fifty-seven wells of the LFW series monitor the <span class="hlt">groundwater</span> quality in Steed Pond Aquifer (formerly Aquifer Zone I/IIC[sub 2]) (Water Table) beneath the Sanitary Landfill. These wells are sampled quarterly for certain indicator parameters, inorganics, metals, radionuclides, volatile organics, and other constituents as part of the SRS <span class="hlt">Groundwater</span> Monitoring Program and to comply with the SCDHEC domestic waste permit. This report reviews the 1992 activities of the SRS <span class="hlt">Groundwater</span> Monitoring Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23970694','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23970694"><span><span class="hlt">Groundwater</span> arsenic contamination throughout China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rodríguez-Lado, Luis; Sun, Guifan; Berg, Michael; Zhang, Qiang; Xue, Hanbin; Zheng, Quanmei; Johnson, C Annette</p> <p>2013-08-23</p> <p>Arsenic-contaminated <span class="hlt">groundwater</span> used for drinking in China is a health threat that was first recognized in the 1960s. However, because of the sheer size of the country, millions of <span class="hlt">groundwater</span> wells remain to be tested in order to determine the magnitude of the problem. We developed a statistical risk model that classifies safe and unsafe areas with respect to geogenic arsenic contamination in China, using the threshold of 10 micrograms per liter, the World Health Organization guideline and current Chinese standard for drinking water. We estimate that 19.6 million people are at risk of being affected by the consumption of arsenic-contaminated <span class="hlt">groundwater</span>. Although the results must be confirmed with additional field measurements, our risk model identifies numerous arsenic-affected areas and highlights the potential magnitude of this health threat in China.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999ApJ...523..654R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999ApJ...523..654R"><span>The Spite Lithium <span class="hlt">Plateau</span>: Ultrathin but Postprimordial</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ryan, Sean G.; Norris, John E.; Beers, Timothy C.</p> <p>1999-10-01</p> <p>We have studied 23 very metal-poor field turnoff stars, specifically chosen to enable a precise measurement of the dispersion in the lithium abundance of the Spite Li <span class="hlt">plateau</span>. We concentrated on stars having a narrow range of effective temperature and very low metallicities ([Fe/H]<~-2.5) to reduce the effects of systematic errors and have made particular efforts to minimize random errors. A typical statistical error for our abundances is 0.033 dex (1 σ), which represents a factor of 2 improvement on most previous studies. Our sample does not exhibit a trend with effective temperature, although the temperature range is limited. However, for -3.6<[Fe/H]<-2.3 we do recover a dependence on metallicity at dA(Li)/d[Fe/H]=0.118+/-0.023 (1 σ) dex per dex, almost the same level as discussed previously. Earlier claims for a lack of dependence of A(Li) on abundance are shown to have arisen probably from noisier estimates of effective temperatures and metallicities, which have erased the real trend. The dependence is concordant with theoretical predictions of Galactic chemical evolution (GCE) of Li (even in such metal-poor stars) and with the published level of 6Li in two of the stars of our sample, which we use to infer the GCE 7Li contribution. One of the 23 stars, G186-26, was known already to be strongly Li-depleted. Of the remaining 22 objects, 21 have abundances consistent with an observed spread about the metallicity trend of a mere 0.031 dex (1 σ). Because the formal errors are 0.033 dex, we conclude that the intrinsic spread is effectively zero at the very metal-poor halo turnoff. This is established at much higher precision than previous studies (~0.06-0.08 dex). The essentially zero intrinsic spread leads to the conclusion that either these stars have all changed their surface Li abundances very uniformly, or else they exhibit close to the primordial abundance sought for its cosmological significance. We cannot rule out a uniform depletion mechanism, but economy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9594275','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9594275"><span>Transmission factors of schistosomiasis japonica in the mountainous regions with type of <span class="hlt">plateau</span> canyon and <span class="hlt">plateau</span> basin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, J; Gu, X; Qiu, Z; Hua, Z</p> <p>1997-02-01</p> <p>To provide the scientific basis for formulating the control strategies of schistosomiasis japonica in mountainous regions in China Schistosomiasis Control Programme. We selected Chuanxing Village in Sichuan Province and Zhonghe Village in Yunnan Province as the two pilot areas for an epidemiological investigation according to their geographical and topographical characteristics, i.e. <span class="hlt">plateau</span> canyon and <span class="hlt">plateau</span> basin, respectively. Concentrated-egg hatching method in nylon tissue bag and Kato-Katz technique were used for the survey on prevalence rate and intensity of infection of man and domestic animals. Questionnaires were applied to investigating the infection sources, community behavior and the socioeconomic status. Snail survey and detection of cercaria-infested water bodies were conducted using routine techniques. The results showed that in the endemic areas with <span class="hlt">plateau</span> canyon, the key infection source was cattle. The infection rate in women was higher than that in men. The pattern of water-pollution was wild feces and the pollution source was cattle feces. Snails and infectious snails were distributed over the rice fields and the resident was infected through production activities. In <span class="hlt">plateau</span> basin, the key infection source was human beings. The infection rate in men was higher than that in women. The pattern of water pollution was fertilization. The pollution source was human feces. Snails and infectious snails were distributed over the canals and ditches and the resident was infected through production and daily activities. Therefore, it was suggested that the mountainous endemic areas should be divided into two sub-types, i.e., <span class="hlt">plateau</span> basins and <span class="hlt">plateau</span> canyons. The different control strategies should be formulated in accordance with the environmental situations and socioeconomic factors in the two kinds of endemic areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014WRR....50.2407C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014WRR....50.2407C"><span>Straight thinking about <span class="hlt">groundwater</span> recession</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cuthbert, M. O.</p> <p>2014-03-01</p> <p>While in catchment and hillslope hydrology a more nuanced approach is now taken to streamflow recession analysis, in the context of major aquifers it is commonly still assumed that the <span class="hlt">groundwater</span> head recession rate will take exponential form, an idea originally proposed in the 19th Century. However it is shown here that, in early times, the <span class="hlt">groundwater</span> head recession in a major aquifer should take an almost straight line form with a rate approximately equal to the long-term recharge rate divided by the aquifer storage coefficient. The length of this phase can be estimated from an analytical expression derived in the paper which depends on the aquifer diffusivity, length scale, and the position of the monitoring point. A transitional phase then leads to an exponential phase after some critical time which is independent of the position of the monitoring point. Major aquifers in a state of periodic quasi-steady state are expected to have rates of <span class="hlt">groundwater</span> flux recession which deviate little from the average rate of <span class="hlt">groundwater</span> recharge. Where quasi-exponential <span class="hlt">groundwater</span> declines are observed in nature, their form may be diagnostic of particular types of aquifer properties and/or boundary effects, such as proximity to drainage boundaries, variations in transmissivity with hydraulic head, storage changes due to pumping, nonequilibrium flow at a range of spatial and temporal scales, and variations in specific yield with depth. Recession analysis has applicability to a range of <span class="hlt">groundwater</span> problems and is powerful way of gaining insight into the hydrologic functioning of an aquifer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5663722','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5663722"><span>Viruses in soil and <span class="hlt">groundwater</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vaughn, J.M.; Landry, E.F.</p> <p>1981-01-01</p> <p>Human viruses usually gain access to soil systems through intentional or unintentional discharges of domestic wastewater. Intentional land treatment/disposal systems represent an attractive alternative to surface water discharges, providing both economic and environmental advantages. Major concerns over the possible threat to human health as a result of the large-scale use of such systems are as yet unresolved. One such concern involves the potential for viral contamination of <span class="hlt">groundwater</span> systems which currently supply the drinking-water needs of half the United States population. While no <span class="hlt">groundwater</span>-borne disease outbreaks of viral etiology have as yet been associated with land treatment use, the potential for their occurrence has been clearly indicated by epidemiological studies of outbreaks associated with <span class="hlt">groundwater</span> pollution from unintentional modes of soil application. Epidemiological evidence has been supported by an increasing number of field studies which have demonstrated viral contamination of shallow aquifers resulting from the use of various land treatment modes, such as rapid infiltration/recharge systems. More recent studies have indicated that soil-associated microbial pollution of <span class="hlt">groundwater</span> may be abated by the use of systems management practices based upon an understanding of the physical and chemical factors which influence viral retention in soil including: temperature; pH; moisture, clay and ion content; depth to <span class="hlt">groundwater</span>; infiltration rate; and soil continuity. The proper manipulation of these principles in the operation of land treatment schemes which utilize high-quality wastewater effluents should provide the means for significantly diminishing the likelihood of viral movement to <span class="hlt">groundwater</span> systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4178D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4178D"><span>Food supply reliance on <span class="hlt">groundwater</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dalin, Carole; Puma, Michael; Wada, Yoshihide; Kastner, Thomas</p> <p>2016-04-01</p> <p>Water resources, essential to sustain human life, livelihoods and ecosystems, are under increasing pressure from population growth, socio-economic development and global climate change. As the largest freshwater resource on Earth, <span class="hlt">groundwater</span> is key for human development and food security. Yet, excessive abstraction of <span class="hlt">groundwater</span> for irrigation, driven by an increasing demand for food in recent decades, is leading to fast exhaustion of <span class="hlt">groundwater</span> reserves in major agricultural areas of the world. Some of the highest depletion rates are observed in Pakistan, India, California Central Valley and the North China Plain aquifers. In addition, the growing economy and population of several countries, such as India and China, makes prospects of future available water and food worrisome. In this context, it is becoming particularly challenging to sustainably feed the world population, without exhausting our water resources. Besides, food production and consumption across the globe have become increasingly interconnected, with many areas' agricultural production destined to remote consumers. In this globalisation era, trade is crucial to the world's food system. As a transfer of water-intensive goods, across regions with varying levels of water productivity, food trade can save significant volumes of water resources globally. This situation makes it essential to address the issue of <span class="hlt">groundwater</span> overuse for global food supply, accounting for international food trade. To do so, we quantify the current, global use of non-renewable <span class="hlt">groundwater</span> for major crops, accounting for various water productivity and trade flows. This will highlight areas requiring quickest attention, exposing major exporters and importers of non-renewable <span class="hlt">groundwater</span>, and thus help explore solutions to improve the sustainability of global food supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2014/3096/pdf/fs2014-3096.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2014/3096/pdf/fs2014-3096.pdf"><span><span class="hlt">Groundwater</span> quality in the Sierra Nevada, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fram, Miranda S.; Belitz, Kenneth</p> <p>2014-01-01</p> <p><span class="hlt">Groundwater</span> provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the <span class="hlt">Groundwater</span> Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project (PBP) of the GAMA Program provides a comprehensive assessment of the State’s <span class="hlt">groundwater</span> quality and increases public access to <span class="hlt">groundwater</span>-quality information. The Sierra Nevada Regional study unit constitutes one of the study units being evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2014/3031/pdf/fs2014-3031.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2014/3031/pdf/fs2014-3031.pdf"><span><span class="hlt">Groundwater</span> quality in the Klamath Mountains, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bennett, George L.; Fram, Miranda S.</p> <p>2014-01-01</p> <p><span class="hlt">Groundwater</span> provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the <span class="hlt">Groundwater</span> Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s <span class="hlt">groundwater</span> quality and increases public access to <span class="hlt">groundwater</span>-quality information. The Klamath Mountains constitute one of the study units being evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017825','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017825"><span><span class="hlt">Groundwater</span> and Terrestrial Water Storage</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.</p> <p>2014-01-01</p> <p>Terrestrial water storage (TWS) comprises <span class="hlt">groundwater</span>, soil moisture, surface water, snow,and ice. <span class="hlt">Groundwater</span> typically varies more slowly than the other TWS components because itis not in direct contact with the atmosphere, but often it has a larger range of variability onmultiannual timescales (Rodell and Famiglietti, 2001; Alley et al., 2002). In situ groundwaterdata are only archived and made available by a few countries. However, monthly TWSvariations observed by the Gravity Recovery and Climate Experiment (GRACE; Tapley et al.,2004) satellite mission, which launched in 2002, are a reasonable proxy for unconfinedgroundwater at climatic scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20638540','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20638540"><span>Complexed iron removal from <span class="hlt">groundwater</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Munter, R.; Ojaste, H.; Sutt, J.</p> <p>2005-07-01</p> <p>The paper demonstrates an intensive work carried out and results obtained on the pilot plant of the City of Kogalym Water Treatment Station (Tjumen, Siberia, Russian Federation) to elaborate on a contemporary nonreagent treatment technology for the local iron-rich <span class="hlt">groundwater</span>. Several filter materials (Birm, Pyrolox, hydroanthracite, Everzit, granulated activated carbon) and chemical oxidants (ozone, chlorine, hydrogen peroxide, oxygen, and potassium permanganate) were tested to solve the problem with complexed iron removal from <span class="hlt">groundwater</span>. The final elaborated technology consists of raw water intensive aeration in the gas-degas treatment unit followed by sequential filtration through hydroanthracite and the special anthracite Everzit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/circ/circ1144/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/circ/circ1144/"><span>Water quality in the central Columbia <span class="hlt">Plateau</span>, Washington and Idaho, 1992-95</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Williamson, Alex K.; Munn, Mark D.; Ryker, Sarah J.; Wagner, Richard J.; Ebbert, James C.; Vanderpool, Ann M.</p> <p>1998-01-01</p> <p>Water quality in the Central Columbia <span class="hlt">Plateau</span> of eastern Washington and western Idaho has been adversely affected by agriculture, especially in irrigated areas, according to the results of a five-year investigation by the U. S. Geological Survey (USGS). Some improvements, however, are noticeable, such as less sediment being washed into streams. These improvements may be the result of increased use of best management practices (BMPs) by area farmers. Areas with intensive fertilizer use and irrigation, such as in the Columbia Basin Irrigation Project (CBIP), showed the greatest impacts on <span class="hlt">ground-water</span> quality. (The CBIP includes parts of Franklin, Grant, and Adams counties in eastern Washington.) <Shallow wells, generally those less than 150 feet deep, are the most susceptible to contamination, the USGS report says. A reassuring aspect of this finding, however, is that many public water supplies draw from wells at greater depths and are less susceptible to contamination from agricultural practices. From the standpoint of human health, we were most concerned about checking for nitrate and pesticides in drinking water,' said Sandy Williamson, USGS hydrologist and chief of the study. 'We found nitrate levels exceeding the maximum contaminant level in about 20 percent of all wells.' (A maximum contaminant level-or MCL-is a drinking water regulatory standard that is set by the U.S. Environmental Protection Agency.) 'The story on pesticides is a mixed bag,' Williamson said. 'We found at least one pesticide in nearly half of the drinking water wells sampled, but pesticide levels were only a very small fraction of their MCLs.' As a cautionary note, however, Williamson said that about half of the pesticides detected in Central Columbia <span class="hlt">Plateau</span> wells do not have MCLs established. A lack of information makes it difficult to assess the significance of finding pesticides in drinking water. 'As scientists, we don't know enough yet about what happens when these pesticides are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H21K..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H21K..05H"><span>Quantifying <span class="hlt">Groundwater</span> Model Uncertainty</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hill, M. C.; Poeter, E.; Foglia, L.</p> <p>2007-12-01</p> <p><span class="hlt">Groundwater</span> models are characterized by the (a) processes simulated, (b) boundary conditions, (c) initial conditions, (d) method of solving the equation, (e) parameterization, and (f) parameter values. Models are related to the system of concern using data, some of which form the basis of observations used most directly, through objective functions, to estimate parameter values. Here we consider situations in which parameter values are determined by minimizing an objective function. Other methods of model development are not considered because their ad hoc nature generally prohibits clear quantification of uncertainty. Quantifying prediction uncertainty ideally includes contributions from (a) to (f). The parameter values of (f) tend to be continuous with respect to both the simulated equivalents of the observations and the predictions, while many aspects of (a) through (e) are discrete. This fundamental difference means that there are options for evaluating the uncertainty related to parameter values that generally do not exist for other aspects of a model. While the methods available for (a) to (e) can be used for the parameter values (f), the inferential methods uniquely available for (f) generally are less computationally intensive and often can be used to considerable advantage. However, inferential approaches require calculation of sensitivities. Whether the numerical accuracy and stability of the model solution required for accurate sensitivities is more broadly important to other model uses is an issue that needs to be addressed. Alternative global methods can require 100 or even 1,000 times the number of runs needed by inferential methods, though methods of reducing the number of needed runs are being developed and tested. Here we present three approaches for quantifying model uncertainty and investigate their strengths and weaknesses. (1) Represent more aspects as parameters so that the computationally efficient methods can be broadly applied. This</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70033884','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70033884"><span>Calibration of models using <span class="hlt">groundwater</span> age</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sanford, W.</p> <p>2011-01-01</p> <p>There have been substantial efforts recently by geochemists to determine the age of <span class="hlt">groundwater</span> (time since water entered the system) and its uncertainty, and by hydrologists to use these data to help calibrate <span class="hlt">groundwater</span> models. This essay discusses the calibration of models using <span class="hlt">groundwater</span> age, with conclusions that emphasize what is practical given current limitations rather than theoretical possibilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=groundwater&pg=5&id=ED307155','ERIC'); return false;" href="https://eric.ed.gov/?q=groundwater&pg=5&id=ED307155"><span><span class="hlt">Groundwater</span>: Illinois' Buried Treasure. Education Activity Guide.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Environmental Education Association of Illinois, Chicago.</p> <p></p> <p><span class="hlt">Groundwater</span> is an extremely valuable resource that many feel has been too long neglected and taken for granted. There is growing recognition in Illinois and throughout the United States that comprehensive <span class="hlt">groundwater</span> protection measures are vital. Illinois embarked on a course in protecting <span class="hlt">groundwater</span> resources with the passage of the Illinois…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=contamination+AND+water&pg=7&id=ED307155','ERIC'); return false;" href="http://eric.ed.gov/?q=contamination+AND+water&pg=7&id=ED307155"><span><span class="hlt">Groundwater</span>: Illinois' Buried Treasure. Education Activity Guide.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Environmental Education Association of Illinois, Chicago.</p> <p></p> <p><span class="hlt">Groundwater</span> is an extremely valuable resource that many feel has been too long neglected and taken for granted. There is growing recognition in Illinois and throughout the United States that comprehensive <span class="hlt">groundwater</span> protection measures are vital. Illinois embarked on a course in protecting <span class="hlt">groundwater</span> resources with the passage of the Illinois…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=128725&keyword=530&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=128725&keyword=530&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>REMOVAL OF ORGANIC CONTAMINANTS FROM <span class="hlt">GROUNDWATER</span>.</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>More are than lOO million Americans depend on <span class="hlt">groundwater</span> as a source of drinking water. hree quarters of U.S. cities get their water supplies totally or in part from <span class="hlt">groundwater</span> and one-third of the largest cities rely on <span class="hlt">groundwater</span> for at least part of their potable water supp...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H31C1383H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H31C1383H"><span>Calibrating Treasure Valley <span class="hlt">Groundwater</span> Model using MODFLOW</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernandez, J.; Tan, K.</p> <p>2016-12-01</p> <p>In Idaho, <span class="hlt">groundwater</span> plays an especially important role in the state. According to the Idaho Department of Environmental Quality, <span class="hlt">groundwater</span> supplies 95% of the state's drinking water (2011). The USGS estimates that Idaho withdraws 117 million cubic meters (95,000 acre-feet) per year from <span class="hlt">groundwater</span> sources for domestic usage which includes drinking water. The same report from the USGS also estimates that Idaho withdraws 5,140 million cubic meters (4,170,000 acre-feet) per year from <span class="hlt">groundwater</span> sources for irrigation usage. Quantifying and managing that resource and estimating <span class="hlt">groundwater</span> levels in the future is important for a variety of socio-economic reasons. As the population within the Treasure Valley continues to grow, the demand of clean usable <span class="hlt">groundwater</span> increases. The objective of this study was to develop and calibrate a <span class="hlt">groundwater</span> model with the purpose of understanding short- and long-term effects of existing and alternative land use scenarios on <span class="hlt">groundwater</span> changes. Hydrologic simulations were done using the MODFLOW-2000 model. The model was calibrated for predevelopment period by reproducing and comparing <span class="hlt">groundwater</span> levels of the years before 1925 using steady state boundary conditions representing no change in the land use. Depending on the reliability of the <span class="hlt">groundwater</span> source, the economic growth of the area can be constrained or allowed to flourish. Mismanagement of the <span class="hlt">groundwater</span> source can impact its sustainability, quality and could hamper development by increasing operation and maintenance costs. Proper water management is critical because <span class="hlt">groundwater</span> is such a limited resource.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5492860','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5492860"><span><span class="hlt">Groundwater</span> and geothermal: urban district heating applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mounts, R.; Frazier, A.; Wood, E.; Pyles, O.</p> <p>1982-01-01</p> <p>This report describes how several cities use <span class="hlt">groundwater</span> and geothermal energy in district heating systems. It begins with <span class="hlt">groundwater</span>, introducing the basic technology and techniques of development, and describing two case studies of cities with <span class="hlt">groundwater</span>-based district heating systems. The second half of the report consists of three case studies of cities with district heating systems using higher temperature geothermal resources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/remedytech/groundwater-remedies-selected-superfund-sites','PESTICIDES'); return false;" href="https://www.epa.gov/remedytech/groundwater-remedies-selected-superfund-sites"><span><span class="hlt">Groundwater</span> Remedies Selected at Superfund Sites</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p><span class="hlt">Groundwater</span> remediation continues to be a priority for the U.S. Environmental Protection Agency (EPA), and remedies that have been specified in RODs for <span class="hlt">groundwater</span> remediation include treatment (including <span class="hlt">groundwater</span> pump and treat [P&T] and in situ treat</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2011/3139/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2011/3139/"><span><span class="hlt">Groundwater</span> quality in the San Fernando--San Gabriel <span class="hlt">groundwater</span> basins, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kulongoski, Justin T.; Belitz, Kenneth</p> <p>2012-01-01</p> <p><span class="hlt">Groundwater</span> provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the <span class="hlt">Groundwater</span> Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's <span class="hlt">groundwater</span> quality and increases public access to <span class="hlt">groundwater</span>-quality information. The San Fernando and San Gabriel <span class="hlt">groundwater</span> basins constitute one of the study units being evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9913M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9913M"><span>Living on the edge: The oxygen isotope record of Eocene Basins at the margin of the Cenozoic North American <span class="hlt">plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Methner, Katharina; Mulch, Andreas; Chamberlain, Page</p> <p>2013-04-01</p> <p> the site or within close proximity. However, paleofloral data from e.g. the Chumstick basin to the E of the modern Cascades indicate moderate elevations and montane rain forest conditions during a warm (MAT = 14°C) and rather wet, seasonal Eocene climate. Therefore, we tentatively suggest that these basins were at moderate elevations, allowing dense vegetation and seasonal drying of soils, but were fed by isotopically highly 18O-depleted runoff and <span class="hlt">groundwater</span> from elevated catchment areas in the vicinity of the basins. This requires Eocene highlands of the North American Cordillera to be laterally extensive already during the Eocene and places important constraints on the impact of the <span class="hlt">plateau</span> region on atmospheric circulation patterns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://sbsc.wr.usgs.gov/cprs/news_info/meetings/biennial/proceedings/1993/1993.asp','USGSPUBS'); return false;" href="http://sbsc.wr.usgs.gov/cprs/news_info/meetings/biennial/proceedings/1993/1993.asp"><span>Proceedings of the second biennial conference on research in Colorado <span class="hlt">Plateau</span> National Parks</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>van Riper, Charles</p> <p>1995-01-01</p> <p>On 25-28 October 1993 in Flagstaff, Arizona, the National Biological Service Colorado <span class="hlt">Plateau</span> Research Station (formerly National Park Service Cooperative Park Studies Unit) and Northern Arizona University hosted the Second Biennial Conference of Research on the Colorado <span class="hlt">Plateau</span>. The conference theme focused on research, inventory, and monitoring on the federal, state, and private lands in the Colorado <span class="hlt">Plateau</span> biogeographic province.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol17/pdf/CFR-2010-title40-vol17-sec81-162.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol17/pdf/CFR-2010-title40-vol17-sec81-162.pdf"><span>40 CFR 81.162 - Northeast <span class="hlt">Plateau</span> Intrastate Air Quality Control Region.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... Air Quality Control Regions § 81.162 Northeast <span class="hlt">Plateau</span> Intrastate Air Quality Control Region. The Northeast <span class="hlt">Plateau</span> Intrastate Air Quality Control Region (California) consists of the territorial area... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northeast <span class="hlt">Plateau</span> Intrastate...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC21B1077Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC21B1077Q"><span>Sensitivity of LUCC on the Surface Temperature of Tibetan <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qi, W.; Deng, X.; Wu, F.</p> <p>2016-12-01</p> <p>The Tibetan <span class="hlt">Plateau</span> has an important effect on the ecological security in China, even in Asia, which makes the region become the hot spot in recently research. Under the joint influence of global change and human activities, ecosystem destabilizing and the increasing pressure on resources and environment emerge on the Tibetan <span class="hlt">Plateau</span>, but the potential spatial sensitivity of land use and land cover changes(LUCC) on surface temperature has not been quantitatively analyzed. This study analyzed the mainly types of LUCC, urbanization, grassland degradation, deforestation on Tibetan <span class="hlt">Plateau</span> along with Representative Concentration Pathways (RCPs) of the Intergovernmental Panel on Climate Change (IPCC). The LUCC in recent decades was first quantitatively analyzed in this study to give the basic fact with a significant increase in temperatures, reduced precipitation and increased evaporation. This study focused on the future spatio-temporal heterogeneity of the temperature and precipitation. Finally, the influencing factors with LUCC on Tibetan <span class="hlt">Plateau</span> were simulated with the Weather Research and Forecasting (WRF) model, and the sensitivity of different land use types was spatially analyzed with Singular Value Decomposition (SVD). The results indicate that the large-area alpine grassland plays a more important role in alleviating global warming than other vegetation types do. The changes of the landscape structure resulting from the urban expansion play a significant role in intensifying regional temperature increase. In addition, the effects of LUCC on monthly average temperature change would vary from month to month with obviously spatial heterogeneity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/970658','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/970658"><span>Deep mantle forces and the uplift of the Colorado <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moucha, R; Forte, A M; Rowley, D B; Mitrovica, J X; Simmons, N A; Grand, S P</p> <p>2009-06-23</p> <p>Since the advent of plate tectonics, it has been speculated that the northern extension of the East Pacific Rise, specifically its mantle source, has been over-ridden by the North American Plate in the last 30 Myrs. Consequently, it has also been postulated that the opening of the Gulf of California, the extension in the Basin and Range province, and the uplift of the Colorado <span class="hlt">Plateau</span> are the resulting continental expressions of the over-ridden mantle source of the East Pacific Rise. However, only qualitative models based solely on surface observations and heuristic, simplified conceptions of mantle convection have been used in support or against this hypothesis. We introduce a quantitative model of mantle convection that reconstructs the detailed motion of a warm mantle upwelling over the last 30 Myrs and its relative advance towards the interior of the southwestern USA. The onset and evolution of the crustal uplift in the central Basin and Range province and the Colorado <span class="hlt">Plateau</span> is determined by tracking the topographic swell due to this mantle upwelling through time. We show that (1) the extension and magmatism in the central Basin and Range province between 25 and 10 Ma coincides with the reconstructed past position of this focused upwelling, and (2) the southwestern portion of the Colorado <span class="hlt">Plateau</span> experienced significant uplift between 10 Ma and 5 Ma that progressed towards the northeastern portion of the <span class="hlt">plateau</span>. These uplift estimates are consistent with a young, ca. 6 Ma, Grand Canyon model and the recent commencement of mafic magmatism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=279439','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=279439"><span>Threshold friction velocity of soils within the Columbia <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Wind erosion only occurs when the friction velocity exceeds the threshold friction velocity (TFV) of the surface. The TFV of loessial soils commonly found across the Columbia <span class="hlt">Plateau</span> region of the U.S. Pacific Northwest is virtually unknown even though these soils are highly erodible and a source of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=personal+AND+value+AND+work&pg=5&id=EJ817353','ERIC'); return false;" href="https://eric.ed.gov/?q=personal+AND+value+AND+work&pg=5&id=EJ817353"><span>Factors Associated with Job Content <span class="hlt">Plateauing</span> among Older Workers</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Armstrong-Stassen, Marjorie</p> <p>2008-01-01</p> <p>Purpose: The purpose of this paper is to identify personal and work environment factors associated with the experience of job content <span class="hlt">plateauing</span> among older workers. Design/methodology/approach: Two cross-sectional studies, each including two samples, were conducted. In each study, one sample consisted of a diverse group of older workers and the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=314455','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=314455"><span>Nitrogen loss from windblown agricultural soils in the Columbia <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Wind erosion of agricultural soils can degrade both air quality and soil productivity in the Columbia <span class="hlt">Plateau</span> of the Pacific Northwest United States. Soils in the region contain fine particles that, when suspended, are highly susceptible to long range transport in the atmosphere. Nitrogen (N) associ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/38178','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/38178"><span>Shade tolerance of selected afforestation species on Loess <span class="hlt">Plateau</span>, China</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Naijiang Wang; Yong Wang; Callie J. Schweitzer</p> <p>2011-01-01</p> <p>To select tree and vegetation species for afforestation on Loess <span class="hlt">Plateau</span> of China, we tested the shade tolerance of nine tree and one vine species. We planted 3-year-old seedlings in the greenhouse of the Seedling Nursery at Northwest Agriculture and Forest University in China.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25011940','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25011940"><span>Mapping risk of plague in Qinghai-Tibetan <span class="hlt">Plateau</span>, China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun</p> <p>2014-07-10</p> <p>Qinghai-Tibetan <span class="hlt">Plateau</span> of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan <span class="hlt">Plateau</span>. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the <span class="hlt">Plateau</span>. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan <span class="hlt">Plateau</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4227279','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4227279"><span>Mapping risk of plague in Qinghai-Tibetan <span class="hlt">Plateau</span>, China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background Qinghai-Tibetan <span class="hlt">Plateau</span> of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Methods Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. Results We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan <span class="hlt">Plateau</span>. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the <span class="hlt">Plateau</span>. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. Conclusions This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan <span class="hlt">Plateau</span>. PMID:25011940</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910569Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910569Z"><span>Excessive afforestation and soil drying on China's Loess <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Shulei; Yang, Dawen</p> <p>2017-04-01</p> <p>Afforestation and deforestation are human disturbances to vegetation, which have profound impacts on regional eco-hydrological processes, the water and carbon cycles, and consequently, ecosystem sustainability. Since 1999, large scale revegetation has been carried out across China's Loess <span class="hlt">Plateau</span> following the "Grain-to-Green Program" implemented by the Chinese government. This revegetation, particularly with forest, has caused negative eco-hydrological consequences, including streamflow decline and soil drying. Here, we have used "ecosystem optimality theory" and satellite observations, to assess the water balance under the climate-defined optimal and actual vegetation cover during 1982-2010 and its responses to future climate change (2011-2050) over the Loess <span class="hlt">Plateau</span>. Results show that the current vegetation cover (0.48 on average) has already exceeded the climate-defined optimal cover (0.43 on average) in the most recent decade, especially in the middle-to-east Loess <span class="hlt">Plateau</span>, indicating that it is the widespread over-planting, which is primarily responsible for soil drying in the area. In addition, both the optimal vegetation cover and soil moisture tend to decrease under future climate scenarios. Our findings suggest that further revegetation on the Loess <span class="hlt">Plateau</span> should be applied with caution. To maintain a sustainable eco-hydrological environment in the region, a revegetation threshold should be urgently set, to limit future planting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/21717','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/21717"><span>Black cherry site index curves for the Allegheny <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>L.R. Auchmoody; C.O. Rexrode; C.O. Rexrode</p> <p>1984-01-01</p> <p>Black cherry site index curves were developed for the Allegheny <span class="hlt">Plateau</span> in northwestern Pennsylvania. They show for this region that height rises less sharply prior to the index age and is maintained for a longer period thereafter than described by existing curves. An equation to predict site index from height and age is furnished to allow the use of these curves in...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26674690','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26674690"><span>Levoglucosan and phenols in Antarctic marine, coastal and <span class="hlt">plateau</span> aerosols.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zangrando, Roberta; Barbaro, Elena; Vecchiato, Marco; Kehrwald, Natalie M; Barbante, Carlo; Gambaro, Andrea</p> <p>2016-02-15</p> <p>Due to its isolated location, Antarctica is a natural laboratory for studying atmospheric aerosols and pollution in remote areas. Here, we determined levoglucosan and phenolic compounds (PCs) at diverse Antarctic sites: on the <span class="hlt">plateau</span>, a coastal station and during an oceanographic cruise. Levoglucosan and PCs reached the Antarctic <span class="hlt">plateau</span> where they were observed in accumulation mode aerosols (with median levoglucosan concentrations of 6.4 pg m(-3) and 4.1 pg m(-3), and median PC concentrations of 15.0 pg m(-3) and 7.3 pg m(-3)). Aged aerosols arrived at the coastal site through katabatic circulation with the majority of the levoglucosan mass distributed on larger particulates (24.8 pg m(-3)), while PCs were present in fine particles (34.0 pg m(-3)). The low levoglucosan/PC ratios in Antarctic aerosols suggest that biomass burning aerosols only had regional, rather than local, sources. General acid/aldehyde ratios were lower at the coastal site than on the <span class="hlt">plateau</span>. Levoglucosan and PCs determined during the oceanographic cruise were 37.6 pg m(-3) and 58.5 pg m(-3) respectively. Unlike levoglucosan, which can only be produced by biomass burning, PCs have both biomass burning and other sources. Our comparisons of these two types of compounds across a range of Antarctic marine, coastal, and <span class="hlt">plateau</span> sites demonstrate that local marine sources dominate Antarctic PC concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16260075','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16260075"><span>Wear patterns on tibial <span class="hlt">plateau</span> from varus osteoarthritic knees.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moschella, D; Blasi, A; Leardini, A; Ensini, A; Catani, F</p> <p>2006-02-01</p> <p>The knowledge of cartilage wear patterns at the medial tibial <span class="hlt">plateau</span> is important to understand the main causes of arthritis in varus knees. The most important factors influencing knee arthritis in fact seem to be the severity of the degenerative changes determined by the lower limb mechanical axis and the abnormal knee joint kinematics which frequently results from dysfunction of the anterior cruciate ligament. We studied the wear patterns of cartilage damage in 70 medial tibial plateaus resected at operation during total knee arthroplasty indicated for varus osteoarthritic knee. Anterior cruciate ligament and medial meniscus integrity was assessed intra-operatively. Calibrated digital images were used to measure the wear patterns with a standard software tool. The medial compartment of the tibial <span class="hlt">plateau</span> was divided into six zones, and the amount of cartilage and bone destruction in each zone was classified into two grades. The wear pattern was found to be highly dependent upon knee varus deformity (Mann Whitney P<0.001) and anterior cruciate ligament integrity (Friedman P<0.0005). Anterior cruciate ligament was found intact in 35.7% of the cases. Wear patterns on intact anterior cruciate ligament knees occurred in the central to medial aspect of the tibial <span class="hlt">plateau</span>. Anterior cruciate ligament deficient knees had significantly larger wear patterns anteriorly and posteriorly in the most medial region of the medial <span class="hlt">plateau</span>. These observations suggest altered joint mechanics exist in anterior cruciate ligament deficient varus knees, which would worsen cartilage degeneration and osteoarthritis progression.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJEaS.104.2253I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJEaS.104.2253I"><span>Structural model of the Balkassar area, Potwar <span class="hlt">Plateau</span>, Pakistan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iqbal, Shahid; Akhter, Gulraiz; Bibi, Sehrish</p> <p>2015-11-01</p> <p>Balkassar is an important hydrocarbon producing area of the Potwar <span class="hlt">Plateau</span>, Pakistan. Two-dimensional seismic reflection data of the area revealed tectonically controlled, distinct episodes of (1) normal faulting in the basement followed by (2) reverse faulting in the cover sequence. Himalayan orogeny and associated diapirism of the Precambrian Salt Range Formation have produced many salt-cored anticlines in the Potwar <span class="hlt">Plateau</span>, and one such salt-cored anticline is present in the Balkassar. This anticline has NE-SW-oriented axis, and both the SE and NW limbs are bounded by reverse faults. The basement normal faults indicate Jurassic rifting and splitting of Pangaea. We interpret reverse faults with dip angles of about 60°-75° in the cover sequence, having both hinterland and foreland vergence. Both NW- and SE-dipping faults are present in contrast to the only southward-directed thrusts of previous models. Duplexes and triangle zones, which are common in the northern part of the Potwar <span class="hlt">Plateau</span>, are not developed in the Balkassar area due to comparatively less crustal shortening in the area. The present interpretation can help in understanding the complex structures in other parts of the Potwar <span class="hlt">Plateau</span> for hydrocarbons exploration and also in deformed foreland basins worldwide that display similar characteristics but are considered to be dominated by low-angle thrust tectonics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=self+AND+efficacy+AND+employers&pg=2&id=EJ817353','ERIC'); return false;" href="http://eric.ed.gov/?q=self+AND+efficacy+AND+employers&pg=2&id=EJ817353"><span>Factors Associated with Job Content <span class="hlt">Plateauing</span> among Older Workers</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Armstrong-Stassen, Marjorie</p> <p>2008-01-01</p> <p>Purpose: The purpose of this paper is to identify personal and work environment factors associated with the experience of job content <span class="hlt">plateauing</span> among older workers. Design/methodology/approach: Two cross-sectional studies, each including two samples, were conducted. In each study, one sample consisted of a diverse group of older workers and the…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T13C4677X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T13C4677X"><span>Stratified crustal shortening under the Longmenshan thrust belt, Tibetan <span class="hlt">plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, X.</p> <p>2014-12-01</p> <p>Stratified crustal shortening under the Longmenshan thrust belt, Tibetan <span class="hlt">plateau</span> Xiwei Xu1&2, Baojin Liu3, John H. Shaw2, Guihua Yu11. Key Lab of Active Tectonics & Volcano, Institute of Geology, CEA, Beijing 100029, China 2. Department of Earth & Planetary Science, Harvard University, Cambridge, MA 02138, USA 3. Geophysical Prospecting Center, CEA, Zhengzhou 450002, China Crustal velocity structure and new seismic reflection profiling across the foothills of the Longmen Shan and Sichuan Basin reveals a distinct pattern of crustal structure under Longmenshan thrust belt: brittle thrust faults with multiple detachments in the upper crust that are localized above, but decoupled from, a steep contact (FL) in the lower crust and upper mantle across which the lower crust thickens abruptly. Then two models are presented: 1) Model showing breakthrough thrusting of the <span class="hlt">plateau</span> crust over the Sichuan Basin above the basal detachment (FD2); 2) Model showing indentation of a strong structural wedge of the Yangtze Craton into the weak <span class="hlt">plateau</span>, but no sliding on the contact FL or sliding on the contact FL. This observation provides insights that help us to understand the mechanisms of crustal shortening, thickening, and uplift of the Tibetan <span class="hlt">Plateau</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.uapress.arizona.edu/Books/bid2255.htm','USGSPUBS'); return false;" href="http://www.uapress.arizona.edu/Books/bid2255.htm"><span>The Colorado <span class="hlt">Plateau</span> IV: shaping conservation through science and management</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wakeling, Brian F.; Sisk, Thomas D.; van Riper, Charles</p> <p>2010-01-01</p> <p>Roughly centered on the Four Corners region of the southwestern United States, the Colorado <span class="hlt">Plateau</span> covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the <span class="hlt">plateau</span> are dramatically varied, from desert to alpine conditions. This book focuses on the integration of science and resource management issues in this unique and highly varied environment. Broken into three subsections, this volume addresses conservation biology, biophysical resources, and inventory and monitoring concerns. The chapters range in content, addressing conservation issues–past, present, and future–on the Colorado <span class="hlt">Plateau</span>, measurement of human impacts on resources, grazing and wildland-urban interfaces, and tools and methods for monitoring habitats and species. An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado <span class="hlt">Plateau</span>, as well as scientists interested in methods and tools for land and resource management throughout the West.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/tei/0588/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/tei/0588/report.pdf"><span>Behavior of Colorado <span class="hlt">Plateau</span> uranium minerals during oxidation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Garrels, Robert Minard; Christ, C.L.</p> <p>1956-01-01</p> <p>Uranium occurs as U(VI) and U(IV) in minerals of the Colorado <span class="hlt">Plateau</span> ores. The number of species containing U(VI) is large, but only two U(IV) minerals are known from the <span class="hlt">Plateau</span>: uraninite, and oxide, and coffinite, a hydroxy-silicate. These oxidize to yield U(VI) before reacting significantly with other mineral constituents. Crystal-structure analysis has shown that U(VI) invariable occurs as uranyl ion, UO2+2. Uranyl ion may form complex carbonate or sulfate ions with resulting soluble compounds, but only in the absence of quinquevalent vanadium, arsenic, or phosphorous. In the presence of these elements in the +5 valence state, the uranyl ion is fixed in insoluble layer compounds formed by union of uranyl ion with orthovanadate, orthophosphate, or orthoarsenate. Under favorable conditions UO2+2 may react to form the relatively insoluble rutherfordine, UO2CO3, or hydrated uranyl hydroxides. These are rarely found on the Colorado <span class="hlt">Plateau</span> as opposed to their excellent development in other uraniferous areas, a condition which is apparently related to the semiarid climate and low water table of the <span class="hlt">Plateau</span>. Uranium may also be fixed as uranyl silicate, but little is known about minerals of this kind. In the present study emphasis has been placed on a detailing of the chemical and crystal structural changes which occur in the oxidation paragenetic sequence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840025613','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840025613"><span>Second <span class="hlt">Plateau</span> Voltage in Nickel-cadmium Cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vasanth, K. L.</p> <p>1984-01-01</p> <p>Sealed nickel cadmium cells having large number of cycles on them are discharged using Hg/HgO reference electrode. The negative electrode exhibits the second <span class="hlt">plateau</span>. A SEM of negative plates of such cells show a number of large crystals of cadmium hydroxide. The large crystals on the negative plates disappear after continuous overcharging in flooded cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5161424','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5161424"><span>Basin history in fracture zone setting: Falkland <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lorenzo, J.M.</p> <p>1986-05-01</p> <p>Although virtually all passive continental margins are intersected by fracture zones, models describing margin evolution seldom include the tectonic effects of the latter. On the Falkland <span class="hlt">Plateau</span>, whose northern margin is dominated by a large fracture zone, up to 5 km of terrigenous, transitional, and hemipelagic sediments have been deposited since the Middle Jurassic, largely under the control of a northern basement high. This high marks the Falkland fracture zone, formed during the opening of the South Atlantic in the Early Cretaceous. The Falkland <span class="hlt">Plateau</span> lies submerged in 2500 m of water and can be physiographically subdivided into (1) the Maurice Ewing Bank, a broad, triangular, shallow feature on its eastern extremity, (2) a boundary steep Falkland Escarpment in the north, (3) a southern Falkland Trough, and (4) a central saddle. Using well data (DSDP sites 511, 330, and 327) and extensive single-channel and regional multichannel seismic data, a detailed seismic stratigraphy has been developed for the Falkland <span class="hlt">Plateau</span>. Results show four widespread depositional sequences dipping southward over both oceanic (in the west) and continental basement (in the east). Late Jurassic sapropelic black shales overlain by claystones thin and possibly crop out along the northern margin of the <span class="hlt">plateau</span>. Good control of structure has allowed recalculation of geophysical models, thus confirming three-dimensional basin geometry estimated seismically. Basin evolution is intimately related to the plate-tectonic setting and history, and may provide additional constraints on the breakup of Gondwanaland.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/42239','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/42239"><span>Discovery of cryptic Armillaria solidipes genotypes within the Colorado <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>J. W. Hanna; N. B. Klopfenstein; M. -S. Kim; S. M. Ashiglar; A. L. Ross-Davis; G. I. McDonald</p> <p>2012-01-01</p> <p>Armillaria solidipes (= A. ostoyae) is a root-disease pathogen that causes severe losses in growth and productivity of forest trees throughout the Northern Hemisphere. This species is genetically diverse with variable disease activities across different regions of the world. In North America, A. solidipes in the Colorado <span class="hlt">Plateau</span> exists in drier habitats and causes more...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JAESc..53....3P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JAESc..53....3P"><span>Tectonic evolution of the Qinghai-Tibet <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pan, Guitang; Wang, Liquan; Li, Rongshe; Yuan, Sihua; Ji, Wenhua; Yin, Fuguang; Zhang, Wanping; Wang, Baodi</p> <p>2012-07-01</p> <p>The Qinghai-Tibet <span class="hlt">Plateau</span>, composed of several continental slivers within the eastern Tethyan domain, is one of the pivotal sites to examine to better understand the theory of plate tectonics and the orogenic evolution on Earth. This <span class="hlt">plateau</span> is generally inferred to be a collage of several continental blocks that rifted from Gondwanaland and subsequently accreted to the Asian continent. However, recent recognition of over twenty ophiolite mélange zones and their associated island arcs indicates that the traditional model of tectonic evolution requires revision. Based on 177 recently finished 1:250,000 scale geological maps and related studies, we summarize the main tectonic context of the Qinghai-Tibet <span class="hlt">Plateau</span> and propose a new integrated model to account for the new findings. The complex orogen of the immense Qinghai-Tibet <span class="hlt">Plateau</span>, consisting of multiple island arc-basin systems that developed at different stages while surrounded by the North China, Yangtze, Tarim, and Indian plates, is emphasized. The entire orogen, surrounded by suture zones that mark the locations of oceanic closure, is investigated by examining (I) the first-order tectonic units and ophiolitic mélanges (including arc-arc/continent collision zones) and (II) their internally enclosed blocks as the second-order tectonic units. Therefore, the Qinghai-Tibet <span class="hlt">Plateau</span> is divided into three major orogenic systems, namely, from northeast to southwest, the Early Paleozoic Qinling-Qilianshan-Kunlunshan (Qin-Qi-Kun), the Late Paleozoic-Triassic Qiangtang-Sanjiang, and the Late Paleozoic to Cenozoic Gangdese-Himalaya orogenic systems, which are separated by the Kangxiwa-Muzitagh-Maqin-Mianxian and the Bangong-Shuanghu-Changning-Menglian sutures, respectively. We propose that the formation and evolution of the Qinghai-Tibet <span class="hlt">Plateau</span> to have been intrinsically related to those of the eastern Tethys, recorded by the Longmu Co-Shuanghu ophiolite mélange zone, the Southern Qiangtang Paleozoic accretionary arc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/0113-02/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/0113-02/report.pdf"><span>Investigation of the geology and hydrology of the Coconino <span class="hlt">Plateau</span> of northern Arizona: a project of the Arizona Rural Watershed Initiative</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Flynn, Marilyn E.; Bills, Donald J.</p> <p>2002-01-01</p> <p>The water resources of the Coconino <span class="hlt">Plateau</span> in northern Arizona are under increasing demand as a result of development. The population of this arid region continues to grow, and the number of visitors to the many national and state parks and monuments in the region has increased annually. The sustainability, protection, and maintenance of springs and seeps and associated riparian habitat on the Coconino <span class="hlt">Plateau</span> are major issues that have broad public and governmental support. Regional stakeholders agree that an improved understanding of the regional hydrogeologic system is needed to address the concerns of water supply and <span class="hlt">ground-water</span> sustainability. The base of information required to adequately describe the hydrogeology of the Coconino <span class="hlt">Plateau</span> currently does not exist. Hydrogeologic data is most abundant for large population centers like Flagstaff and Sedona, but is sparse for less populated areas like Williams, Tusayan, Valle, and Cameron. There are still large parts of the Coconino <span class="hlt">Plateau</span> for which there is no basic geologic or hydrologic information available. In order to develop a hydrogeologic framework for the Coconino <span class="hlt">Plateau</span>, a comprehensive effort is needs to compile existent data and collect additional data to fill in data gaps and reinforce limited information. In 1999, the U.S. Geological Survey (USGS) began an assessment of the hydrogeology of the Coconino <span class="hlt">Plateau</span> in cooperation with the Arizona Department of Water Resources (ADWR) as part of the Rural Watershed Initiative, a program established by the State of Arizona and managed by the ADWR. Assessments also are underway in the upper-middle Verde River watershed (Woodhouse and others, 2002) to the south and in the Mogollon Highlands to the southeast (Parker and Flynn, 2000). Each study has as its objectives: (1) the collection, compilation, and evaluation of all existing geologic, hydrologic, and related data pertaining to the study area and the creation of a database that is readily accessible</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1010875','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1010875"><span>Systematic Application of Flow-and-Transport Modeling for Wellfield Design: the Hanford 200-ZP-1 <span class="hlt">Groundwater</span> Pump-and-Treat Remedy - 10320</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tonkin, Matthew J.; Karanovic, Marinko; Byrnes, Mark E.; Morse, John G.; Murray, Christopher J.; Clement, Paul</p> <p>2010-03-08</p> <p>During 2007 a Feasibility Study and Proposed Plan were completed that describe the selection of a combined <span class="hlt">groundwater</span> pump-and-treat, monitored natural attenuation, and flow-path-control remedy for contaminants present in the Hanford 200-ZP-1 <span class="hlt">groundwater</span> operable unit. In anticipation of the September 2008 signing of the final record of decision, work began on the development of a <span class="hlt">groundwater</span> flow and contaminant transport model encompassing the 200-ZP-1 OU. The model was developed to support the preparation of the remedial design/remedial action work plan and subsequent design documents; to provide estimates of influent concentrations and mass removal rates for several contaminants of concern, including carbon tetrachloride, technetium-99, and hexavalent chromium; and to assist in the integration of remedial decision making across the Hanford Central <span class="hlt">Plateau</span>. This paper describes the initial development and application of the flow and transport model, through Spring 2009.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816099F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816099F"><span>Global <span class="hlt">Groundwater</span> related Risk Indicators: quantifying <span class="hlt">groundwater</span> stress and <span class="hlt">groundwater</span> table decline (1990-2010) at global scale</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faneca Sanchez, Marta; Sutanudjaja, Edwin; Kuijper, Marijn; Bierkens, Marc</p> <p>2016-04-01</p> <p><span class="hlt">Groundwater</span> is an invisible but indispensable resource for the economic development of many countries. Due to the need for this resource, in many cases it is exploited under severe pressure and the exploitation can become not sustainable. The non-sustainable exploitation of water is a well-known problem on both regional and global scales. However, most currently-available assessments on water stress still mostly focus on surface water and on water balances. In this work, we presented two global maps of <span class="hlt">groundwater</span> risk indicators: an updated version of the <span class="hlt">groundwater</span> stress (Gleeson et al., 2011, DOI: 10.1038/nature11295) and an indicator on <span class="hlt">groundwater</span> table decline for the period 1990-2010. To calculate both indicators, we used the updated PCR-GLOBWB model output at 5 arcmin resolution (about 10 km at the equator), that is extended with an offline coupling to a global <span class="hlt">groundwater</span> MODFLOW model. PCR-GLOBWB simulates daily river discharge and <span class="hlt">groundwater</span> recharge, as well as surface water and <span class="hlt">groundwater</span> abstraction rates. The latter are estimated internally within the model based on the simulation of their availabilities and water demands for irrigation and other sectors. The daily output of PCR-GLOBWB would then be aggregated to the monthly resolution and used to force the MODFLOW <span class="hlt">groundwater</span> model resolving spatio-temporal <span class="hlt">groundwater</span> table dynamics, incorporating the simulated <span class="hlt">groundwater</span> abstraction of PCR-GLOBWB. Using the PCR-GLOBWB and MODFLOW simulation results from the period 1990-2010, we then quantified <span class="hlt">groundwater</span> stress and assessed the <span class="hlt">groundwater</span> table decline. Results are presented on four different spatial scales: 5 arcmin pixel, drainage/sub-catchment unit, state level, and major aquifer unit. The maps clearly show where <span class="hlt">groundwater</span> is under stress, where there is a trend in the drop of the <span class="hlt">groundwater</span> table, the slope of the drop and the significance of it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2014/3024/pdf/fs2014-3024.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2014/3024/pdf/fs2014-3024.pdf"><span><span class="hlt">Groundwater</span> studies: principal aquifer surveys</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Burow, Karen R.; Belitz, Kenneth</p> <p>2014-01-01</p> <p>In 1991, the U.S. Congress established the National Water-Quality Assessment (NAWQA) program within the U.S. Geological Survey (USGS) to develop nationally consistent long-term datasets and provide information about the quality of the Nation’s streams and <span class="hlt">groundwater</span>. The USGS uses objective and reliable data, water-quality models, and systematic scientific studies to assess current water-quality conditions, to identify changes in water quality over time, and to determine how natural factors and human activities affect the quality of streams and <span class="hlt">groundwater</span>. NAWQA is the only non-regulatory Federal program to perform these types of studies; participation is voluntary. In the third decade (Cycle 3) of the NAWQA program (2013–2023), the USGS will evaluate the quality and availability of <span class="hlt">groundwater</span> for drinking supply, improve our understanding of where and why water quality is degraded, and assess how <span class="hlt">groundwater</span> quality could respond to changes in climate and land use. These goals will be addressed through the implementation of a new monitoring component in Cycle 3: Principal Aquifer Surveys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=groundwater&pg=6&id=EJ193130','ERIC'); return false;" href="https://eric.ed.gov/?q=groundwater&pg=6&id=EJ193130"><span>The Management of <span class="hlt">Groundwater</span> Supplies.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hall, P. L.</p> <p>1978-01-01</p> <p>The manager of a <span class="hlt">groundwater</span> supply system must be involved in many different disciplines if he or she is to manage the system effectively. In areas in which specialized expertise is necessary, it can be obtained from consultants or government agencies. (BB)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=126443&keyword=user+AND+experience&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=126443&keyword=user+AND+experience&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>COMPLEX MIXTURES AND <span class="hlt">GROUNDWATER</span> QUALITY</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Experience has shown that many soil and <span class="hlt">ground-water</span> contamination problems involve complex mixtures of chemicals. his manuscript identifies and discusses, in a generic sense, some of the important processes which must be considered when dealing with complex mixtures in the subsu...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70175745','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70175745"><span><span class="hlt">Groundwater</span> regulation and integrated planning</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Quevauviller, Philippe; Batelaan, Okke; Hunt, Randall J.</p> <p>2016-01-01</p> <p>The complex nature of <span class="hlt">groundwater</span> and the diversity of uses and environmental interactions call for emerging <span class="hlt">groundwater</span> problems to be addressed through integrated management and planning approaches. Planning requires different levels of integration dealing with: the hydrologic cycle (the physical process) including the temporal dimension; river basins and aquifers (spatial integration); socioeconomic considerations at regional, national and international levels; and scientific knowledge. The great natural variation in <span class="hlt">groundwater</span> conditions obviously affects planning needs and options as well as perceptions from highly localised to regionally-based approaches. The scale at which planning is done therefore needs to be carefully evaluated against available policy choices and options in each particular setting. A solid planning approach is based on River Basin Management Planning (RBMP), which covers: (1) objectives that management planning are designed to address; (2) the way various types of measures fit into the overall management planning; and (3) the criteria against which the success or failure of specific strategies or interventions can be evaluated (e.g. compliance with environmental quality standards). A management planning framework is to be conceived as a “living” or iterated document that can be updated, refined and if necessary changed as information and experience are gained. This chapter discusses these aspects, providing an insight into European Union (EU), United States and Australia <span class="hlt">groundwater</span> planning practices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10123576','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10123576"><span>Modeling <span class="hlt">groundwater</span> flow on MPPs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ashby, S.F.; Falgout, R.D.; Smith, S.G.; Tompson, A.F.B.</p> <p>1993-10-01</p> <p>The numerical simulation of <span class="hlt">groundwater</span> flow in three-dimensional heterogeneous porous media is examined. To enable detailed modeling of large contaminated sites, preconditioned iterative methods and massively parallel computing power are combined in a simulator called PARFLOW. After describing this portable and modular code, some numerical results are given, including one that demonstrates the code`s scalability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16098643','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16098643"><span>Natural radioactivity in Brazilian <span class="hlt">groundwater</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Godoy, José Marcus; Godoy, Maria Luiza</p> <p>2006-01-01</p> <p>More than 220 <span class="hlt">groundwater</span> samples were analyzed for 228Ra, 226Ra, 222Rn, 210Pb, U(nat), Th(nat), pH, conductivity, fluoride and some additional elements determined by ICP-MS. Since samples from several Brazilian states were taken, involving areas with quite different geologies, no general trend was observed relating the chemical composition and the natural radionuclide content. On the other hand, 210Pb strongly depends on the water content of its progenitor, 222Rn. The values obtained during the present work were compared with those reported by Hainberger et al. [Hainberger, P.L., de Oliveira Paiva, I.R., Salles Andrade, H.A., Zundel, G., Cullen, T.L., 1974. Radioactivity in Brazilian mineral waters. Radiation Data and Reports, 483-488.], when more than 270 <span class="hlt">groundwater</span> samples were analyzed, mainly, for 226Ra. Based on the results of both works, it was possible to build a database including the results of both works, generating a set with the radium content of circa 350 <span class="hlt">groundwater</span> sources. It was demonstrated that 228Ra, 226Ra, 222Rn, 210Pb and U(nat) content in Brazilian <span class="hlt">groundwater</span> follows a lognormal distribution and the obtained geometric mean were 0.045, 0.014, 57.7, 0.040 BqL(-1) and 1.2 microgL(-1), respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982EOSTr..63.1178A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982EOSTr..63.1178A"><span><span class="hlt">Groundwater</span> Resources: Investigation and Development</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, Mary P.</p> <p></p> <p>A glance through the table of contents of this volume might suggest that it is yet another introductory text on principles of <span class="hlt">groundwater</span> hydrology. All of the usual basic topics are covered including definitions of terms and concepts, aquifer types, drilling methods, and pumping tests. But partly because this book is intended for practicing <span class="hlt">groundwater</span> consultants rather than students, other less elementary topics such as environmental isotope techniques, geochemical methods, interpretation and utilization of spring flow, geophysical methods, and <span class="hlt">groundwater</span> balances are also included.According to the preface, ‘practical applicability’ is stressed ‘to show how <span class="hlt">groundwater</span> investigations should be conducted using a systematic, well-directed effort’ and to describe ‘… what to do, what to avoid, and what kind of results one can reasonably expect …’ While this book was published as part of a series of monographs on water pollution, it is more in the nature of a handbook than a true monograph. That is, it is not an in-depth treatment of a single topic but presents a broad introduction to the ways in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19294524','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19294524"><span>Development of <span class="hlt">groundwater</span> quality index.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saeedi, Mohesn; Abessi, Ozeair; Sharifi, Farid; Meraji, Hamed</p> <p>2010-04-01</p> <p>Assessing the water quality status for special use is the main objective of any water quality monitoring studies. The water quality index (WQI) is a mathematical instrument used to transform large quantities of water quality data into a single number which represents the water quality level. In fact, developing WQI in an area is a fundamental process in the planning of land use and water resources management. In this study, a simple methodology based on multivariate analysis is developed to create a <span class="hlt">groundwater</span> quality index (GWQI), with the aim of identifying places with best quality for drinking within the Qazvin province, west central of Iran. The methodology is based on the definition of GWQI using average value of eight cation and anion parameters for 163 wells during a 3-year period. The proportion of observed concentrations to the maximum allowable concentration is calculated as normalized value of each parameter in observing wells. Final indices for each well are calculated considering weight of each parameter. In order to assess the <span class="hlt">groundwater</span> quality of study area, the derived indices are compared with those of well-known mineral waters. Using developed indices, <span class="hlt">groundwater</span> iso-index map for study area and the map of areas of which the indices are near to mineral waters was drawn. In the case study, the GWQI map reveals that <span class="hlt">groundwater</span> quality in two areas is extremely near to mineral water quality. Created index map provides a comprehensive picture of easily interpretable for regional decision makers for better planning and management.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCC...6.1100H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCC...6.1100H"><span><span class="hlt">Groundwater</span> vulnerability on small islands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holding, S.; Allen, D. M.; Foster, S.; Hsieh, A.; Larocque, I.; Klassen, J.; van Pelt, S. C.</p> <p>2016-12-01</p> <p>The majority of naturally occurring freshwater on small islands is <span class="hlt">groundwater</span>, which is primarily recharged by precipitation. Recharge rates are therefore likely to be impacted by climate change. Freshwater resources on small islands are particularly vulnerable to climate change because they are limited in size and easily compromised. Here we have compiled available aquifer system characteristics and water-use data for 43 small island developing states distributed worldwide, based on local expert knowledge, publications and regional data sets. Current vulnerability was assessed by evaluating the recharge volume per capita. For future vulnerability, climate change projections were used to estimate changes in aquifer recharge. We find that 44% of islands are in a state of water stress, and while recharge is projected to increase by as much as 117% on 12 islands situated in the western Pacific and Indian Ocean, recharge is projected to decrease by up to 58% on the remaining 31 islands. Of great concern is the lack of enacted <span class="hlt">groundwater</span> protection legislation for many of the small island developing states identified as highly vulnerable to current and future conditions. Recharge indicators, shown alongside the state of legal <span class="hlt">groundwater</span> protections, provide a global picture of <span class="hlt">groundwater</span> supply vulnerability under current and future climate change conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Groundwater&pg=6&id=EJ193130','ERIC'); return false;" href="http://eric.ed.gov/?q=Groundwater&pg=6&id=EJ193130"><span>The Management of <span class="hlt">Groundwater</span> Supplies.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hall, P. L.</p> <p>1978-01-01</p> <p>The manager of a <span class="hlt">groundwater</span> supply system must be involved in many different disciplines if he or she is to manage the system effectively. In areas in which specialized expertise is necessary, it can be obtained from consultants or government agencies. (BB)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H53A1672E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H53A1672E"><span>Dynamics of Small-Scale Perched Aquifers in the Semi-Arid South-Western Region of Madagascar and Implications for the Sustainable <span class="hlt">Groundwater</span> Exploitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Englert, A.; Brinkmann, K.; Kobbe, S.; Buerkert, A.</p> <p>2016-12-01</p> <p>The south-western region of Madagascar is characterized by limited water resources throughout the year and recurrent droughts, which affect agricultural production and increase the risk of food insecurity. To deliver reliable estimates on the availability and dynamics of water resources, we studied the hydrogeology of several villages in the Mahafaly region. Detailed investigations were conducted for a selected village on a calcareous <span class="hlt">plateau</span> to predict the local water resources under changing boundary conditions including enhanced water abstraction and changes in <span class="hlt">groundwater</span> recharge. In 2014 a participatory monitoring network was established, which allowed <span class="hlt">groundwater</span> level measurements in three wells twice a day. Additional hydrogeological investigations included pumping tests, automatic monitoring of meteorological data, daily <span class="hlt">groundwater</span> abstraction appraisal and mapping of the spatial extent of the perched aquifer using satellite data. Analysis of the measured data unraveled the aquifer dynamic to be dominated by a <span class="hlt">groundwater</span> level driven leakage process. The latter is superimposed by <span class="hlt">groundwater</span> recharge in the rainy season and a daily <span class="hlt">groundwater</span> abstraction. Based on these findings we developed a model for the aquifer, which allows to predict the duration of <span class="hlt">groundwater</span> availability as a function of annual precipitation and daily water abstraction. The latter will be implemented in an agent-based land-use model, were <span class="hlt">groundwater</span> abstraction is a function of population and livestock. The main objective is to model land use scenarios and global trends (climate, market trends and population development) through explicit imbedding of artificial and natural <span class="hlt">groundwater</span> dynamics. The latter is expected to enable the evaluation of additional water abstraction for agricultural purposes without endangering water supply of the local population and their livestock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990JHyd..119...71L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990JHyd..119...71L"><span><span class="hlt">Groundwater</span> resources development in the eastern Sahara</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lloyd, John William</p> <p>1990-11-01</p> <p>Aspects of the regional hydrogeology of the Nubian Sandstone aquifer system in the Sudan, Egypt and eastern Libya and the associated Tertiary aquifers of the Sirte Basin, Libya are described. It is concluded that major <span class="hlt">groundwater</span> resources are present that can be developed by abstraction adjacent to the River Nile, by <span class="hlt">groundwater</span> mining or by abstraction from throughflow. Examples of aquifer control parameters and potential resources development are given. The problems of in situ <span class="hlt">groundwater</span> development in the harsh desert environment are discussed and it is indicated that such development is not constrained by <span class="hlt">groundwater</span> resources potential but by socioeconomic factors. The solution of <span class="hlt">groundwater</span> conveyance adopted in Libya is detailed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4744761','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4744761"><span>Quantifying renewable <span class="hlt">groundwater</span> stress with GRACE</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Richey, Alexandra S.; Thomas, Brian F.; Lo, Min‐Hui; Reager, John T.; Voss, Katalyn; Swenson, Sean; Rodell, Matthew</p> <p>2015-01-01</p> <p>Abstract <span class="hlt">Groundwater</span> is an increasingly important water supply source globally. Understanding the amount of <span class="hlt">groundwater</span> used versus the volume available is crucial to evaluate future water availability. We present a <span class="hlt">groundwater</span> stress assessment to quantify the relationship between <span class="hlt">groundwater</span> use and availability in the world's 37 largest aquifer systems. We quantify stress according to a ratio of <span class="hlt">groundwater</span> use to availability, which we call the Renewable <span class="hlt">Groundwater</span> Stress ratio. The impact of quantifying <span class="hlt">groundwater</span> use based on nationally reported <span class="hlt">groundwater</span> withdrawal statistics is compared to a novel approach to quantify use based on remote sensing observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. Four characteristic stress regimes are defined: Overstressed, Variable Stress, Human‐dominated Stress, and Unstressed. The regimes are a function of the sign of use (positive or negative) and the sign of <span class="hlt">groundwater</span> availability, defined as mean annual recharge. The ability to mitigate and adapt to stressed conditions, where use exceeds sustainable water availability, is a function of economic capacity and land use patterns. Therefore, we qualitatively explore the relationship between stress and anthropogenic biomes. We find that estimates of <span class="hlt">groundwater</span> stress based on withdrawal statistics are unable to capture the range of characteristic stress regimes, especially in regions dominated by sparsely populated biome types with limited cropland. GRACE‐based estimates of use and stress can holistically quantify the impact of <span class="hlt">groundwater</span> use on stress, resulting in both greater magnitudes of stress and more variability of stress between regions. PMID:26900185</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.5696H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.5696H"><span>Trend Analyses of Nitrate in Danish <span class="hlt">Groundwater</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hansen, B.; Thorling, L.; Dalgaard, T.; Erlandsen, M.</p> <p>2012-04-01</p> <p>This presentation assesses the long-term development in the oxic <span class="hlt">groundwater</span> nitrate concentration and nitrogen (N) loss due to intensive farming in Denmark. Firstly, up to 20-year time-series from the national <span class="hlt">groundwater</span> monitoring network enable a statistically systematic analysis of distribution, trends and trend reversals in the <span class="hlt">groundwater</span> nitrate concentration. Secondly, knowledge about the N surplus in Danish agriculture since 1950 is used as an indicator of the potential loss of N. Thirdly, <span class="hlt">groundwater</span> recharge CFC (Chlorofluorocarbon) age determination allows linking of the first two dataset. The development in the nitrate concentration of oxic <span class="hlt">groundwater</span> clearly mirrors the development in the national agricultural N surplus, and a corresponding trend reversal is found in <span class="hlt">groundwater</span>. Regulation and technical improvements in the intensive farming in Denmark have succeeded in decreasing the N surplus by 40% since the mid 1980s while at the same time maintaining crop yields and increasing the animal production of especially pigs. Trend analyses prove that the youngest (0-15 years old) oxic <span class="hlt">groundwater</span> shows more pronounced significant downward nitrate trends (44%) than the oldest (25-50 years old) oxic <span class="hlt">groundwater</span> (9%). This amounts to clear evidence of the effect of reduced nitrate leaching on <span class="hlt">groundwater</span> nitrate concentrations in Denmark. Are the Danish <span class="hlt">groundwater</span> monitoring strategy obtimal for detection of nitrate trends? Will the nitrate concentrations in Danish <span class="hlt">groundwater</span> continue to decrease or are the Danish nitrate concentration levels now appropriate according to the Water Framework Directive?</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23788184','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23788184"><span>Differences of glycolysis in skeletal muscle and lactate metabolism in liver between <span class="hlt">plateau</span> zokor (Myospalax baileyi) and <span class="hlt">plateau</span> pika (Ochotona curzoniae).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Sheng-Zhen; Wei, Lian; Wei, Deng-Bang; Wang, Duo-Wei; Ma, Ben-Yuan</p> <p>2013-06-25</p> <p>The <span class="hlt">plateau</span> pika (Ochotona curzoniae) and <span class="hlt">plateau</span> zokor (Myospalax baileyi) are specialized native species of the Qinghai-Tibetan <span class="hlt">plateau</span>. The goal of this study was to examine physiological differences in skeletal muscle glycolysis and hepatic lactate metabolism between these two species. The partial sequence of pyruvate carboxylase (PC) gene was cloned and sequenced. The mRNA expression levels of PC and lactate dehydrogenases (LDH-A, LDH-B) were determined by real-time PCR. The enzymatic activity of PC was measured using malic acid coupling method. The concentration of lactic acid (LD) and the specific activities of LDH in liver and skeletal muscle of two species were measured. The different isoenzymes of LDH were determined by native polyacrylamide gel electrophoresis (PAGE). The results showed that, (1) LDH-B mRNA level in skeletal muscle of <span class="hlt">plateau</span> zokor was significantly higher than that of <span class="hlt">plateau</span> pika (P < 0.01), but no differences was found at LDH-A mRNA levels between them (P > 0.05); (2) PC, LDH-A and LDH-B mRNA levels in liver of <span class="hlt">plateau</span> pika were significantly higher than those of <span class="hlt">plateau</span> zokor (P < 0.01); (3) The LDH activity and concentration of LD in skeletal muscle and liver, as well as the PC activity in liver of <span class="hlt">plateau</span> pika were significantly higher than those of <span class="hlt">plateau</span> zokor (P < 0.01); (4) The isoenzymatic spectrum of lactate dehydrogenase showed that the main LDH isoenzymes were LDH-A4, LDH-A3B and LDH-A2B2 in skeletal muscle of <span class="hlt">plateau</span> pika, while the main LDH isoenzymes were LDH-AB3 and LDH-B4 in skeletal muscle of <span class="hlt">plateau</span> zokor; the main isoenzymes were LDH-A3B, LDH-A2B2, LDH-AB3 and LDH-B4 in liver of <span class="hlt">plateau</span> pika, while LDH-A4 was the only isoenzyme in liver of <span class="hlt">plateau</span> zokor. These results indicate that the <span class="hlt">plateau</span> pika gets most of its energy for sprint running through enhancing anaerobic glycolysis, producing more lactate in their skeletal muscle, and converting lactate into glucose and glycogen in the liver by enhancing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2014/5149/pdf/sir2014-5149.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2014/5149/pdf/sir2014-5149.pdf"><span>Aquifers of Arkansas: protection, management, and hydrologic and geochemical characteristics of <span class="hlt">groundwater</span> resources in Arkansas</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kresse, Timothy M.; Hays, Phillip D.; Merriman, Katherine R.; Gillip, Jonathan A.; Fugitt, D. Todd; Spellman, Jane L.; Nottmeier, Anna M.; Westerman, Drew A.; Blackstock, Joshua M.; Battreal, James L.</p> <p>2014-01-01</p> <p>The Interior Highlands of western Arkansas has less reported <span class="hlt">groundwater</span> use than other areas of the State, reflecting a combination of factors. These factors include prevalent and increasing use of surface water, less intensive agricultural uses, lower population and industry densities, lesser potential yield of the resource, and lack of detailed reporting. The overall low yields of aquifers of the Interior Highlands result in domestic supply as the dominant use, with minor industrial, public, and commercial-supply use. Where greater volumes are required for growth of population and industry, surface water is the greatest supplier of water needs in the Interior Highlands. The various aquifers of the Interior Highlands generally occur in shallow, fractured, well-indurated, structurally modified bedrock of this mountainous region of the State, as compared to the relatively flat-lying, unconsolidated sediments of the Coastal Plain. In terms of age from youngest to oldest, the aquifers of the Interior Highlands include: the Arkansas River Valley alluvial aquifer, the Ouachita Mountains aquifer, the Western Interior Plains confining system, the Springfield <span class="hlt">Plateau</span> aquifer, and the Ozark aquifer. Spatial trends in <span class="hlt">groundwater</span> geochemistry in the Interior Highlands differ greatly from trends noted for aquifers of the Coastal Plain. In the Coastal Plain, the prevalence of long regional flow paths results in regionally predictable and mappable geochemical changes along the flow paths. In the Interior Highlands, short, topographically controlled flow paths (from hilltops to valleys) within small watersheds represent the predominant <span class="hlt">groundwater</span>-flow system. As such, dense data coverage from numerous wells would be required to effectively characterize these <span class="hlt">groundwater</span> basins and define small-scale geochemical changes along any given flow path for aquifers of the Interior Highlands. Changes in geochemistry generally were related to rock type and residence time along</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014WRR....50.8845J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014WRR....50.8845J"><span>The pronounced seasonality of global <span class="hlt">groundwater</span> recharge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jasechko, Scott; Birks, S. Jean; Gleeson, Tom; Wada, Yoshihide; Fawcett, Peter J.; Sharp, Zachary D.; McDonnell, Jeffrey J.; Welker, Jeffrey M.</p> <p>2014-11-01</p> <p><span class="hlt">Groundwater</span> recharged by meteoric water supports human life by providing two billion people with drinking water and by supplying 40% of cropland irrigation. While annual <span class="hlt">groundwater</span> recharge rates are reported in many studies, fewer studies have explicitly quantified intra-annual (i.e., seasonal) differences in <span class="hlt">groundwater</span> recharge. Understanding seasonal differences in the fraction of precipitation that recharges aquifers is important for predicting annual recharge <span class="hlt">groundwater</span> rates under changing seasonal precipitation and evapotranspiration regimes in a warming climate, for accurately interpreting isotopic proxies in paleoclimate records, and for understanding linkages between ecosystem productivity and <span class="hlt">groundwater</span> recharge. Here we determine seasonal differences in the <span class="hlt">groundwater</span> recharge ratio, defined here as the ratio of <span class="hlt">groundwater</span> recharge to precipitation, at 54 globally distributed locations on the basis of 18O/16O and 2H/1H ratios in precipitation and <span class="hlt">groundwater</span>. Our analysis shows that arid and temperate climates have wintertime <span class="hlt">groundwater</span> recharge ratios that are consistently higher than summertime <span class="hlt">groundwater</span> recharge ratios, while tropical <span class="hlt">groundwater</span> recharge ratios are at a maximum during the wet season. The isotope-based recharge ratio seasonality is consistent with monthly outputs from a global hydrological model (PCR-GLOBWB) for most, but not all locations. The pronounced seasonality in <span class="hlt">groundwater</span> recharge ratios shown in this study signifies that, from the point of view of predicting future <span class="hlt">groundwater</span> recharge rates, a unit change in winter (temperate and arid regions) or wet season (tropics) precipitation will result in a greater change to the annual <span class="hlt">groundwater</span> recharge rate than the same unit change to summer or dry season precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26658457','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26658457"><span>Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian <span class="hlt">Plateau</span> to the Hinterland of Tibetan <span class="hlt">Plateau</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Qiang; Wang, Xiaoming</p> <p>2015-01-01</p> <p>This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan <span class="hlt">Plateau</span> within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian <span class="hlt">Plateau</span>, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan <span class="hlt">Plateau</span> during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan <span class="hlt">Plateau</span> or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan <span class="hlt">Plateau</span> and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27047483','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27047483"><span>Shiga Toxin-Producing Escherichia coli in <span class="hlt">Plateau</span> Pika (Ochotona curzoniae) on the Qinghai-Tibetan <span class="hlt">Plateau</span>, China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bai, Xiangning; Zhang, Wang; Tang, Xinyuan; Xin, Youquan; Xu, Yanmei; Sun, Hui; Luo, Xuelian; Pu, Ji; Xu, Jianguo; Xiong, Yanwen; Lu, Shan</p> <p>2016-01-01</p> <p>Shiga toxin-producing Escherichia coli (STEC) are an emerging group of zoonotic pathogens. Ruminants are the natural reservoir of STEC. In this study we determined the prevalence and characteristics of the STEC in <span class="hlt">plateau</span> pika (Ochotona curzoniae) on the Qinghai-Tibetan <span class="hlt">Plateau</span>, China. A total of 1116 pika samples, including 294 intestinal contents samples, 317 fecal samples, and 505 intestinal contents samples, were collected from May to August in the years 2012, 2013, and 2015, respectively. Twenty-one samples (1.88%) yielded at least one STEC isolate; in total, 22 STEC isolates were recovered. Thirteen different O serogroups and 14 serotypes were identified. One stx 1 subtype (stx 1a) and three stx 2 subtypes (stx 2a, stx 2b, and stx 2d) were present in the STEC isolates. Fifteen, fourteen, and three STEC isolates harbored the virulence genes ehxA, subA, and astA, respectively. Adherence-associated genes iha and saa were, respectively, present in 72.73 and 68.18% of the STEC isolates. Twenty antibiotics were active against all the STEC isolates; all strains were resistant to penicillin G, and some to cephalothin or streptomycin. The 22 STEC isolates were divided into 16 pulsed-field gel electrophoresis patterns and 12 sequence types. <span class="hlt">Plateau</span> pikas may play a role in the ongoing circulation of STEC in the Qinghai-Tibetan <span class="hlt">plateau</span>. This study provides the first report on STEC in <span class="hlt">plateau</span> pikas and new information about STEC reservoirs in wildlife. Based on the serotypes, virulence gene profiles and multi-locus sequence typing (MLST) analysis, the majority of these pika STECs may pose a low public health risk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4802371','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4802371"><span>Shiga Toxin-Producing Escherichia coli in <span class="hlt">Plateau</span> Pika (Ochotona curzoniae) on the Qinghai-Tibetan <span class="hlt">Plateau</span>, China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bai, Xiangning; Zhang, Wang; Tang, Xinyuan; Xin, Youquan; Xu, Yanmei; Sun, Hui; Luo, Xuelian; Pu, Ji; Xu, Jianguo; Xiong, Yanwen; Lu, Shan</p> <p>2016-01-01</p> <p>Shiga toxin-producing Escherichia coli (STEC) are an emerging group of zoonotic pathogens. Ruminants are the natural reservoir of STEC. In this study we determined the prevalence and characteristics of the STEC in <span class="hlt">plateau</span> pika (Ochotona curzoniae) on the Qinghai-Tibetan <span class="hlt">Plateau</span>, China. A total of 1116 pika samples, including 294 intestinal contents samples, 317 fecal samples, and 505 intestinal contents samples, were collected from May to August in the years 2012, 2013, and 2015, respectively. Twenty-one samples (1.88%) yielded at least one STEC isolate; in total, 22 STEC isolates were recovered. Thirteen different O serogroups and 14 serotypes were identified. One stx1 subtype (stx1a) and three stx2 subtypes (stx2a, stx2b, and stx2d) were present in the STEC isolates. Fifteen, fourteen, and three STEC isolates harbored the virulence genes ehxA, subA, and astA, respectively. Adherence-associated genes iha and saa were, respectively, present in 72.73 and 68.18% of the STEC isolates. Twenty antibiotics were active against all the STEC isolates; all strains were resistant to penicillin G, and some to cephalothin or streptomycin. The 22 STEC isolates were divided into 16 pulsed-field gel electrophoresis patterns and 12 sequence types. <span class="hlt">Plateau</span> pikas may play a role in the ongoing circulation of STEC in the Qinghai-Tibetan <span class="hlt">plateau</span>. This study provides the first report on STEC in <span class="hlt">plateau</span> pikas and new information about STEC reservoirs in wildlife. Based on the serotypes, virulence gene profiles and multi-locus sequence typing (MLST) analysis, the majority of these pika STECs may pose a low public health risk. PMID:27047483</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAESc.107...62L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAESc.107...62L"><span>Crustal rheological strength heterogeneities control the formation of continental <span class="hlt">plateau</span> margins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Chang; Zhu, Bojing; Yang, Xiaolin</p> <p>2015-08-01</p> <p>The margins bordering the Tibetan <span class="hlt">Plateau</span> show two end-member morphologies in topographic gradient: steep margins and low-gradient margins. To investigate the formation mechanism of convergent intracontinental <span class="hlt">plateau</span> margins, we conduct 2D numerical experiments to simulate crustal deformation process across <span class="hlt">plateau</span> margins. Our numerical experiments demonstrate that heterogeneities in crustal rheological strength control significantly the formation of <span class="hlt">plateau</span> margins when subjected to crustal convergence. A very steep margin is the result of crustal convergence between <span class="hlt">plateau</span> with weak lower crust and foreland basin with strong lower crust. By contrast, a low-gradient margin could result from crustal convergence between <span class="hlt">plateau</span> and foreland with less strength contrast. This finding suggests that the diversity in topographic gradient along the Tibetan <span class="hlt">Plateau</span> borders reflects heterogeneities in crustal rheological strength across the <span class="hlt">plateau</span> margins. Steep gradient at the margins indicate large crustal rheological strength contrasts between the weak ductile lower crust of the Tibetan <span class="hlt">Plateau</span> and its strong surrounding foreland basins, like the Sichuan Basin, the Tarim Basin and the Qaidam Basin. Beneath these steep margins the horizontal flow of the Tibetan ductile lower crust is inhibited and forced to extrude to support escarpments. Low-gradient at the margins indicate less crustal strength variations between the <span class="hlt">plateau</span> and outer forelands, like at the northeastern and southeastern margins, where they might be outlets for the weak ductile Tibetan lower crust to flow away from the <span class="hlt">plateau</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2981Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2981Q"><span>A primary study on finding hot <span class="hlt">groundwater</span> using infrared remote sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qiao, Y.; Wu, Q.</p> <p></p> <p>Hot <span class="hlt">groundwater</span> is a kind of valuable natural resources to be explored utilized. Shanxi Province, located in the eastern Loess <span class="hlt">Plateau</span> of China, is rich in geothermal resources, most of which was found in irrigation well drilling or geological survey. Basic study is weak. Now new developed Remote Sensing technique provides geothermal study with an advanced way. Air-RS information of thermal infrared and dada from thermal channel of Meteorological Landset AVHRR has been used widely. A thermal infrared channel (TM6) was installed in the U. S. second Landset, Its resolving power of space is as high as 120 m, 10 times more t an one ofh AVHRR. A Landset earth recourses launched by China and Brazil (CBERS-1) in 1999, including a spectrum of thermal infrared. It is paid a great interested and attention to survey geothermal resources using thermal infrared. This article is a brief introduction of finding hot <span class="hlt">groundwater</span> with on the bases of differences of thermal radiation of objects reflected by thermal infrared in the Landset, and treated with HIS colors changes. This study provides an advanced way widely used to exploit hot <span class="hlt">groundwater</span> and to promote the development of tourism and geothermal medical in China.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860065131&hterms=Cenozoic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DCenozoic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860065131&hterms=Cenozoic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DCenozoic"><span>On the cenozoic uplift and tectonic stability of the Colorado <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morgan, P.; Swanberg, C. A.</p> <p>1985-01-01</p> <p>Models of <span class="hlt">plateau</span> uplift which can be applied to the Colorado <span class="hlt">Plateau</span> are presented. The sequence and consequences of the 2-km Cenzoic uplift of the <span class="hlt">Plateau</span> and volcanism and rifting in the adjoining Basin and Range and Southern Rocky Mountain-Rio Grande rift provinces are examined. Geologic and geophysical data suggest that more than one mechanism is required to explain the 2 km of uplift, and that thermal expansion and magmatic crustal thickening are the dominant mechanisms. It is argued that the early Cenzoic stability of the <span class="hlt">Plateau</span> was related to the relatively cool geotherm and hence high strength of the <span class="hlt">Plateau</span> lithosphere relative to the adjoining regions. As the <span class="hlt">Plateau</span> lithosphere has been heated and uplift has occurred, the overall stability of the <span class="hlt">Plateau</span> has decreased.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24298083','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24298083"><span>Exploring the undulating <span class="hlt">plateau</span>: the future of global oil supply.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jackson, Peter M; Smith, Leta K</p> <p>2014-01-13</p> <p>In this paper, we analyse the factors that will influence long-term oil supply and describe the future form of the global oil supply profile as an 'undulating <span class="hlt">plateau</span>' rather than an irreversible, short-term peak or an ever upward trend of increasing production. The ultimate transition from a world of relatively plentiful and cheap oil to one of tight supply and high cost will be slow and challenging. An understanding of the signposts for the future path of supply and the drivers of that profile will be critical to managing the transition. The ultimate form of the global supply curve may well be dictated by demand evolution rather than a limited resource endowment in the longer term. Several factors will probably control future global oil supply. We believe that the scale of global oil resource will not constitute a physical supply limit for at least the next two or three decades. However, all categories of oil resources are already more expensive to develop than in the past, requiring high oil prices to stimulate supply growth. Lower rates of oil demand growth relative to economic growth, combined with more challenging supply growth, will probably lead to an undulating <span class="hlt">plateau</span> sometime after 2040, with demand from non-Organization for Economic Cooperation and Development states continuing to dominate. Upstream investment requirements and oil price volatility will increase towards and beyond the undulating production <span class="hlt">plateau</span>. In this new world, high oil prices will induce demand destruction, fuel substitution and ever increasing energy efficiency. As we discuss below, the fundamental differences between the IHS Cambridge Energy Research Associates' (IHS CERA) view of the future of oil supply and many peak oil supply models are the timing of the onset of a dramatic slowdown in the rate of growth of supply and the existence or otherwise of a production <span class="hlt">plateau</span>. We do not dispute that supply will <span class="hlt">plateau</span> and eventually fall; the question is when, how and at what price</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24529264','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24529264"><span>[The pathogenic ecology research on plague in Qinghai <span class="hlt">plateau</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dai, Rui-xia; Wei, Bai-qing; Li, Cun-xiang; Xiong, Hao-ming; Yang, Xiao-yan; Fan, Wei; Qi, Mei-ying; Jin, Juan; Wei, Rong-jie; Feng, Jian-ping; Jin, Xing; Wang, Zu-yun</p> <p>2013-12-01</p> <p>To study the pathogenic ecology characteristics of plague in Qinghai <span class="hlt">plateau</span>. Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai <span class="hlt">plateau</span> plague foci, which were separated from different host and media in different regions during 1954 to 2012. The ecotypes of these strains were Qingzang <span class="hlt">plateau</span> (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai <span class="hlt">plateau</span> plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai <span class="hlt">plateau</span> had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. The main host and media of Qinghai <span class="hlt">plateau</span> plague foci directly affected the spatial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGC32B..03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGC32B..03K"><span>High pre-industrial and modern Tibetan <span class="hlt">Plateau</span> fire activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kehrwald, N. M.; Li, Q.; Wang, N.; Zennaro, P.; Zangrando, R.; Barbante, C.</p> <p>2013-12-01</p> <p>The South Asian brown cloud created from a mix of biomass burning and fossil fuel aerosols is warming the atmosphere between 5000 to 7000 meters above sea level (m asl) along the southern slope of the Himalaya. The extent to which this atmospheric brown cloud is transported up and over the 7000 to 8000 m asl ridge of the Himalaya and northward across the Tibetan <span class="hlt">Plateau</span> is unknown. Intense Eastern Asian industry and associated coal burning may also export fossil fuel burning products to the Tibetan <span class="hlt">Plateau</span>. In addition, local cooking, agricultural and natural fires emit combustion products that alter atmospheric chemistry and are deposited on glacier surfaces. It is essential to differentiate between the effects of fossil fuel and biomass burning across the Tibetan <span class="hlt">Plateau</span> to determine if combustion products affect glacier surfaces and, by extension, glacier volume. The specific biomarker levoglucosan can only be produced by biomass burning at temperatures of 300°C or higher and is trapped and preserved in glaciers across the globe. This specificity may allow the possibility of differentiating between fossil fuel and biomass burning contributions when comparing levoglucosan concentrations with more general ice core combustion proxies such as black carbon. Here, we present a biomass burning record from the entire 164 m Muztag ice core (36.35°N; 87.17°E; 5780 m asl) and from a southwest to northeast transect of snow pits across the Tibetan <span class="hlt">Plateau</span>. Multiple total organic carbon and dissolved organic carbon surface samples demonstrate organic carbon concentrations at or near detection limits. However, these samples have high levoglucosan concentrations suggesting that the biomass burning recorded in these sites may be from a regional rather than local source. The Tibetan <span class="hlt">Plateau</span> levoglucosan concentrations are surprisingly substantially greater than Kilimanjaro levoglucosan concentrations, where Kilimanjaro is located in a relatively similar low-latitude high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/206407','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/206407"><span>Work plan for the Oak Ridge National Laboratory <span class="hlt">groundwater</span> program: Continuous <span class="hlt">groundwater</span> collection</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>1995-08-01</p> <p>The continuous collection of <span class="hlt">groundwater</span> data is a basic and necessary part of Lockeheed Martin Energy Systems` ORNL Environmental Restoration Area-Wide <span class="hlt">Groundwater</span> Program. Continuous <span class="hlt">groundwater</span> data consist primarily of continually recorded <span class="hlt">groundwater</span> levels, and in some instances, specific conductivity, pH, and/or temperature measurements. These data will be collected throughout the ORNL site. This Work Plan (WP) addresses technical objectives, equipment requirements, procedures, documentation requirements, and technical instructions for the acquisition of the continuous <span class="hlt">groundwater</span> data. Intent of this WP is to provide an approved document that meets all the necessary requirements while retaining the flexibility necessary to effectively address ORNL`s <span class="hlt">groundwater</span> problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23243867','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23243867"><span>[Construction of <span class="hlt">groundwater</span> contamination prevention mapping system].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Jun-Jie; He, Jiang-Tao; Lu, Yan; Liu, Li-Ya; Zhang, Xiao-Liang</p> <p>2012-09-01</p> <p><span class="hlt">Groundwater</span> contamination prevention mapping is an important component of <span class="hlt">groundwater</span> contamination geological survey and assessment work, which could provide the basis for making and implementing <span class="hlt">groundwater</span> contamination prevention planning. A <span class="hlt">groundwater</span> contamination prevention mapping system was constructed in view of the synthetic consideration on nature perspective derived from <span class="hlt">groundwater</span> contamination sources and aquifer itself, social-economic perspective, policy perspective derived from outside. During the system construction process, analytic hierarchy process and relevant overlaying principles were used to couple <span class="hlt">groundwater</span> contamination risk assessment, <span class="hlt">groundwater</span> value as well as wellhead protection area zoning. Data processing and visualization of mapping results were achieved in the GIS environment. The research on <span class="hlt">groundwater</span> contamination prevention mapping in Beijing Plain indicated that the final <span class="hlt">groundwater</span> prevention map was in accordance with the actual conditions and well reflected the priorities of <span class="hlt">groundwater</span> prevention, which could play a guidance role in designing and implementing further practical prevention and supervision measures. Besides, because of the dynamical properties of the system components, it was suggested to analyze the update frequency of the mapping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816557L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816557L"><span>Global estimates of fresh submarine <span class="hlt">groundwater</span> discharge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luijendijk, Elco; Gleeson, Tom; Moosdorf, Nils</p> <p>2016-04-01</p> <p>Fresh submarine <span class="hlt">groundwater</span> discharge, the flow of fresh <span class="hlt">groundwater</span> to oceans, may be a significant contributor to the water and chemical budgets of the world's oceans. We present new estimates of the flux of fresh <span class="hlt">groundwater</span> to the world's oceans. We couple density-dependent numerical simulations of generic models of coastal basins with geospatial databases of hydrogeological parameters and topography to resolve the rate of terrestrially-derived submarine <span class="hlt">groundwater</span> discharge globally. We compare the model results to a new global compilation of submarine <span class="hlt">groundwater</span> discharge observations. The results show that terrestrially-derived SGD is highly sensitive to permeability. In most watersheds only a small fraction of <span class="hlt">groundwater</span> recharge contributes to submarine <span class="hlt">groundwater</span> discharge, with most recharge instead contributing to terrestrial discharge in the form of baseflow or evapotranspiration. Fresh submarine <span class="hlt">groundwater</span> discharge is only significant in watersheds that contain highly permeable sediments, such as coarse-grained siliciclastic sediments, karstic carbonates or volcanic deposits. Our estimates of global submarine <span class="hlt">groundwater</span> discharge are much lower than most previous estimates. However, many tropical and volcanic islands are hotspots of submarine <span class="hlt">groundwater</span> discharge and solute fluxes towards the oceans. The comparison of model results and data highlights the spatial variability of SGD and the difficulty of scaling up observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H11H..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H11H..05M"><span>Simulating <span class="hlt">groundwater</span>-induced sewer flooding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mijic, A.; Mansour, M.; Stanic, M.; Jackson, C. R.</p> <p>2016-12-01</p> <p>During the last decade, Chalk catchments of southern England experienced severe <span class="hlt">groundwater</span> flooding. High <span class="hlt">groundwater</span> levels resulted in the <span class="hlt">groundwater</span> ingress into the sewer network that led to restricted toilet use and the overflow of diluted, but untreated sewage to road surfaces, rivers and water courses. In response to these events the water and sewerage company Thames Water Utilities Ltd (TWUL) had to allocate significant funds to mitigate the impacts. It was estimated that approximately £19m was spent responding to the extreme wet weather of 2013-14, along with the use of a fleet of over 100 tankers. However, the magnitude of the event was so large that these efforts could not stop the discharge of sewage to the environment. This work presents the analysis of the risk of <span class="hlt">groundwater</span>-induced sewer flooding within the Chalk catchment of the River Lambourn, Berkshire. A spatially distributed <span class="hlt">groundwater</span> model was used to assess historic <span class="hlt">groundwater</span> flood risk and the potential impacts of changes in future climate. We then linked this model to an urban <span class="hlt">groundwater</span> model to enable us to simulate <span class="hlt">groundwater</span>-sewer interaction in detail. The modelling setup was used to identify relationships between infiltration into sewers and <span class="hlt">groundwater</span> levels at specific points on TWUL's sewer network, and to estimate historic and future <span class="hlt">groundwater</span> flood risk, and how this varies across the catchment. The study showed the significance of understanding the impact of <span class="hlt">groundwater</span> on the urban water systems, and producing information that can inform a water company's response to <span class="hlt">groundwater</span> flood risk, their decision making process and their asset management planning. However, the knowledge gained through integrated modelling of <span class="hlt">groundwater</span>-sewer interactions has highlighted limitations of existing approaches for the simulation of these coupled systems. We conclude this work with number of recommendations about how to improve such hydrological/sewer analysis.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014HESSD..11.5217D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014HESSD..11.5217D"><span>A high resolution global scale <span class="hlt">groundwater</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Graaf, I. E. M.; Sutanudjaja, E. H.; van Beek, L. P. H.; Bierkens, M. F. P.</p> <p>2014-05-01</p> <p><span class="hlt">Groundwater</span> is the world's largest accessible source of fresh water. It plays a vital role in satisfying needs for drinking water, agriculture and industrial activities. During times of drought <span class="hlt">groundwater</span> sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global scale hydrological models (GHMs) do not include a <span class="hlt">groundwater</span> flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and <span class="hlt">groundwater</span> head dynamics a realistic physical representation of the <span class="hlt">groundwater</span> system is needed, especially for GHMs that run at finer resolution. In this study we present a global scale <span class="hlt">groundwater</span> model (run at 6' as dynamic steady state) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The aquifer schematization and properties were based on available global datasets of lithology and transmissivities combined with estimated aquifer thickness of an upper unconfined aquifer. The model is forced with outputs from the land-surface model PCR-GLOBWB, specifically with net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed variation in saturated conductivity causes most of the <span class="hlt">groundwater</span> level variations. Simulated <span class="hlt">groundwater</span> heads were validated against reported piezometer observations. The validation showed that <span class="hlt">groundwater</span> depths are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional scale <span class="hlt">groundwater</span> patterns and flowpaths confirm the relevance of taking lateral <span class="hlt">groundwater</span> flow into account in GHMs. Flowpaths show inter-basin <span class="hlt">groundwater</span> flow that can be a significant part of a basins water budget and helps to sustain river baseflow, explicitly during times of droughts. Also important aquifer systems are recharged by inter-basin <span class="hlt">groundwater</span> flows that positively affect water</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3133Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3133Z"><span>Reconstruction of <span class="hlt">groundwater</span> circulation after seashore reclamation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xiaoying; Hu, Bill; Yang, Lei; Chen, Junbing</p> <p>2017-04-01</p> <p>In recent years, the effects of land reclamation on the coastal <span class="hlt">groundwater</span> system have received increasing attention in China as extensive reclamation activities have altered the original <span class="hlt">groundwater</span> dynamics and salinity distribution in the coastal subsurface. Previous studies focused on either the steady-state <span class="hlt">groundwater</span> flow or the large scale numerical simulation after land reclamation, however the short-period variation of <span class="hlt">groundwater</span> flow and its impacts on hydrogeochemical system have not often been considered. Furthermore, a permeable coastal boundary assumed exclusively in previous work is often not the case in contemporary engineering practice, and an impermeable coastal boundary with dikes has been adopted in this study. We investigate the temporal variation of <span class="hlt">groundwater</span> levels in the un-reclaimed clay layer and reclaimed layer based on the continuous observation of 14 monitoring wells in Zhoushan island, China. We use the morphological wave analysis method to study the effect of nonstationary tidal signals on <span class="hlt">groundwater</span> level fluctuations. The results indicate that the method of continuous wavelet transform is suitable for analyzing the <span class="hlt">groundwater</span> flow pattern, where short period <span class="hlt">groundwater</span> level fluctuations are affected by tidal activities through pipes built in the reclamation dike. In particular, the method of discrete wavelet transform (DWT) is proved effective in extracting tidal signals from <span class="hlt">groundwater</span> level time series. The approximation term in the multi-resolution analysis is well in agreement with original <span class="hlt">groundwater</span> level data, demonstrating the advantages of the DWT method in obtaining the change trends of geological, hydrological, and climate variables. Additionally, an examination of <span class="hlt">groundwater</span> samples indicates that saltwater exists in entire reclamation regions. Our study reveals some different <span class="hlt">groundwater</span> features in reclamation regions where the coastal boundary is impermeable, which could provide significant implications</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AdWR..102...53D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdWR..102...53D"><span>A global-scale two-layer transient <span class="hlt">groundwater</span> model: Development and application to <span class="hlt">groundwater</span> depletion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Graaf, Inge E. M.; van Beek, Rens L. P. H.; Gleeson, Tom; Moosdorf, Nils; Schmitz, Oliver; Sutanudjaja, Edwin H.; Bierkens, Marc F. P.</p> <p>2017-04-01</p> <p><span class="hlt">Groundwater</span> is the world's largest accessible source of freshwater to satisfy human water needs. Moreover, <span class="hlt">groundwater</span> buffers variable precipitation rates over time, thereby effectively sustaining river flows in times of droughts and evaporation in areas with shallow water tables. In this study, building on previous work, we simulate <span class="hlt">groundwater</span> head fluctuations and <span class="hlt">groundwater</span> storage changes in both confined and unconfined aquifer systems using a global-scale high-resolution (5‧) <span class="hlt">groundwater</span> model by deriving new estimates of the distribution and thickness of confining layers. Inclusion of confined aquifer systems (estimated 6-20% of the total aquifer area) improves estimates of timing and amplitude of <span class="hlt">groundwater</span> head fluctuations and changes <span class="hlt">groundwater</span> flow paths and <span class="hlt">groundwater</span>-surface water interaction rates. <span class="hlt">Groundwater</span> flow paths within confining layers are shorter than paths in the underlying aquifer, while flows within the confined aquifer can get disconnected from the local drainage system due to the low conductivity of the confining layer. Lateral <span class="hlt">groundwater</span> flows between basins are significant in the model, especially for areas with (partially) confined aquifers were long flow paths crossing catchment boundaries are simulated, thereby supporting water budgets of neighboring catchments or aquifer systems. The developed two-layer transient <span class="hlt">groundwater</span> model is used to identify hot-spots of <span class="hlt">groundwater</span> depletion. Global <span class="hlt">groundwater</span> depletion is estimated as 7013 km3 (137 km3y-1) over 1960-2010, which is consistent with estimates of previous studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990081162&hterms=moon+base&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmoon%2Bbase','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990081162&hterms=moon+base&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmoon%2Bbase"><span>Exploring Aristarchus <span class="hlt">Plateau</span> as a Potential Lunar Base Site</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coombs, Cassandra R.; Hawke, B. Ray; Allen, Carlton C.</p> <p>1998-01-01</p> <p>As part the exploration strategy, NASA has been studying the feasibility of a low cost human return to the Moon. The currently planned mission has a dual focus on the advancement of lunar science and the use of in situ resources. Thus far, our space exploration plans have relied almost exclusively on equipment and supplies transported from Earth. This may be appropriate for operations in Earth orbit, or for short duration stays on the lunar surface. However, the ability to "live off the land," will prove vital for long term habitation of the Moon and planets. This study takes a close look at the Aristarchus <span class="hlt">Plateau</span>, one of the primary candidate sites for human lunar exploration. Based on this synthesis study, we recommend two sites on the Aristarchus <span class="hlt">Plateau</span> that will maximize science return and provide a convincing demonstration of the use of in situ resources and which may be a viable future lunar base site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760003523','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760003523"><span>Tectonic analysis of folds in the Colorado <span class="hlt">plateau</span> of Arizona</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, G. H.</p> <p>1975-01-01</p> <p>Structural mapping and analysis of folds in Phanerozoic rocks in northern Arizona, using LANDSAT-1 imagery, yielded information for a tectonic model useful in identifying regional fracture zones within the Colorado <span class="hlt">Plateau</span> tectonic province. Since the monoclines within the province developed as a response to differential movements of basement blocks along high-angle faults, the monoclinal fold pattern records the position and trend of many elements of the regional fracture system. The <span class="hlt">Plateau</span> is divided into a mosaic of complex, polyhedral crustal blocks whose steeply dipping faces correspond to major fracture zones. Zones of convergence and changes in the trend of the monoclinal traces reveal the corners of the blocks. Igneous (and salt) diapirs have been emplaced into many of the designated zones of crustal weakness. As loci of major fracturing, folding, and probably facies changes, the fractures exert control on the entrapment of oil and gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5482058','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5482058"><span>Expansion of the Tibetan <span class="hlt">Plateau</span> during the Neogene</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Weitao; Zheng, Wenjun; Zhang, Peizhen; Li, Qiang; Kirby, Eric; Yuan, Daoyang; Zheng, Dewen; Liu, Caicai; Wang, Zhicai; Zhang, Huiping; Pang, Jianzhang</p> <p>2017-01-01</p> <p>The appearance of detritus shed from mountain ranges along the northern margin of the Tibetan <span class="hlt">Plateau</span> heralds the Cenozoic development of high topography. Current estimates of the age of the basal conglomerate in the Qaidam basin place this event in Paleocene-Eocene. Here we present new magnetostratigraphy and mammalian biostratigraphy that refine the onset of basin fill to ∼25.5 Myr and reveal that sediment accumulated continuously until ∼4.8 Myr. Sediment provenance implies a sustained source in the East Kunlun Shan throughout this time period. However, the appearance of detritus from the Qilian Shan at ∼12 Myr suggests emergence of topography north of the Qaidam occurred during the late Miocene. Our results imply that deformation and mountain building significantly post-date Indo-Asian collision and challenge the suggestion that the extent of the <span class="hlt">plateau</span> has remained constant through time. Rather, our results require expansion of high topography during the past 25 Myr. PMID:28635970</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20353056','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20353056"><span>[Carbon sequestration of young Robinia pseudoacacia plantation in Loess <span class="hlt">Plateau</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Jing-qun; Su, Yin-quan; Kang, Yong-xiang; Xu, Xi-ming; Qin, Yue</p> <p>2009-12-01</p> <p>In order to understand the carbon sequestration of ecological forests in Loess <span class="hlt">Plateau</span>, a comparative study was made on the organic carbon density (OCD) of soil, litter, and plant organs in an 8-year-old Robinia pseudoacacia plantation and nearby barren land. Comparing with the barren land, the young R. pseudoacacia plantation had a decrease (0.26 kg x m(-2)) of soil OCD, but the OCD in its litter, root system, and aboveground organs increased by 121.1%, 202.0%, and 656. 7%, respectively, with a total carbon sequestration increased by 3.3% annually, which illustrated that R. pseudoacacia afforestation on Loess <span class="hlt">Plateau</span> had an obvious positive effect on carbon sequestration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990081162&hterms=lunar+base&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlunar%2Bbase','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990081162&hterms=lunar+base&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlunar%2Bbase"><span>Exploring Aristarchus <span class="hlt">Plateau</span> as a Potential Lunar Base Site</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coombs, Cassandra R.; Hawke, B. Ray; Allen, Carlton C.</p> <p>1998-01-01</p> <p>As part the exploration strategy, NASA has been studying the feasibility of a low cost human return to the Moon. The currently planned mission has a dual focus on the advancement of lunar science and the use of in situ resources. Thus far, our space exploration plans have relied almost exclusively on equipment and supplies transported from Earth. This may be appropriate for operations in Earth orbit, or for short duration stays on the lunar surface. However, the ability to "live off the land," will prove vital for long term habitation of the Moon and planets. This study takes a close look at the Aristarchus <span class="hlt">Plateau</span>, one of the primary candidate sites for human lunar exploration. Based on this synthesis study, we recommend two sites on the Aristarchus <span class="hlt">Plateau</span> that will maximize science return and provide a convincing demonstration of the use of in situ resources and which may be a viable future lunar base site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14755852','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14755852"><span>[Radon-222 in drinking water of Karkonoskie <span class="hlt">Plateau</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pachocki, Krzysztof A; Gorzkowski, Bohdan; Rózycki, Zdzisław; Wieprzowski, Kamil; Bekas, Marcin; Wilejczyk, Elzbieta; Smoter, Jacek</p> <p>2003-01-01</p> <p>Radon-222 concentration in surface water, wells water and tap water in the main towns and villages which are located in area of Karkonoskie <span class="hlt">Plateau</span> has been quantitative determined. The measurements were performed using the alpha liquid scintillation counting method. Majority of waterworks in Karkonoskie <span class="hlt">Plateau</span> is supplied with the ground water in which the radon concentration is high from 87.5 Bq/l to 818.1 Bq/l. The waterworks in Karpacz are supplied with the surface water, which main characteristic is low radon concentration (below 10 Bq/l) and with the ground water have a high radon concentration (to 541 Bq/l). Radon-222 concentration in water of individual wells was similar to concentration in the ground water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19723249','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19723249"><span>Carbon sequestration in two alpine soils on the Tibetan <span class="hlt">Plateau</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tian, Yu-Qiang; Xu, Xing-Liang; Song, Ming-Hua; Zhou, Cai-Ping; Gao, Qiong; Ouyang, Hua</p> <p>2009-09-01</p> <p>Soil carbon sequestration was estimated in a conifer forest and an alpine meadow on the Tibetan <span class="hlt">Plateau</span> using a carbon-14 radioactive label provided by thermonuclear weapon tests (known as bomb-(14)C). Soil organic matter was physically separated into light and heavy fractions. The concentration spike of bomb-(14)C occurred at a soil depth of 4 cm in both the forest soil and the alpine meadow soil. Based on the depth of the bomb-(14)C spike, the carbon sequestration rate was determined to be 38.5 g C/m(2) per year for the forest soil and 27.1 g C/m(2) per year for the alpine meadow soil. Considering that more than 60% of soil organic carbon (SOC) is stored in the heavy fraction and the large area of alpine forests and meadows on the Tibetan <span class="hlt">Plateau</span>, these alpine ecosystems might partially contribute to "the missing carbon sink".</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGP53A3760H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGP53A3760H"><span>Independently dated paleomagnetic secular variation records from the Tibetan <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haberzettl, T.; Henkel, K.; Kasper, T.; Ahlborn, M.; Su, Y.; Appel, E.; St-Onge, G.; Stoner, J. S.; Daut, G.; Wang, J.; Zhu, L.; Maeusbacher, R.</p> <p>2014-12-01</p> <p>Magnetostratigraphy has been serving as a valuable tool for dating and confirming chronologies of lacustrine sediments in many parts of the world. However, suitable paleomagnetic records on the Tibetan <span class="hlt">Plateau</span> (TP) and adjacent areas are extremely scarce. Here, independently radiocarbon dated sediments of two lakes on the southern central TP, Tangra Yumco and Taro Co some 250 km further west, were investigated for their potential to record paleomagnetic secular variations. Multiple sediment cores resemble a very similar inclination pattern for the past 4000 years. This demonstrates the high potential of inclination to compare records over the Tibetan <span class="hlt">Plateau</span> and eventually date other Tibetan records stratigraphically. Comparisons to an existing record from Nam Co, a lake 350 km west of Tangra Yumco, a varve dated record from the Makran Accretionary Wedge, and a stack record from East Asia reveal many similarities. However, model output data of geomagnetic field models for the coordinates of Tangra Yumco do not agree with our findings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25241526','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25241526"><span>[Minimally invasive treatment of tibial <span class="hlt">plateau</span> fracture under arthroscopy monitoring].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Lixin; Ma, Shaoyun; Li, Xianpeng</p> <p>2014-05-01</p> <p>Twenty six patients with fracture of tibial <span class="hlt">plateau</span> was under arthroscopy assisted reduction, the joint surface of bone graft, and USES the steel plate fixation treatment. Average surgery time was 65 min (70-120 min), average fracture healing time was 15 weeks (12-17 weeks), joint surface anatomical reattachment rate was 92.9%. Using break knee function criteria evaluation of curative effect: 18 cases great 6 cases wed, 2 cases ok, fine rate was 92.3%. No infection, deep venous thrombosis and small leg fascia chamber syndrome and other complications. Conclusion is that treatment of tibial <span class="hlt">plateau</span> fractures under arthroscope has advantages of small trauma, check intuitively and reset accurately, functional recovery of patients are satisfied, the treatment has certain clinical application value.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatCo...815887W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatCo...815887W"><span>Expansion of the Tibetan <span class="hlt">Plateau</span> during the Neogene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Weitao; Zheng, Wenjun; Zhang, Peizhen; Li, Qiang; Kirby, Eric; Yuan, Daoyang; Zheng, Dewen; Liu, Caicai; Wang, Zhicai; Zhang, Huiping; Pang, Jianzhang</p> <p>2017-06-01</p> <p>The appearance of detritus shed from mountain ranges along the northern margin of the Tibetan <span class="hlt">Plateau</span> heralds the Cenozoic development of high topography. Current estimates of the age of the basal conglomerate in the Qaidam basin place this event in Paleocene-Eocene. Here we present new magnetostratigraphy and mammalian biostratigraphy that refine the onset of basin fill to ~25.5 Myr and reveal that sediment accumulated continuously until ~4.8 Myr. Sediment provenance implies a sustained source in the East Kunlun Shan throughout this time period. However, the appearance of detritus from the Qilian Shan at ~12 Myr suggests emergence of topography north of the Qaidam occurred during the late Miocene. Our results imply that deformation and mountain building significantly post-date Indo-Asian collision and challenge the suggestion that the extent of the <span class="hlt">plateau</span> has remained constant through time. Rather, our results require expansion of high topography during the past 25 Myr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70030515','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70030515"><span>Mantle structure beneath the western edge of the Colorado <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sine, C.R.; Wilson, D.; Gao, W.; Grand, S.P.; Aster, R.; Ni, J.; Baldridge, W.S.</p> <p>2008-01-01</p> <p>Teleseismic traveltime data are inverted for mantle Vp and Vs variations beneath a 1400 km long line of broadband seismometers extending from eastern New Mexico to western Utah. The model spans 600 km beneath the moho with resolution of ???50 km. Inversions show a sharp, large-magnitude velocity contrast across the Colorado <span class="hlt">Plateau</span>-Great Basin transition extending ???200 km below the crust. Also imaged is a fast anomaly 300 to 600 km beneath the NW portion of the array. Very slow velocities beneath the Great Basin imply partial melting and/or anomalously wet mantle. We propose that the sharp contrast in mantle velocities across the western edge of the <span class="hlt">Plateau</span> corresponds to differential lithospheric modification, during and following Farallon subduction, across a boundary defining the western extent of unmodified Proterozoic mantle lithosphere. The deep fast anomaly corresponds to thickened Farallon plate or detached continental lithosphere at transition zone depths. Copyright 2008 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70013725','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70013725"><span><span class="hlt">Groundwater</span> flow and transport modeling</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Konikow, L.F.; Mercer, J.W.</p> <p>1988-01-01</p> <p>Deterministic, distributed-parameter, numerical simulation models for analyzing <span class="hlt">groundwater</span> flow and transport problems have come to be used almost routinely during the past decade. A review of the theoretical basis and practical use of <span class="hlt">groundwater</span> flow and solute transport models is used to illustrate the state-of-the-art. Because of errors and uncertainty in defining model parameters, models must be calibrated to obtain a best estimate of the parameters. For flow modeling, data generally are sufficient to allow calibration. For solute-transport modeling, lack of data not only limits calibration, but also causes uncertainty in process description. Where data are available, model reliability should be assessed on the basis of sensitivity tests and measures of goodness-of-fit. Some of these concepts are demonstrated by using two case histories. ?? 1988.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920001551','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920001551"><span>A Martian global <span class="hlt">groundwater</span> model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Howard, Alan D.</p> <p>1991-01-01</p> <p>A global <span class="hlt">groundwater</span> flow model was constructed for Mars to study hydrologic response under a variety of scenarios, improving and extending earlier simple cross sectional models. The model is capable of treating both steady state and transient flow as well as permeability that is anisotropic in the horizontal dimensions. A single near surface confining layer may be included (representing in these simulations a coherent permafrost layer). Furthermore, in unconfined flow, locations of complete saturation and seepage are determined. The flow model assumes that <span class="hlt">groundwater</span> gradients are sufficiently low that DuPuit conditions are satisfied and the flow component perpendicular to the ground surface is negligible. The flow equations were solved using a finite difference method employing 10 deg spacing of latitude and longitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol26/pdf/CFR-2011-title40-vol26-sec265-91.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol26/pdf/CFR-2011-title40-vol26-sec265-91.pdf"><span>40 CFR 265.91 - <span class="hlt">Ground-water</span> monitoring system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 26 2011-07-01 2011-07-01 false <span class="hlt">Ground-water</span> monitoring system. 265.91... DISPOSAL FACILITIES <span class="hlt">Ground-Water</span> Monitoring § 265.91 <span class="hlt">Ground-water</span> monitoring system. (a) A <span class="hlt">ground-water</span> monitoring system must be capable of yielding <span class="hlt">ground-water</span> samples for analysis and must consist of:...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol27/pdf/CFR-2013-title40-vol27-sec265-91.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol27/pdf/CFR-2013-title40-vol27-sec265-91.pdf"><span>40 CFR 265.91 - <span class="hlt">Ground-water</span> monitoring system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 40 Protection of Environment 27 2013-07-01 2013-07-01 false <span class="hlt">Ground-water</span> monitoring system. 265.91... DISPOSAL FACILITIES <span class="hlt">Ground-Water</span> Monitoring § 265.91 <span class="hlt">Ground-water</span> monitoring system. (a) A <span class="hlt">ground-water</span> monitoring system must be capable of yielding <span class="hlt">ground-water</span> samples for analysis and must consist of: (1...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol27/pdf/CFR-2012-title40-vol27-sec265-91.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol27/pdf/CFR-2012-title40-vol27-sec265-91.pdf"><span>40 CFR 265.91 - <span class="hlt">Ground-water</span> monitoring system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 40 Protection of Environment 27 2012-07-01 2012-07-01 false <span class="hlt">Ground-water</span> monitoring system. 265.91... DISPOSAL FACILITIES <span class="hlt">Ground-Water</span> Monitoring § 265.91 <span class="hlt">Ground-water</span> monitoring system. (a) A <span class="hlt">ground-water</span> monitoring system must be capable of yielding <span class="hlt">ground-water</span> samples for analysis and must consist of:...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol26/pdf/CFR-2014-title40-vol26-sec265-91.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol26/pdf/CFR-2014-title40-vol26-sec265-91.pdf"><span>40 CFR 265.91 - <span class="hlt">Ground-water</span> monitoring system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 40 Protection of Environment 26 2014-07-01 2014-07-01 false <span class="hlt">Ground-water</span> monitoring system. 265.91... DISPOSAL FACILITIES <span class="hlt">Ground-Water</span> Monitoring § 265.91 <span class="hlt">Ground-water</span> monitoring system. (a) A <span class="hlt">ground-water</span> monitoring system must be capable of yielding <span class="hlt">ground-water</span> samples for analysis and must consist of:...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/471593','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/471593"><span>Computers bail out <span class="hlt">groundwater</span> cleanup</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Harte, R.</p> <p>1997-01-01</p> <p>Using computers to automate <span class="hlt">groundwater</span> remediation systems can increase efficiency and improve record keeping. This article uses an example of leakage of petroleum products from a petroleum storage facility which is mitigated within a 17 acre area. The Mistic computer center is a stand-alone processing unit that receives status inputs from each piece of equipment, interprets the condition of the system and then instructs the equipment how to respond. 1 fig.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70019338','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70019338"><span>Direct simulation of <span class="hlt">groundwater</span> age</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Goode, D.J.</p> <p>1996-01-01</p> <p>A new method is proposed to simulate <span class="hlt">groundwater</span> age directly, by use of an advection-dispersion transport equation with a distributed zero-order source of unit (1) strength, corresponding to the rate of aging. The dependent variable in the governing equation is the mean age, a mass- weighted average age. The governing equation is derived from residence- time-distribution concepts for the case of steady flow. For the more general case of transient flow, a transient governing equation for age is derived from mass-conservation principles applied to conceptual 'age mass.' The age mass is the product of the water mass and its age, and age mass is assumed to be conserved during mixing. Boundary conditions include zero age mass flux across all noflow and inflow boundaries trod no age mass dispersive flux across outflow boundaries. For transient-flow conditions, the initial distribution of age must be known. The solution of the governing transport equation yields the spatial distribution of the mean <span class="hlt">groundwater</span> age and includes diffusion, dispersion, mixing, and exchange processes that typically are considered only through tracer-specific solute transport simulation. Traditional methods have relied on advective transport to predict point values of <span class="hlt">groundwater</span> travel time and age. The proposed method retains the simplicity and tracer-independence of advection-only models, but incorporates the effects of dispersion and mixing on volume- averaged age. Example simulations of age in two idealized regional aquifer systems, one homogeneous and the other layered, demonstrate the agreement between the proposed method and traditional particle-tracking approaches and illustrate use of the proposed method to determine the effects of diffusion, dispersion, and mixing on <span class="hlt">groundwater</span> age.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12830933','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12830933"><span><span class="hlt">Groundwater</span> abstraction pollution risk assessment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lytton, L; Howe, S; Sage, R; Greenaway, P</p> <p>2003-01-01</p> <p>A generic <span class="hlt">groundwater</span> pollution risk assessment methodology has been developed to enable the evaluation and ranking of the potential risk of pollution to <span class="hlt">groundwater</span> abstractions. The ranking can then be used to prioritise risk management or mitigation procedures in a robust and quantifiable framework and thus inform business investment decisions. The risk assessment consider the three components of the pollution transport model: source-pathway-receptor. For <span class="hlt">groundwater</span> abstractions these correspond to land use (with associated pollutants and shallow subsurface characteristics), aquifer and the abstraction borehole. An hierarchical approach was chosen to allow the risk assessment to be successfully carried out with different quality data for different parts of the model. The 400-day <span class="hlt">groundwater</span> protection zone defines the catchment boundary that form the spatial limit of the land use audit for each receptor. A risk score is obtained for each land use (potential pollution source) within the catchment. These scores are derived by considering the characteristics (such as load, persistence and toxicity) of all pollutants pertaining to each land use, their on-site management and the potential for the unsaturated subsurface to attenuate their effects in the event of a release. Risk scores are also applied to the aquifer characteristics (as pollutant pathway) and to the abstraction borehole (as pollutant receptor). Each risk score is accompanied by an uncertainty score which provides a guide to the confidence in the data used to compile the risk assessment. The application of the methodology has highlighted a number of problems in this type of work and results of initial case studies are being used to trial alternative scoring methods and a more simplified approach to accelerate the process of pollution risk assessment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA622572','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA622572"><span>Surface Wave Attenuation in the Tibetan <span class="hlt">Plateau</span> from Ambient Noise</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-08-31</p> <p>is unlimited. 16 DISTRIBUTION LIST DTIC/OCP 8725 John J. Kingman Rd, Suite 0944 Ft Belvoir, VA 22060-6218 1 cy AFRL /RVIL Kirtland AFB, NM... AFRL -RV-PS- TR-2015-0150 AFRL -RV-PS- TR-2015-0150 SURFACE WAVE ATTENUATION IN THE TIBETAN <span class="hlt">PLATEAU</span> FROM AMBIENT NOISE University of Illinois at...DISTRIBUTION IS UNLIMITED. AIR FORCE RESEARCH LABORATORY Space Vehicles Directorate 3550 Aberdeen Ave SE AIR FORCE MATERIEL COMMAND KIRTLAND AIR</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S31E2283Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S31E2283Z"><span>Crustal Lg-wave attenuation in and around Tibetan <span class="hlt">plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Xie, X.; Yao, Z.</p> <p>2011-12-01</p> <p>Based on regional Lg-wave data, we develop a broadband high-resolution attenuation model for Tibetan <span class="hlt">Plateau</span> and its surrounding regions. We collect vertical component seismograms recorded at 146 stations form 232 crustal earthquakes to calculate the Lg-wave amplitude spectra. The spectra are sampled at 58 discrete frequencies distributed log evenly between 0.05 and 10.0 Hz. Both dual-station and single-station datasets are constructed for jointly inverting the Lg Q distribution and Lg wave excitation function. The maximum spatial resolution is approximately 0.8°×0.8° in well-covered areas and for frequencies between 0.5 and 2.0 Hz. The Lg Q image reveals the relations between attenuations and geological structures. The average Lg Q0 (1 Hz Q) is 280 for Tibetan <span class="hlt">Plateau</span> (regions with elevations above 4,000 m ). The Q0 values change from the south to north by first decrease (the Himalaya: 386, Lhasa : 284, Qiangtang: 238, and Songpan-Ganze blocks: 217), and then increase ( East Kunlun: 289, West Kunlun: 330, and Qilianshan blocks: 315). The QLg distributions are consistent with the lower crust material flow around the Eastern Himalayan syntaxis and the rigid Sichuan basin. The regions surrounding the Tibetan <span class="hlt">plateau</span> are characterized by high Q0 values (Tarim basin: 433, Altyn mountain: 517, Qaidam basin: 385, Alashan uplift: 452, Inner Mongolian platform: 444, Ordos: 395, and Sichuan basins: 456), except for Yungui <span class="hlt">Plateau</span> which has a relatively low Q0 of 247. A statistical method is used to investigate the regional variations of the Lg Q frequency dependence. The Lg Q generally increases with the increase of frequencies but show complex frequency dependency, indicating the commonly used power-law Q model may not be appropriate within a broad frequency band. The Lg Q frequency dependence also shows regional variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/50273','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/50273"><span>Evaluating first-year pine seedling survival <span class="hlt">plateau</span> in Louisiana</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Puskar N. Khana; Thomas J. Dean; Scott D. Roberts; Donald L. Grebner</p> <p>2016-01-01</p> <p>First-year seeding survival has been a continuing problem since the start of commercial pine plantation forestry in the 1950s. First-year survival of bare-root loblolly pine seedlings on intensively prepared sites in Louisiana has maintained a survival <span class="hlt">plateau</span> between 79 to 89 percent with an average of about 82 percent. The specific objectives of this study were to...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.uapress.arizona.edu/Books/bid1540.htm','USGSPUBS'); return false;" href="http://www.uapress.arizona.edu/Books/bid1540.htm"><span>The Colorado <span class="hlt">Plateau</span>: cultural, biological, and physical research</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cole, Kenneth L.; van Riper, Charles</p> <p>2004-01-01</p> <p>Stretching from the four corners of Arizona, New Mexico, Colorado, and Utah, the Colorado <span class="hlt">Plateau</span> is a natural laboratory for a wide range of studies. This volume presents 23 original articles drawn from more than 100 research projects presented at the Sixth Biennial Conference of Research on the Colorado <span class="hlt">Plateau</span>. This scientific gathering revolved around research, inventory, and monitoring of lands in the region. The book's contents cover management techniques for cultural, biological, and physical resources, representing collaborative efforts among federal, university, and private sector scientists and land managers. Chapters on cultural concerns cover benchmarks of modern southwestern anthropological knowledge, models of past human activity and impact of modern visitation at newly established national monuments, challenges in implementing the 1964 Wilderness Act, and opportunities for increased federal research on Native American lands. The section on biological resources comprises sixteen chapters, with coverage that ranges from mammalian biogeography to responses of elk at the urban-wildland interface. Additional biological studies include the effects of fire and grazing on vegetation; research on bald eagles at Grand Canyon and tracking wild turkeys using radio collars; and management of palentological resources. Two final chapters on physical resources consider a proposed rerouting of the Rio de Flag River in urban Flagstaff, Arizona, and an examination of past climate patterns over the <span class="hlt">Plateau</span>, using stream flow records and tree ring data. In light of similarities in habitat and climate across the Colorado <span class="hlt">Plateau</span>, techniques useful to particular management units have been found to be applicable in many locations. This volume highlights an abundance of research that will prove useful for all of those working in the region, as well as for others seeking comparative studies that integrate research into land management actions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5779N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5779N"><span>Landslide development within the Barlad <span class="hlt">Plateau</span> of Eastern Romania</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niacsu, Lilian; Ionita, Ion</p> <p>2014-05-01</p> <p>The Barlad <span class="hlt">Plateau</span>, extending about 8,230 square kilometers is considered as the most typical unit of the Moldavian <span class="hlt">Plateau</span> of the Eastern Romania. The Miocene-Pliocene clay-sandy layers are inter-bedded with shallow sandstone and limestone seams. These sedimentary layers that have outcropped as a result of erosion are gently dipping toward S-SE in the form of a monocline. Landslides have been recognized as an important environmental threat in the major subunits of the Barlad <span class="hlt">Plateau</span>, namely: Central Moldavian <span class="hlt">Plateau</span>, Falciu Hills and Tutova Rolling Hills. Four main areas of monitoring landslides were explored such as successive aerial photographs of the 1960, 1970, 2005 and 2009 flights, repeated field surveys for a thorough reconnaissance of the study area, classical levelling work and GIS software applications as TNT Mips and Arc GIS. Also, the Caesium-137 technique has been used to get information on documenting sedimentation rates in some small catchments. Results have indicated that the landslide development is strongly controlled by the northern and western looking steep faces of cuestas, by changes of rock composition and by human impact. Also, it showed great pulses in conjunction with the rainfall distribution. For example, half of the Upper Barlad catchment that drains an area of 22,560 ha is covered by landslides. Furthermore, the active landslides amounted 11% of the total (2,317 ha) after the rainy 1968-1973 period and since 1982 under drier conditions they gradually limited to 444.0 ha (2% of the total).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...806..225P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...806..225P"><span>On the Intrinsic Diversity of Type II-<span class="hlt">Plateau</span> Supernovae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pejcha, Ondřej; Prieto, Jose L.</p> <p>2015-06-01</p> <p>Hydrogen-rich Type II-<span class="hlt">Plateau</span> supernovae (SNe) exhibit correlations between the <span class="hlt">plateau</span> luminosity {L}{pl}, the nickel mass {M}{Ni}, the explosion energy {E}{exp}, and the ejecta mass {M}{ej}. Using our global, self-consistent, multi-band model of nearby well-observed SNe, we find that the covariances of these quantities are strong and that the confidence ellipsoids are oriented in the direction of the correlations, which reduces their significance. By proper treatment of the covariance matrix of the model, we discover a significant intrinsic width to the correlations between {L}{pl}, {E}{exp} and {M}{Ni}, where the uncertainties due to the distance and the extinction dominate. For fixed {E}{exp}, the spread in {M}{Ni} is about 0.25 dex, which we attribute to the differences in the progenitor internal structure. We argue that the effects of incomplete γ-ray trapping are not important in our sample. Similarly, the physics of the Type II-<span class="hlt">Plateau</span> SN light curves leads to inherently degenerate estimates of {E}{exp} and {M}{ej}, which makes their observed correlation weak. Ignoring the covariances of SN parameters or the intrinsic width of the correlations causes significant biases in the slopes of the fitted relations. Our results imply that Type II-<span class="hlt">Plateau</span> SN explosions are not described by a single physical parameter or a simple one-dimensional trajectory through the parameter space, but instead reflect the diversity of the core and surface properties of their progenitors. We discuss the implications for the physics of the explosion mechanism and possible future observational constraints.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ngmdb.usgs.gov/Prodesc/proddesc_6570.htm','USGSPUBS'); return false;" href="http://ngmdb.usgs.gov/Prodesc/proddesc_6570.htm"><span>Florida-Hatteras shelf and slope, and inner Blake <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Paull, Charles K.; Popenoe, Peter; Dillon, William P.; McCarthy, Susan M.</p> <p>1980-01-01</p> <p>During 1976 more than 5000 kilometers (km) of seismic-reflection profiles were obtained on the Florida-Hatteras shelf and slope, and the inner Blake <span class="hlt">Plateau</span>. From these data reflecting units were traced regionally (Paull and Dillon, 1979; Edsal, 1979), and the structure and stratigraphy of the shelf were determined This geologic subcrop map is based largely on the interpretation of Paull and Dillon (1979).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22293649','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22293649"><span>Construction of the Largest Radionuclide Commingled Plume <span class="hlt">Groundwater</span> Treatment Facility for the Department of Energy at the Hanford Site - 12411</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pargmann, Delise</p> <p>2012-07-01</p> <p>CH2M Hill <span class="hlt">Plateau</span> Remediation Company (CHPRC) has constructed the largest <span class="hlt">groundwater</span> treatment systems of its kind throughout the DOE Complex at the Hanford Site in an accelerated manner with American Recovery and Reinvestment Act (ARRA) funds. This complex, one of a kind <span class="hlt">groundwater</span> treatment facility in Washington State has also attained Leadership in Energy and Environmental Design (LEED) Gold certification. The original concept for the 200 West Area <span class="hlt">groundwater</span> treatment facility was a 6100 liter per minute (1,600 gallon per minute) facility. With additional ARRA funding, the plant design was improved to construct a 9500 liter per minute (2,500 gallon per minute) facility with expansion areas up to 14,000 liter per minute (3,750 gallon per minute). The current design will remove 53 percent more mass per year for faster clean-up. It is also expected to treat extracted <span class="hlt">groundwater</span> to 25 percent or less than the Record of Decision-specified limit which improves Monitored Natural Attenuation (MNA) effectiveness. (author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H21F1119Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H21F1119Z"><span><span class="hlt">Groundwater</span> subsidies and penalties to corn yield</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zipper, S. C.; Booth, E.; Loheide, S. P.</p> <p>2013-12-01</p> <p>Proper water management is critical to closing yield gaps (observed yield below potential yield) as global populations continue to expand. However, the impacts of shallow <span class="hlt">groundwater</span> on crop production and surface processes are poorly understood. The presence of <span class="hlt">groundwater</span> within or just below the root zone has the potential to cause (via oxygen stress in poorly drained soils) or eliminate (via water supply in dry regions) yield gaps. The additional water use by a plant in the presence of shallow <span class="hlt">groundwater</span>, compared to free drainage conditions, is called the <span class="hlt">groundwater</span> subsidy; the depth at which the <span class="hlt">groundwater</span> subsidy is greatest is the optimal depth to <span class="hlt">groundwater</span> (DTGW). In wet years or under very shallow water table conditions, the <span class="hlt">groundwater</span> subsidy is likely to be negative due to increased oxygen stress, and can be thought of as a <span class="hlt">groundwater</span> penalty. Understanding the spatial dynamics of <span class="hlt">groundwater</span> subsidies/penalties and how they interact with weather is critical to making sustainable agricultural and land-use decisions under a range of potential climates. Here, we examine patterns of <span class="hlt">groundwater</span> subsidies and penalties in two commercial cornfields in the Yahara River Watershed, an urbanizing agricultural watershed in south-central Wisconsin. Water table levels are generally rising in the region due to a long-term trend of increasing precipitation over the last several decades. Biophysical indicators tracked throughout both the 2012 and 2013 growing seasons show a strong response to variable <span class="hlt">groundwater</span> levels on a field scale. Sections of the field with optimal DTGW exhibit consistently higher stomatal conductance rates, taller canopies and higher leaf area index, higher ET rates, and higher pollination success rates. Patterns in these biophysical lines of evidence allow us to pinpoint specific periods within the growing season that plants were experiencing either oxygen or water stress. Most importantly, <span class="hlt">groundwater</span> subsidies and penalties are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873659','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873659"><span>Situ treatment of contaminated <span class="hlt">groundwater</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>McNab, Jr., Walt W.; Ruiz, Roberto; Pico, Tristan M.</p> <p>2001-01-01</p> <p>A system for treating dissolved halogenated organic compounds in <span class="hlt">groundwater</span> that relies upon electrolytically-generated hydrogen to chemically reduce the halogenated compounds in the presence of a suitable catalyst. A direct current is placed across at least a pair, or an array, of electrodes which are housed within <span class="hlt">groundwater</span> wells so that hydrogen is generated at the cathode and oxygen at the anode. A pump is located within the well housing in which the cathode(s) is(are) located and draws in <span class="hlt">groundwater</span> where it is hydrogenated via electrolysis, passes through a well-bore treatment unit, and then transported to the anode well(s) for reinjection into the ground. The well-bore treatment involves a permeable cylinder located in the well bore and containing a packed bed of catalyst material that facilitates the reductive dehalogenation of the halogenated organic compounds by hydrogen into environmentally benign species such as ethane and methane. Also, electro-osmatic transport of contaminants toward the cathode also contributes to contaminant mass removal. The only above ground equipment required are the transfer pipes and a direct circuit power supply for the electrodes. The electrode wells in an array may be used in pairs or one anode well may be used with a plurality of cathode wells. The DC current flow between electrode wells may be periodically reversed which controls the formation of mineral deposits in the alkaline cathode well-bore water, as well as to help rejuvenate the catalysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.springer.com/earth+sciences+and+geography/geology/book/978-94-007-4374-8','USGSPUBS'); return false;" href="http://www.springer.com/earth+sciences+and+geography/geology/book/978-94-007-4374-8"><span>Modeling <span class="hlt">groundwater</span> flow and quality</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Konikow, Leonard F.; Glynn, Pierre D.; Selinus, Olle</p> <p>2013-01-01</p> <p>In most areas, rocks in the subsurface are saturated with water at relatively shallow depths. The top of the saturated zone—the water table—typically occurs anywhere from just below land surface to hundreds of feet below the land surface. <span class="hlt">Groundwater</span> generally fills all pore spaces below the water table and is part of a continuous dynamic flow system, in which the fluid is moving at velocities ranging from feet per millennia to feet per day (Fig. 33.1). While the water is in close contact with the surfaces of various minerals in the rock material, geochemical interactions between the water and the rock can affect the chemical quality of the water, including pH, dissolved solids composition, and trace-elements content. Thus, flowing <span class="hlt">groundwater</span> is a major mechanism for the transport of chemicals from buried rocks to the accessible environment, as well as a major pathway from rocks to human exposure and consumption. Because the mineral composition of rocks is highly variable, as is the solubility of various minerals, the human-health effects of <span class="hlt">groundwater</span> consumption will be highly variable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009HydJ...17..367S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009HydJ...17..367S"><span><span class="hlt">Groundwater</span> management in northern Iraq</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stevanovic, Zoran; Iurkiewicz, Adrian</p> <p>2009-03-01</p> <p><span class="hlt">Groundwater</span> is vital and the sole resource in most of the studied region of northern Iraq. It has a significant role in agriculture, water supply and health, and the elimination of poverty in rural areas. Although Iraq is currently dramatically disturbed by complex political and socio-economic problems, in its northern part, i.e. the Kurdish-inhabited region, fast urbanization and economic expansion are visible everywhere. Monitoring and water management schemes are necessary to prevent aquifer over-exploitation in the region. Artificial recharge with temporary runoff water, construction of subsurface dams and several other aquifer management and regulation measures have been designed, and some implemented, in order to improve the water situation. Recommendations, presented to the local professionals and decision-makers in water management, include creation of Water Master Plans and Water User Associations, synchronization of drilling programmes, rehabilitation of the existing well fields, opening of new well fields, and the incorporation of new spring intakes in some areas with large <span class="hlt">groundwater</span> reserves, as well as construction of numerous small-scale schemes for initial in situ water treatment where saline <span class="hlt">groundwater</span> is present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/467722','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/467722"><span>Sparging effectiveness for <span class="hlt">groundwater</span> restoration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Boersma, P.M.; Piontek, K.R.; Newman, P.A.B.</p> <p>1995-12-31</p> <p>Sparging is becoming a widely applied <span class="hlt">groundwater</span> remediation technology, even though there are few published case studies with post-sparging <span class="hlt">groundwater</span> monitoring data to document cleanup. The best way to monitor the effectiveness of sparging systems and predict achievable postsparging contaminant concentrations is still uncertain. Most monitoring data from sparging systems are indirect measurements of system performance [dissolved oxygen, <span class="hlt">groundwater</span> levels, soil vapor pressures, soil vapor oxygen/volatile organic compound (VOC) concentrations] rather than direct analysis of dissolved-phase contaminants. Furthermore, few distinctions have been made regarding achievable cleanup levels and required treatment durations in (1) dissolved-phase plumes and (2) source areas with residual nonaqueous-phase liquid (NAPL). This paper discusses changes in dissolved-phase chlorinated volatile organic compound (CVOC) concentrations at two sites where sparging was undertaken. Both sites are favorable for sparging, having relatively uniform, clean, fine- to medium-grained sandy soil. One site had a known presence of NAPL, while the other was a dissolved-phase plume without NAPL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T13B2991S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T13B2991S"><span>Regional Phase Attenuation across the Turkish-Iranian <span class="hlt">Plateau</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandvol, E. A.; Kaviani, A.; Ku,