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Sample records for hydrogeology

  1. Hydrogeology

    SciTech Connect

    Back, W.; Rosenshein, J.S.; Seaber, P.R.

    1988-01-01

    This book demonstrates hydrogeologic principles, concepts, and processes that control the occurrence, movement, storage, and chemical character of ground water. It aims to identify, clarify, and describe systematically the basic relation of hydrogeology to other disciplines of geology, such as geomorphology, stratigraphy, structure, and historical geology.

  2. Contaminant hydrogeology

    SciTech Connect

    Fetter, C.W.

    1993-01-01

    Hydrogeology is a rapidly evolving field in which new approaches and tools are being applied to solve problems. This new book fills an important niche. Fetter focuses primarily on chemical processes in the subsurface, avoiding duplication of materials that are covered in other, more classical texts. This book is an excellent follow-up to his earlier text, Applied Hydrogeology, and reviews only briefly the foundational concepts covered in the earlier textbook. Contaminant Hydrogeology is written at the graduate student level and assumes prerequisite courses in physics, chemistry, and hydrogeology. For the most part, each of the nine chapters covers a major area of concern common to applied contaminant studies. A thorough, theoretical treatment of solute transport through the vadose zone is presented, and a sample problem and a case study add unusually high value to this discussion of a topic that generally is not well understood in the practice. Topics covered include the Buckingham Flux Law, the Richards Equation, vapor-phase transport, equilibrium and nonequilibrium models of mass transport, and preferential flow paths. Nonaqueous-phase liquid migrations under both saturated and unsaturated conditions is covered for horizontal as well as vertical migration. Both light and dense nonaqueous phase liquids are presented, and Darcy's Law for two-phase flow is introduced. The strength of Contaminant Hydrogeology lies in the author's ability to translate concepts through practical experience. This book links the theoretical to the practical through example problems and case histories. It should be considered for use in graduate classes and would be a valuable reference in the library of any practicing hydrogeologist.

  3. Undergraduate Education in Hydrogeology.

    ERIC Educational Resources Information Center

    Tinker, John Richard, Jr.

    1989-01-01

    Discusses a course at the University of Wisconsin-Eau Claire which improved instruction in physical hydrogeology, chemical hydrogeology, and water resources. Describes 14 laboratory activities including objectives, methods, and a list of equipment needed. (Author/MVL)

  4. Fault zone hydrogeology

    NASA Astrophysics Data System (ADS)

    Bense, V. F.; Gleeson, T.; Loveless, S. E.; Bour, O.; Scibek, J.

    2013-12-01

    Deformation along faults in the shallow crust (< 1 km) introduces permeability heterogeneity and anisotropy, which has an important impact on processes such as regional groundwater flow, hydrocarbon migration, and hydrothermal fluid circulation. Fault zones have the capacity to be hydraulic conduits connecting shallow and deep geological environments, but simultaneously the fault cores of many faults often form effective barriers to flow. The direct evaluation of the impact of faults to fluid flow patterns remains a challenge and requires a multidisciplinary research effort of structural geologists and hydrogeologists. However, we find that these disciplines often use different methods with little interaction between them. In this review, we document the current multi-disciplinary understanding of fault zone hydrogeology. We discuss surface- and subsurface observations from diverse rock types from unlithified and lithified clastic sediments through to carbonate, crystalline, and volcanic rocks. For each rock type, we evaluate geological deformation mechanisms, hydrogeologic observations and conceptual models of fault zone hydrogeology. Outcrop observations indicate that fault zones commonly have a permeability structure suggesting they should act as complex conduit-barrier systems in which along-fault flow is encouraged and across-fault flow is impeded. Hydrogeological observations of fault zones reported in the literature show a broad qualitative agreement with outcrop-based conceptual models of fault zone hydrogeology. Nevertheless, the specific impact of a particular fault permeability structure on fault zone hydrogeology can only be assessed when the hydrogeological context of the fault zone is considered and not from outcrop observations alone. To gain a more integrated, comprehensive understanding of fault zone hydrogeology, we foresee numerous synergistic opportunities and challenges for the discipline of structural geology and hydrogeology to co-evolve and

  5. HYDROGEOLOGIC CASE STUDIES

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  6. Principles of Hydrogeology, Second Edition

    NASA Astrophysics Data System (ADS)

    Ferø, Paul

    Hydrogeology is a broadbased field of study, bringing together geology, physics, hydraulics, chemistry, geography, biology, and many branches of engineering. As a result, practicing hydrogeologists come from diverse back-grounds and must work closely with professionals with skills and experiences different from their own. Thorough understanding of the underlying physical, geological, and chemical principles of hydrogeology is a requisite basis for technical communication among hydrogeologists. A convenient source of working definitions and commonly used parameters is a useful tool for hydrogeologic practice.Principles of Hydrogeology falls somewhere between a complete introduction to the underlying concepts of hydrogeology and a detailed description of hydrogeologic methods. The simplified, schematic figures used throughout the text are clear and readable, well-suited for use in classroom instruction. Many sample calculations are provided together with tables of useful parameter values. A wide range of topics relevant to the practice of hydrogeology are introduced. Its clarity and brevity will make this book a useful primer for professionals working in fields related to hydrogeology for students at the beginning of their careers, and for hydrogeologic technicians who need an accessible source of definitions of hydrogeologic concepts.

  7. Education and Employment in Hydrogeology.

    ERIC Educational Resources Information Center

    Pederson, Darryll T.

    1987-01-01

    Reports on a study of position descriptions in the field of hydrogeology appearing in want ads, published studies describing the working professional, and published descriptions of hydrogeology programs. Results indicate an increase in positions of ten times that of five years ago. Suggests basic training requirements for beginning…

  8. Hydrogeologic Case Studies (Seattle, WA)

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  9. HYDROGEOLOGIC CASE STUDIES (CHICAGO, IL)

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  10. HYDROGEOLOGIC CASE STUDIES (DENVER PRESENTATION)

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  11. Coral reef hydrogeology

    SciTech Connect

    Buddemeier, R.W.; Oberdorfer, J.A.

    1985-05-21

    Knowledge of internal flow velocities and pore water residence time is important in understanding pore water geochemistry, nutrient fluxes at the benthic boundary, reef diagenesis, and fresh water resources in reef islands. Hydrogeologic studies of Pacific and Indian Ocean reef and atoll islands indicate a dual aquifer systems; the major Pleistocene aquifer has hydraulic conductivities on the order of 1000 m/d, while the overlying Holocene aquifer of unconsolidated sediments is at least an order of magnitude less permeable. The high permeability in the Pleistocene formation is the result of large voids, both constructional and from subaerial solution during low stands of the sea. Wind, wave and tide induced head differences ranging from a few centimeters to several tens of centimeters provide the driving force for internal flow. Pore water residence times and geochemistry will vary greatly, depending on whether the water is in a major flow channel or in more restricted pores. Studies of both submerged reefs and atoll islands give bulk pore water residence times on the order of months to a few years. Chemical analyses of pore water indicate that both carbonate solution and precipitation are taking place, which will alter porosity and permeability with time. The dual aquifer model also suggests that the Ghyben-Herzberg lens approach to reef island fresh water resources is inaccurate and can lead to a gross overestimation of the potable resource. 18 refs., 5 figs.

  12. Hydrogeologic characterization of Illinois wetlands

    SciTech Connect

    Miner, J.J.; Miller, M.V.; Rorick, N.L.; Fucciolo, C.S. )

    1994-04-01

    The Illinois State Geological Survey (ISGS), under contract from the Illinois Department of Transportation (IDOT), is evaluating a series of selected wetlands and sites proposed for wetland construction and/or restoration. The program is associated with wetland mitigation for unavoidable effects of state highway construction. The goal of this ongoing program is: (1) to collect commonly lacking geologic, geomorphic, hydrologic, and geochemical data from various wetland sites; and (2) to create a database of this information for use by government agencies and the private sector. Some of the potential uses of this database include: (1) determination of history, role, and possible life cycle of various wetland types allowing more effective design criteria; (2) functional comparison of constructed or restored wetlands versus natural wetlands; (3) testing of wetland hypotheses and delineation techniques under a variety of known hydrogeologic conditions in Illinois; (4) hydrogeologic assessment of potential mitigation sites against a suite of known sites; and (5) determination of data and collection methods appropriate for hydrogeologic wetland studies. A series of tasks is required to complete each study. Historical information is collected from ISGS records, including data regarding topography, soils, sediments, bedrock, and local well records. A field-testing plan is prepared, which includes goals of the study, methods, research potential, and potential results. An initial report is prepared after geologic and geochemical characterization and the installation of needed ground water monitoring wells and surface water gauges. After one year of water-level monitoring, a final report is prepared regarding the present conditions of a site. Further monitoring may be required to determine the performance at constructed and/or restored sites.

  13. SRS Geology/Hydrogeology Environmental Information Document

    SciTech Connect

    Denham, M.E.

    1999-08-31

    The purpose of the Savannah River Site Geology and Hydrogeology Environmental Information Document (EID) is to provide geologic and hydrogeologic information to serve as a baseline to evaluate potential environmental impacts. This EID is based on a summary of knowledge accumulated from research conducted at the Savannah River Site (SRS) and surrounding areas.

  14. Classification of hydrogeologic areas and hydrogeologic flow systems in the basin and range physiographic province, southwestern United States

    USGS Publications Warehouse

    Anning, David W.; Konieczki, Alice D.

    2005-01-01

    The hydrogeology of the Basin and Range Physiographic Province in parts of Arizona, California, New Mexico, Utah, and most of Nevada was classified at basin and larger scales to facilitate information transfer and to provide a synthesis of results from many previous hydrologic investigations. A conceptual model for the spatial hierarchy of the hydrogeology was developed for the Basin and Range Physiographic Province and consists, in order of increasing spatial scale, of hydrogeologic components, hydrogeologic areas, hydrogeologic flow systems, and hydrogeologic regions. This hierarchy formed a framework for hydrogeologic classification. Hydrogeologic areas consist of coincident ground-water and surface-water basins and were delineated on the basis of existing sets of basin boundaries that were used in past investigations by State and Federal government agencies. Within the study area, 344 hydrogeologic areas were identified and delineated. This set of basins not only provides a framework for the classification developed in this report, but also has value for regional and subregional purposes of inventory, study, analysis, and planning throughout the Basin and Range Physiographic Province. The fact that nearly all of the province is delineated by the hydrogeologic areas makes this set well suited to support regional-scale investigations. Hydrogeologic areas are conceptualized as a control volume consisting of three hydrogeologic components: the soils and streams, basin fill, and consolidated rocks. The soils and streams hydrogeologic component consists of all surface-water bodies and soils extending to the bottom of the plant root zone. The basin-fill hydrogeologic component consists of unconsolidated and semiconsolidated sediment deposited in the structural basin. The consolidated-rocks hydrogeologic component consists of the crystalline and sedimentary rocks that form the mountain blocks and basement rock of the structural basin. Hydrogeologic areas were

  15. Advanced Borehole Radar for Hydrogeology

    NASA Astrophysics Data System (ADS)

    Sato, M.

    2014-12-01

    Ground Penetrating Radar is a useful tool for monitoring the hydrogeological environment. We have developed GPR systems which can be applied to these purposes, and we will demonstrate examples borehole radar measurements. In order to have longer radar detection range, frequency lower than100MHz has been normally adopted in borehole radar. Typical subsurface fractures of our interests have a few mm aperture and radar resolution is much poorer than a few cm in this frequency range. We are proposing and demonstrating to use radar polarimetry to solve this problem. We have demonstrated that a full-polarimetry borehole radar can be used for characterization of subsurface fractures. Together with signal processing for antenna characteristic compensation to equalize the signal by a dipole antenna and slot antennas, we could demonstrate that polarimetric borehole radar can estimate the surface roughness of subsurface fractures, We believe the surface roughness is closely related to water permeability through the fractures. We then developed a directional borehole radar, which uses optical field sensor. A dipole antenna in a borehole has omni-directional radiation pattern, and we cannot get azimuthal information about the scatterers. We use multiple dipole antennas set around the borehole axis, and from the phase differences, we can estimate the 3-diemnational orientation of subsurface structures. We are using optical electric field sensor for receiver of borehole radar. This is a passive sensor and connected only with optical fibers and does not require any electric power supply to operate the receiver. It has two major advantages; the first one is that the receiver can be electrically isolated from other parts, and wave coupling to a logging cable is avoided. Then, secondary, it can operate for a long time, because it does not require battery installed inside the system. It makes it possible to set sensors in fixed positions to monitor the change of environmental

  16. Emerging Challenges and "Weird" Models in Hydrogeology

    NASA Astrophysics Data System (ADS)

    Carrera, J.

    2015-12-01

    Hydrogeological research and practice have dealt in recent years with problems related to groundwater quantity and quality. Models have been used for water flow, solute transport and, at most, chemical reactions, which were required to address issues such as water resources assessment, artificial recharge, seawater intrusion, impact of public works, and the like. "Weird" (i.e., outside the mainstream practical hydrogeology, restricted to academy) models were virtually restricted to spatial variability of permeability and the problems it imposed on transport (i.e., scale dependence of dispersivity, mixing, etc.). Yet, a broad gap has grown between academy and practical hydrogeology. Energy demands have created a new suite of problems that need to be solved to address CO2 storage, shale gas impacts or enhanced geothermal systems. These require solving mechanical and thermal equations. We contend, and will use example from our own work for illustration, that (1) these problems are not so new (hydrogeologists started working on them some 40 years ago), (2) hydrogeological tools are as needed to solve energy problems as they were for water problems (permeability remains the key parameter for most of them), (3) collaboration with sister Earth Sciences remains essential (the problems are highly coupled and no one can master all disciplines involved). The real challenge is not so much whether hydrogeology can address these problems, it can, as whether hydrogeologists can reduce the gap between academy and practice, which will be strongly stretched by these emerging problems.

  17. The hydrogeology of Kilauea volcano

    SciTech Connect

    Ingebritsen, S.E.; Scholl, M.A. )

    1993-08-01

    The hydrogeology of Kilauea volcano and adjacent areas has been studied since the turn of this century. However, most studies to date have focused on the relatively shallow, low-salinity parts of the ground-water system, and the deeper hydrothermal system remains poorly understood. The rift zones of adjacent Mauna Loa volcano bound the regional ground-water flow system that includes Kilauea, and the area bounded by the rift zones of Kilauea and the ocean may comprise a partly isolated subsystem. Rates of ground-water recharge vary greatly over the area, and discharge is difficult to measure, because streams are ephemeral and most ground-water discharges diffusely at or below sea level. Hydrothermal systems exist at depth in Kilauea's east and southwest rift zone, as evidenced by thermal springs at the coast and wells in the lower east-rift zone. Available data suggest that dike-impounded, heated ground water occurs at relatively high elevations in the upper east- and southwest-rift zones of Kilauea, and that permeability at depth in the rift zones. Available data suggest that dike-impounded, heated ground water occurs at relatively high elevations in the upper east- and southwest-rift zones of Kilauea, and that permeability at depth in the rift zones (probably [le]10[sup [minus]15] m[sup 2]) is much lower than that of unaltered basalt flows closer to the surface ([ge]10[sup [minus]10] m[sup 2]). Substantial variations in permeability and the presence of magmatic heat sources influence that structure of the fresh water-salt water interface, so the Ghyben-Herzberg model will often fail to predict its position. Numerical modeling studies have considered only subsets of the hydrothermal system, because no existing computer code solves the coupled fluid-flow, heat- and solute-transport problem over the temperature and salinity range encountered at Kilauea. 73 refs., 7 figs., 2 tabs.

  18. SRP baseline hydrogeologic investigation, Phase 2

    SciTech Connect

    Bledsoe, H.W.

    1987-11-01

    As discussed in the program plan for the Savannah River Plant (SRP) Baseline Hydrogeologic Investigation, this program has been implemented for the purpose of updating and improving the current state of knowledge and understanding of the hydrogeologic systems underlying the Savannah River Plant (SRP). The objective of the program is to install a series of observation well clusters (wells installed in each major water bearing formation at the same site) at key locations across the plant site in order to: (1) provide detailed information on the lithology, stratigraphy, and groundwater hydrology, (2) provide observation wells to monitor the groundwater quality, head relationships, gradients, and flow paths.

  19. SRP baseline hydrogeologic investigation: Aquifer characterization

    SciTech Connect

    Strom, R.N.; Kaback, D.S.

    1992-03-31

    An investigation of the mineralogy and chemistry of the principal hydrogeologic units and the geochemistry of the water in the principal aquifers at Savannah River Site (SRS) was undertaken as part of the Baseline Hydrogeologic Investigation. This investigation was conducted to provide background data for future site studies and reports and to provide a site-wide interpretation of the geology and geochemistry of the Coastal Plain Hydrostratigraphic province. Ground water samples were analyzed for major cations and anions, minor and trace elements, gross alpha and beta, tritium, stable isotopes of hydrogen, oxygen, and carbon, and carbon-14. Sediments from the well borings were analyzed for mineralogy and major and minor elements.

  20. SRP Baseline Hydrogeologic Investigation, Phase 3

    SciTech Connect

    Bledsoe, H.W.

    1988-08-01

    The SRP Baseline Hydrogeologic Investigation was implemented for the purpose of updating and improving the knowledge and understanding of the hydrogeologic systems underlying the SRP site. Phase III, which is discussed in this report, includes the drilling of 7 deep coreholes (sites P-24 through P-30) and the installation of 53 observation wells ranging in depth from approximately 50 ft to more than 970 ft below the ground surface. In addition to the collection of geologic cores for lithologic and stratigraphic study, samples were also collected for the determination of physical characteristics of the sediments and for the identification of microorganisms.

  1. Small Scale Multisource Site – Hydrogeology Investigation

    EPA Science Inventory

    A site impacted by brackish water was evaluated using traditional hydrogeologic and geochemical site characterization techniques. No single, specific source of the brine impacted ground water was identified. However, the extent of the brine impacted ground water was found to be...

  2. The ancient Chinese notes on hydrogeology

    NASA Astrophysics Data System (ADS)

    Zhou, Yu; Zwahlen, François; Wang, Yanxin

    2011-08-01

    The ancient Chinese notes on hydrogeology are summarized and interpreted, along with records of some related matters, like groundwater exploration and utilization, karst springs, water circulation, water conservation and saline-land transformation, mine drainage, and environmental hydrogeology. The report focuses only on the earliest recorded notes, mostly up until the Han Dynasty (206 BC - AD 25). Besides the references cited, the discussion in this report is based mainly on archaeological material, the preserved written classic literature, and some assumptions and/or conclusions that have been handed down in legends to later ages. Although most material relates to ancient China, the lessons learned may have practical significance worldwide. Compared to other contemporary parts of the world, ancient China, without doubt, took the lead in the field of groundwater hydrology. The great achievements and experience of the Chinese ancestors should provide motivation and inspiration for hydrogeologists to carry out their scientific research and exploration passionately and actively.

  3. Hydrogeology of the West Siberian Basin

    SciTech Connect

    Foley, M.G.; Bradley, D.J.; Cole, C.R.

    1996-08-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in extensive radioactive contaminant releases to the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. We have assumed that ground-water flow in the West Siberian Basin is topographically driven, with recharge to the basin occurring in the highlands on the west, east, and south, and internal discharge localized in numerous river valleys and lakes that ultimately discharge north to the ocean. We are modeling the regional hydrogeology as three-dimensional, steady-state, saturated flow that is recharged from above. We acquired topographic, geologic, hydrostratigraphic, hydrogeologic, and water-balance data for the West Siberian Basin and constructed a regional water table. We correlated and combined 70 different rock types derived from published descriptions of West Siberian Basin rocks into 17 rock types appropriate for assignment of hydrogeologic properties on the basis of spatial heterogeneity and constituent (i.e., sand, silt, and clay) diversity. Examination of resulting three-dimensional assemblages of rock types showed that they were consistent with published and inferred paleogeography and depositional processes. Calibrating the basin`s moisture balance (i.e., recharge and discharge) to the derived water table determined plausible input parameter values for unknowns such as hydraulic conductivities. The general directions of calculated ground-water flow suggest that major rivers act as discharge areas, with upwelling below the rivers extending down into the basement rocks, and that ground-water divides that penetrate the entire thickness of the model are evident between major rivers.

  4. Hydrogeology, waste disposal, science and politics: Proceedings

    SciTech Connect

    Link, P.K.

    1994-07-01

    A total of 48 papers were presented at the Engineering Geology and Geotechnical Engineering 30th Symposium. These papers are presented in this proceedings under the following headings: site characterization--Pocatello area; site characterization--Boise Area; site assessment; Idaho National Engineering Laboratory; geophysical methods; remediation; geotechnical engineering; and hydrogeology, northern and western Idaho. Individual papers have been processed separately for inclusion in the Energy Science and Technology Database.

  5. Stochastic hydrogeology: what professionals really need?

    PubMed

    Renard, Philippe

    2007-01-01

    Quantitative hydrogeology celebrated its 150th anniversary in 2006. Geostatistics is younger but has had a very large impact in hydrogeology. Today, geostatistics is used routinely to interpolate deterministically most of the parameters that are required to analyze a problem or make a quantitative analysis. In a small number of cases, geostatistics is combined with deterministic approaches to forecast uncertainty. At a more academic level, geostatistics is used extensively to study physical processes in heterogeneous aquifers. Yet, there is an important gap between the academic use and the routine applications of geostatistics. The reasons for this gap are diverse. These include aspects related to the hydrogeology consulting market, technical reasons such as the lack of widely available software, but also a number of misconceptions. A change in this situation requires acting at different levels. First, regulators must be convinced of the benefit of using geostatistics. Second, the economic potential of the approach must be emphasized to customers. Third, the relevance of the theories needs to be increased. Last, but not least, software, data sets, and computing infrastructure such as grid computing need to be widely available. PMID:17760580

  6. Is Current Hydrogeologic Research Addressing Long-TermPredictions?

    SciTech Connect

    Tsang, Chin-Fu

    2004-09-10

    Hydrogeology is a field closely related to the needs of society. Many problems of current national and local interest require predictions of hydrogeological system behavior, and, in a number of important cases, the period of prediction is tens to hundreds of thousands of years. It is argued that the demand for such long-term hydrogeological predictions casts a new light on the future needs of hydrogeological research. Key scientific issues are no longer concerned only with simple processes or narrowly focused modeling or testing methods, but also with assessment of prediction uncertainties and confidence, couplings among multiple physico-chemical processes occurring simultaneously at a site, and the interplay between site characterization and predictive modeling. These considerations also have significant implications for hydrogeological education. With this view, it is asserted that hydrogeological directions and education need to be reexamined and possibly refocused to address specific needs for long-term predictions.

  7. Hydrogeology of the Islamic Republic of Mauritania

    USGS Publications Warehouse

    Friedel, Michael J.; Finn, Carol

    2008-01-01

    Hydrogeologic maps were constructed for the Islamic Republic of Mauritania. The ground-water flow system in the country can best be described as two interconnected regional systems: the porous Continental Terminal coastal system and the interior, fractured sedimentary Taoudeni Basin system. In these systems, ground-water flow occurs in fill deposits and carbonate, clastic, metasedimentary, and metavolcanic rocks. Based on an evaluation of the potentiometric surface, there are three areas of ground-water recharge in the Taoudeni Basin system. One region occurs in the northwest at the edge of the Shield, one occurs to the south overlying the Tillites, and one is centered at the city of Tidjikdja. In contrast to the flow system in the Taoudeni Basin, the potentiometric surfaces reveal two areas of discharge in the Continental Terminal system but no localized recharge areas; the recharge is more likely to be areal. In addition to these recharge and discharge areas, ground water flows across the country's borders. Specifically, ground water from the Atlantic Ocean flows into Mauritania, transporting dissolved sodium from the west as a salt water intrusion, whereas fresh ground water discharges from the east into Mali. To the north, there is a relatively low gradient with inflow of fresh water to Mauritania, whereas ground-water flow discharges to the Senegal River to the south. A geographical information system (GIS) was used to digitize, manage, store, and analyze geologic data used to develop the hydrogeologic map. The data acquired for map development included existing digital GIS files, published maps, tabulated data in reports and public-access files, and the SIPPE2 Access database. Once in digital formats, regional geologic and hydrologic features were converted to a common coordinate system and combined into one map. The 42 regional geologic map units were then reclassified into 13 hydrogeologic units, each having considerable lateral extent and distinct

  8. Two-hundred years of hydrogeology in the United States

    USGS Publications Warehouse

    Rosenshein, J. S., (Edited By); Moore, J.E.; Lohman, S.W.; Chase, E.B.

    1986-01-01

    The Hydrogeology Division of the Geological Society of America (GSA) sponsored a symposium entitled ' Hydrogeology in the United States, 1776- 1976 ' at the annual meeting of the GSA on November 9, 1976. The symposium was organized to provide a forum for discussion of major eras in the history of American hydrogeology and to contribute to the bicentennial celebration of the founding of the United States. Presentations were broken down into 3 sections: The Early Era (with a tribute to Oscar E. Meinzer), 1776-1920; Meinzer Era, 1910-1940; and the Modern Era (including scientific advantages; the quantification of hydrogeology; geochemistry; surface and borehole geophysics; and hydrogeology, policy, and politics) 1940-1976. (Lantz-PTT)

  9. Case studies in organic contaminant hydrogeology

    NASA Astrophysics Data System (ADS)

    Baker, John A.

    1989-07-01

    The effective management of domestic solid waste and hazardous, toxic, and radioactive waste is a major problem in the area of environmental geology and water sciences over the world. This series of case studies of organic contaminants from both solid and hazardous waste disposal facilities provides examples of these problems. The facilities were investigated to determine risks and liabilities before acquisition, to determine the site hydrogeologic conditions for design of appropriate groundwater monitoring plans, and/or to determine the potential for groundwater contamination. The results of these studies and investigations by Waste Management Inc. (WMI) and its consultants have shown certain relationships in the distribution of organic pollutants to the different geologic and hydrogeologic charac teristics of each facility. In each of the case studies, all 129 priority pollutants were analyzed in private wells and/or monitoring wells at the request of regulatory agencies. The 31 volatile organic compounds (VOCs) of the priority pollutant list were the majority of the organic compounds detected and these data are evaluated in each case study. The case studies are on disposal facilities located in glacial tills, carbonaceous weathered clay soils, weathered shale, limestone bedrock, dolomite bedrock, and alluvial and sedimentary deposits. A brief discussion of groundwater quality impacts and remedial measures also is included.

  10. Hydrogeologic framework and borehole yields in Ghana

    NASA Astrophysics Data System (ADS)

    Dapaah-Siakwan, S.; Gyau-Boakye, P.

    2000-08-01

    In Ghana, 68% of the population live in rural communities, which are scattered and remote. Groundwater is the most feasible source of potable water supply for most of these dispersed and remote settlements. To meet the present and future challenges of population expansion vis-à-vis the observed declining rainfall in most parts of Africa including Ghana, it is necessary to assess, efficiently manage, and utilize the groundwater resources. The objective of this paper is therefore to describe the hydrogeologic framework and analyze borehole yields as part of the groundwater-resources assessment of Ghana. The hydrogeologic units are broadly categorized as: (1) the Basement Complex (crystalline rocks), which underlies about 54% of the country; (2) the Voltaian System, which underlies about 45%; and (3) the Cenozoic, Mesozoic, and Paleozoic sedimentary strata (Coastal Provinces), which underlie the remaining 1% of the country. The Basement Complex and the Coastal Provinces have higher groundwater potential than the Voltaian System. This is particularly significant, because the Basement Complex and the Coastal Provinces underlie the most densely populated areas of the country and can hence be tapped for human use. The average borehole yields of the Basement Complex, the Coastal Provinces and the Voltaian System range from 2.7-12.7, 3.9-15.6, and 6.2-8.5 m3/h, respectively.

  11. SRS baseline hydrogeologic investigation: Summary report

    SciTech Connect

    Bledsoe, H.W.; Aadland, R.K. ); Sargent, K.A. . Dept. of Geology)

    1990-11-01

    Work on the Savannah River Site (SRS) Baseline Hydrogeologic Investigation began in 1983 when it was determined that the knowledge of the plant hydrogeologic systems needed to be expanded and improved in response to changing stratigraphic and hydrostratigraphic terminology and increased involvement by regulatory agencies (Bledsoe, 1984). Additionally, site-wide data were needed to determine flow paths, gradients, and velocities associated with the different aquifers underlying the plant site. The program was divided into three phases in order to allow the results of one phase to be evaluated and necessary changes and improvements incorporated into the following phases. This report summarizes the results of all three phases and includes modified graphic logs, lithologic descriptions of the different geologic formations, profiles of each cluster site, hydrostratigraphic cross sections, hydrographs of selected wells within each cluster for the first full year of uninterrupted water level measurements, potentiometric maps developed from data collected from all clusters, completion diagrams for each well, and a summary of laboratory tests. Additionally, the proposed new classification of hydrostratigraphic units at SRS (Aadland and Bledsoe, 1990) has been incorporated.

  12. The Contribution of Hydrogeophysics to Hydrogeological Modeling

    NASA Astrophysics Data System (ADS)

    Christensen, N. B.; Auken, E.; Sorensen, K.

    2005-12-01

    Electrical and electromagnetic (E&EM) methods are some of the most commonly used geophysical techniques for hydrogeophysical investigations. In this presentation, the use of E&EM methods for watershed-scale hydrogeological investigations are reviewed. Over the past two decades a tremendous development has taken place with regard to E&EM instrumentation, field procedures and interpretation algorithms; a process that to a large extent has been focussed on hydrogeological investigations. The primary parameter mapped by E&EM methods is the electrical resistivity (or the inverse: conductivity). High and low values of the resistivity of geological materials enable the discernment between sand and clay, unsaturated and saturated, fresh and salt water, unaffected and polluted, bedrock and sediment, respectively - all fundamental to hydrogeological modeling. Time-consuming, single-site, individual electrical sounding acquisition geometries have now been replaced by multi-electrode, profile oriented measurements that have the capability to image the variation in resistivity with both depth and along profiles to a depth of 70-100m and a productivity of 1-1.5 km/day/field person. Pulled-array methods, which acquire measurements using multiple electrode configurations while moving, can traverse 10-15 km per day with a depth penetration of approximately 20 m. Transient electromagnetic soundings are carried out as both single-site and pulled-array methods, and recently by helicopter. Very cost-efficient transient methods are now commercially available. E&EM data are complicated, nonlinear functions of the resistivity distribution and the full potential of the data can only be realized by inverting the data to obtain a physical model describing the subsurface resistivity distribution. Model calibration and inverse hydraulic modeling is most often carried out based on very sparse data sets and geological information from a few boreholes. Geophysical models covering an extended area

  13. Insights into Mejerda basin hydrogeology, Tunisia

    NASA Astrophysics Data System (ADS)

    Guellala, Rihab; Tagorti, Mohamed Ali; Inoubli, Mohamed Hédi; Amri, Faouzi

    2012-09-01

    The present study concentrates on the interpretation of Vertical Electrical Soundings (VES) and well logs to understand the geometry and the functioning of the Ghardimaou multilayered aquifer, a potential target for water supply in the Mejerda basin (Tunisia). The analysis of isobath and isopach maps established in this study, shows a tectonic influence on the reservoirs structure; the Villafranchian folding and the NE-SW, and E-W normal faulting in the recent Quaternary created an aquifer system compartmentalized by raised and tilted blocks. Geoelectrical cross sections reveal that this structure influences the thickness of permeable formations and the groundwater circulation. These results will be useful for rationalizing the future hydrogeological research that will be undertaken in the Mejerda basin.

  14. Chemical hydrogeology in natural and contaminated environments

    USGS Publications Warehouse

    Back, W.; Baedecker, M.J.

    1989-01-01

    Chemical hydrogeology, including organic and inorganic aspects, has contributed to an increased understanding of groundwater flow systems, geologic processes, and stressed environments. Most of the basic principles of inorganic-chemical hydrogeology were first established by investigations of organic-free, regional-scale systems for which simplifying assumptions could be made. The problems of groundwater contamination are causing a shift of emphasis to microscale systems that are dominated by organic-chemical reactions and that are providing an impetus for the study of naturally occurring and manmade organic material. Along with the decrease in scale, physical and chemical heterogeneity become major controls. Current investigations and those selected from the literature demonstrate that heterogeneity increases in importance as the study site decreases from regional-scale to macroscale to microscale. Increased understanding of regional-scale flow systems is demonstrated by selection of investigations of carbonate and volcanic aquifers to show how applications of present-day concepts and techniques can identify controlling chemical reactions and determine their rates; identify groundwater flow paths and determine flow velocity; and determine aquifer characteristics. The role of chemical hydrogeology in understanding geologic processes of macroscale systems is exemplified by selection of investigations in coastal aquifers. Phenomena associated with the mixing zone generated by encroaching sea water include an increase in heterogeneity of permeability, diagenesis of minerals, and formation of geomorphic features, such as caves, lagoons, and bays. Ore deposits of manganese and uranium, along with a simulation model of ore-forming fluids, demonstrate the influence of heterogeneity and of organic compounds on geochemical reactions associated with genesis of mineral deposits. In microscale environments, importance of heterogeneity and consequences of organic reactions in

  15. Hydrogeological Conditions Changes of Tomsk, Russia

    NASA Astrophysics Data System (ADS)

    Pokrovsky, V. D.; Dutova, E. M.; Kuzevanov, K. I.; Pokrovsky, D. S.; Nalivaiko, N. G.

    2015-11-01

    The hydro-geological conditions of Tomsk are determined by both natural factors and the impact of the urban infrastructure. Important impact on subsurface water flows involves the complex hydraulic relationship of several geological layers and the ancient and modern relief. Increasing groundwater abstraction has generally led to lowered piezometric heads in the deeper aquifer horizons, while in the uppermost horizons, rises in the water table and formation of new perched water tables are experienced due to leaking pipes and impedance of groundwater flow by deep foundations. In this paper special attention is paid to the Quaternary aquifer complex. Barrage effects of pile foundations and the intensive development of perched water distributed on flat surfaces of the watersheds and high terraces, complicated conditions for the construction and operation of facilities, leading in some cases to emergency situations.

  16. Stochastic hydrogeologic units and hydrogeologic properties development for total-system performance assessments. Yucca Mountain Site Characterization Project

    SciTech Connect

    Schenker, A.R.; Guerin, D.C.; Robey, T.H.; Rautman, C.A.; Barnard, R.W.

    1995-09-01

    A stochastic representation of the lithologic units and associated hydrogeologic parameters of the potential high-level nuclear waste repository are developed for use in performance-assessment calculations, including the Total-System Performance Assessment for Yucca Mountain-SNL Second Iteration (TSPA-1993). A simplified lithologic model has been developed based on the physical characteristics of the welded and nonwelded units at Yucca Mountain. Ten hydrogeologic units are developed from site-specific data (lithologic and geophysical logs and core photographs) obtained from the unsaturated and saturated zones. The three-dimensional geostatistical model of the ten hydrogeologic units is based on indicator-coding techniques and improves on the two-dimensional model developed for TSPA91. The hydrogeologic properties (statistics and probability distribution functions) are developed from the results of laboratory tests and in-situ aquifer tests or are derived through fundamental relationships. Hydrogeologic properties for matrix properties, bulk conductivities, and fractures are developed from existing site specific data. Extensive data are available for matrix porosity, bulk density, and matrix saturated conductivity. For other hydrogeologic properties, the data are minimal or nonexistent. Parameters for the properties are developed as beta probability distribution functions. For the model units without enough data for analysis, parameters are developed as analogs to existing units. A relational, analytic approach coupled with bulk conductivity parameters is used to develop fracture parameters based on the smooth-wall-parallel-plate theory. An analytic method is introduced for scaling small-core matrix properties to the hydrogeologic unit scales.

  17. Marine hydrogeology: recent accomplishments and future opportunities

    NASA Astrophysics Data System (ADS)

    Fisher, A. T.

    2005-03-01

    Marine hydrogeology is a broad-ranging scientific discipline involving the exploration of fluid-rock interactions below the seafloor. Studies have been conducted at seafloor spreading centers, mid-plate locations, and in plate- and continental-margin environments. Although many seafloor locations are remote, there are aspects of marine systems that make them uniquely suited for hydrologic analysis. Newly developed tools and techniques, and the establishment of several multidisciplinary programs for oceanographic exploration, have helped to push marine hydrogeology forward over the last several decades. Most marine hydrogeologic work has focused on measurement or estimation of hydrogeologic properties within the shallow subsurface, but additional work has emphasized measurements of local and global fluxes, fluid source and sink terms, and quantitative links between hydrogeologic, chemical, tectonic, biological, and geophysical processes. In addition to summarizing selected results from a small number of case studies, this paper includes a description of several new experiments and programs that will provide outstanding opportunities to address fundamental hydrogeologic questions within the seafloor during the next 20-30 years. L'hydrogéologie marine est une large discipline scientifique impliquant l' exploration des interactions entre les fluides et les roches sous les fonds marins. Des études ont été menées dans les différents environnements sous-marins (zone abyssale, plaque océanique, marges continentales). Bien que de nombreux fonds marins soient connus, il existe des aspects des systèmes marins qui les rendent inadaptés à l'analyse hydrologique. De nouveaux outils et techniques, et la mise en oeuvre de nombreux programmes multidisciplinaires d'exploration océanographique, ont aidé à pousser en avant l'hydrogéologie marine ces dix dernières années. La plus part des études hydrogéologiques se sont concentrées jusqu'à présent sur la mesure ou

  18. HYDROGEOLOGIC CASE STUDIE(PRESENTATION FOR MNA WORKSHOP)

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  19. Hydrogeology in North America: past and future

    NASA Astrophysics Data System (ADS)

    Narasimhan, T. N.

    2005-03-01

    This paper is a retrospective on the evolution of hydrogeology in North America over the past two centuries, and a brief speculation of its future. The history of hydrogeology is marked by developments in many different fields such as groundwater hydrology, soil mechanics, soil science, economic geology, petroleum engineering, structural geology, geochemistry, geophysics, marine geology, and more recently, ecology. The field has been enriched by the contributions of distinguished researchers from all these fields. At present, hydrogeology is in transition from a state of discovering new resources and exploiting them efficiently for maximum benefit, to one of judicious management of finite, interconnected resources that are vital for the sustenance of humans and other living things. The future of hydrogeology is likely to be dictated by the subtle balance with which the hydrological, erosional, and nutritional cycles function, and the decision of a technological society to either adapt to the constraints imposed by the balance, or to continue to exploit hydrogeological systems for maximum benefit. Although there is now a trend towards ecological and environmental awareness, human attitudes could change should large parts of the populated world be subjected to the stresses of droughts that last for many decades. Cet article est une rétrospective de l'évolution de l'hydrogéologie en Amérique du Nord sur les deux derniers siècles, et une brève évaluation de son futur. L'histoire de l'hydrogéologie est marquée par le développement de plusieurs techniques de terrain telles, l'hydrologie des eaux souterraines, la mécanique des sols, les sciences du sol, la géologie économique, l' ingénierie pétrolière, la géologie structurale, la géochimie, la géophysique, la géologie marine et plus récemment l'écologie. La science a été enrichie par la contribution de plusieurs chercheurs distingués, provenant de toutes ces branches. A présent, l

  20. Hydrogeology in North America: past and future

    NASA Astrophysics Data System (ADS)

    Narasimhan, T. N.

    2005-03-01

    This paper is a retrospective on the evolution of hydrogeology in North America over the past two centuries, and a brief speculation of its future. The history of hydrogeology is marked by developments in many different fields such as groundwater hydrology, soil mechanics, soil science, economic geology, petroleum engineering, structural geology, geochemistry, geophysics, marine geology, and more recently, ecology. The field has been enriched by the contributions of distinguished researchers from all these fields. At present, hydrogeology is in transition from a state of discovering new resources and exploiting them efficiently for maximum benefit, to one of judicious management of finite, interconnected resources that are vital for the sustenance of humans and other living things. The future of hydrogeology is likely to be dictated by the subtle balance with which the hydrological, erosional, and nutritional cycles function, and the decision of a technological society to either adapt to the constraints imposed by the balance, or to continue to exploit hydrogeological systems for maximum benefit. Although there is now a trend towards ecological and environmental awareness, human attitudes could change should large parts of the populated world be subjected to the stresses of droughts that last for many decades. Cet article est une rétrospective de l'évolution de l'hydrogéologie en Amérique du Nord sur les deux derniers siècles, et une brève évaluation de son futur. L'histoire de l'hydrogéologie est marquée par le développement de plusieurs techniques de terrain telles, l'hydrologie des eaux souterraines, la mécanique des sols, les sciences du sol, la géologie économique, l' ingénierie pétrolière, la géologie structurale, la géochimie, la géophysique, la géologie marine et plus récemment l'écologie. La science a été enrichie par la contribution de plusieurs chercheurs distingués, provenant de toutes ces branches. A présent, l

  1. Chemical Hydrogeology: Fifty Years of Advances, Breakthroughs, and Innovation

    NASA Astrophysics Data System (ADS)

    Brusseau, M. L.

    2015-12-01

    Chemical hydrogeology focuses on the composition, properties, and biogeochemical processes inherent to water in subsurface environments. Multiple avenues of research coalesced in the 1960's to foment the development of chemical hydrogeology as a distinct field. In the intervening 50 years, chemical hydrogeology principles have been applied to innumerable issues and problems, and concomitantly, the field has continually experienced advances, breakthroughs, and innovations in theory, analysis, and application. An overarching theme to chemical hydrogeology in both theory and application is integration--- integration of disciplines (interdisciplinary, multidisciplinary), integration of approaches (theoretical, experimental, analytical), and integration of scales (spatial, temporal). Chemical hydrogeology has never been more relevant and more challenged as today, as we face critical issues related to for example water scarcity and availability of clean water, impacts of energy development, production and storage, and human interactions with ecosystem services. This presentation will illustrate recent advances in chemical hydrogeology, ranging from application of advanced imaging for characterization of pore-scale multiphase systems to integrated physical and biogeochemical assessments of field-scale contaminant transport.

  2. Peatland hydrogeological function at the regional scale

    NASA Astrophysics Data System (ADS)

    Larocque, M.; Avard, K.; Pellerin, S.

    2012-12-01

    Peatlands are important components of northern landscapes. In the Canadian province of Quebec, peatlands of the St. Lawrence Valley are rapidly disappearing, threatened by rapidly growing pressures from development. Peatlands are to varying extents groundwater dependent and as such are likely to respond drastically to changes in groundwater flow conditions and to contribute to the maintenance of groundwater levels within a superficial aquifer. Yet, there is very little understanding of the hydrogeological function of peatlands at the regional scale. For this reason, they are often simply discarded in complex groundwater management decisions. The implications are not clearly understood but could lead to the disruption of ecologically important fluxes and to significant impacts for the maintenance of long term water reservoirs across the land. This study was initiated in the Centre-du-Quebec region of southern Quebec to quantify how the peatland landscape has evolved in the last decades and to understand the hydrogeological function of peatlands at the regional scale. The study area (2856 km2) is located in the St. Lawrence Lowlands. The last deglaciation has contributed to a complex stratigraphy of unconsolidated sediments and peatlands have developed at the foot of the Appalachians. A recent regional study of Quaternary deposits has shown that a majority of these peatlands are found on aeolian deposits or reworked till, while only a few are set on marine clay, littoral deposits or directly on the bedrock. The area occupied by peatlands was measured with aerial photographs dating from 1966 and 2010. In 2010, peatlands were found on 6.1 % of the territory. Of these peatlands, 10 485 ha were intact and 7 015 underwent limited perturbations (e.g. drainage ditch, forest roads). Between 1966 and 2010, nearly a quarter of the peatlands observed in 1966 underwent irreversible perturbations (e.g. agriculture, paved roads). The main cause of peatland disappearance was from

  3. Contaminant hydrogeology — Dollars and sense

    NASA Astrophysics Data System (ADS)

    Schwartz, Franklin W.

    1988-07-01

    The unprecedented growth in contaminant-related aspects of hydrogeology has left an amazing legacy of science and technology. The stimulus for this growth in the United States was a group of regulations designed to clean up existing problems involving hazardous wastes and eliminate future problems. At the same time, there has been a continuing effort in developing subsurface repositories for the disposal of high-level nuclear waste. There have been impressive technological achievements in direct and indirect methods for plume definition, new techniques for site remediation, and measurement of hydraulic parameters for low-permeability rock at great depths. Achievements on the theoretical side of the science are no less impressive. Great strides have been made in understanding some old transport processes (e.g., dispersion) and describing new ones (e.g., diffusion into the matrix), verifying these theoretical ideas in field tests, and dealing with an old nemesis — fractured rocks. Sprinkled in this mix are some disappointments, the great difficulty that seems to exist in translating theory into practice, the apparent difficulty in technology transfer. and the aimlessness of too much of our theoretical work. Trends for the future that seem to be emerging include a return to field and experimental work, a more systematic look at problems, an increased reliance on computer technology, and the demise of "blue-sky research".

  4. Hydrogeology of formation waters, northwestern Alberta basin

    SciTech Connect

    Bachu, S.; Underschultz, J.R. )

    1993-10-01

    Generally, temperature seems to be the main controlling factor on salinity distributions. The salinity of formation waters increases in the vicinity of evaporitic beds, and decreases close to the surface because of mixing with fresh meteoric water introduced through local flow systems. The Lower and Middle Devonian pre-Prairie aquifer systems, beneath the regionally extensive Prairie aquiclude, are characterized by regional topographically-driven flow updip to the northeast. The flow of formation waters in the northeastern Alberta played an important role in the formation of the huge Athabasca oil sands deposits. Hydrocarbons that migrated into the area from the west were trapped into local reservoirs, and biodegraded and washed by fresh meteoric water introduced by local flow systems. Environmentally, the subsurface hydrogeology in the area imposes specific constraints on waste disposal in deep formations mostly because of the absence of a thick, continuous regional aquitard and because most aquifers subcrop at shallow depth or crop out and discharge along the valleys of the Athabasca River system and at the basin edge.

  5. 2101-M Pond hydrogeologic characterization report

    SciTech Connect

    Chamness, M.A.; Luttrell, S.P.; Bates, D.J.; Martin, W.J.

    1990-09-01

    This report documents information collected by the Pacific Northwest Laboratory {sup (a)} at the request of Westinghouse Hanford Company. Presented in this report is the interpretation of the hydrogeologic environment at the 2101-M Pond, located in the 200-East Area of the Hanford Site. This information and its accompanying interpretation were derived from sampling and testing activities associated with the installation of four ground-water monitoring wells, in addition to data gathered from several previously existing wells. The new monitoring wells were installed as part of a groundwater monitoring program initiated in 1988. The four new monitoring wells were installed around the 2101-M Pond between May 23 and August 27, 1988. Geologic sampling, aquifer testing, and initial ground-water sampling were performed during the installation of these wells. Laboratory analyses of the sediment samples for particle size, calcium carbonate content, and selected natural and contaminant constituents were performed. A full year of quarterly ground-water sampling and the first statistical analysis of background and downgradient data have also been performed. 112 refs., 49 figs., 18 tabs.

  6. Geology and hydrogeology of the Florida Keys

    USGS Publications Warehouse

    Halley, Robert B.; Vacher, H. L.; Shinn

    1997-01-01

    This chapter discusses the geology and hydrogeology of the Florida Keys, and focuses on the islands formed of Pleistocene limestone. These islands, which are crossed when driving from Miami to Key West, are typically regarded as "the Florida Keys." The outstanding and fragile character of ecosystems on and around the Florida Keys has prompted State and Federal efforts to protect and preserve the remaining public portions of the region. The Florida Keys were largely ignored during the sixteenth, seventeenth, and eighteenth centuries, although the waters just offshore provided a major shipping thoroughfare to and from the New World. The Florida Keys are now recognized as one of the great recreational and environmental resources of the United States. The islands are outposts of a laid-back, tropical resort culture that has as its foundation warmth and clear water. A significant part of the attraction is fishing, diving, and boating around the area's coral reefs, which the islands protect. But the reefs were not always so highly valued. The Florida Keys that have protected the reefs for millennia, may now be the source of the agents that may accomplish what Agassiz thought was beyond man's power a century ago.

  7. Airborne EM for geothermal and hydrogeological mapping

    NASA Astrophysics Data System (ADS)

    Menghini, A.; Manzella, A.; Viezzoli, A.; Montanari, D.; Maggi, S.

    2012-12-01

    Within the "VIGOR" project, aimed at assessing the geothermal potential of four regions in southern Italy, Airborne EM data have been acquired, modeled and interpreted. The system deployed was SkyTEM, a time-domain helicopter electromagnetic system designed for hydrogeophysical, environmental and mineral investigations. The AEM data provide, after data acquisition, analysis, processing, and modeling, a distribution volume of electrical resistivity, spanning an investigation depth from ground surface of few hundred meters, depending on resistivity condition. Resistivity is an important physical parameter for geothermal investigation, since it proved to be very effective in mapping anomalies due to hydrothermal fluid circulation, which usually has high salt content and produces clayey alteration minerals. Since the project required, among other issues, to define geothermal resources at shallow level, it was decided to perform a test with an airborne electromagnetic geophysical survey, to verify the advantages offered by the system in covering large areas in a short time. The geophysical survey was carried out in Sicily, Italy, in late 2011, over two test sites named "Termini" and "Western Sicily". The two areas were chosen on different basis. "Termini" area is covered by extensive geological surveys, and was going to be investigated also by means of electrical tomography in its northern part. Since geological condition of Sicily, even at shallow depth, is very complex, this area provided a good place for defining the resistivity values of the main geological units outcropping in the region. "Termini" survey has been also an occasion to define relations between resistivity distribution, lithological units and thermal conductivity. The "Western Sicily" area cover the main thermal manifestations of western Sicily, and the research target was to establish whether they are characterized by common hydrogeological or tectonic features that could be mapped by resistivity

  8. Python-Based Applications for Hydrogeological Modeling

    NASA Astrophysics Data System (ADS)

    Khambhammettu, P.

    2013-12-01

    Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Add-on packages supporting fast array computation (numpy), plotting (matplotlib), scientific /mathematical Functions (scipy), have resulted in a powerful ecosystem for scientists interested in exploratory data analysis, high-performance computing and data visualization. Three examples are provided to demonstrate the applicability of the Python environment in hydrogeological applications. Python programs were used to model an aquifer test and estimate aquifer parameters at a Superfund site. The aquifer test conducted at a Groundwater Circulation Well was modeled with the Python/FORTRAN-based TTIM Analytic Element Code. The aquifer parameters were estimated with PEST such that a good match was produced between the simulated and observed drawdowns. Python scripts were written to interface with PEST and visualize the results. A convolution-based approach was used to estimate source concentration histories based on observed concentrations at receptor locations. Unit Response Functions (URFs) that relate the receptor concentrations to a unit release at the source were derived with the ATRANS code. The impact of any releases at the source could then be estimated by convolving the source release history with the URFs. Python scripts were written to compute and visualize receptor concentrations for user-specified source histories. The framework provided a simple and elegant way to test various hypotheses about the site. A Python/FORTRAN-based program TYPECURVEGRID-Py was developed to compute and visualize groundwater elevations and drawdown through time in response to a regional uniform hydraulic gradient and the influence of pumping wells using either the Theis solution for a fully-confined aquifer or the Hantush-Jacob solution for a leaky confined aquifer. The program supports an arbitrary number of wells that can operate according to arbitrary schedules. The

  9. Hydrogeologic atlas of aquifers in Indiana

    USGS Publications Warehouse

    Fenelon, Joseph M.; Bobay, K.E.; Greeman, T.K.; Hoover, M.E.; Cohen, D.A.; Fowler, K.K.; Woodfield, M.C.; and Durbin, J. M.

    1994-01-01

    Aquifers in 12 water-management basins of Indiana are identified in a series of 104 hydrogeologic sections and 12 maps that show the thickness and configuration of aquifers. The vertical distribution of water-bearing units and a generalized potentiometric profile are shown along 3,500 miles of section lines that were constructed from drillers' logs of more than 4,200 wells. The horizontal scale of the sections is 1:125,000. Maps of aquifers showing the areal distribution of each aquifer type were drawn at a scale of 1:500,000. Unconsolidated aquifers are the most widely used aquifers in Indiana and include surficial, buried, and discontinuous layers of sand and gravel. Most of the surficial sand and gravel is in large outwash plains in northern Indiana and along the major rivers. Buried sand and gravel aquifers are interbedded with till deposits in much of the northern two-thirds of Indiana. Discontinuous sand and gravel deposits are present as isolated lenses, primarily in glaciated areas. The bedrock aquifers generally have lower yields than most of the sand and gravel aquifers; however, bedrock aquifers are areally widespread and are an important source of water. Bedrock aquifer types consist of carbonates; sandstones; complexly interbedded sandstones, siltstones, shales, limestones, and coals; and an upper weathered zone in low permeability rock. Carbonate aquifers underlie about one-half of Indiana and are the most productive of the bedrock aquifers. The other principal bedrock aquifer type, sandstone, underlies large areas in the southwestern one-fifth of Indiana. No aquifer is known to be present in the southeastern corner of Indiana.

  10. DRASTIC: A STANDARDIZED SYSTEM FOR EVALUATING GROUND WATER POLLUTION POTENTIAL USING HYDROGEOLOGIC SETTINGS

    EPA Science Inventory

    A methodology is described that will allow the pollution potential of any hydrogeologic setting to be systematically evaluated anywhere in the United States. The system has two major portions: the designation of mappable units, termed hydrogeologic settings, and the superposition...

  11. DRASTIC: A STANDARDIZED SYSTEM FOR EVALUATING GROUND WATER POLLUTION USING HYDROGEOLOGIC SETTINGS

    EPA Science Inventory

    A methodology is described that will allow the pollution potential of any hydrogeologic setting to be systematically evaluated anywhere in the United States. The system has two major portions: the designation of mappable units, termed hydrogeologic settings, and the superposit...

  12. The French network of hydrogeological sites H+

    NASA Astrophysics Data System (ADS)

    Davy, P.; Le Borgne, T.; Bour, O.; Gautier, S.; Porel, G.; Bodin, J.; de Dreuzy, J.; Pezard, P.

    2008-12-01

    For groundwater issues (potential leakages in waste repository, aquifer management "), the development of modeling techniques is far ahead of the actual knowledge of aquifers. This raises two fundamental issues: 1) which and how much data are necessary to make predictions accurate enough for aquifer management issues; 2) which models remain relevant to describe the heterogeneity and complexity of geological systems. The French observatory H+ was created in 2002 with the twofold motivation of acquiring a large database for validating models of heterogeneous aquifers, and of surveying groundwater quality evolution in the context of environmental changes. H+ is a network of 4 sites (Ploemeur, Brittany, France; HES Poitiers, France; Cadarache, France; Campos, Mallorca, Spain) with different geological, climatic, and economic contexts. All of them are characterized by a highly heterogeneous structure (fractured crystalline basement for Ploemeur, karstified and fractured limestone for Poitiers, Cadarache and Mallorca), which is far to be taken into account by basic models. Ploemeur is exploited as a tap-water plant for a medium-size coastal city (15,000 inhabitants) for 20 years. Each site is developed for long term investigation and monitoring. They involves a dense network of boreholes, detailed geological and geophysical surveys, periodic campaigns and/or permanent measurements of groundwater flow, water chemistry, geophysical signals (including ground motions), climatic parameter, etc. Several large-scale flow experiments are scheduled per year to investigate the aquifer structure with combined geophysical, hydrogeological, and geochemical instruments. All this information is recorded in a database that has been developed to improve the sustainability and quality of data, and to be used as a collaborative tool for both site researchers and modelers. This project lasts now for 5 years. It is a short time to collect the amount of information necessary to apprehend the

  13. Hydrogeology of the Azores volcanic archipelago (Portugal)

    NASA Astrophysics Data System (ADS)

    Cruz, J.; Coutinho, R.; Antunes, P.; Freire, P.

    2009-04-01

    the volcanic edifices slopes. The basal aquifer system is in the coastal area, presenting generally a very low hydraulic gradient. Hydrogeological surveys that have been made in the Azores archipelago points out to more than 1000 springs and wells spread all over the archipelago (950 springs and 83 drilled wells). Spring distribution is heterogeneous, with densities varying between 0.01 springs/km2 at Pico island and 0.72 springs/km2 estimated at Santa Maria. Specific capacity ranges from 1.4x10-2 to 266.7 L/sm, with a median value of 32.3 L/sm. Transmissivity also present a large range, with values ranging between 1.65x10-5 and 4.03x10-1 m2/s, and a median of 3.66x10-2 m2/s. The heterogeneous distribution shown by these values expresses the influence of the hydrogeological characteristics of volcanic terrain, resulting from syngenetic characteristics and secondary processes, like weathering. The highest values are observed in wells drilled in recent basaltic lava flows, which generally are thin and fractured, with frequent clincker levels interbedded, and the lowest data was estimated in the older volcanic formations of Santa Maria island. Groundwater on perched-water bodies, excluding the numerous mineral waters that are spread in several islands of the archipelago, present usually a low mineralization, shown by the electrical conductivity values (36-725 S/cm; median=158.0 S/cm). The average temperature is equal to 15°C. Waters have an average temperature of 15°C and are mainly slightly acid to slightly alkaline, with a pH range from 4.7 to 8.6, but showing a median value of 7.2. The main water types are Na-Cl to Na-HCO3 waters, with numerous samples lying in the intermediate compositional fields that characterize Na-Cl-HCO3 and Na-HCO3-Cl waters. The groundwater composition in the basal aquifer system is usually from the Na-Cl type and presents a higher mineralization, resulting in a median value for electrical conductivity equal to 1044 S/cm, expressing the

  14. Groundwater availability as constrained by hydrogeology and environmental flows

    USGS Publications Warehouse

    Watson, Katelyn A.; Mayer, Alex S.; Reeves, Howard W.

    2014-01-01

    Groundwater pumping from aquifers in hydraulic connection with nearby streams has the potential to cause adverse impacts by decreasing flows to levels below those necessary to maintain aquatic ecosystems. The recent passage of the Great Lakes-St. Lawrence River Basin Water Resources Compact has brought attention to this issue in the Great Lakes region. In particular, the legislation requires the Great Lakes states to enact measures for limiting water withdrawals that can cause adverse ecosystem impacts. This study explores how both hydrogeologic and environmental flow limitations may constrain groundwater availability in the Great Lakes Basin. A methodology for calculating maximum allowable pumping rates is presented. Groundwater availability across the basin may be constrained by a combination of hydrogeologic yield and environmental flow limitations varying over both local and regional scales. The results are sensitive to factors such as pumping time, regional and local hydrogeology, streambed conductance, and streamflow depletion limits. Understanding how these restrictions constrain groundwater usage and which hydrogeologic characteristics and spatial variables have the most influence on potential streamflow depletions has important water resources policy and management implications.

  15. An integrated theoretical and practical approach for teaching hydrogeology

    NASA Astrophysics Data System (ADS)

    Bonomi, Tullia; Fumagalli, Letizia; Cavallin, Angelo

    2013-04-01

    Hydrogeology as an earth science intersects the broader disciplines of geology, engineering, and environmental studies but it does not overlap fully with any of them. It is focused on its own range of problems and over time has developed a rich variety of methods and approaches. The resolution of many hydrogeological problems requires knowledge of elements of geology, hydraulics, physics and chemistry; moreover in recent years the knowledge of modelling techniques has become a necessary ability. Successful transfer of all this knowledge to the students depends on the breadth of material taught in courses, the natural skills of the students and any practical experience the students can obtain. In the Department of Earth and Environmental Sciences of the University of Milano-Bicocca, the teaching of hydrogeology is developed in three inter-related courses: 1) general hydrogeology, 2) applied hydrogeology, 3) groundwater pollution and remediation. The sequence focuses on both groundwater flux and contaminant transport, supplemented by workshops involving case studies and computer labs, which provide the students with practical translation of the theoretical aspects of the science into the world of work. A second key aspect of the program utilizes the students' skill at learning through online approaches, and this is done through three approaches: A) by developing the courses on a University e-learning platform that allows the students to download lectures, articles, and teacher comments, and to participate in online forums; B) by carring out exercises through computer labs where the student analyze and process hydrogeological data by means of different numerical codes, that in turn enable them to manage databases and to perform aquifer test analysis, geostatistical analysis, and flux and transport modelling both in the unsaturated and saturated zone. These exercises are of course preceded by theoretical lectures on codes and software, highlighting their features and

  16. Geophysical characterization of Hydrogeological processes at the catchment scale

    NASA Astrophysics Data System (ADS)

    Flores Orozco, Adrian; Gallistl, Jakob; Schlögel, Ingrid; Chwatal, Werner; Oismüller, Markus; Blöschl, Günter

    2016-04-01

    The characterization of hydrogeological properties in the subsurface with high resolution across space and time scales is critical to improve our understanding of water flow and transport processes. However, to date, hydrogeological investigations are mainly performed through well-tests or the analysis of samples, thus, limiting the spatial resolution of the investigation. To properly capture heterogeneities in the subsurface controlling surface-groundwater interactions, modern hydrogeological studies require the development of innovative investigation techniques that permit to gain continuous information about subsurface state with high spatial and temporal resolution at different scales: from the pore-space all the way to the catchment. To achieve this, we propose the conduction of geophysical surveys, in particular field-scale Spectral Induced Polarization (SIP) imaging measurements. SIP images provide information about the complex electrical conductivity (CEC), which is controlled by important hydrogeological parameters, such as porosity, water content and the chemical properties of the pore-water. Here, we present imaging results collected at the catchment scale (approximately 66 ha), which permitted to gain detailed information about the spatial variability of hydrogeological parameters at different scales. The heterogeneities observed in the geophysical images revealed consistency with independent information collected at the study area. In addition to this, and taking into account that different geophysical methods yield information about different properties and at diverse scales, interpretation of the SIP images was improved by incorporation of complementary measurements, such as: ElectroMagnetic Induction (EMI), Ground Penetrating Radar (GPR), Multichannel Analysis of Surface-Waves (MASW) and Seismic Refraction-Reflection (SRR).

  17. Development of China Hydrogeology Exploring Techniques in 30 Years --Comparison of Handbook of Hydrogeology of 1st and 2nd Edition

    NASA Astrophysics Data System (ADS)

    Tong, Y.

    2013-12-01

    Handbook of Hydrogeology (2nd edition) is supported by one program from China Geological Survey (CGS): Research of Technical Methods of Hydrogeological Survey and Revision of Handbook of Hydrogeology. It is a reference book for those who are engaged in hydrogeological survey and research in China and covers fundamental principles, theories, survey and exploring techniques, and traditional experiences and achievements in hydrogeology. By comparing the 1st (1978) and 2nd (2012) edition of Handbook of Hydrogeology (in Chinese), this paper analyses the development of China hydrogeological survey and exploring techniques in last 30 years, especially the great change and progress in survey techniques of hydro-remote sensing and hydro-geophysical prospecting. In the first edition of Handbook of Hydrogeology, hydro-remote sensing was only mentioned as an interpretation of aerial pictures in a hydrogeological way, but had not yet formed an independent system and discipline. In the second edition, hydro-remote sensing is an important and independent chapter as one of the hydrogeological techniques. In it, various survey techniques of hydro-remote sensing and types and features of remote sensing data are classified. General systems of interpretation marks of remote sensing images are established, including marks of landform and Quaternary sediment, bedrock, structure types, water yield property, environmental elements of hydrogeology, aquifer group and so on. Systematic workflow is constructed, esp. in remote sensing images mapping and interpreting techniques. GPS and GIS are integrated into remote sensing. Remote sensing exploring instruments and interpreting softwares are also introduced and classified. Although hydro-geophysical prospecting, in the first edition of Handbook of Hydrogeology, was one independent chapter, there were only 10 exploring techniques. Equipments and instruments were simple and lagged in comparison to those in the second edition. The precision and

  18. Hydrogeological controls on post-fire moss recovery in peatlands

    NASA Astrophysics Data System (ADS)

    Lukenbach, Max; Devito, Kevin; Kettridge, Nicholas; Petrone, Richard; Waddington, James

    2015-04-01

    Wildfire is the largest disturbance affecting peatlands, however, little is known about the spatiotemporal variability of post-fire recovery in these ecosystems. High water table (WT) positions after wildfire are critical to limit atmospheric carbon losses and enable the re-establishment of keystone peatland mosses (i.e. Sphagnum). While small-scale variation in burn severity can reduce capillary flow from the WT and lead to a dry surface after fire, steep WT declines can also limit post-fire moss water availability. As such, post-fire moss water availability is also a function of large-scale controls on peatland WT dynamics, specifically, connectivity to groundwater flow systems (i.e. hydrogeological setting). For this reason, we assessed the interacting controls of hydrogeological setting and burn severity on post-fire moss water availability by measuring peatland WTs, soil tension (Ψ) and surface volumetric moisture content (θ) in three burned, Sphagnum-dominated peatlands located in different hydrogeological settings for three years following wildfire. The effect of burn severity on post-fire moss water availability did not vary with hydrogeological setting, however, the spatial coverage of high and low burn severity did vary between peatlands located in different hydrogeological settings due to its influence on pre-fire fuel loads and species cover. Locations covered by S. fuscum prior to fire exhibited decreasing post-fire water availability with increasing burn severity. In contrast, the lowest water availability (Ψ > 400 cm, θ < 0.02) was observed in feather mosses that underwent low burn severity (residual branches identifiable). Where depth of burn was > 0.05 m (high burn severity) and pre-fire species were not identifiable, water availability was highest (Ψ < 90 cm). Where burn severity did not limit water availability through a reduction of capillary flow, depth to WT (and therefore hydrogeological setting) played a large role in affecting post

  19. Hydrogeologic framework and estimates of ground-water volumes in Tertiary and upper Cretaceous hydrogeologic units in the Powder River basin, Wyoming

    USGS Publications Warehouse

    Hinaman, Kurt

    2005-01-01

    The Powder River Basin in Wyoming and Montana is an important source of energy resources for the United States. Coalbed methane gas is contained in Tertiary and upper Cretaceous hydrogeologic units in the Powder River Basin. This gas is released when water pressure in coalbeds is lowered, usually by pumping ground water. Issues related to disposal and uses of by-product water from coalbed methane production have developed, in part, due to uncertainties in hydrologic properties. One hydrologic property of primary interest is the amount of water contained in Tertiary and upper Cretaceous hydrogeologic units in the Powder River Basin. The U.S. Geological Survey, in cooperation with the Bureau of Land Management, conducted a study to describe the hydrogeologic framework and to estimate ground-water volumes in different facies of Tertiary and upper Cretaceous hydrogeologic units in the Powder River Basin in Wyoming. A geographic information system was used to compile and utilize hydrogeologic maps, to describe the hydrogeologic framework, and to estimate the volume of ground water in Tertiary and upper Cretaceous hydrogeologic units in the Powder River structural basin in Wyoming. Maps of the altitudes of potentiometric surfaces, altitudes of the tops and bottoms of hydrogeologic units, thicknesses of hydrogeologic units, percent sand of hydrogeologic units, and outcrop boundaries for the following hydrogeologic units were used: Tongue River-Wasatch aquifer, Lebo confining unit, Tullock aquifer, Upper Hell Creek confining unit, and the Fox Hills-Lower Hell Creek aquifer. Literature porosity values of 30 percent for sand and 35 percent for non-sand facies were used to calculate the volume of total ground water in each hydrogeologic unit. Literature specific yield values of 26 percent for sand and 10 percent for non-sand facies, and literature specific storage values of 0.0001 ft-1 (1/foot) for sand facies and 0.00001 ft-1 for non-sand facies, were used to calculate a

  20. Hydrogeologic Framework of Onslow County, North Carolina, 2008

    USGS Publications Warehouse

    Fine, Jason M.

    2008-01-01

    The unconsolidated sediments that underlie the Onslow County area are composed of interlayered permeable and impermeable beds, which overlie the crystalline basement rocks. The aquifers, composed mostly of sand and limestone, are separated by confining units composed mostly of clay and silt. The aquifers from top to bottom are the surficial, Castle Hayne, Beaufort, Peedee, Black Creek, and Upper and Lower Cape Fear aquifers. For this study, the Castle Hayne aquifer is informally divided into the upper and lower Castle Hayne aquifers. The eight aquifers and seven confining units of the Tertiary and Cretaceous strata beneath Onslow County are presented in seven hydrogeologic sections. The hydrogeologic framework was refined from existing interpretations by using geophysical logs, driller's logs, and other available data from 123 wells and boreholes.

  1. HYDROGEOLOGIC CHARACTERIZATION OF THE U-3bl COLLAPSE ZONE

    SciTech Connect

    Bechtel Nevada and National Security Technologies, LLC

    2006-09-01

    The U-3bl collapse crater was formed by an underground nuclear test in August 1962. This crater and the adjoining U-3ax crater were subsequently developed and used as a bulk low-level radioactive waste disposal cell (U-3ax/bl), which is part of the Area 3 Radioactive Waste Management Site at the Nevada Test Site (NTS). Various investigations have been conducted to assess the hydrogeologic characteristics and properties in the vicinity of the U-3ax/bl waste disposal cell. This report presents data from one of these investigations, conducted in 1996. Also included in this report is a review of pertinent nuclear testing records, which shows that the testing operations and hydrogeologic setting of the U-3ax/bl site were typical for the period and location of testing.

  2. The hydrogeologic-geochemical model of Cerro Prieto revisited

    SciTech Connect

    Lippmann, M.J.; Halfman, S.E.; Truesdell, A.H.; Manon M., A.

    1989-01-01

    As the exploitation of the Cerro Prieto, Mexico, geothermal field continues, there is increasing evidence that the hydrogeologic model developed by Halfman et al. (1984, 1986) presents the basic features controlling the movement of geothermal fluids in the system. At the present time the total installed capacity at Cerro Prieto is 620 MWe requiring the production of more than 10,500 tonnes/hr of a brine-steam mixture. This significant rate of fluid production has resulted in changes in reservoir thermodynamic conditions and in the chemistry of the produced fluids. After reviewing the hydrogeologic-geochemical model of Cerro Prieto, some of the changes observed in the field due to its exploitation are discussed and interpreted on the basis of the model. 21 refs., 11 figs., 1 tab.

  3. Land Use and Hydrogeological Characteristics Influence Groundwater Invertebrate Communities.

    PubMed

    Tione, María Laura; Bedano, José Camilo; Blarasin, Mónica

    2016-08-01

    We examine the influence of land use and hydrogeological characteristics on the abundance, composition and structure of groundwater invertebrate communities in a loessic aquifer from Argentina. Seven wells, selected according to surrounding land use and hydrogeological characteristics, were sampled twice. Groundwater was characterized as sodium bicarbonate, bicarbonate sulfate or sulfate type. NO3(-) was detected in all samples. Land use in the area surrounding the well, unsaturated zone thickness and geochemical characteristics of groundwater influenced the abundance, composition and community structure of groundwater invertebrates. Copepoda, Oligochaeta, Cladocera, Ostracoda and Amphipoda were highly influenced by land use, particularly by point pollution sources that produced higher abundance and changes in taxonomic composition. The lowest invertebrate abundance was observed at the wells situated in areas with the thickest unsaturated zone. Groundwater salinity and geochemical type influenced the presence of certain species, particularly Stygonitocrella sp. PMID:27456146

  4. Hydrogeologic data from parts of the Denver Basin, Colorado

    USGS Publications Warehouse

    Major, T.J.; Robson, S.G.; Romero, J.C.; Zawistowski, Stanley

    1983-01-01

    This report presents hydrogeologic data collected and compiled during 1956-81 as part of a comprehensive hydrogeologic data collected and compiled during 1956-81 as part of a comprehensive hdryogeologic investigation of the Denver basin, Colorado, by the U.S. Geological Survey in cooperation with the Colorado Department of Natural Resources, Division of Water Resources, Office of the State Engineer. The data, in tabular and graphic form, consist of records for 870 wells which include water-level data for 158 wells and water-quality analyses for 561 wells; geophysical logs from three wells which include resistivity, self potential, and natural gamma logs; and gain-and-loss data of streamflow measured at 54 sites. (USGS)

  5. Hydrogeologic model of the Ahuachapan geothermal field, El Salvador

    SciTech Connect

    Laky, C.; Lippmann, M.J.; Bodvarsson, G.S. ); Retana, M.; Cuellar, G. )

    1989-01-01

    A hydrogeological model of the Ahuachapan geothermal field has been developed. It considers the lithology and structural features of the area and discerns their impact on the movement of cold and hot fluids in the system. Three aquifers were identified, their zones of mixing and flow patterns were obtained on the basis of temperature and geochemical data from wells and surface manifestations. 12 refs., 9 figs.

  6. Coastal hydrogeological system of Mar Piccolo (Taranto, Italy).

    PubMed

    Zuffianò, L E; Basso, A; Casarano, D; Dragone, V; Limoni, P P; Romanazzi, A; Santaloia, F; Polemio, M

    2016-07-01

    The Mar Piccolo basin is an internal sea basin located along the Ionian coast (Southern Italy), and it is surrounded primarily by fractured carbonate karstic environment. Because of the karstic features, the main continental water inflow is from groundwater discharge. The Mar Piccolo basin represents a peculiar and sensitive environment and a social emergency because of sea water and sediment pollution. This pollution appears to be caused by the overlapping effects of dangerous anthropogenic activities, including heavy industries and commercial and navy dockyards. The paper aims to define the contribution of subaerial and submarine coastal springs to the hydrological dynamic equilibrium of this internal sea basin. A general approach was defined, including a hydrogeological basin border assessment to detect inflowing springs, detailed geological and hydrogeological conceptualisation, in situ submarine and subaerial spring measurements, and flow numerical modelling. Multiple sources of data were obtained to define a relevant geodatabase, and it contained information on approximately 2000 wells, located in the study area (1600 km(2)). The conceptualisation of the hydrogeological basin, which is 978 km(2) wide, was supported by a 3D geological model that interpolated 716 stratigraphic logs. The variability in hydraulic conductivity was determined using hundreds of pumping tests. Five surveys were performed to acquire hydro-geochemical data and spring flow-yield measurements; the isotope groundwater age was assessed and used for model validation. The mean annual volume exchanged by the hydrogeological basin was assessed equal to 106.93 10(6) m(3). The numerical modelling permitted an assessment of the mean monthly yield of each spring outflow (surveyed or not), travel time, and main path flow. PMID:26201653

  7. Characterization of hydrogeologic units using matrix properties, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Flint, L.E.

    1998-01-01

    Determination of the suitability of Yucca Mountain, in southern Nevada, as a geologic repository for high-level radioactive waste requires the use of numerical flow and transport models. Input for these models includes parameters that describe hydrologic properties and the initial and boundary conditions for all rock materials within the unsaturated zone, as well as some of the upper rocks in the saturated zone. There are 30 hydrogeologic units in the unsaturated zone, and each unit is defined by limited ranges where a discrete volume of rock contains similar hydrogeologic properties. These hydrogeologic units can be easily located in space by using three-dimensional lithostratigraphic models based on relation- ships of the properties with the lithostratigraphy. Physical properties of bulk density, porosity, and particle density; flow properties of saturated hydraulic conductivity and moisture-retention characteristics; and the state variables (variables describing the current state of field conditions) of saturation and water potential were determined for each unit. Units were defined using (1) a data base developed from 4,892 rock samples collected from the coring of 23 shallow and 8 deep boreholes, (2) described lithostratigraphic boundaries and corresponding relations to porosity, (3) recognition of transition zones with pronounced changes in properties over short vertical distances, (4) characterization of the influence of mineral alteration on hydrologic properties such as permeability and moisture-retention characteristics, and (5) a statistical analysis to evaluate where boundaries should be adjusted to minimize the variance within layers. This study describes the correlation of hydrologic properties to porosity, a property that is well related to the lithostratigraphy and depositional and cooling history of the volcanic deposits and can, therefore, be modeled to be distributed laterally. Parameters of the hydrogeologic units developed in this study and the

  8. Developing Hydrogeological Site Characterization Strategies based on Human Health Risk

    NASA Astrophysics Data System (ADS)

    de Barros, F.; Rubin, Y.; Maxwell, R. M.

    2013-12-01

    In order to provide better sustainable groundwater quality management and minimize the impact of contamination in humans, improved understanding and quantification of the interaction between hydrogeological models, geological site information and human health are needed. Considering the joint influence of these components in the overall human health risk assessment and the corresponding sources of uncertainty aid decision makers to better allocate resources in data acquisition campaigns. This is important to (1) achieve remediation goals in a cost-effective manner, (2) protect human health and (3) keep water supplies clean in order to keep with quality standards. Such task is challenging since a full characterization of the subsurface is unfeasible due to financial and technological constraints. In addition, human exposure and physiological response to contamination are subject to uncertainty and variability. Normally, sampling strategies are developed with the goal of reducing uncertainty, but less often they are developed in the context of their impacts on the overall system uncertainty. Therefore, quantifying the impact from each of these components (hydrogeological, behavioral and physiological) in final human health risk prediction can provide guidance for decision makers to best allocate resources towards minimal prediction uncertainty. In this presentation, a multi-component human health risk-based framework is presented which allows decision makers to set priorities through an information entropy-based visualization tool. Results highlight the role of characteristic length-scales characterizing flow and transport in determining data needs within an integrated hydrogeological-health framework. Conditions where uncertainty reduction in human health risk predictions may benefit from better understanding of the health component, as opposed to a more detailed hydrogeological characterization, are also discussed. Finally, results illustrate how different dose

  9. Geological realism in hydrogeological and geophysical inverse modeling: A review

    NASA Astrophysics Data System (ADS)

    Linde, Niklas; Renard, Philippe; Mukerji, Tapan; Caers, Jef

    2015-12-01

    Scientific curiosity, exploration of georesources and environmental concerns are pushing the geoscientific research community toward subsurface investigations of ever-increasing complexity. This review explores various approaches to formulate and solve inverse problems in ways that effectively integrate geological concepts with geophysical and hydrogeological data. Modern geostatistical simulation algorithms can produce multiple subsurface realizations that are in agreement with conceptual geological models and statistical rock physics can be used to map these realizations into physical properties that are sensed by the geophysical or hydrogeological data. The inverse problem consists of finding one or an ensemble of such subsurface realizations that are in agreement with the data. The most general inversion frameworks are presently often computationally intractable when applied to large-scale problems and it is necessary to better understand the implications of simplifying (1) the conceptual geological model (e.g., using model compression); (2) the physical forward problem (e.g., using proxy models); and (3) the algorithm used to solve the inverse problem (e.g., Markov chain Monte Carlo or local optimization methods) to reach practical and robust solutions given today's computer resources and knowledge. We also highlight the need to not only use geophysical and hydrogeological data for parameter estimation purposes, but also to use them to falsify or corroborate alternative geological scenarios.

  10. Impacts of rainfall spatial variability on hydrogeological response

    NASA Astrophysics Data System (ADS)

    Sapriza-Azuri, Gonzalo; Jódar, Jorge; Navarro, Vicente; Slooten, Luit Jan; Carrera, Jesús; Gupta, Hoshin V.

    2015-02-01

    There is currently no general consensus on how the spatial variability of rainfall impacts and propagates through complex hydrogeological systems. Most studies to date have focused on the effects of rainfall spatial variability (RSV) on river discharge, while paying little attention to other important aspects of system response. Here, we study the impacts of RSV on several responses of a hydrological model of an overexploited system. To this end, we drive a spatially distributed hydrogeological model for the semiarid Upper Guadiana basin in central Spain with stochastic daily rainfall fields defined at three different spatial resolutions (fine → 2.5 km × 2.5 km, medium → 50 km × 50 km, large → lumped). This enables us to investigate how (i) RSV at different spatial resolutions, and (ii) rainfall uncertainty, are propagated through the hydrogeological model of the system. Our results demonstrate that RSV has a significant impact on the modeled response of the system, by specifically affecting groundwater recharge and runoff generation, and thereby propagating through to various other related hydrological responses (river discharge, river-aquifer exchange, groundwater levels). These results call into question the validity of management decisions made using hydrological models calibrated or forced with spatially lumped rainfall.

  11. Summary of hydrogeologic conditions by county for the state of Michigan

    USGS Publications Warehouse

    Apple, Beth A.; Reeves, Howard W.

    2007-01-01

    Summaries of the major hydrogeologic features for each county in Michigan are presented. Each summary includes a listing of the major watersheds in the county and a description of the hydrogeology of the major aquifers in the county. Aquifer properties reported in the literature are given if available. Reports describing the hydrogeology of each county are cited. This work was prepared to provide a brief introduction to the ground‑water setting for each county.

  12. Hydrogeological controls on post-fire moss recovery in peatlands

    NASA Astrophysics Data System (ADS)

    Lukenbach, M. C.; Devito, K. J.; Kettridge, N.; Petrone, R. M.; Waddington, J. M.

    2015-11-01

    Wildfire is the largest disturbance affecting boreal peatlands, however, little is known about the controls on post-fire peatland vegetation recovery. While small-scale variation in burn severity can reduce post-fire moss water availability, high water table (WT) positions following wildfire are also critical to enable the re-establishment of keystone peatland mosses (i.e. Sphagnum). Thus, post-fire moss water availability is also likely a function of landscape-scale controls on peatland WT dynamics, specifically, connectivity to groundwater flow systems (i.e. hydrogeological setting). For this reason, we assessed the interacting controls of hydrogeological setting and burn severity on post-fire moss water availability in three burned, Sphagnum-dominated peatlands in Alberta's Boreal Plains. At all sites, variation in burn severity resulted in a dichotomy between post-fire surface covers that: (1) exhibited low water availability, regardless of WT position, and had minimal (<5%) moss re-establishment (i.e. lightly burned feather mosses and severely burned Sphagnum fuscum) or (2) exhibited high water availability, depending on WT position, and had substantial (>50%) moss re-establishment (i.e. lightly burned S. fuscum and where depth of burn was >0.05 m). Notably, hydrogeological setting influenced the spatial coverage of these post-fire surface covers by influencing pre-fire WTs and stand characteristics (e.g., shading). Because feather moss cover is controlled by tree shading, lightly burned feather mosses were ubiquitous (>25%) in drier peatlands (deeper pre-fire WTs) that were densely treed and had little connection to large groundwater flow systems. Moreover, hydrogeological setting also controlled post-fire WT positions, thereby affecting moss re-establishment in post-fire surface covers that were dependent on WT position (e.g., lightly burned S. fuscum). Accordingly, higher recolonization rates were observed in a peatland located in a groundwater flow through

  13. Application of three dimensional geological models to hydrogeology

    NASA Astrophysics Data System (ADS)

    Dong, M.; Neukum, C.; Azzam, R.

    2009-04-01

    Recently, three dimensional (3D) numerical simulation of subsurface structure has become a common engineering geological tool to investigate a variety of geological settings. Besides, hydrogeology always tightly combines with geological structures. For these reasons, coupling 3D geological models with hydrogeology will not only improve understanding of subsurface conditions, but also provide a common stratigraphic framework for hydrogeological applications. The reliability of 3D geological models largely depends on the quality and quantity of data. Normally, before 3D geological models are constructed in the software package, the initial data (borehole descriptions, geological maps, geological cross sections, outcrop data, geo-electrical survey, digital elevation model, etc.) are acquired from archive as much as possible and standardized in a single table. To ensure the precision of models, new drilling data should be gathered from local authorities such as Geological Survey in time. Some experimental data are necessary to be kept at the initial moment to create a subset for verification of the models. In particular, the resulting models will be used for hydrogeological applications. So, more parameters should be collected to construct the 3D property models. Properties contain porosities of soil, bearing capacity, compressibility and particular geological phenomenon such as the regional aquifers, aquitard and faults. During the processing of model construction, the minimum element of the models is grid, which can be converted to some finite elements software. Further studies of these models to hydrogeological application involve: integrating faulted horizons of the 3D geological model into the groundwater modeling software package and simulating the groundwater flow within the main relevant aquifers using a finite elements approach; simulating distribution and calculating volume of groundwater in particular area; providing 3D parameters for vulnerability maps of

  14. Characterization of hydrogeologic units using matrix properties, Yucca Mountain, Nevada

    SciTech Connect

    Flint, L.E.

    1998-09-01

    Determination of the suitability of Yucca Mountain, in southern Nevada, as a geologic repository for high-level radioactive waste requires the use of numerical flow and transport models. Input for these models includes parameters that describe hydrologic properties and the initial and boundary conditions for all rock materials within the unsaturated zone, as well as some of the upper rocks in the saturated zone. There are 30 hydrogeologic units in the unsaturated zone, and each unit is defined by limited ranges where a discrete volume of rock contains similar hydrogeologic properties. These hydrogeologic units can be easily located in space by using three-dimensional lithostratigraphic models based on relationships of the properties with the lithostratigraphy. Physical properties of bulk density, porosity, and particle density; flow properties of saturated hydraulic conductivity and moisture-retention characteristics; and the state variables (variables describing the current state of field conditions) of saturation and water potential were determined for each unit. Units were defined using (1) a data base developed from 4,892 rock samples collected from the coring of 23 shallow and 8 deep boreholes, (2) described lithostratigraphic boundaries and corresponding relations to porosity, (3) recognition of transition zones with pronounced changes in properties over short vertical distances, (4) characterization of the influence of mineral alteration on hydrologic properties such as permeability and moisture-retention characteristics, and (5) a statistical analysis to evaluate where boundaries should be adjusted to minimize the variance within layers. This study describes the correlation of hydrologic properties to porosity, a property that is well related to the lithostratigraphy and depositional and cooling history of the volcanic deposits and can, therefore, be modeled to be distributed laterally.

  15. Hydrogeological modeling of prb for remediation of a contaminated site

    NASA Astrophysics Data System (ADS)

    Yang, Y. S.; McGeogh, K. L.; Kalin, R. M.

    2003-04-01

    In recent decades great effort has been spent on restoration of contaminated environment and considerable progress has been made in improving environmental quality. However, challenges still exist in some areas, such as remediation of contaminated land and groundwater. To provide sufficient remediation and protection for land and groundwater underneath, minimize environmental risk in infrastructure maintenance and urban re-development in terms of contamination remediation, it is necessary to incorporate understanding of the sub-surface conditions in the decision-making process. Characterization of regional and site-specific hydrogeological systems plays an important role in remediation of contaminated sites. Advanced modeling techniques can realize and improve characterization of complex hydrogeological systems. Numerical models can provide straightforward approaches for remediation designs. In this paper, a case study on hydrogeologic modeling of Permeable Reactive Barriers (PRB) for remediation of a contaminated site in the dockland area of Dublin, Ireland, is presented. The groundwater modeling maneuvers were carried out in three strands: regional characterization, zoom-in model in a smaller area; and detailed site-specific study. The regional hydrogeology and groundwater systems were characterized to form a regional conceptual model; a more detailed zoom-in 3-D model was further constructed in the quayside area to simulate the impact of adjacent remedial action and diurnally tidal fluctuation; finally, a site-specific model was built to study the detailed flow field and design the best remediation option. This site model was calibrated with field-monitored data under natural condition; hydraulic parameter, time varying river boundary and head-dependant boundary conditions were calibrated to achieve best fits between modeled and observed groundwater heads. The calibrated model then was used to carry out a remediation plan design using Permeable Reactive Barriers

  16. Hydrogeology of the Pine Ridge Indian Reservation, South Dakota

    USGS Publications Warehouse

    Ellis, M.J.; Adolphson, D.G.

    1971-01-01

    Data on which this report is based, including logs of wells and test holes, chemical analyses of water and records of wells and springs, have been summarized by the authors in a basic-data report published jointly by the South Dakota Geological Survey and South Dakota Water Resources Commission (Water Resources Report 4, Basic hydrogeologic data - Pine Ridge Indian Reservation, South Dakota).  A selected bibliography of reports pertaining to the geology of the area has been included in the basic-data report.  This atlas will be more useful if studied in conjunction with a copy of the basic-data report.

  17. Martian hydrogeology sustained by thermally insulating gas and salt hydrates

    NASA Astrophysics Data System (ADS)

    Kargel, Jeffrey S.; Furfaro, Roberto; Prieto-Ballesteros, Olga; Rodriguez, J. Alexis P.; Montgomery, David R.; Gillespie, Alan R.; Marion, Giles M.; Wood, Stephen E.

    2007-11-01

    Numerical simulations and geologic studies suggest that high thermal anomalies beneath, within, and above thermally insulating layers of buried hydrated salts and gas hydrates could have triggered and sustained hydrologic processes on Mars, producing or modifying chaotic terrains, debris flows, gullies, and ice-creep features. These simulations and geologic examples suggest that thick hydrate deposits may sustain such geothermal anomalies, shallow ground-water tables, and hydrogeologic activity for eons. The proposed mechanism may operate and be self-reinforcing even in today's cold Martian climate without elevated heat flux.

  18. Hydrogeologic Assessment of the Pixley National WildlifeRefuge

    SciTech Connect

    Quinn, Nigel W.T.

    2007-10-01

    A hydrogeological assessment of Pixley National Wildlife Refuge was conducted using published reports from the USGS and private engineering consultants that pertained to land in close proximity to the Refuge and from monitoring conducted by refuge staff in collaboration with Reclamation. The compiled data clearly show that there are a large number of agricultural wells throughout the Basin and that water levels are responsive to rates of pumping - in some cases declining more than 100 ft in a matter of a few years. Aquifer properties support a groundwater conjunctive use solution to the provision of additional water supply to the Refuge. The report provides justification for this approach.

  19. First USA/USSR joint conference on environmental hydrology and hydrogeology

    SciTech Connect

    Moore, J.E.; Kanivetsky, R.A.; Rosenshein, J.S.; Zenone, C.; Csallany, S.C.

    1991-01-01

    The objectives of this conference were: to present an overview of issues in hydrology and hydrogeology; to review the effects of global changes on the hydrologic environment; to review surface and ground water pollution, including transport modeling; and to discuss research and practical applications in hydrology and hydrogeology.

  20. Mapping pollution and coastal hydrogeology with helicopterborne transient electromagnetic measurements

    NASA Astrophysics Data System (ADS)

    Christensen, Niels B.; Halkjær, Max

    2014-03-01

    Coastal hydrology is becoming the focus of increasing interest for several reasons. Hydrogeological models need good boundary conditions at the coastline, and with the expected sea level rise due to climate changes, it becomes increasingly important to grasp the dynamics of coastal hydrology in order to predict the consequences of sea level rise for nature and society. We present a helicopterborne transient electromagnetic survey from a region at the North Sea coast in western Jutland, Denmark, carried out at a seriously polluted site with the dual purpose of assessing the extent of the pollution and mapping the coastal hydrogeology to provide data for remediation activities. Data are subjected to constrained inversion with one-dimensional multi-layer (smooth) models. The extent of the pollution plume estimated from a conductive anomaly in the survey results is mainly in accordance with results from other investigations, but also points to hitherto unknown directions of seepage. The interleaving of freshwater extending under the offshore shallow sea and saltwater infiltrating under the onshore freshwater aquifer can be clearly discerned and preferential flow channels are revealed.

  1. The application of seismic techniques to hydrogeological investigations

    NASA Astrophysics Data System (ADS)

    Jarvis, Kevin Donald Gibson

    The objective of this thesis is to demonstrate some new applications of seismic techniques for hydrogeological applications. A compressional-wave, surface-based, reflection seismic technique is used to map aquifer boundaries within a series of Pleistocene near-surface sediments. The interpretation uses both water wells and sequence stratigraphic concepts to identify the boundaries of new and existing aquifers. The use of the cone penetrometer is an integral part of this thesis. The seismic cone is demonstrated to be both cost-effective and reliable for the acquisition of high-quality vertical seismic profile (VSP) data. Other data from the cone, in particular the tip resistance data, are shown to be an integral link for the conversion of shear-wave velocities to values of hydraulic conductivity. Surface-based, shear-wave reflection seismic data are used to image an aquifer contained within Holocene deltaic sediments. A Bayesian inversion of the shear-wave seismic amplitudes (using cone-derived velocities) results in the generation of a two-dimensional profile of shear-wave velocity that is a direct indication of aquifer heterogeneity. Conversion of the velocity to hydraulic conductivity (using a cone-derived relationship) results in the distribution of a key hydrogeologic property within the aquifer. The results from the thesis show significant promise for improving groundwater flow models and providing new techniques for the management and protection of our groundwater resources.

  2. Proceedings of the joint Russian-American hydrogeology seminar

    SciTech Connect

    Tsang, C.F.; Mironenko, V.; Pozdniakov, S.

    1997-12-31

    Hydrogeology research has been very active in both Russia and the US because of the concerns for migration of radioactive and chemical contaminants in soils and geologic formations, as well as for water problems related to mining and other industrial operations. Russian hydrogeologists have developed various analysis and field testing techniques, sometimes in parallel with US counterparts. These Proceedings come out of a Seminar held to bring together a small group (about 15) of active Russian researchers in geologic flow and transport associated with the disposal of radioactive and chemical wastes either on the soils or through deep injection wells, with a corresponding group (about 25) of American hydrogeologists. The meeting was intentionally kept small to enable informal, detailed and in-depth discussions on hydrogeological issues of common interest. Out of this interaction, the authors hope that, firstly, they will have learned from each other and secondly, that research collaborations will be established where there is the opportunity. This proceedings presents the summaries and viewgraphs from the presentations. What cannot be conveyed here is the warm and cooperative atmosphere of these interactions, both inside and outside the formal sessions, which may well lead to future collaborations.

  3. Hydrogeology and groundwater ecology: Does each inform the other?

    NASA Astrophysics Data System (ADS)

    Humphreys, W. F.

    2009-02-01

    The known, perceived and potential relationships between hydrogeology and groundwater ecology are explored, along with the spatial and temporal scale of these relations, the limit of knowledge and areas in need of research. Issues concerned with the subterranean part of the water cycle are considered from the perspective of the biology of those invertebrate animals that live, of necessity, in groundwater and the microbiological milieu essential for their survival. Groundwater ecosystems are placed in a hydrogeological context including the groundwater evolution along a flowpath, the significance of the biodiversity and of the ecosystem services potentially provided. This is considered against a background of three major components essential to the functioning of groundwater ecosystems, each of which can be affected by activities over which hydrogeologists often have control, and each, in turn, may have implications for groundwater management; these are, a place to live, oxygen and food (energy). New techniques and increasing awareness amongst hydrogeologists of the diversity and broad distribution of groundwater ecosystems offer new opportunities to develop cross disciplinary work between hydrogeologists and groundwater ecologists, already demonstrated to be a field for collaboration with broad benefits.

  4. Hydrogeologic framework of the middle San Pedro watershed, southeastern Arizona

    USGS Publications Warehouse

    Dickinson, Jesse E.; Kennedy, Jeffrey R.; Pool, D.R.; Cordova, Jeffrey T.; Parker, John T.; Macy, J.P.; Thomas, Blakemore

    2010-01-01

    Water managers in rural Arizona are under increasing pressure to provide sustainable supplies of water despite rapid population growth and demands for environmental protection. This report describes the results of a study of the hydrogeologic framework of the middle San Pedro watershed. The components of this report include: (1) a description of the geologic setting and depositional history of basin fill sediments that form the primary aquifer system, (2) updated bedrock altitudes underlying basin fill sediments calculated using a subsurface density model of gravity data, (3) delineation of hydrogeologic units in the basin fill using lithologic descriptions in driller's logs and models of airborne electrical resistivity data, (4) a digital three-dimensional (3D) hydrogeologic framework model (HFM) that represents spatial extents and thicknesses of the hydrogeologic units (HGUs), and (5) description of the hydrologic properties of the HGUs. The lithologic interpretations based on geophysical data and unit thickness and extent of the HGUs included in the HFM define potential configurations of hydraulic zones and parameters that can be incorporated in groundwater-flow models. The hydrogeologic framework comprises permeable and impermeable stratigraphic units: (1) bedrock, (2) sedimentary rocks predating basin-and-range deformation, (3) lower basin fill, (4) upper basin fill, and (5) stream alluvium. The bedrock unit includes Proterozoic to Cretaceous crystalline rocks, sedimentary rocks, and limestone that are relatively impermeable and poor aquifers, except for saturated portions of limestone. The pre-basin-and-range sediments underlie the lower basin fill but are relatively impermeable owing to cementation. However, they may be an important water-bearing unit where fractured. Alluvium of the lower basin fill, the main water-bearing unit, was deposited in the structural trough between the uplifted ridges of bedrock and (or) pre-basin-and-range sediments. Alluvium of

  5. Importance of Hydrogeological Conditions on Open-loop Geothermal System

    NASA Astrophysics Data System (ADS)

    Park, D.; Bae, G.; Kim, S.; Lee, K.

    2013-12-01

    The open-loop geothermal system has been known as an eco-friendly, energy-saving, and cost-efficient alternative for the cooling and heating of buildings with directly using the relatively stable temperature of groundwater. Thus, hydrogeological properties of aquifer, such as hydraulic conductivity and storage, must be important in the system application. The study site is located near Han-river, Korea, and because of the well-developed alluvium it might be a typical site appropriate to this system requiring an amount of groundwater. In this study, the first objective of numerical experiments was to find the best distributions of pumping and injection wells suitable to the hydrogeological conditions of the site for the efficient and sustainable system operation. The aquifer has a gravel layer at 15m depth below the ground surface and the river and the agricultural field, which may be a potential contaminant source, are located at the west and east sides, respectively. Under the general conditions that the regional groundwater flows from the east to the river, the locally reversed well distribution, locating the pumping well at upgradient and the injection well at downgradient of the regional flow, was most sustainable. The gravel layer with high hydraulic conductivity caused a little drawdown despite of an amount of pumping and allowed to stably reinject the used groundwater in all the cases, but it provided a passage transferring the injected heat to the pumping well quickly, particularly in the cases locating the injection well at the upgradient. This thermal interference was more severe in the cases of the short distance between the wells. The high conductive layer is also a reason that the seasonal role conversion of wells for the aquifer thermal energy storage was ineffective in this site. Furthermore, the well distribution vertical to the regional groundwater flow was stable, but not best, and, thus, it may be a good choice in the conditions that the regional

  6. Application of End-Member Mixing Analysis to karst hydrogeology

    NASA Astrophysics Data System (ADS)

    Marechal, J.; Ladouche, B.; Batiot-Guilhe, C.; Seidel, J.

    2013-12-01

    The End-Member Mixing Analysis (EMMA) is used in hydrology to determine the origin of water from solute contents measurements. This method assumes that the water collected at a sampling point originates from a mixing between several end-members. Classically, in hydrology, the water sampled at the outlet of a small head watershed may result from a mixing between rainfall, soil water and groundwater. The objective of EMMA is to compute the relative contributions of the end-members and their evolution with time. This provides valuable information on the origin of water and hydrologic characteristics of the water cycle. Similarly, in hydrogeology, the origin of groundwater can vary according to hydrological conditions, during a pumping test for example or during a flood event. In this paper, this approach still poorly used in hydrogeology, is applied to two Mediterranean karst systems with contrasted objectives. The Lez karst system is a major resource for the water supply of Montpellier city in Southern France. During autumn, it is observed that the first rainy events create an increase of water mineralization at the main karstic spring. An EMMA analysis (Figure 1) has been conducted on the spring water during three hydrological cycles. It determines the respective contributions of two carbonate reservoirs to the spring discharge that fluctuate according to hydrologic conditions. In addition, a contribution from a deep aquifer during the first rainy events is also highlighted (Figure 2). The Nîmes city (Southern France) faced many flood events with devastating inundations. The main spring of the Nimes karst system is located in the centre of the city. Hydrochemical and water level data have highlighted the role of the karst groundwater in the flood genesis in surface streams. EMMA has confirmed the role of the epikarst during flood event once the karst system is saturated. The monitoring of water streams during high flow conditions shows the relative contributions of

  7. Incorporating Fuzzy Systems Modeling and Possibility Theory in Hydrogeological Uncertainty Analysis

    NASA Astrophysics Data System (ADS)

    Faybishenko, B.

    2008-12-01

    Hydrogeological predictions are subject to numerous uncertainties, including the development of conceptual, mathematical, and numerical models, as well as determination of their parameters. Stochastic simulations of hydrogeological systems and the associated uncertainty analysis are usually based on the assumption that the data characterizing spatial and temporal variations of hydrogeological processes are random, and the output uncertainty is quantified using a probability distribution. However, hydrogeological systems are often characterized by imprecise, vague, inconsistent, incomplete or subjective information. One of the modern approaches to modeling and uncertainty quantification of such systems is based on using a combination of statistical and fuzzy-logic uncertainty analyses. The aims of this presentation are to: (1) present evidence of fuzziness in developing conceptual hydrogeological models, and (2) give examples of the integration of the statistical and fuzzy-logic analyses in modeling and assessing both aleatoric uncertainties (e.g., caused by vagueness in assessing the subsurface system heterogeneities of fractured-porous media) and epistemic uncertainties (e.g., caused by the selection of different simulation models) involved in hydrogeological modeling. The author will discuss several case studies illustrating the application of fuzzy modeling for assessing the water balance and water travel time in unsaturated-saturated media. These examples will include the evaluation of associated uncertainties using the main concepts of possibility theory, a comparison between the uncertainty evaluation using probabilistic and possibility theories, and a transformation of the probabilities into possibilities distributions (and vice versa) for modeling hydrogeological processes.

  8. Hydrogeologic Unit Flow Characterization Using Transition Probability Geostatistics

    SciTech Connect

    Jones, N L; Walker, J R; Carle, S F

    2003-11-21

    This paper describes a technique for applying the transition probability geostatistics method for stochastic simulation to a MODFLOW model. Transition probability geostatistics has several advantages over traditional indicator kriging methods including a simpler and more intuitive framework for interpreting geologic relationships and the ability to simulate juxtapositional tendencies such as fining upwards sequences. The indicator arrays generated by the transition probability simulation are converted to layer elevation and thickness arrays for use with the new Hydrogeologic Unit Flow (HUF) package in MODFLOW 2000. This makes it possible to preserve complex heterogeneity while using reasonably sized grids. An application of the technique involving probabilistic capture zone delineation for the Aberjona Aquifer in Woburn, Ma. is included.

  9. Hydrogeology and quality of ground water in Orange County, Florida

    USGS Publications Warehouse

    Adamski, James C.; German, Edward R.

    2004-01-01

    Ground water is the main source of water supply in central Florida and is critical for aquatic habitats and human consumption. To provide a better understanding for the conservation, development, and management of the water resources of Orange County, Florida, a study of the hydrogeologic framework, water budget, and ground-water quality characteristics was conducted from 1998 through 2002. The study also included extensive analyses of the surface-water resources, published as a separate report. An increase in population from about 264,000 in 1960 to 896,000 in 2000 and subsequent urban growth throughout this region has been accompanied by a substantial increase in water use. Total ground-water use in Orange County increased from about 82 million gallons per day in 1965 to about 287 million gallons per day in 2000. The hydrogeology of Orange County consists of three major hydrogeologic units: the surficial aquifer system, the intermediate confining unit, and the Floridan aquifer system. Data were compiled from 634 sites to construct hydrogeologic maps and sections of Orange County. Water-level elevations measured in 23 wells tapping the surficial aquifer system ranged from about 10.6 feet in eastern Orange County to 123.8 feet above NGVD 29 in northwestern Orange County from March 2000 through September 2001. Water levels also were measured in 14 wells tapping the Upper Floridan aquifer. Water levels fluctuate over time from seasonal and annual variations in rainfall; however, water levels in a number of wells tapping the Upper Floridan aquifer have declined over time. Withdrawal of ground water from the aquifers by pumping probably is causing the declines because the average annual precipitation rate has not changed substantially in central Florida since the 1930s, although yearly rates can vary. A generalized water budget was computed for Orange County from 1991 to 2000. Average rates for the 10-year period for the following budget components were computed based

  10. Hydrogeology of the unsaturated zone, Yucca Mountain, Nevada

    SciTech Connect

    Montazer, P.; Wilson, W.E.

    1985-12-31

    The unsaturated volcanic tuff beneath Yucca Mountain, Nevada, is being evaluated by the US Department of Energy as a host rock for a potential mined geologic repository for high-level radioactive waste. Assessment of site suitability needs an efficient and focused investigative program. A conceptual hydrogeologic model that simulates the flow of fluids through the unsaturated zone at Yucca Mountain was developed to guide the program and to provide a basis for preliminary assessment of site suitability. The study was made as part of the Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy. Thickness of the unsaturated zone is about 1640 to 2460 feet (500 to 750 meters). Based on physical properties, the rocks in the unsaturated zone are grouped for the purpose of this paper into five informal hydrogeologic units. From top to bottom these units are: Tiva Canyon welded unit, Paintbrush nonwelded unit. Topopah Spring welded unit, Calico Hills nonwelded unit, and Crater Flat unit. Welded units have a mean fracture density of 8 to 40 fractures per unit cubic meter, mean matrix porosities of 12 to 23%, matrix hydraulic conductivities with geometric means ranging from 6.5 x 10{sup -6} to 9.8 x 10{sup -6} foot per day (2 x 10{sup -6} to 3 x 10{sup -6} meter per day), and bulk hydraulic conductivities of 0.33 to 33 feet per day (0.1 to 10 meters per day). The nonwelded units have a mean fracture density of 1 to 3 fractures per unit cubic meter, mean matrix porosities of 31 to 46%, and saturated hydraulic conductivities with geometric means ranging from 2.6 x 10{sup -5} to 2.9 x 10{sup -2} foot per day (8 x 10{sup -6} to 9 x 10{sup -3} meter per day). 15 refs., 4 figs., 1 tab.

  11. Geographic information system data sets of hydrogeologic conditions in Pequea and Mill Creek watersheds, Pennsylvania; Part II, Hydrogeologic interpretations

    USGS Publications Warehouse

    Low, Dennis J.; Chichester, Douglas C.; Char, Stephen J.

    1995-01-01

    This report describes Geographic Information System data sets of ground-water levels, unsaturated-zone thickness, and regolith thickness in the Pequea and Mill Creek watersheds, a 210-square-mile area in Lancaster and Chester Counties, Pa. The data sets, which represent hydrogeologic interpretations, were developed by the use of ARC/INFO software during 1990-93 by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Environmental Resources. The U.S. Environmental Protection Agency proposes to use these interpretive data sets, and those from other sources, to aid in the assessment of ground-water vulnerability to pesticides in the Pequea and Mill Creek watersheds.

  12. Hydrogeologic framework of the Johns Creek subbasin and vicinity, Mason County, Washington

    USGS Publications Warehouse

    Welch, Wendy B.; Savoca, Mark E.

    2011-01-01

    This report describes the hydrogeologic framework of the groundwater-flow system in the Johns Creek subbasin and vicinity. The study area covers 97 square miles in southeastern Mason County, Washington, and includes the Johns Creek subbasin, which drains an area of about 11 square miles. The study area extends beyond the Johns Creek subbasin to include major hydrologic features that could be used as regional groundwater-flow model boundaries. The subbasin is underlain by a thick sequence of unconsolidated Quaternary glacial and interglacial deposits, which overlie Tertiary igneous and sedimentary bedrock units. Geologic units were grouped into eight hydrogeologic units consisting of aquifers, confining units, undifferentiated deposits, and an underlying bedrock unit. A surficial hydrogeologic map was developed and used with lithologic information from 200 drillers' logs to construct 4 hydrogeologic sections, and unit extent and thickness maps.

  13. Hydrogeologic correlations for selected wells on Long Island, New York; a data base with retrieval program

    USGS Publications Warehouse

    Buxton, H.T.; Shernoff, P.K.; Smolensky, D.A.

    1989-01-01

    Accurate delineation of the internal hydrogeologic structure of Long Island, NY is integral to the understanding and management of the groundwater system. This report presents a computerized data base of hydrogeologic correlations for 3,146 wells on Long Island and adjacent parts of New York City. The data base includes the well identification number, the latitude-longitude of the well location, the altitude of land surface at the well and of the bottom of the drilled hole, and the altitude of the top of the major hydrogeologic units penetrated by the well. A computer program is included that allows retrieval of selected types of data for all of, or any local area of, Long Island. These data retrievals are a valuable aid to the construction of hydrogeologic surface maps. (USGS)

  14. Using GA-Ridge regression to select hydro-geological parameters influencing groundwater pollution vulnerability.

    PubMed

    Ahn, Jae Joon; Kim, Young Min; Yoo, Keunje; Park, Joonhong; Oh, Kyong Joo

    2012-11-01

    For groundwater conservation and management, it is important to accurately assess groundwater pollution vulnerability. This study proposed an integrated model using ridge regression and a genetic algorithm (GA) to effectively select the major hydro-geological parameters influencing groundwater pollution vulnerability in an aquifer. The GA-Ridge regression method determined that depth to water, net recharge, topography, and the impact of vadose zone media were the hydro-geological parameters that influenced trichloroethene pollution vulnerability in a Korean aquifer. When using these selected hydro-geological parameters, the accuracy was improved for various statistical nonlinear and artificial intelligence (AI) techniques, such as multinomial logistic regression, decision trees, artificial neural networks, and case-based reasoning. These results provide a proof of concept that the GA-Ridge regression is effective at determining influential hydro-geological parameters for the pollution vulnerability of an aquifer, and in turn, improves the AI performance in assessing groundwater pollution vulnerability. PMID:22124584

  15. Hydrogeologic Data Fusion. Industry Programs/Characterization, Monitoring, and Sensor Technology Crosscut Program. OST Reference #2944

    SciTech Connect

    None, None

    1999-09-01

    Problem: The fate and transport of contaminants in the subsurface requires knowledge of the hydrogeologic system. Site characterization typically involves the collection of various data sets needed to create a conceptual model that represents what’s known about contaminant migration in the subsurface at a particular site. How Hydrogeologic Data Fusion Works Hydrogeologic Data Fusion is a mathematical tool that can be used to combine various types of geophysical, geologic, and hydrologic data from different types of sensors to estimate geologic and hydrogeologic properties. It can be especially useful at hazardous waste sites where the hydrology, geology, or contaminant distribution is significantly complex such that groundwater modeling is required to enable a reasonable and accurate prediction of subsurface conditions.

  16. GIS-based hydrogeological databases and groundwater modelling

    NASA Astrophysics Data System (ADS)

    Gogu, Radu Constantin; Carabin, Guy; Hallet, Vincent; Peters, Valerie; Dassargues, Alain

    2001-12-01

    Reliability and validity of groundwater analysis strongly depend on the availability of large volumes of high-quality data. Putting all data into a coherent and logical structure supported by a computing environment helps ensure validity and availability and provides a powerful tool for hydrogeological studies. A hydrogeological geographic information system (GIS) database that offers facilities for groundwater-vulnerability analysis and hydrogeological modelling has been designed in Belgium for the Walloon region. Data from five river basins, chosen for their contrasting hydrogeological characteristics, have been included in the database, and a set of applications that have been developed now allow further advances. Interest is growing in the potential for integrating GIS technology and groundwater simulation models. A "loose-coupling" tool was created between the spatial-database scheme and the groundwater numerical model interface GMS (Groundwater Modelling System). Following time and spatial queries, the hydrogeological data stored in the database can be easily used within different groundwater numerical models. Résumé. La validité et la reproductibilité de l'analyse d'un aquifère dépend étroitement de la disponibilité de grandes quantités de données de très bonne qualité. Le fait de mettre toutes les données dans une structure cohérente et logique soutenue par les logiciels nécessaires aide à assurer la validité et la disponibilité et fournit un outil puissant pour les études hydrogéologiques. Une base de données pour un système d'information géographique (SIG) hydrogéologique qui offre toutes les facilités pour l'analyse de la vulnérabilité des eaux souterraines et la modélisation hydrogéologique a été établi en Belgique pour la région Wallonne. Les données de cinq bassins de rivières, choisis pour leurs caractéristiques hydrogéologiques différentes, ont été introduites dans la base de données, et un ensemble d

  17. A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using GIS Techniques

    USGS Publications Warehouse

    Faunt, Claudia C.; D'Agnese, Frank A.; Turner, A. Keith

    1997-01-01

    In support of Yucca Mountain site characterization studies, a hydrogeologic framework was developed, and a hydrogeologic map was constructed for the Death Valley region. The region, covering approximately 100,000 km 2 along the Nevada-California border near Las Vegas, is characterized by isolated mountain ranges juxtaposed against broad, alluvium-filled valleys. Geologic conditions are typical of the Basin and Range Province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. The regional ground-water flow system can best be described as a series of connected intermontane basins in which ground-water flow occurs in basin-fill deposits, carbonate rocks, clastic rocks, and volcanic rocks. Previous investigations have developed more site-specific hydrogeologic relationships; however, few have described all the lithologies within the Death Valley regional ground-water flow system. Information required to characterize the hydrogeologic units in the region was obtained from regional geologic maps and reports. Map data were digitized from regional geologic maps and combined into a composite map using a geographic information system. This map was simplified to show 10 laterally extensive hydrogeologic units with distinct hydrologic properties. The hydraulic conductivity values for the hydrogeologic units range over 15 orders of magnitude due to the variability in burial depth and degree of fracturing.

  18. Sandia National Laboratories site-wide hydrogeologic characterization project calendar year 1992 annual report

    SciTech Connect

    Crowson, D.; Gibson, J.D.; Haase, C.S.; Holt, R.; Hyndman, D.; Krumhansl, J.; Lauffer, F.; McCord, J.P.; McCord, J.T.; Neel, D.

    1993-10-01

    The Sandia National Laboratories, New Mexico (SNL/NM) Site-Wide Hydrogeologic Characterization (SWHC) project has been implemented as part of the SNL/NM Environmental Restoration (ER) Program to develop the regional hydrogeologic framework and baseline for the approximately 100 mi of Kirtland Air Force Base (KAFB) and adjacent withdrawn public lands upon which SNL/NM has performed research and development activities. Additionally, the SWHC project will investigate and characterize generic hydrogeologic issues associated with the 172 ER sites owned by SNL/NM across its facilities on KAFB. As called for in the Hazardous and Solid Waste Amendments (HSWA) to the Resource Conservation and Recovery Act (RCRA) Part B permit agreement between the U.S. Environmental Protection Agency (EPA) as the permitter and the U.S. Department of Energy (DOE) and SNL/NM as the permittees, an annual report is to be prepared by the SWHC project team. This document serves two primary purposes: (1) to identify and describe the conceptual framework for the hydrogeologic system underlying SNL/NM and (2) to describe characterization activities undertaken in the preceding year that add to our understanding (reduce our uncertainties) regarding the conceptual and quantitative hydrogeologic framework. This SWHC project annual report focuses primarily on purpose 1, providing a summary description of the current {open_quotes}state of knowledge{close_quotes} of the Sandia National Laboratories/Kirtland Air Force Base (SNL/KAFB) hydrogeologic setting.

  19. A hydrogeologic map of the Death Valley region, Nevada, and California, developed using GIS techniques

    SciTech Connect

    Faunt, C.C.; D`Agnese, F.A.; Turner, A.K.

    1997-12-31

    In support of Yucca Mountain site characterization studies, a hydrogeologic framework was developed, and a hydrogeologic map was constructed for the Death Valley region. The region, covering approximately 100,000 km{sup 2} along the Nevada-California border near Las Vegas, is characterized by isolated mountain ranges juxtaposed against broad, alluvium-filled valleys. Geologic conditions are typical of the Basin and Range Province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. The regional ground-water flow system can best be described as a series of connected intermontane basins in which ground-water flow occurs in basin-fill deposits, carbonate rocks, clastic rocks, and volcanic rocks. Previous investigations have developed more site-specific hydrogeologic relationships; however, few have described all the lithologies within the Death Valley regional ground-water flow system. Information required to characterize the hydrogeologic units in the region was obtained from regional geologic maps and reports. Map data were digitized from regional geologic maps and combined into a composite map using a geographic information system. This map was simplified to show 10 laterally extensive hydrogeologic units with distinct hydrologic properties. The hydraulic conductivity values for the hydrogeologic units range over 15 orders of magnitude due to the variability in burial depth and degree of fracturing.

  20. West Siberian basin hydrogeology - regional framework for contaminant migration from injected wastes

    SciTech Connect

    Foley, M.G.

    1994-05-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in massive contamination of the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. Our long-term goal at Pacific Northwest Laboratory is to help determine future environmental and human impacts given the releases that have occurred to date and the current waste management practices. In FY 1993, our objectives were to (1) refine and implement the hydrogeologic conceptual models of the regional hydrogeology of western Siberia developed in FY 1992 and develop the detailed, spatially registered digital geologic and hydrologic databases to test them, (2) calibrate the computer implementation of the conceptual models developed in FY 1992, and (3) develop general geologic and hydrologic information and preliminary hydrogeologic conceptual models relevant to the more detailed models of contaminated site hydrogeology. Calibration studies of the regional hydrogeologic computer model suggest that most precipitation entering the ground-water system moves in the near-surface part of the system and discharges to surface waters relatively near its point of infiltration. This means that wastes discharged to the surface and near-surface may not be isolated as well as previously thought, since the wastes may be carried to the surface by gradually rising ground waters.

  1. Hydrogeologic Modeling at the Sylvania Corning FUSRAP Site - 13419

    SciTech Connect

    Ewy, Ann; Heim, Kenneth J.; McGonigal, Sean T.; Talimcioglu, Nazmi M.

    2013-07-01

    A comparative groundwater hydrogeologic modeling analysis is presented herein to simulate potential contaminant migration pathways in a sole source aquifer in Nassau County, Long Island, New York. The source of contamination is related to historical operations at the Sylvania Corning Plant ('Site'), a 9.49- acre facility located at 70, 100 and 140 Cantiague Rock Road, Town of Oyster Bay in the westernmost portion of Hicksville, Long Island. The Site had historically been utilized as a nuclear materials manufacturing facility (e.g., cores, slug, and fuel elements) for reactors used in both research and electric power generation in early 1950's until late 1960's. The Site is contaminated with various volatile organic and inorganic compounds, as well as radionuclides. The major contaminants of concern at the Site are tetrachloroethene (PCE), trichloroethene (TCE), nickel, uranium, and thorium. These compounds are present in soil and groundwater underlying the Site and have migrated off-site. The Site is currently being investigated as part of the Formerly Utilized Sites Remedial Action Program (FUSRAP). The main objective of the current study is to simulate the complex hydrogeologic features in the region, such as numerous current and historic production well fields; large, localized recharge basins; and, multiple aquifers, and to assess potential contaminant migration pathways originating from the Site. For this purpose, the focus of attention was given to the underlying Magothy formation, which has been impacted by the contaminants of concern. This aquifer provides more than 90% of potable water supply in the region. Nassau and Suffolk Counties jointly developed a three-dimensional regional groundwater flow model to help understand the factors affecting groundwater flow regime in the region, to determine adequate water supply for public consumption, to investigate salt water intrusion in localized areas, to evaluate the impacts of regional pumping activity, and to

  2. Interpretation, modeling and forecasting runoff of regional hydrogeologic systems

    NASA Astrophysics Data System (ADS)

    Shun, Tongying

    1999-10-01

    Long-range modeling of a precipitation-runoff process has become indispensable to predict/forecast runoff and study the impact of modern anthropogenic factors and land change use on watersheds. The purpose of this thesis research is to interpret, model and forecast complex drainage basins using advanced signal processing technique and a physically-based low-dimensional dynamic model. The first emphasis is placed on a hydrogeologic interpretation of a complex drainage basin. The space- time patterns of annual, interannual, and decadal components of precipitation, temperature, and runoff (P- T-R) using long-record time series across the steep topographic gradient of the Wasatch Front in northern Utah, are examined. The singular spectrum analysis is used to detect dominant oscillations and spatial patterns in the data and to discuss the relation to the unique mountain and basin hydrologic setting. For precipitation and temperature, only the annual/seasonal spectral peaks were found to be significantly different from the underlying noise floor. Spectral peaks in runoff show increasing low-frequency components at intermediate and low elevation. A conceptual hydrogeologic model for the mountain and basin system proposes how losing streams and deep upwelling groundwater in the alluvial aquifer could explain the strong low-frequency component in streams. The research shows that weak interannual and decadal oscillations in the climate signal are strengthened where groundwater discharge dominates streamflow. The second emphasis is focused on developing a long-range physically-based precipitation-runoff model. A low- dimensional integral-balance model is developed for a hydrologic system where multiple time scales of basin storage play the dominant role on a precipitation-runoff process. The genetic algorithm (GA) technique is implemented for parameter identification with the observed data. The model is developed for the Upper West Branch of the Susquehanna River in

  3. Hydrogeologic framework of fractured sedimentary rock, Newark Basin, New Jersey

    USGS Publications Warehouse

    Lacombe, Pierre J.; Burton, William C.

    2010-01-01

    The hydrogeologic framework of fractured sedimentary bedrock at the former Naval Air Warfare Center (NAWC), Trenton, New Jersey, a trichloroethylene (TCE)-contaminated site in the Newark Basin, is developed using an understanding of the geologic history of the strata, gamma-ray logs, and rock cores. NAWC is the newest field research site established as part of the U.S. Geological Survey Toxic Substances Hydrology Program, Department of Defense (DoD) Strategic Environmental Research and Development Program, and DoD Environmental Security Technology Certification Program to investigate contaminant remediation in fractured rock. Sedimentary bedrock at the NAWC research site comprises the Skunk Hollow, Byram, and Ewing Creek Members of the Lockatong Formation and Raven Rock Member of the Stockton Formation. Muds of the Lockatong Formation that were deposited in Van Houten cycles during the Triassic have lithified to form the bedrock that is typical of much of the Newark Basin. Four lithotypes formed from the sediments include black, carbon-rich laminated mudstone, dark-gray laminated mudstone, light-gray massive mudstone, and red massive mudstone. Diagenesis, tectonic compression, off-loading, and weathering have altered the rocks to give some strata greater hydraulic conductivity than other strata. Each stratum in the Lockatong Formation is 0.3 to 8 m thick, strikes N65 degrees E, and dips 25 degrees to 70 degrees NW. The black, carbon-rich laminated mudstone tends to fracture easily, has a relatively high hydraulic conductivity and is associated with high natural gamma-ray count rates. The dark-gray laminated mudstone is less fractured and has a lower hydraulic conductivity than the black carbon-rich laminated mudstone. The light-gray and the red massive mudstones are highly indurated and tend to have the least fractures and a low hydraulic conductivity. The differences in gamma-ray count rates for different mudstones allow gamma-ray logs to be used to correlate and

  4. Feedbacks Between Numerical and Analytical Models in Hydrogeology

    NASA Astrophysics Data System (ADS)

    Zlotnik, V. A.; Cardenas, M. B.; Toundykov, D.; Cohn, S.

    2012-12-01

    Hydrogeology is a relatively young discipline which combines elements of Earth science and engineering. Mature fundamental disciplines (e.g., physics, chemistry, fluid mechanics) have centuries-long history of mathematical modeling even prior to discovery of Darcy's law. Thus, in hydrogeology, relatively few classic analytical models (such those by Theis, Polubarinova-Kochina, Philip, Toth, Henry, Dagan, Neuman) were developed by the early 1970's. The advent of computers and practical demands refocused mathematical models towards numerical techniques. With more diverse but less mathematically-oriented training, most hydrogeologists shifted from analytical methods to use of standardized computational software. Spatial variability in internal properties and external boundary conditions and geometry, and the added complexity of chemical and biological processes will remain major challenges for analytical modeling. Possibly, analytical techniques will play a subordinate role to numerical approaches in many applications. On the other hand, the rise of analytical element modeling of groundwater flow is a strong alternative to numerical models when data demand and computational efficiency is considered. The hallmark of analytical models - transparency and accuracy - will remain indispensable for scientific exploration of complex phenomena and for benchmarking numerical models. Therefore, there will always be feedbacks and complementarities between numerical and analytical techniques, as well as a certain ideological schism among various views to modeling. We illustrate the idea of feedbacks by reviewing evolution of Joszef Toth's analytical model of gravity driven flow systems. Toth's (1963) approach was to reduce the flow domain to a rectangle which allowed for closed-form solution of the governing equations. Succeeding numerical finite-element models by Freeze and Witherspoon (1966-1968) explored the effects of geometry and heterogeneity on regional groundwater flow

  5. Hydrogeology of the Potsdam Sandstone in northern New York

    USGS Publications Warehouse

    Williams, John H.; Reynolds, Richard J.; Franzi, David A.; Romanowicz, Edwin A.; Paillet, Frederick L.

    2010-01-01

    The Potsdam Sandstone of Cambrian age forms a transboundary aquifer that extends across northern New York and into southern Quebec. The Potsdam Sandstone is a gently dipping sequence of arkose, subarkose, and orthoquartzite that unconformably overlies Precambrian metamorphic bedrock. The Potsdam irregularly grades upward over a thickness of 450 m from a heterogeneous feldspathic and argillaceous rock to a homogeneous, quartz-rich and matrix-poor rock. The hydrogeological framework of the Potsdam Sandstone was investigated through an analysis of records from 1,500 wells and geophysical logs from 40 wells, and through compilation of GIS coverages of bedrock and surficial geology, examination of bedrock cores, and construction of hydrogeological sections. The upper several metres of the sandstone typically is weathered and fractured and, where saturated, readily transmits groundwater. Bedding-related fractures in the sandstone commonly form sub-horizontal flow zones of relatively high transmissivity. The vertical distribution of sub-horizontal flow zones is variable; spacings of less than 10 m are common. Transmissivity of individual flow zones may be more than 100 m2/d but typically is less than 10 m2/d. High angle fractures, including joints and faults, locally provide vertical hydraulic connection between flow zones. Hydraulic head gradients in the aquifer commonly are downward; a laterally extensive series of sub-horizontal flow zones serve as drains for the groundwater flow system. Vertical hydraulic head differences between shallow and deep flow zones range from 1 m to more than 20 m. The maximum head differences are in recharge areas upgradient from the area where the Chateauguay and Chazy Rivers, and their tributaries, have cut into till and bedrock. Till overlies the sandstone in much of the study area; its thickness is generally greatest in the western part, where it may exceed 50 m. A discontinuous belt of bedrock pavements stripped of glacial drift extends

  6. The deep hydrogeologic flow system underlying the Oak Ridge Reservation

    SciTech Connect

    Nativ, R.; Hunley, A.E.

    1993-07-01

    The deep hydrogeologic system underlying the Oak Ridge Reservation contains some areas contaminated with radionuclides, heavy metals, nitrates, and organic compounds. The groundwater at that depth is saline and has previously been considered stagnant. On the basis of existing and newly collected data, the nature of flow of the saline groundwater and its potential discharge into shallow, freshwater systems was assessed. Data used for this purpose included (1) spatial and temporal pressures and hydraulic heads measured in the deep system, (2) hydraulic parameters of the formations in question, (3) spatial temperature variations, and (4) spatial and temporal chemical and isotopic composition of the saline groundwater. In addition, chemical analyses of brine in adjacent areas in Tennessee, Kentucky, Ohio, Pennsylvania, and West Virginia were compared with the deep water underlying the reservation to help assess the origin of the brine. Preliminary conclusions suggest that the saline water contained at depth is old but not isolated (in terms of recharge and discharge) from the overlying active and freshwater-bearing units. The confined water (along with dissolved solutes) moves along open fractures (or man-made shortcuts) at relatively high velocity into adjacent, more permeable units. Groundwater volumes involved in this flow probably are small.

  7. A New Hydrogeological Research Site in the Willamette River Floodplain

    NASA Astrophysics Data System (ADS)

    Faulkner, B. R.; Cline, S. P.; Landers, D. H.; Forshay, K. J.

    2008-12-01

    The Willamette River is a ninth-order tributary of the Columbia which passes through a productive and populous region in northwest Oregon. Where unconstrained by shoreline revetments, the floodplain of this river is a high-energy, dynamic system which supports a variety of riparian forests and floodplain habitats. On the Green Island Restoration Site, north of the city of Eugene, several geomorphological features common to much of the Willamette floodplain are present. These features, ranging from young bare gravel bars, islands supporting mature forest stands, to agricultural areas bounded by levees. As part of a Memorandum of Understanding with the McKenzie River Trust, USEPA has constructed a network of fifty shallow monitoring wells on the Green Island site. Among the purposes are to characterize the hydrogeology of the multiple- island floodplain, the extent of hyporheic flow, and the temperature regime. The monitoring wells are located in areas ranging from a few meters from the river edge to several hundred meters away, within the agricultural areas. By automatic data-logging, flow nets will be developed using numerical modeling. Water quality data will be collected to measure the degee to which subsurface biogeochemistry is influenced by geomorphologic features that are determined by the processes of river channel migration, island formation, and colonization by riparian forest. The monitoring network will also be used to measure the groundwater quality effects of restoration projects currently underway. These include reforestation of previously agricultural areas, and levee removal.

  8. Hydrogeological study of an anti-tank range.

    PubMed

    Mailloux, Michel; Martel, Richard; Gabriel, Uta; Lefebvre, René; Thiboutot, Sonia; Ampleman, Guy

    2008-01-01

    The Arnhem Anti-Tank Range (Canadian Forces Base [CFB] Valcartier, Canada, in operation since the 1970s) has been characterized, including the drilling, installation, and characterization of 25 wells and a ground-penetrating radar survey. The observed particular features of this site include highly variable flow velocities (from < 3 to 1200 m/yr) and transient flow regime in the regional aquifer below the contaminant source zone of the impact area, sharp flow direction shifts, discontinuous stratigraphy and a local perched aquifer. A transient ground water flow model permitted us to understand how the complex hydrogeological setting shapes contaminant transport in the regional aquifer. The model explains the highly variable energetic material (EM) concentrations measured in the plume with peaks associated to spring and to a lesser extent to fall recharge events. As a conclusion from this work, the authors suggest that the characterization of contaminant sources on slopes should extend over all seasons to be sure to detect potential transient flow conditions and variable contaminant concentrations. PMID:18574178

  9. Hydrogeologic data for the northern Rocky Mountains intermontane basins, Montana

    USGS Publications Warehouse

    Dutton, DeAnn M.; Lawlor, Sean M.; Briar, D.W.; Tresch, R.E.

    1995-01-01

    The U.S. Geological Survey began a Regional Aquifer- System Analysis of the Northern Rocky Mountains Intermontane Basins of western Montana and central and central and northern Idaho in 1990 to establish a regional framework of information for aquifers in 54 intermontane basins in an area of about 77,500 square miles. Selected hydrogeologic data have been used as part of this analysis to define the hydro- logic systems. Records of 1,376 wells completed in 31 of the 34 intermontane basins in the Montana part of the study area are tabulated in this report. Data consist of location, alttiude of land surface, date well constructed, geologic unit, depth of well, diameter of casing, type of finish, top of open interval, primary use of water, water level, date water level measured, discharge, specific capacity, source of discharge data, type of log available, date water-quality parameters measured, specific conductance, pH, and temperature. Hydrographs for selected wells also are included. Locations of wells and basins are shown on the accompanying plate.

  10. Quantitative methods to direct exploration based on hydrogeologic information

    USGS Publications Warehouse

    Graettinger, A.J.; Lee, J.; Reeves, H.W.; Dethan, D.

    2006-01-01

    Quantitatively Directed Exploration (QDE) approaches based on information such as model sensitivity, input data covariance and model output covariance are presented. Seven approaches for directing exploration are developed, applied, and evaluated on a synthetic hydrogeologic site. The QDE approaches evaluate input information uncertainty, subsurface model sensitivity and, most importantly, output covariance to identify the next location to sample. Spatial input parameter values and covariances are calculated with the multivariate conditional probability calculation from a limited number of samples. A variogram structure is used during data extrapolation to describe the spatial continuity, or correlation, of subsurface information. Model sensitivity can be determined by perturbing input data and evaluating output response or, as in this work, sensitivities can be programmed directly into an analysis model. Output covariance is calculated by the First-Order Second Moment (FOSM) method, which combines the covariance of input information with model sensitivity. A groundwater flow example, modeled in MODFLOW-2000, is chosen to demonstrate the seven QDE approaches. MODFLOW-2000 is used to obtain the piezometric head and the model sensitivity simultaneously. The seven QDE approaches are evaluated based on the accuracy of the modeled piezometric head after information from a QDE sample is added. For the synthetic site used in this study, the QDE approach that identifies the location of hydraulic conductivity that contributes the most to the overall piezometric head variance proved to be the best method to quantitatively direct exploration. ?? IWA Publishing 2006.

  11. Hydrogeological-Geophysical Methods for Subsurface Site Characterization - Final Report

    SciTech Connect

    Rubin, Yoram

    2001-01-01

    The goal of this research project is to increase water savings and show better ecological control of natural vegetation by developing hydrogeological-geophysical methods for characterizing the permeability and content of water in soil. The ground penetrating radar (GPR) tool was developed and used as the surface geophysical method for monitoring water content. Initial results using the tool suggest that surface GPR is a viable technique for obtaining precision volumetric water content profile estimates, and that laboratory-derived petrophysical relationships could be applied to field-scale GPR data. A field-scale bacterial transport study was conducted within an uncontaminated sandy Pleistocene aquifer to evaluate the importance of heterogeneity in controlling the transport of bacteria. Geochemical, hydrological, geological, and geophysical data were collected to characterize the site prior to and after chemical and bacterial injection experiments. Study results shows that, even within the fairly uniform shallow marine deposits of the narrow channel focus area, heterogeneity existed that influenced the chemical tracer transport over lateral distances of a few meters and vertical distances of less than a half meter. The interpretation of data suggest that the incorporation of geophysical data with limited hydrological data may provide valuable information about the stratigraphy, log conductivity values, and the spatial correlation structure of log conductivity, which have traditionally been obtainable only by performing extensive and intrusive hydrological sampling.

  12. Hydrogeologic insights for a Devil's Slide-like system

    NASA Astrophysics Data System (ADS)

    Thomas, Matthew A.; Loague, Keith

    2014-08-01

    Tectonically active coastal margins commonly host landslides that are influenced by hydrologic, geologic, and/or anthropogenic perturbations. The work reported here is motivated by the hydrologically driven, deep-seated bedrock slides that intersect the (former) Pacific Coast Highway in the active landslide zone at Devil's Slide near Pacifica, California. Numerical simulation of subsurface flow is employed to investigate saturated zone fluid pressure scenarios for 3-D Devil's Slide-like systems. The four-phase concept-development effort is comprised of 134 hydrogeologic simulation scenarios which investigate fluid pressure response for complex subsurface conditions and historically based climate forcings. Recharge, heterogeneity, and anisotropy are shown to increase fluid pressures in targeted failure-prone locations by up to 73.8, 10.3, and 1.8 %, respectively. The interaction between fault zone characteristics and topographically driven flow are shown to influence fluid pressures for up to 85% of the approximately 7.0 × 105 m2 study area. Simulated fluid pressures support the known slope instability for the Devil's Slide site. A quantitative hypothesis-testing discussion explores the likelihood of perched water above the regional water table at the site. Further understanding of hydrologically driven slope movement in the active landslide zone will require additional data focused on rigorous characterization of the unsaturated zone.

  13. Hydrogeological and geotechnical aspects of the Tennessee-Tombigbee Waterway

    NASA Astrophysics Data System (ADS)

    Bryan, Jack H.

    1985-03-01

    The Tennessee-Tombigbee Waterway is in the East Gulf Coastal Plain physiographic province The River and Canal sections were constructed on the floodplain of the Tombigbee River Locks and dams in this section are founded on sediments of Upper Cretaceous age, composed predominantly of sands, clays, and silts of the Eutaw and Gordo formations The 39-mile long Divide Cut was excavated through higher topography which is underlain by these same formations, along with the McShan formation of similar character Bay Springs Lock and Dam, at the south end of the Divide Cut, is founded on shale of the Hartselle formation, which is Mississippian in age Comprehensive studies and tests were made to evaluate and monitor potential impacts of the waterway on the hydrogeologic environment Observations to date show that adverse impacts are very minimal overall, and these are partially offset by beneficial effects Geologic and groundwater conditions were primary factors in the location and design of major features of the waterway During construction, extensive control of groundwater and dewatering effort was required The excavation, utilization, and disposal of over 200 million cubic yards of material, construction of 10 locks and dams, and over 80 miles of canal were accomplished essentially as planned and designed within budget and ahead of schedule

  14. Geomorphology and hydrogeology of the Edwards Plateau karst, central Texas

    NASA Astrophysics Data System (ADS)

    Kastning, E. H., Jr.

    The Edwards Plateau is one of the largest continuous karst regions of the United States; yet, its geomorphic evolution has previously received little systematic study. The overall objectives of this investigation are to: (1) describe the physical characteristics of karst features, (2) determine which geomorphic and hydrogeologic controls and processes have governed their development, and (3) relate genesis of karst spatially and chronologically to the geomorphic evolution of the Edwards Plateau. Cavern development provides a record of evolution of karst and the development of major carbonate aquifers of the region. Some control on cavern development are region-wide; nevertheless, many caves exhibit characteristics that suggest a strong influence of local factors. Development of cave chambers and passages has responded to the lithic character of bedrocks. Solution conduits were guided by variations in calcite and dolomite content, thickness of strata, and frequency of bedding-plane partings. This is particularly true of the Glen Rose Formation, limestone beds of the Edwards Group, and the Gorman Formation, the three principal cave-forming units.

  15. Hydrogeologic effects of natural disruptive events on nuclear waste repositories

    SciTech Connect

    Davis, S.N.

    1980-06-01

    Some possible hydrogeologic effects of disruptive events that may affect repositories for nuclear wastte are described. A very large number of combinations of natural events can be imagined, but only those events which are judged to be most probable are covered. Waste-induced effects are not considered. The disruptive events discussed above are placed into four geologic settings. Although the geology is not specific to given repository sites that have been considered by other agencies, the geology has been generalized from actual field data and is, therefore, considered to be physically reasonable. The geologic settings considered are: (1) interior salt domes of the Gulf Coast, (2) bedded salt of southeastern New Mexico, (3) argillaceous rocks of southern Nevanda, and (4) granitic stocks of the Basin and Range Province. Log-normal distributions of permeabilities of rock units are given for each region. Chapters are devoted to: poresity and permeability of natural materials, regional flow patterns, disruptive events (faulting, dissolution of rock forming minerals, fracturing from various causes, rapid changes of hydraulic regimen); possible hydrologic effects of disruptive events; and hydraulic fracturing.

  16. Hydrogeologic characterization of a fractured granitic rock aquifer, Raymond, California

    SciTech Connect

    Cohen, A.J.B.

    1993-10-01

    The hydrogeologic properties of a shallow, fractured granitic rock aquifer in the foothills of the Sierra Nevada, California were investigated via the analysis of borehole geophysical logs and pumping tests. The drawdowns produced during these tests are not indicative of any simple conceptual aquifer model, and borehole logs show that the granite is intensely fractured. These observations are suggestive of a complex fracture-flow geometry which is extremely difficult to decipher. However, through the measurement of orientations of individual subsurface fractures from acoustic televiewer logs, and correlation between particular fractures and electrical resistivity and thermal-pulse flowmeter logs, it was found that the aquifer is, in general, comprised of two subhorizontal and nearly parallel zones of unloading fractures. Downhole flowmeter measurements taken in several wells provide further evidence for the inferred dual-layer structure of the aquifer, as well as yield quantitative measures of the contribution of flow from each zone. Analysis of drawdowns in pumped wells reveals that there are zones of relatively high transmissivity immediately around them. It was found that these properties, as well as a nearby zone of lower transmissivity, can account for their observed drawdowns. A numerical model was constructed to test whether these major heterogeneities could also account for the drawdowns in observation wells. This stepwise analysis of both the geophysical and hydrological data resulted in the formulation of a conceptual model of the aquifer which is consistent with observations, and which can account for its behavior when subjected to pumping.

  17. Analysis of Hydrogeologic Conceptual Model and Parameter Uncertainty

    SciTech Connect

    Meyer, Philip D.; Nicholson, Thomas J.; Mishra, Srikanta

    2003-06-24

    A systematic methodology for assessing hydrogeologic conceptual model, parameter, and scenario uncertainties is being developed to support technical reviews of environmental assessments related to decommissioning of nuclear facilities. The first major task being undertaken is to produce a coupled parameter and conceptual model uncertainty assessment methodology. This task is based on previous studies that have primarily dealt individually with these two types of uncertainties. Conceptual model uncertainty analysis is based on the existence of alternative conceptual models that are generated using a set of clearly stated guidelines targeted at the needs of NRC staff. Parameter uncertainty analysis makes use of generic site characterization data as well as site-specific characterization and monitoring data to evaluate parameter uncertainty in each of the alternative conceptual models. Propagation of parameter uncertainty will be carried out through implementation of a general stochastic model of groundwater flow and transport in the saturated and unsaturated zones. Evaluation of prediction uncertainty will make use of Bayesian model averaging and visualization of model results. The goal of this study is to develop a practical tool to quantify uncertainties in the conceptual model and parameters identified in performance assessments.

  18. Hydrogeology of the Lake Tahoe Basin, California and Nevada

    USGS Publications Warehouse

    Plume, Russell W.; Tumbusch, Mary L.; Welborn, Toby L.

    2009-01-01

    Ground water in the Lake Tahoe basin is the primary source of domestic and municipal water supply and an important source of inflow to Lake Tahoe. Over the past 30-40 years, Federal, State, and local agencies, and research institutions have collected hydrologic data to quantify the ground-water resources in the Lake Tahoe basin. These data are dispersed among the various agencies and institutions that collected the data and generally are not available in a format suitable for basin-wide assessments. To successfully and efficiently manage the ground-water resources throughout the Lake Tahoe basin, the U.S. Geological Survey (USGS) in cooperation with the U.S. Forest Service (USFS) compiled and evaluated the pertinent geologic, geophysical, and hydrologic data, and built a geodatabase incorporating the consolidated and standardized data for the Lake Tahoe basin that is relevant for examining the extent and characteristics of the hydrogeologic units that comprise the aquifers. The geodatabase can be accessed at http://water.usgs.gov/lookup/getspatial?SIM3063.

  19. A New Assessment Framework for Transience in Hydrogeological Systems.

    PubMed

    Currell, Matthew; Gleeson, Tom; Dahlhaus, Peter

    2016-01-01

    The importance of transience in the management of hydrogeologic systems is often uncertain. We propose a clear framework for determining the likely importance of transient behavior in groundwater systems in a management context. The framework incorporates information about aquifer hydraulics, hydrological drivers, and time scale of management. It is widely recognized that aquifers respond on different timescales to hydrological change and that hydrological drivers themselves, such as climate, are not stationary in time. We propose that in order to assess whether transient behavior is likely to be of practical importance, three factors need to be examined simultaneously: (1) aquifer response time, which can be expressed in terms of the response to a step hydrological change (τstep ) or periodic change (τcycle ); (2) temporal variation of the dominant hydrological drivers, such as dominant climatic systems in a region; (3) the management timescale and spatial scale of interest. Graphical tools have been developed to examine these factors in conjunction, and assess how important transient behavior is likely to be in response to particular hydrological drivers, and thus which drivers are most likely to induce transience in a specified management timeframe. The method is demonstrated using two case studies; a local system that responds rapidly and is managed on yearly to decadal timeframes and a regional system that exhibits highly delayed responses and was until recently being assessed as a high level nuclear waste repository site. Any practical groundwater resource problem can easily be examined using the proposed framework. PMID:25495337

  20. Hydrogeology in The Semi-Arid South-West of Madagascar - a Multi-Scale Approach

    NASA Astrophysics Data System (ADS)

    Englert, A.; Dworak, L.; Rasoloariniaina, J.; Brinkmann, K.; Kobbe, S.; Buerkert, A.

    2014-12-01

    The project „Sustainable Land Management" (SuLaMa) aims at the participatory development and implementation of alternative land-use management practices to protect the ecosystem and its biodiversity and improve the livelihood of the local population in a sustainable manner. One critical aspect within this project is the availability of sustainable water resources. To approach reliable estimates about the availability and dynamics of the water resources, we started a study to understand in detail the hydrogeology of the South-West of Madagascar. As this area has an extend of about 40000 square kilometers, the study is based on a multi-scale approach. Rough large scale estimates are utilized to develop a general understanding of the hydrogeology in the South-West of Madagascar, which allows for large scale estimates of hydrogeology under changing boundary conditions like climate change. Detailed investigations at target villages of the SuLaMa project, combined with boundary conditions derived from the large scale hydrogeological model, allows for estimates of the local hydrogeology under changing boundary conditions like enhanced water abstraction. Although several governmental and nongovernmental institutions have been working on the water resources of the South-West of Madagascar in the past, only few sources on the hydrogeology of this area can be found in literature. To improve the data base we installed five automatic loggers in the area to measure groundwater levels as function of time and investigated in detail about one hundred wells in terms of geometry, groundwater level, electrical conductivity and pH. First preliminary results of the study show that the hydrogeology in the study area is dominated by four major hydrogeological units (fractured crystalline basement, karstic plateau, porous perched aquifers and a porous coastal area) and can be analyzed effectively by assuming a radial symmetric geometry. Ongoing efforts are the development of a model for

  1. Hydrogeologic controls on water quality at a university dairy farm

    NASA Astrophysics Data System (ADS)

    McKay, L. D.; Hunter, R. W.; Lee, J.

    2010-12-01

    Dairy farms typically produce large quantities of manure and other waste products which are often stored or treated in lagoons and then applied to local fields as fertilizer. Contamination of nearby streams by dairy farm wastes through surface runnoff, drainage tile discharge, direct release of wastes or inundation of waste storage facilities during seasonal flooding have long been recognized as major environmental concerns. However, much less attention has been paid to fate and transport of dairy wastes in the subsurface and their potential impact on water quality in aquifers or in groundwater discharge to streams. One of the challenges in evaluating the environmental impact of dairy operations is that there are relatively few field research sites where all of the potential pathways for waterborne transport of dairy wastes are monitored and quantititatively evaluated. There are even fewer sites where extensive baseline water quality monitoring programs were established prior to operation of the dairy. This is essential to distinguish between environmental impacts from dairy operations and other nearby sources, such as beef production and human sewage from septic fields. This talk describes the development of a an integrated hydrogeologic/hydrologic site assessment and groundwater/surface water quality monitoring program at the University of Tennessee - Little River Dairy Farm, located near Townsend, TN. The dairy is currently under construction and the first cows are expected to arrive in late 2010. Hydrologic/hydrogeologic investigations of streams and groundwater at the site have been underway for more than 3 years, and these are expected to provide background data for assessing impacts of dairy wastes and for testing the effectiveness of different management practises. The lower half of the ~180 ha site consists of low-relief fields used for row crops, which are underlain by 4 - 8 m of alluvial deposits (mainly interbedded silt and fine-grained sands) on top of

  2. Hydrogeologic Characterization of the U-3bl Collapse Zone

    SciTech Connect

    NSTec Geotechnical Services

    2006-09-01

    The U-3bl collapse crater was formed by an underground nuclear test in August 1962. This crater and the adjoining U-3ax crater were subsequently developed and used as a bulk low-level radioactive waste disposal cell (U-3ax/bl), which is part of the Area 3 Radioactive Waste Management Site at the Nevada Test Site (NTS). Various investigations have been conducted to assess the hydrogeologic characteristics and properties in the vicinity of the U-3ax/bl waste disposal cell. This report presents data from one of these investigations, conducted in 1996. Also included in this report is a review of pertinent nuclear testing records, which shows that the testing operations and hydrogeologic setting of the U-3ax/bl site were typical for the period and location of testing. Borehole U-3bl-D2 is a 45-degree-angle hole drilled from the edge of the crater under the waste cell to intercept the U-3bl collapse zone, the disturbed alluvium between the crater (surface collapse sink) and the nuclear test cavity. A casing-advance system with an air percussion hammer was used to drill the borehole, and air was used as the drilling fluid. Properties of the U-3bl crater collapse zone were determined from cores collected within the interval, 42.1 to 96.6 meters (138 to 317 feet) below the ground surface. Selected core samples were analyzed for particle density, particle size, bulk density, water retention, hydraulic conductivity, water content, water potential, chloride, carbonate, stable isotopes, and tritium. Physical and hydraulic properties were typical of alluvial valley sediments at the NTS. No visual evidence of preferential pathways for water transport was observed in the core samples. Soil parameters showed no trends with depth. Volumetric water content values ranged from 0.08 to 0.20 cubic meters per cubic meter, and tended to increase with depth. Water-retention relations were typical for soils of similar texture. Water potentials ranged from -1.9 MegaPascals at a depth of 42

  3. Groundwater quality in the San Diego Drainages Hydrogeologic Province, California

    USGS Publications Warehouse

    Wright, Michael T.; Belitz, Kenneth

    2011-01-01

    More than 40 percent of California's drinking water is from groundwater. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The San Diego Drainages Hydrogeologic Province (hereinafter referred to as San Diego) is one of the study units being evaluated. The San Diego study unit is approximately 3,900 square miles and consists of the Temecula Valley, Warner Valley, and 12 other alluvial basins (California Department of Water Resources, 2003). The study unit also consists of all areas outside defined groundwater basins that are within 3 kilometers of a public-supply well. The study unit was separated, based primarily on hydrogeologic settings, into four study areas: Temecula Valley, Warner Valley, Alluvial Basins, and Hard Rock (Wright and others, 2005). The sampling density for the Hard Rock study area, which consists of areas outside of groundwater basins, was much lower than for the other study areas. Consequently, aquifer proportions for the Hard Rock study area are not used to calculate the aquifer proportions shown by the pie charts. An assessment of groundwater quality for the Hard Rock study area can be found in Wright and Belitz, 2011. The temperatures in the coastal part of the study unit are mild with dry summers, moist winters, and an average annual rainfall of about 10 inches. The temperatures in the mountainous eastern part of the study unit are cooler than in the coastal part, with an annual precipitation of about 45 inches that occurs mostly in the winter. The primary aquifers consist of Quaternary-age alluvium and weathered bedrock in the Temecula Valley, Warner Valley, and Alluvial Basins study areas, whereas in the Hard Rock study area the primary aquifers consist mainly of fractured and

  4. A Conceptual Hydrogeologic Model of the Vicinity of DUSEL Homestake

    NASA Astrophysics Data System (ADS)

    Murdoch, L. C.; Germanovich, L. N.; Boutt, D. F.; Kieft, T. L.; Wang, H. F.; Onstott, T. C.

    2009-12-01

    The Deep Underground Science and Engineering Laboratory (DUSEL) is a research facility planned to occupy the workings of the former Homestake gold mine in the northern Black Hills, South Dakota. The hydrogeology was of minor importance to locating and recovering gold ore, so it was overlooked during mining and is relatively unknown. This knowledge gap hinders planning of the Deep EcoHydrology Experiment at DUSEL and motivated the work described here. The conceptual hydrogeologic model is characterized by permeability that is assumed to be anisotropic and controlled by regional foliation, which strikes approximately N20W and dips steeply to the NE. Permeability is on the order of 0.1 mD in fresh rock, but increases to roughly 100 mD at shallow depths. The permeability distribution is assumed to result from unloading of the foliated rock, and a simple model of stress-dependence explains the permeability distribution and suggests that the more permeable zone is on the order of ~100 m thick. A stream hydrograph from Whitetail Creek (station 06436156) was analyzed to estimate recharge flux and the result indicates an average value of approximately 5 x 10-9 m/s. A numerical model of the vicinity of the mine was developed by representing the mine workings as a dual- porosity inclusion embedded in a single-porosity, anisotropic material. The extent of the dual-porosity medium was advanced downward based on the mining records and the hydraulic head within the material representing the mine workings was adjusted to represent filling and draining of the workings. The results suggest that the groundwater is characterized by a shallow flow system of distributed recharge that mostly discharges to nearby streams. The mine itself acts like a large sink that moves downward and to the southeast during mining, and then is controlled by variations in pumping rate once the mine reaches its greatest depth. The deep flow system consists of (i) a zone of relatively rapid flow from the

  5. Hydrogeologic Modeling for Monitoring, Reporting and Verification of Geologic Sequestration

    NASA Astrophysics Data System (ADS)

    Kolian, M.; De Figueiredo, M.; Lisa, B.

    2011-12-01

    In December 2010, EPA finalized Subpart RR of the Greenhouse Gas (GHG) Reporting Program, which requires facilities that conduct geologic sequestration (GS) of carbon dioxide (CO2) to report GHG data to EPA annually. The GHG Reporting Program requires reporting of GHGs and other relevant information from certain source categories in the United States, and information obtained through Subpart RR will inform Agency decisions under the Clean Air Act related to the use of carbon dioxide capture and sequestration for mitigating GHGs. This paper examines hydrogeologic modeling necessities and opportunities in the context of Subpart RR. Under Subpart RR, facilities that conduct GS by injecting CO2 for long-term containment in subsurface geologic formations are required to develop and implement an EPA-approved site-specific monitoring, reporting, and verification (MRV) plan; and report basic information on CO2 received for injection, annual monitoring activities and the amount of CO2 geologically sequestered using a mass balance approach. The major components of the MRV plan include: identification of potential surface leakage pathways for CO2 and the likelihood, magnitude, and timing, of surface leakage of CO2 through these pathways; delineation of the monitoring areas; strategy for detecting and quantifying any surface leakage of CO2; and the strategy for establishing the expected baselines for monitoring CO2 surface leakage. Hydrogeologic modeling is an integral aspect of the design of an MRV plan. In order to prepare an adequate monitoring program that addresses site specific risks over the full life of the project the MRV plan must reflect the full spatial extent of the free phase CO2 over time. Facilities delineate the maximum area that the CO2 plume is predicted to cover and how monitoring can be phased in over this area. The Maximum Monitoring Area (MMA) includes the extent of the free phase CO2 plume over the lifetime of the project plus a buffer zone of one

  6. Hydrogeologic characterization of the Modesto Area, San Joaquin Valley, California

    USGS Publications Warehouse

    Burow, Karen R.; Shelton, Jennifer L.; Hevesi, Joseph A.; Weissmann, Gary S.

    2004-01-01

    Hydrogeologic characterization was done to develop an understanding of the hydrogeologic setting near Modesto by maximizing the use of existing data and building on previous work in the region. A substantial amount of new lithologic and hydrologic data are available that allow a more complete and updated characterization of the aquifer system. In this report, geologic units are described, a database of well characteristics and lithology is developed and used to update the regional stratigraphy, a water budget is estimated for water year 2000, a three-dimensional spatial correlation map of aquifer texture is created, and recommendations for future data collection are summarized. The general physiography of the study area is reflected in the soils. The oldest soils, which have low permeability, exist in terrace deposits, in the interfan areas between the Stanislaus, Tuolumne, and Merced Rivers, at the distal end of the fans, and along the San Joaquin River floodplain. The youngest soils have high permeability and generally have been forming on the recently deposited alluvium along the major stream channels. Geologic materials exposed or penetrated by wells in the Modesto area range from pre-Cretaceous rocks to recent alluvium; however, water-bearing materials are mostly Late Tertiary and Quaternary in age. A database containing information from more than 3,500 drillers'logs was constructed to organize information on well characteristics and subsurface lithology in the study area. The database was used in conjunction with a limited number of geophysical logs and county soil maps to define the stratigraphic framework of the study area. Sequences of red paleosols were identified in the database and used as stratigraphic boundaries. Associated with these paleosols are very coarse grained incised valley-fill deposits. Some geophysical well logs and other sparse well information suggest the presence of one of these incised valley-fill deposits along and adjacent to the

  7. Hydrogeology and water quality of the Leetown area, West Virginia

    USGS Publications Warehouse

    Kozar, Mark D.; McCoy, Kurt J.; Weary, David J.; Field, Malcolm S.; Pierce, Herbert A.; Schill, William Bane; Young, John A.

    2008-01-01

    The U.S. Geological Survey’s Leetown Science Center and the co-located U.S. Department of Agriculture’s National Center for Cool and Cold Water Aquaculture both depend on large volumes of cold clean ground water to support research operations at their facilities. Currently, ground-water demands are provided by three springs and two standby production wells used to augment supplies during periods of low spring flow. Future expansion of research operations at the Leetown Science Center is dependent on assessing the availability and quality of water to the facilities and in locating prospective sites for additional wells to augment existing water supplies. The hydrogeology of the Leetown area, West Virginia, is a structurally complex karst aquifer. Although the aquifer is a karst system, it is not typical of most highly cavernous karst systems, but is dominated by broad areas of fractured rock drained by a relatively small number of solution conduits. Characterization of the aquifer by use of fluorometric tracer tests, a common approach in most karst terranes, therefore only partly defines the hydrogeologic setting of the area. In order to fully assess the hydrogeology and water quality in the vicinity of Leetown, a multi-disciplinary approach that included both fractured rock and karst research components was needed. The U.S. Geological Survey developed this multi-disciplinary research effort to include geologic, hydrologic, geophysical, geographic, water-quality, and microbiological investigations in order to fully characterize the hydrogeology and water quality of the Leetown area, West Virginia. Detailed geologic and karst mapping provided the framework on which hydrologic investigations were based. Fracture trace and lineament analysis helped locate potential water-bearing fractures and guided installation of monitoring wells. Monitoring wells were drilled for borehole geophysical surveys, water-quality sampling, water-level measurements, and aquifer tests to

  8. A methodological integrated approach to optimize a hydrogeological engineering work

    NASA Astrophysics Data System (ADS)

    Loperte, A.; Satriani, A.; Bavusi, M.; Cerverizzo, G.

    2012-04-01

    The geoelectrical survey applied to hydraulic engineering is a well known in literature. However, despite of its large number of successful cases of application, the use of geophysics is still often not considered; this due to different reasons as: the poor knowledge of the potential performances; the difficulties in the practical implementation; the cost limitations. In this work, an integrated study of non-invasive (geoelectrical) and direct surveys is described, aimed at identifying a subsoil foundation where it possible to set up a watertight concrete structure able to protect the purifier of Senise, a little town in Basilicata Region (Southern Italy). The purifier, used by several villages, is located in a particularly dangerous hydrogeological position, as it is very close to the Sinni river, which has been obstructed from many years by the Monte Cotugno dam. During the rainiest periods, the river could flood the purifier, causing the drainage of waste waters in the Monte Cotugno artificial lake. The purifier is located in Pliocene- Calabrian clay and clay - marly formations covered by about 10m layer of alluvional gravelly-sandy materials carried by the Sinni river. The electrical resistivity tomography acquired with the Wenner Schlumberger array was revealed meaningful for the purpose to identify the potential depth of impermeable clays with high accuracy. In particular, the geoelectrical acquisition, orientated along the long side of purifier, was carried out using a multielectrodes system with 48 electrodes 2 m spaced leading to an achievable investigation depth of about 15 m The subsequent direct surveys have confirmed this depth so that it was possible to set up the foundation concrete structure with precision to protect the purifier. It is worth noting that the use of this methodological approach has allowed a remarkable economic saving as it has made it possible to correct the wrong information, regarding the depth of impermeably clays, previously

  9. Research of Hydro-Geological Precursors of Earthquakes in Armenia

    NASA Astrophysics Data System (ADS)

    Pashayan, R.

    2007-12-01

    The observations of hydro-geological regime of underground waters in observed boreholes began in Armenia in 1986. Now these work is concentrated in National Seismic Service. For a long time observations are carried out studying several parameters (debit, temperature, chemical and gas composition) in several deposits of carbon mineral waters of Armenia. The interpretation of materials shows that that a number of strong and medium-strength earthquakes are accompanied by anomal changes in the level of underground waters. Regarding mineral waters, in connection with earthquakes some parameters are immediately changed: debit, temperature, chemical and gas composition. The study of hydrogeodynamic characteristics of precursors specify that the quantity of registered hydrogeodynamic precursors decreases with the increase of epicentrical distance. The majority of precursors is registered at the distance of 200 km from epicenter. There is a tendency of gradual increase of time and amplitude of a precursor of an earthquake depending on the rise of magnitude and epicentral distance. The behaviour of hydrogeodynamic precursors depends on the angle between the faults, to which this or that borehole reaches; with increase of this angle the deformation in the zone of the fault during the preparation of earthquakes is stronger, than in terms of small angles. 1. S1 2. Earthquake processes, Precursors and Forecasts 3. Garni Geophysical Observatory of the National Academy of Sciences of Armenia, 375019, Yerevan, Republic of Armenia, email: hakhleon@sci.am 4. O 5. 10808801 6. Artavazd Payment Type: select 'Purchase Order' PO Number: AGU WAIVER Billing Address: Enter Your Institution City: Enter Your City Country Code: Enter Your Country Name: Enter Your Name Phone: Enter Your Telephone Number

  10. Hydrogeologic role of geologic structures. Part 1: the paradigm

    NASA Astrophysics Data System (ADS)

    Levens, Russell L.; Williams, Roy E.; Ralston, Dale R.

    1994-04-01

    Grouting to reduce fracture permeability is one option for minimizing ground water inflow to a large, acid-producing lead-zinc mine in fractured metamorphic rock in north Idaho. For grouting to reduce mine water inflow effectively, the hydrogeologic characteristics of the various scales of structurally controlled fracturing must be identified and a conceptual model of the ground water flow system must be developed. This paper is the first of two papers which use fracture mapping, geologic structural mapping, and a series of underground hydraulic stress tests to develop a conceptual model of structurally controlled ground water flow in the vicinity of the mine. These data were collected in an effort to identify order within the structurally controlled spatial permeability distribution. Geologic structural discontinuities, ranging from joints to faults that extend for several miles, form a geologic structural hierarchy in the rock surrounding the mine. The tiers of the hierarchy control ground water flow into the mine at different scales. The most prominent faults control ground water inflow on the scale of the entire mine. Various levels of hydraulic continuity are evident within the rock mass bounded by two of the most prominent faults. The highest level of hydraulic continuity appears to be associated with a set of sub-parallel, steeply dipping faults. Minor faults, joints, and relict bedding planes to a limited extent connect the fractures of this set and form a lower level of hydraulic continuity. The next lower level of hydraulic continuity within the hierarchy is related to a major fault that is characterized in drill core by abundant gouge. The hydraulic continuity of the matrix within the unfractured quartzite is the lowest level within the hierarchy. These levels constitute the components of the order within the spatial permeability distribution that we have interpreted from the structural and hydraulic stress test data.

  11. A new hydrogeologic model to predict anthropogenic uplift of Venice

    NASA Astrophysics Data System (ADS)

    Teatini, P.; Castelletto, N.; Ferronato, M.; Gambolati, G.; Tosi, L.

    2011-12-01

    Recent numerical studies based on a simplified lithostratigraphy of the Venice subsurface suggest that the city may be raised by pumping seawater into deep aquifers through 12 wells located on a 10 km diameter circle. Using an updated 3-D reconstruction of the Quaternary deposits, developed very recently from about 1050 km of multichannel seismic profiles and eight exploration wells, along with a more accurate representation of the injection boreholes, novel finite-element predictions are performed. The new model simulates the lithostratigraphy of the lagoon subsurface and allows for a reliable assessment of the water volumes injected into the geologic formations based on the actual bottom hole overpressure that can vary both in space and time. Pumping occurs into two Pleistocene sequences that are originated from the Alps and Apennine sedimentation and terminate just south and north of Venice, respectively, and the shelf portion of a Pliocene sequence that is rather continuous below the central lagoon with arenite layers to depths as much as 1000 m below mean sea level. With a proper tuning of the injection pressure the new hydrogeologic model allows for a prediction of a quite uniform 25-30 cm uplift over 10 years after the inception of injection. The gradient of the vertical displacement ξz does not exceed 5 × 10-5 and 1 × 10-5 in the whole lagoon and Venice, respectively, i.e., well below the most conservative bound recommended for the safety of the structures. If ad hoc calibrated injection overpressures are implemented in each single well, ξz may be reduced to as much as 0.1 × 10-5 throughout the city.

  12. Hydrogeology of the middle Wilcox aquifer system in Mississippi

    SciTech Connect

    Taylor, R.E.; Arthur, J.K. )

    1992-01-01

    A study has been performed to provide water resource planners and managers with hydrogeologic data on the predominantly undeveloped middle Wilcox aquifer system in Mississippi, and to describe its potential as an alternative source of water. The principal source of recharge to the middle Wilcox aquifer system is from precipitation in the outcrop area, a crescent-shaped belt extending from north to east, and dipping west to southwest. Most of the water that percolates into the ground is lost by evapotranspiration or groundwater discharge to local streams. Locally, the rate and direction of groundwater movement is controlled by the hydraulic conductivity of the sand bed and by withdrawal from wells. The potentiometric surface of the aquifer was mapped to represent the approximate altitude of water levels in wells screened in the middle Wilcox aquifer system in 1983. Near some pumping centers in and near the recharge area, water-level declines in recent years have been in the range of about 0.5 to 1.0 ft/yr. The aquifer system is capable of yielding 100-500 gpm from large wells; however, the availability of freshwater at shallower depths has limited the development of this aquifer system farther downdip, and results of aquifer tests are sparse. Groundwater in the outcrop area of the aquifer system generally is of a mixed, calcium-sodium bicarbonate type. There is a general trend of increasing pH values and concentrations of dissolved sodium, bicarbonate, nitrate, and iron with increasing depth. Typically, water in the middle Wilcox aquifer system has concentrations much smaller than the recommended limits for drinking water for nitrate, sulfate, and fluoride. Water from this aquifer system is generally suitable for most uses.

  13. Hydrogeologic Framework of the Yakima River Basin Aquifer System, Washington

    USGS Publications Warehouse

    Vaccaro, J.J.; Jones, M.A.; Ely, D.M.; Keys, M.E.; Olsen, T.D.; Welch, W.B.; Cox, S.E.

    2009-01-01

    The Yakima River basin aquifer system underlies about 6,200 square miles in south-central Washington. The aquifer system consists of basin-fill deposits occurring in six structural-sedimentary basins, the Columbia River Basalt Group (CRBG), and generally older bedrock. The basin-fill deposits were divided into 19 hydrogeologic units, the CRBG was divided into three units separated by two interbed units, and the bedrock was divided into four units (the Paleozoic, the Mesozoic, the Tertiary, and the Quaternary bedrock units). The thickness of the basin-fill units and the depth to the top of each unit and interbed of the CRBG were mapped. Only the surficial extent of the bedrock units was mapped due to insufficient data. Average mapped thickness of the different units ranged from 10 to 600 feet. Lateral hydraulic conductivity (Kh) of the units varies widely indicating the heterogeneity of the aquifer system. Average or effective Kh values of the water-producing zones of the basin-fill units are on the order of 1 to 800 ft/d and are about 1 to 10 ft/d for the CRBG units as a whole. Effective or average Kh values for the different rock types of the Paleozoic, Mesozoic, and Tertiary units appear to be about 0.0001 to 3 ft/d. The more permeable Quaternary bedrock unit may have Kh values that range from 1 to 7,000 ft/d. Vertical hydraulic conductivity (Kv) of the units is largely unknown. Kv values have been estimated to range from about 0.009 to 2 ft/d for the basin-fill units and Kv values for the clay-to-shale parts of the units may be as small as 10-10 to 10-7 ft/d. Reported Kv values for the CRBG units ranged from 4x10-7 to 4 ft/d. Variations in the concentrations of geochemical solutes and the concentrations and ratios of the isotopes of hydrogen, oxygen, and carbon in groundwater provided information on the hydrogeologic framework and groundwater movement. Stable isotope ratios of water (deuterium and oxygen-18) indicated dispersed sources of groundwater recharge to

  14. David L. Parkhurst as the recipient of the 2012 O.E. Meinzer Award of the Hydrogeology Division of the Geological Society of America

    USGS Publications Warehouse

    Glynn, Pierre D.

    2012-01-01

    Describes the impact of USGS scientist David Parkhurst's influential contributions to the fields of aqueous geochemistry and hydrogeology. Parkhurst is the recipient of the 2012 O.E. Meinzer award of the Geological Society of America's Hydrogeology Division.

  15. Theoretical principles of petroleum hydrogeology of the West Siberian megabasin (WSMB)

    NASA Astrophysics Data System (ADS)

    Matusevich, V.; Popov, V.; Kovyatkina, L.; Pozdeeva, G.

    2016-03-01

    Comprehensive study of the chemical and gas composition, temperatures, levels, pressure of deep underground water in deep wells is associated with the beginning of the systematic development of the oil and gas potential in Western Siberia and the first discovery of large deposits here. The development of new branches of hydrogeology is due to the fact of more and more available data. Thus, fundamental understandings of the WSMB hydrogeological conditions are being translated into new theories. Geodynamically, the WSMB structure was revised and based on hydrogeological data, regional and local prediction of oil and gas occurrence exploration criteria were developed. Based on the dispersion halo water-dissolved substance theory, exploration methodology of “neglected” deposits were formulated, conceptual issues of technogenic changes of oil and gas hydrogeosphere areas were being developed.

  16. Fault control on the hydrogeological setting of the Sibillini Mountains aquifers (Central Apennines, Italy): an example of hydrogeological structures in thrust-belt contexts

    NASA Astrophysics Data System (ADS)

    Tarragoni, C.

    2012-04-01

    This work is aimed at highlighting the importance of fault control on the hydrogeological setting in orogenic areas. In Sibillini Montains, Umbrian-Marchean pelagic succession outcrops. This succession, characterized by calcareous, calcareous-marly and silicate could presents condensed succession and is involved in fold and overthrust deformation, followed by a development of normal faults. The lithostratigraphical and structural study allowed defining the aquifer settings. Several cross-sections have been drawn to identify the three-dimensional geological setting and aquifer's boundaries that consist on: lithological limit between permeable and very low permeable complexes and structural features (groundwater divide and faults). The analyses of principals structural features (e.g. overthrust) have allowed to identify the prominent groundwater flow direction: the Sibillini Montains, Monte Val di Fibbia-P.ta Bambucerta and Visso overthrusts represent three important inverse faults oriented NNW-SSE having aquiclude role due to the high displacement. The altitude gradual decrease forward N of aquiclude handing aquifers combined to Apennine orientation of overthrusts induce a SSE-NNW groundwater flow. A detailed analysis of base flow has allowed to: 1) define the river's base flow; 2) recognize the punctual, diffused and linear springs; 3) quantify the water resource on average drained; and 4) determine the discharge regime of springs and rivers. The geologic-structural analyses with the quantitative hydrogeological studies have allowed to prepare the Conceptual Hydrogeological Model (CHM) and to calculate the hydrogeological balance for each aquifer. This double approach let to carry out a detailed study and make out hypotheses about groundwater circulation for each aquifer. These hypotheses represent the bases for the groundwater modelling that could give an important contribute to confirm or not them. The CHM of main aquifer has been adopted to carry out the

  17. AGU Chapman Conference Hydrogeologic Processes: Building and Testing Atomistic- to Basin-Scale Models

    SciTech Connect

    Weaver, B.

    1994-12-31

    This report presents details of the Chapman Conference given on June 6--9, 1994 in Lincoln, New Hampshire. This conference covered the scale of processes involved in coupled hydrogeologic mass transport and a concept of modeling and testing from the atomistic- to the basin- scale. Other topics include; the testing of fundamental atomic level parameterizations in the laboratory and field studies of fluid flow and mass transport and the next generation of hydrogeologic models. Individual papers from this conference are processed separately for the database.

  18. SRP baseline hydrogeologic investigation: Aquifer characterization. Groundwater geochemistry of the Savannah River Site and vicinity

    SciTech Connect

    Strom, R.N.; Kaback, D.S.

    1992-03-31

    An investigation of the mineralogy and chemistry of the principal hydrogeologic units and the geochemistry of the water in the principal aquifers at Savannah River Site (SRS) was undertaken as part of the Baseline Hydrogeologic Investigation. This investigation was conducted to provide background data for future site studies and reports and to provide a site-wide interpretation of the geology and geochemistry of the Coastal Plain Hydrostratigraphic province. Ground water samples were analyzed for major cations and anions, minor and trace elements, gross alpha and beta, tritium, stable isotopes of hydrogen, oxygen, and carbon, and carbon-14. Sediments from the well borings were analyzed for mineralogy and major and minor elements.

  19. Final Technical Report - Integrated Hydrogeophysical and Hydrogeologic Driven Parameter Upscaling for Dual-Domain Transport Modeling

    SciTech Connect

    Shafer, John M

    2012-11-05

    The three major components of this research were: 1. Application of minimally invasive, cost effective hydrogeophysical techniques (surface and borehole), to generate fine scale (~1m or less) 3D estimates of subsurface heterogeneity. Heterogeneity is defined as spatial variability in hydraulic conductivity and/or hydrolithologic zones. 2. Integration of the fine scale characterization of hydrogeologic parameters with the hydrogeologic facies to upscale the finer scale assessment of heterogeneity to field scale. 3. Determination of the relationship between dual-domain parameters and practical characterization data.

  20. Hydrogeological influences on radionuclide migration from the major radioactive waste burial sites at Chernobyl (A review)

    SciTech Connect

    Dgepo, S.P.; Skalsky, A.S.; Bugai, D.A.; Marchuk, V.V.; Waters, R.D.

    1994-03-01

    This paper summarizes the recent hydrogeological investigations of several research organizations on waste confinement at the major radioactive waste (RW) burial sites immediately adjacent to the Chernobyl Nuclear Power Plant (Ch. NPP). Hydrogeological conditions and radiologic ground-water contamination levels are described. Ongoing ground-water monitoring practices are evaluated. The chemical and physical characteristics of the radionuclides within the burial sites are considered. Ground water and radionuclide transport modeling studies related to problems of the RW disposal sites are also reviewed. Current concerns on future impacts of the RW burial sites on the hydrological environment and water resources of the Ch.NPP area are discussed.

  1. Conceptual model of hydrogeology in the Ozark Plateaus region during Pennsylvanian time

    SciTech Connect

    Brahana, J.V. )

    1993-03-01

    Recently completed studies of the Ozark Plateaus region of southern Missouri and northern Arkansas provide a conceptual framework for understanding current hydrogeology, and form the basis for numerical models that can be used to quantitatively assess flow and solute transport in the aquifers of this area. Three separate investigations were completed as part of the Regional Aquifer-Systems Analysis (RASA) program of the US Geological Survey during 1985--1993. Although the objectives of these RASA studies [Northern Midwest (NM) RASA, Gulf Coast (GC) RASA, and Central Midwest (CM) RASA] focused on recent hydrologic conditions, each study has contributed o increased understanding of the evolution of the hydrogeology of the region.

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

    USGS Publications Warehouse

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

    1970-01-01

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

  3. Combined Estimation of Hydrogeologic Conceptual Model and Parameter Uncertainty

    SciTech Connect

    Meyer, Philip D.; Ye, Ming; Neuman, Shlomo P.; Cantrell, Kirk J.

    2004-03-01

    The objective of the research described in this report is the development and application of a methodology for comprehensively assessing the hydrogeologic uncertainties involved in dose assessment, including uncertainties associated with conceptual models, parameters, and scenarios. This report describes and applies a statistical method to quantitatively estimate the combined uncertainty in model predictions arising from conceptual model and parameter uncertainties. The method relies on model averaging to combine the predictions of a set of alternative models. Implementation is driven by the available data. When there is minimal site-specific data the method can be carried out with prior parameter estimates based on generic data and subjective prior model probabilities. For sites with observations of system behavior (and optionally data characterizing model parameters), the method uses model calibration to update the prior parameter estimates and model probabilities based on the correspondence between model predictions and site observations. The set of model alternatives can contain both simplified and complex models, with the requirement that all models be based on the same set of data. The method was applied to the geostatistical modeling of air permeability at a fractured rock site. Seven alternative variogram models of log air permeability were considered to represent data from single-hole pneumatic injection tests in six boreholes at the site. Unbiased maximum likelihood estimates of variogram and drift parameters were obtained for each model. Standard information criteria provided an ambiguous ranking of the models, which would not justify selecting one of them and discarding all others as is commonly done in practice. Instead, some of the models were eliminated based on their negligibly small updated probabilities and the rest were used to project the measured log permeabilities by kriging onto a rock volume containing the six boreholes. These four

  4. Aquifer Hydrogeologic Layer Zonation at the Hanford Site

    SciTech Connect

    Savelieva-Trofimova, Elena A.; Kanevski, Mikhail; timonin, v.; Pozdnukhov, A.; Murray, Christopher J.; Scheibe, Timothy D.; Xie, YuLong; Thorne, Paul D.; Cole, Charles R.

    2003-09-10

    Sedimentary aquifer layers are characterized by spatial variability of hydraulic properties. Nevertheless, zones with similar values of hydraulic parameters (parameter zones) can be distinguished. This parameter zonation approach is an alternative to the analysis of spatial variation of the continuous hydraulic parameters. The parameter zonation approach is primarily motivated by the lack of measurements that would be needed for direct spatial modeling of the hydraulic properties. The current work is devoted to the problem of zonation of the Hanford formation, the uppermost sedimentary aquifer unit (U1) included in hydrogeologic models at the Hanford site. U1 is characterized by 5 zones with different hydraulic properties. Each sampled location is ascribed to a parameter zone by an expert. This initial classification is accompanied by a measure of quality (also indicated by an expert) that addresses the level of classification confidence. In the current study, the coneptual zonation map developed by an expert geologist was used as an a priori model. The parameter zonation problem was formulated as a multiclass classification task. Different geostatistical and machine learning algorithms were adapted and applied to solve this problem, including: indicator kriging, conditional simulations, neural networks of different architectures, and support vector machines. All methods were trained using additional soft information based on expert estimates. Regularization methods were used to overcome possible overfitting. The zonation problem was complicated because there were few samples for some zones (classes) and by the spatial non-stationarity of the data. Special approaches were developed to overcome these complications. The comparison of different methods was performed using qualitative and quantitative statistical methods and image analysis. We examined the correspondence of the results with the geologically based interpretation, including the reproduction of the

  5. A Task-oriented Approach for Hydrogeological Site Characterization

    NASA Astrophysics Data System (ADS)

    Rubin, Y.; Nowak, W.; de Barros, F.

    2010-12-01

    Hydrogeological site characterization is a challenging task from several reasons: (1) the large spatial variability and scarcity of prior information render the outcome of any planned sampling campaign uncertain; (2) there are no simple tools for comparing between the many alternative measurement techniques and data acquisition strategies, and (3) physical and budgetary constraints associated with data acquisition. This paper presents several ideas on how to plan sampling campaigns in a rational manner while addressing these challenges. The first idea is to recognize that different sites and different problems require different characterization strategies. Hence the idea is to plan data acquisition according to its capability for meeting site-specific goals. For example, the characterization needs at a “research problem” site (e.g., a site intended to investigate the transport of uranium in the subsurface such as in Hanford) are different from those of a “problem” site (e.g., contaminated site associated with a health risk to human such as Camp Lejeune, or determining the safe yield of an aquifer). This distinction requires planners to define the characterization goal(s) in a quantitative manner. The second idea is to define metrics that could link specific data types and data acquisition strategies with the site-specific goals in a way that would allow planners to compare between strongly different, alternatives strategies at the design stage (even prior to data acquisition) and to modify the strategies as more data become available. To meet this goal, we developed the concept of the (comparative) information yield curve. Finally, we propose to look at site characterization from the perspective of statistical hypothesis testing, whereby data acquisition strategies could be evaluated in terms of their ability to support or refute various hypotheses made with regard to the characterization goals, and the strategies could be modified once the test is

  6. Evaluation of Hydrochemical and Hydrogeological Characteristics of Riverbank Filtration Aquifer

    NASA Astrophysics Data System (ADS)

    Ko, K.; Suk, H.

    2009-12-01

    The riverbank filtration is a feasible method to secure potable water resources where surface water cannot be directly provided. Bank filtrate water has been recently recognized as an alternative water resource around Nakdong River area in South Korea. The high manganese and iron, which are mainly produced from microbial reduction of aquifer, are frequently observed problems in bank filtrated water and the causes of them have been studied by restricted researchers. To understand the source and occurrence of manganese and iron in bank filtration water, we examined the hydrochemical and isotopic characteristics of water and the features of aquifer sediments which are collected from two bank filtration application area, Ddan Island and Jeungsan-ri. Most of waters collected from Ddan island have Ca-(Cl+SO4) type and the variation of water chemistry are mainly induced by anions such as bicarbonate and nitrate that are sensitive to the redox condition of aquifer. Nitrate is not detected in deep (>20m) water with low dissolved oxygen (<2 mg/L) but is very high (max. 120 mg/L), presumably indicating the input of surface agricultural green house, in shallow (<10m) water. The bicarbonate in the Ddan Island aquifer can be increased by the biodegradation of organic matters and the dissolution of shellfishes which are included in aquifer sediments. The high carbon isotope values of dissolved inorganic carbon indicate that the main process of bicarbonate production is the microbial degradation of organic matter in the aquifer. The oxygen and hydrogen isotopic values in water are plotted at the lower region below the line of local meteoric water line (LMWL). The spatial distribution of redox sensitive components such as iron, manganese, sulfate, nitrate, and bicarbonate implicate the redox processes of the Ddan Island aquifer. We also investigated the hydrogeologic structure, bank filtrate quality analysis and modified sequential analysis for Ddan Island aquifer at Nakdong River

  7. Integrated Research Methods for Applied Urban Hydrogeology of Karst Sites

    NASA Astrophysics Data System (ADS)

    Epting, J.; Romanov, D. K.; Kaufmann, G.; Huggenberger, P.

    2008-12-01

    Integrated and adaptive surface- and groundwater monitoring and management in urban areas require innovative process-oriented approaches. To accomplish this, it is necessary to develop and combine interdisciplinary instruments that facilitate adequately quantifying cumulative effects on groundwater flow regimes. While the characterization and modeling of flow in heterogeneous and fractured media has been investigated intensively, there are no well-developed long-term hydrogeological research sites for gypsum karst. Considering that infrastructures in karst regions, particularly in gypsum, are prone to subsidence, severe problems can arise in urban areas. In the 1880's, a river dam was constructed on gypsum-containing rock, Southeast of Basel, Switzerland. Over the last 30 years, subsidence of the dam and an adjacent highway has been observed. Surface water infiltrates upstream of the dam, circulates in the gravel deposits and in the weathered bedrock around and beneath the dam and exfiltrates downstream into the river. These processes enhance karstification processes in the soluble units of the gypsum. As a result an extended weathering zone within the bedrock and the development of preferential flow paths within voids and conduits can be observed. To prevent further subsidence, construction measures were conducted in two major project phases in 2006 and 2007. The highway was supported by a large number of pillars embedded in the non- weathered rock and by a sealing pile wall, to prevent infiltrating river water circulating around the dam and beneath the foundation of the highway. To safeguard surface and subsurface water resources during the construction measures, an extensive observation network was set up. Protection schemes and geotechnical investigations that are necessary for engineering projects often provide "windows of opportunity", bearing the possibility to change perceptions concerning the sustainable development of water resources and coordinate future

  8. Application of the self-potential method in hydrogeology

    NASA Astrophysics Data System (ADS)

    Moore, Jeffrey Ralston

    The self-potential (SP) method is a passive electrical tool that measures naturally occurring voltages created by fluid flow in earth materials. SP monitoring has proven to be a fast and inexpensive means for evaluating subsurface hydrology. This dissertation presents the results of three studies, demonstrating innovative use of the SP method for describing both historical and new hydrogeologic scenarios. The cumulative result encourages application of SP monitoring in a variety of situations, and demonstrates the unique ability of the SP method to describe the physical processes controlling subsurface fluid flow. Three topics were investigated by means of SP monitoring: hydraulic fracturing of low-permeability intact rock, liquid CO2 flow through rock in support of carbon sequestration research, and seepage characterization at a remote moraine dam. In the case of hydraulic fracturing, SP observations responded to permeability variations prior to fracturing caused by dilatancy of microcracks at high pore pressure. An asymmetric spatial SP response was observed as injectate moved into aligned dilatant zones during pressurization, which in most cases revealed the impending crack geometry. SP measurements described the direction of crack propagation after initial fracturing due to strong anisotropic flow through the new fracture zone. During liquid CO 2 injection into reservoir rock, differences in the magnitude of the SP coupling coefficient (Cc) were observed for various stages of a CO 2 flood. The Cc was found to decrease by an order of magnitude as CO 2 replaced mobile water in the rock porosity, and the variation of the Cc during CO2 and water mixing was characterized. These results allow mapping of the various phase boundaries present during liquid CO 2 injection, and may contribute to the success of carbon sequestration. Finally, a preliminary description of the hydraulic regime at a remote moraine dam was obtained through analysis of SP and accompanying

  9. Hydrogeology of a Transboundary Sandstone Aquifer, Quebec - New York

    NASA Astrophysics Data System (ADS)

    Nastev, M.; Lamontagne, C.; Morin, R.; Williams, J.; Lavigne, M.; Croteau, A.; Tremblay, T.; Godin, R.; Dagenais, M.; Rouleau, A.

    2005-12-01

    The Potsdam sandstone aquifer of Cambrian age straddles southern Quebec and northern New York in a region known for its abundant and good quality groundwater, a resource that recently has been coveted by several bottling companies. The potential conflicts and concerns of the mainly rural and groundwater dependent population about the possible overuse of this resource has led the Quebec Ministry of Environment, Geological Survey of Canada and the U. S. Geological Survey to jointly carry out a transboundary hydrogeological study of the Potsdam sandstone aquifer. The Potsdam sandstone aquifer consists of a lower unit of arkose and conglomerate and an upper unit of well-cemented quartz arenite. The thickness of the regional aquifer ranges from nil at the base of Adirondacks to more than 500 m near the St. Lawrence River. Glacial till, littoral sand and gravel, and marine silt and clay discontinuously overlie the aquifer. The aquifer's water budget is characterized by low rates of surface runoff and high rates of infiltration and sub-surface runoff. Major recharge areas are present at higher altitudes near and to the south of the border. Strong downward hydraulic gradients in these areas result in cascading water and water-level depths of more than 30 m in deep wells. Bedding in the Potsdam sandstone is gently dipping with fractures along sub-horizontal bedding planes forming major flow conduits. Bedrock folds and faults, mainly developed by east-west compression during the Appalachian orogenies, locally complicates aquifer geometry and groundwater flow. Hydraulic tests (pump, slug, flowmeter and straddle packer) indicate similar horizontal transmissivities in the lower and upper aquifer units. However, differences in lithology and structure of the aquifer units impose some apparent differences in hydraulic properties and groundwater flow patterns. In the lower unit, regional flow appears to be sustained by a limited number of laterally extensive bedding-plane fractures

  10. A conceptual hydrogeologic model for the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

    USGS Publications Warehouse

    Thomas, Jonathan V.; Stanton, Gregory P.; Bumgarner, Johnathan R.; Pearson, Daniel K.; Teeple, Andrew P.; Houston, Natalie A.; Payne, Jason D.; Musgrove, MaryLynn

    2013-01-01

    Several previous studies have been done to compile or collect physical and chemical data, describe the hydrogeologic processes, and develop conceptual and numerical groundwater-flow models of the Edwards-Trinity aquifer in the Trans-Pecos region. Documented methods were used to compile and collect groundwater, surface-water, geochemical, geophysical, and geologic information that subsequently were used to develop this conceptual model.

  11. Inventory and Review of Existing PRISM Hydrogeologic Data for the Islamic Republic of Mauritania, Africa

    USGS Publications Warehouse

    Friedel, Michael J.

    2008-01-01

    The USGS entered into an agreement with the Mauritania Ministry of Mines and Industry to inventory and review the quality of information collected as part of the Project for Strengthening of the Institutions in the Mining Sector (PRISM). Whereas the PRISM program collected geophysical, geochemical, geological, satellite, and hydrogeologic information, this report focuses on an inventory and review of available hydrogeologic data provided to the USGS in multiple folders, files, and formats. Most of the information pertained to the hydrogeologic setting and the water budget of evaporation, evapotranspiration, and precipitation in the Choum-Zouerate area in northwestern Mauritania, and the country of Mauritania itself. Other information about the quantity and quality of groundwater was found in the relational Access database. In its present form, the limited hydrogeologic information was not amenable to conducting water balance, geostatistical, and localized numerical modeling studies in support of mineral exploration and development. Suggestions are provided to remedy many of the data's shortcomings, such as performing quality assurance on all SIPPE2 data tables and sending questionnaires to appropriate agencies, mining and other companies to populate the database with additional meteorology, hydrology, and groundwater data.

  12. ASSESSING THE HYDROGEOLOGIC CLASSIFICATION SYSTEM IN MID-ATLANTIC COASTAL PLAIN STREAMS USING BENTHIC MACROINVERTEBRATES

    EPA Science Inventory

    Assessing classification systems that describe natural variation across regions is an important first step for developing indicators. We evaluated a hydrogeologic framework for first order streams in the mid-Atlantic Coastal Plain as part of the LIPS-MACS (Landscape Indicators f...

  13. Analysis of natural ground-water level variations for hydrogeologic conceptualization, Hanford Site, Washington

    NASA Astrophysics Data System (ADS)

    Nevulis, Richard H.; Davis, Donald R.; Sorooshian, Soroosh

    1989-07-01

    This study involves the analysis of groundwater level time series for the purpose of obtaining details for a conceptual hydrogeologic model at a time when conventional hydraulic stress testing was not feasible due to regulatory considerations. The study area is located in south central Washington in the Pasco Basin which was a candidate site for underground disposal of high-level radioactive nuclear wastes. Advantages of such passive methods of analysis may include relative simplicity, low cost, and avoidance of disturbances typically associated with stress testing of aquifers. Through this approach, natural and incidental man-made groundwater level variations, most of which are quite small, are examined by statistical and analytical methods in conjunction with hydrogeologic models to draw inferences on the hydrogeology. Vertical connectivity of the hydrostratigraphic units is also examined by analyzing groundwater level time series of five units at three piezometer nests. It is concluded that a combination of statistical/analytical approaches used in a complementary fashion can provide useful information about the hydrogeology of a given area. A meaningful analysis requires that there is (1) a source of influence on the groundwater levels, (2) a response to that influence, (3) a sufficiently long data record, and (4) measurement and analytical techniques which allow the detection and identification of the influence and response.

  14. HYDROGEOLOGIC CONTROLS ON NITRATE TRANSPORT IN A SMALL AGRICULTURAL CATCHMENT, IOWA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of subsurface lithology on nitrate loss in stream riparian zones are recognized but little attention has been focused on similar processes occurring in upland agricultural settings. In this paper, we evaluated hydrogeologic controls on nitrate transport processes occurring in a small 7.6 ha ...

  15. INVESTIGATION OF HYDROGEOLOGIC MAPPING TO DELINEATE PROTECTION ZONES AROUND SPRINGS: REPORT OF TWO CASE STUDIES

    EPA Science Inventory

    Methods commonly used to delineate protection zones for water-supply wells are often not directly applicable for springs. This investigation focuses on the use of hydrogeologic mapping methods to identify physical and hydrologic features that control ground-water flow to springs...

  16. American hydrogeology at the millennium: An annotated chronology of 100 most influential papers

    USGS Publications Warehouse

    Back, W.; Herman, J.S.

    1997-01-01

    Hydrogeology developed as scientists undertook activities to describe how a groundwater system functions to explain why it is that way, in order to solve practical problems of water supply. This paper demonstrates the evolutionary nature and growth of hydrogeology in the United States on the basis of a selection of one hundred papers that had a significant impact on subsequent activities. We have identified three revolutionary concepts that resulted directly from this evolutionary understanding and have selected papers that demonstrate important consequences. These three concepts are 1) that the mathematical expression for heat flow can be paraphrased for groundwater and used in transient flow conditions to determine aquifer characteristics; 2) that the distribution of fluid potential can be formulated in mathematical equations suitable for solution by various analytical techniques; and 3) that chemical thermodynamics can be applied to hydrogeologic systems in order to understand the processes controlling the chemical character of groundwater. One purpose of this paper is to encourage scientists to gain an additional dimension of satisfaction from their work by being aware of the contributions of those who went before them and to see how their own work fits into the current understanding of hydrogeology.

  17. Linking Physical and Numerical Modelling in Hydrogeology Using Sand Tank Experiments and Comsol Multiphysics

    ERIC Educational Resources Information Center

    Singha, Kamini; Loheide, Steven P., II

    2011-01-01

    Visualising subsurface processes in hydrogeology and building intuition for how these processes are controlled by changes in forcing is hard for many undergraduate students. While numerical modelling is one way to help undergraduate students explore outcomes of multiple scenarios, many codes are not user-friendly with respect to defining domains,…

  18. Waterborne toxoplasmosis investigated and analyzed under hydrogeological assessment: new data and perspectives for further research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analyzed in light of groundwater vulnerability information in an area of endemic waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to conduct water collection from wel...

  19. Theoretical model of the hydrogeology of a pull-apart basin

    SciTech Connect

    White, P.M.

    1991-03-01

    An accurate model of the hydrogeology of a basin is important in assessing the migration path of oil and its potential for remaining within a trap. Fluid flow in a basin is influenced by three driving forces: gravity, compaction, and density. The hydrogeology of most basins is affected by a combination of these three forces, but one is usually dominant. The hydrogeology of a pull-apart basin, such as the Los Angeles basin, is controlled by a combination of gravity and compaction forces. Tectonic movement within the Los Angeles basin has produced a number of small mountain ranges. These elevated features produce a large hydraulic head, driving groundwater into the basin. At the same time, the basin is undergoing compaction driving groundwater out of the basin. The complex interaction of these two forces has influenced the hydrogeologic flow within the Los Angeles basin. Oilgen, a computer modeling program, was used to develop a theoretical model for fluid flow within the Los Angeles basin. Extraction of oil in the early part of this century caused extensive subsidence in parts of the basin. To prevent further subsidence Long Beach established a water injection program in 1958. The water injection program has been successful in inhibiting subsidence and has even produced small, but measurable, amounts of rebound. Modeling was done both pre- and postinjection to allow the effects of the water injection on the hydrology of the basin to be evaluated.

  20. Development of a Hydrogeological Site Description Based on a Discrete Fracture Network Concept and the Integration of Geological, Hydrogeological and Hydrochemical Data

    NASA Astrophysics Data System (ADS)

    Jackson, C.; Hartley, L. J.; Hoch, A.; Holton, D.; Hunter, F. M.; McCarthy, R.; Marsic, N.; Gylling, B.

    2006-12-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is carrying out site investigations in two different areas in Sweden with the objective of describing the in-situ conditions for a deep rock repository for spent nuclear fuel. The two candidate areas are Forsmark and Laxemar, both located on the east coast of Sweden. An important aspect of site investigations is to develop and demonstrate an understanding of groundwater flow and solute transport. Since the geology in both candidate areas is comprised of hard crystalline rocks, the groundwater flow is predominantly contained within fractures, and therefore a discrete fracture network (DFN) concept has been applied to describe and model the hydrogeological situation at the sites. Much observed field data from several different disciplines (geology, rock mechanics, geophysics, hydrogeology and hydrochemistry) has been acquired from the sites, including from several deep cored boreholes, to inform an overall description. Many aspects of the site description are brought together in constructing a regional scale hydrogeological model to integrate the concepts and data interpretations, which are then tested against a range of field observations to build confidence that the models are representative. A methodology has been developed based on assembling a regional hydrogeological model from three main components: hydraulic conductor domains (HCD) that represent deterministic large scale deformation zones; hydraulic rock domains (HRD) that use a stochastic DFN model to represent the background rock between the deformation zones; and hydraulic soil domains (HSD) that represent near-surface Quaternary deposits. The HCD are interpreted from geophysical methods, drilling and single-hole hydraulic tests. For the HRD, borehole image- and core-logs, outcrop maps, and short-interval flow-logging are integrated to parameterise a DFN model for specific hydrogeological rock domains. Geological information, statistical analysis

  1. Hydrogeological characterization of a coastal aquifer in southern Turkey

    NASA Astrophysics Data System (ADS)

    Brehme, M.; Dokuz, U. E.; Scheytt, T.; Çelik, M.

    2012-04-01

    and impermeable layers as well as wetlands in the field allow the localisation of recharge and discharge zones. All sampled wells show similar water chemistry. However, areas of higher concentrations of nitrate (up to 45 mg/L) and sulphate (42 mg/L) can be distinguished, which is a hint of intensive agricultural influence including the use of fertiliser. Generally, the hydrochemistry of the groundwater is characterized by anthropogenic but also geological influence. Remarkable high magnesium concentrations (up to 81 mg/L) at several locations in the area show the influence of water-rock interaction. Ferromagnesian ions are dissolved from serpentinites while increased calcium concentrations result from limestone-dissolution. Relatively low electrical conductivity values and chloride concentrations even in wells near the coast indicate that saltwater intrusion has not yet taken place. Anyway groundwater level measurements compared to former measurements suggest a future intrusion in case the water use remains constant at a high level. This investigation enhances the understanding of the hydrogeological characteristics in this special area and of forthcoming problems in coastal areas in general. However, more emphasis and research is needed including long-term observation of ground- and surface water quality as well as a detailed investigation of hydraulic characteristics of the local aquifer to guarantee a sustainable groundwater use.

  2. Hydrogeologic Factors Influencing Denitrification in Atlantic Coastal Plain Surficial Aquifers

    NASA Astrophysics Data System (ADS)

    Puckett, L. J.

    2001-05-01

    . Nitrate at a second Maryland site was 14 mg/L in ground water, below detection under the stream, and 2.5 mg/L in the stream. At the Maryland sites, nitrate in ground water passed under the riparian forest and discharged into the stream at one location whereas at the other site it was denitrified as ground water was forced through organic rich, near stream sediments by a shallow confining layer. These results suggest that factors such as hydrogeology and aquifer origins and depositional history are important in determining whether and where denitrification will occur.

  3. Hydrogeological modelling as a tool for understanding rockslides evolution

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni B.; De Caro, Mattia; Frattini, Paolo; Volpi, Giorgio

    2015-04-01

    construction of the models, in particular the partition of the slope in different sectors with different hydraulic conductivities, are coherent with the geological, structural, hydrological and hydrogeological field and laboratory data. The sensitivity analysis shows that the hydraulic conductivity of some slope sectors (e.g. morphostructures, compressed or relaxed slope-toe, basal shear band) strongly influence the water table position and evolution. In transient models, the values of specific storage coefficient play a major control on the amplitude of groundwater level fluctuations, deriving from snowmelt or induced reservoir level rise. The calibrated groundwater flow-models are consistent with groundwater levels measured in the proximity of the piezometers aligned along the sections. The two examples can be considered important for a more advanced understanding of the evolution of rockslides and suggest the required set of data and modelling approaches both for seasonal and long term slope stability analyses. The use of the results of such analyses is reported, for both the case studies, in a companion abstract in session 3.7 where elasto-visco-plastic rheologies have been adopted for the shear band materials to replicate the available displacement time-series.

  4. Reconnaissance of the Hydrogeology of Ta'u, American Samoa

    USGS Publications Warehouse

    Izuka, Scot K.

    2005-01-01

    Analysis of existing data and information collected on a reconnaissance field visit supports a conceptual model of ground-water occurrence in Ta'u, American Samoa, in which a thin freshwater lens exists in a predominantly high-permeability aquifer that receives high rates of recharge. Because the freshwater lens is thin throughout most of the island, the productivity of wells, especially those near the coast where the lens is the thinnest, is likely to be limited by saltwater intrusion. The landfill in northwestern Ta'u is closer to the north coast of the island than to any of the existing or proposed well sites. Although this may indicate that ground water beneath the landfill would flow away from the existing and proposed well sites, this interpretation may change depending on the hydraulic properties of a fault and rift zone in the area. Of four plausible scenarios tested with a numerical ground-water flow model, only one scenario indicated that ground water from beneath the landfill would flow toward the existing and proposed well sites; the analysis does not, however, assess which of the four scenarios is most plausible. The analysis also does not consider the change in flow paths that will result from ground-water withdrawals, dispersion of contaminants during transport by ground water, other plausible hydrogeologic scenarios, transport of contaminants by surface-water flow, or that sources of contamination other than the landfill may exist. Accuracy of the hydrologic interpretations in this study is limited by the relatively sparse data available for Ta'u. Understanding water resources on Ta'u can be advanced by monitoring rainfall, stream-flow, evaporation, ground-water withdrawals, and water quality, and with accurate surveys of measuring point elevations for all wells and careful testing of well-performance. Assessing the potential for contaminants in the landfill to reach existing and proposed well sites can be improved with additional information on the

  5. Using Electrical Resistivity Tomography for Constraining a Hydrogeological Model in a Data Sparse Region

    NASA Astrophysics Data System (ADS)

    Foster, S.; Allen, D. M.

    2013-12-01

    Geological and hydrogeological data are often spatially limited in mountainous regions. In these settings, geophysical techniques can be used to constrain hydrogeological models by providing insight into the hydrostratigraphy and the continuity of units in the subsurface. This study we used electrical resistivity tomography coupled with a priori geological data from residential water wells to improve the accuracy and confidence of a hydrogeological model. The study area is situated within the mountainous Cowichan watershed in British Columbia, Canada. Throughout the watershed, unconsolidated deposits of variable thickness overlie bedrock. Based on available water well information, at high elevation, sediment thickness is on the order of a few metres, but within the valley bottom, sediment thickness can be up to 300 m. The unconsolidated deposits are heterogeneous due to a complex depositional environment that was controlled by glacial advances and recessions, most notably during the Fraser Glaciation. Six electrical resistivity transects of various lengths spanning 135 to 830 metres were conducted in an area of the watershed that is particularly data poor. The electrical resistivity transects were strategically placed, first, to make use of available lithology information from existing water wells in order to constrain the geophysical interpretation, and second, to contribute data to areas that lack subsurface lithological records. Electrical resistivity was measured using a AGI SuperSting R1 system, and data were processed using robust inversion software to identify stark geophysical contacts. The technique successfully delineated zones of conductive and resistive units that have been interpreted as aquitards (clay and till formations), aquifers (water bearing sand and gravel lenses), and bedrock based on dielectric contrast. Available surficial geology and bedrock geology maps, coupled with residential well drilling records, further assisted in mapping the

  6. Hydrogeology of the gray limestone aquifer in southern Florida

    USGS Publications Warehouse

    Reese, Ronald S.; Cunningham, Kevin J.

    2000-01-01

    Results from 35 new test coreholes and aquifer-test, water-level, and water-quality data were combined with existing hydrogeologic data to define the extent, thickness, hydraulic properties, and degree of confinement of the gray limestone aquifer in southern Florida. This aquifer, previously known to be present only in southeastern Florida (Miami-Dade, Broward, and Palm Beach Counties) below, and to the west of, the Biscayne aquifer, extends over most of central-south Florida, including eastern and central Collier County and southern Hendry County; it is the same as the lower Tamiami aquifer to the north, and it becomes the water-table aquifer and the upper limestone part of the lower Tamiami aquifer to the west. The aquifer generally is composed of gray, shelly, lightly to moderately cemented limestone with abundant shell fragments or carbonate sand, abundant skeletal moldic porosity, and minor quartz sand. The gray limestone aquifer comprises the Ochopee Limestone of the Tamiami Formation, and, in some areas, the uppermost permeable part of an unnamed formation principally composed of quartz sand. Underlying the unnamed formation is the Peace River Formation of the upper Hawthorn Group, the top of which is the base of the surficial aquifer system. Overlying the aquifer and providing confinement in much of the area is the Pinecrest Sand Member of the Tamiami Formation. The thickness of the aquifer is comparatively uniform, generally ranging from 30 to 100 feet. The unnamed formation part of the aquifer is up to 20 feet thick. The Ochopee Limestone accumulated in a carbonate ramp depositional system and contains a heterozoan carbonate-particle association. The principal rock types of the aquifer are pelecypod lime rudstones and floatstones and permeable quartz sands and sandstones. The pore types are mainly intergrain and separate vug (skeletal-moldic) pore spaces. The rock fabric and associated primary and secondary pore spaces combine to form a dual diffuse

  7. Morphometric analysis with open source software to explore shallow hydrogeological features in Senegal and Guinea

    NASA Astrophysics Data System (ADS)

    Fussi, Fabio; Di Leo, Margherita; Bonomi, Tullia; Di Mauro, Biagio; Fava, Francesco; Fumagalli, Letizia; Hamidou Kane, Cheikh; Faye, Gayane; Niang, Magatte; Wade, Souleye; Hamidou, Barry; Colombo, Roberto

    2015-04-01

    Water represents a vital resource for everyone on this Planet, but, for some populations, the access to potable water is not given for granted. Recently, the interest in low cost technical solutions to improve access to ground water in developing countries, especially for people located in remote areas, has increased. Manual drilling (techniques to drill boreholes for water using human or animal power) is well known and practiced for centuries in many countries and represents a valid alternative to increase water access. Lately, this practice has raised the attention of national governments and international organizations. This technique is applicable only where hydrogeological conditions are suitable, namely in presence of thick layers of unconsolidated sediments and a shallow water table Aim of this study is exploring the potential of morphometric analysis to improve the methodology to identify areas with suitable hydrogeological conditions for manual drilling, supporting the implementation of water supply programs that can have great impact on living condition of the population. The characteristics of shallow geological layers are strongly dependent from geomorphological processes and are usually reflected in the morphological characteristics of landforms. Under these hypotheses, we have been investigating the geo-statistical correlation between several morphometric variables and a set of hydrogeological variables used in the estimation of suitability for manual drilling: thickness of unconsolidated sediments, texture, hydraulic conductivity of shallow aquifer, depth of water table. The morphology of two study areas with different landscape characteristics in Guinea and Senegal has been investigated coupling the Free and Open Source Software GRASS GIS and R. Several morphometric parameters have been extracted from ASTER GDEM digital elevation model, and have been compared with a set of hydrogeological characteristics obtained from semi-automatic analysis of

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

    USGS Publications Warehouse

    Lampe, David C.

    2009-01-01

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

  9. Digital surfaces and thicknesses of selected hydrogeologic units within the Ozark Plateaus aquifer system, northwestern Arkansas

    USGS Publications Warehouse

    Czarnecki, John B.; Bolyard, Susan E.; Hart, Rheannon M.; Clark, Jimmy M.

    2014-01-01

    Digital surfaces and thicknesses of nine hydrogeologic units of the Ozark Plateaus aquifer system from land surface to the top of the Gunter Sandstone in northwestern Arkansas were created using geophysical logs, drillers’ logs, geologist-interpreted formation tops, and previously published maps. The 6,040 square mile study area in the Ozark Plateaus Province includes Benton, Washington, Carroll, Madison, Boone, Newton, Marion, and Searcy Counties. The top of each hydrogeologic unit delineated on geophysical logs was based partly on previously published reports and maps and also from drillers’ logs. These logs were then used as a basis to contour digital surfaces showing the top and thickness of the Fayetteville Shale, the Boone Formation, the Chattanooga Shale, the Everton Formation, the Powell Dolomite, the Cotter Dolomite, the Roubidoux Formation, the Gasconade Dolomite, and the Gunter Sandstone.

  10. Hydrogeologic Framework in Three Drainage Basins in the New Jersey Pinelands, 2004-06

    USGS Publications Warehouse

    Walker, Richard L.; Reilly, Pamela A.; Watson, Kara M.

    2008-01-01

    The U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission, began a multi-phase hydrologic investigation in 2004 to characterize the hydrologic system supporting the aquatic and wetland communities of the New Jersey Pinelands area (Pinelands). The Pinelands is an ecologically diverse area in the southern New Jersey Coastal Plain underlain by the Kirkwood-Cohansey aquifer system. The demand for ground water from this aquifer system is increasing as local development increases. To assess the effects of ground-water withdrawals on Pinelands stream and wetland water levels, three drainage basins were selected for detailed hydrologic assessments, including the Albertson Brook, McDonalds Branch and the Morses Mill Stream basins. Study areas were defined surrounding the three drainage basins to provide sub-regional hydrogeologic data for the ground-water flow modeling phase of this study. In the first phase of the hydrologic assessments, a database of hydrogeologic information and a hydrogeologic framework model for each of the three study areas were produced. These framework models, which illustrate typical hydrogeologic variations among different geographic subregions of the Pinelands, are the structural foundation for predictive ground-water flow models to be used in assessing the hydrologic effects of increased ground-water withdrawals. During 2004-05, a hydrogeologic database was compiled using existing and new geophysical and lithologic data including suites of geophysical logs collected at 7 locations during the drilling of 21 wells and one deep boring within the three study areas. In addition, 27 miles of ground-penetrating radar (GPR) surface geophysical data were collected and analyzed to determine the depth and extent of shallow clays in the general vicinity of the streams. On the basis of these data, the Kirkwood-Cohansey aquifer system was divided into 7 layers to construct a hydrogeologic framework model for each study area. These

  11. Hydrogeologic framework of sedimentary deposits in six structural basins, Yakima River basin, Washington

    USGS Publications Warehouse

    Jones, M.A.; Vaccaro, J.J.; Watkins, A.M.

    2006-01-01

    The hydrogeologic framework was delineated for the ground-water flow system of the sedimentary deposits in six structural basins in the Yakima River Basin, Washington. The six basins delineated, from north to south are: Roslyn, Kittitas, Selah, Yakima, Toppenish, and Benton. Extent and thicknesses of the hydrogeologic units and total basin sediment thickness were mapped for each basin. Interpretations were based on information from about 4,700 well records using geochemical, geophysical, geologist's or driller's logs, and from the surficial geology and previously constructed maps and well interpretations. The sedimentary deposits were thickest in the Kittitas Basin reaching a depth of greater than 2,000 ft, followed by successively thinner sedimentary deposits in the Selah basin with about 1,900 ft, Yakima Basin with about 1,800 ft, Toppenish Basin with about 1,200 ft, Benton basin with about 870 ft and Roslyn Basin with about 700 ft.

  12. Characterizing the hydrogeologic framework of the Death Valley region, Southern Nevada and California

    USGS Publications Warehouse

    Faunt, Claudia; D'Agnese, Frank; Downey, Joe S.; Turner, A. Keith

    1993-01-01

    Three-dimensional (3-D) hydrogeologic modeling of the complex geology of the Death Valley region requires the application of a number of Geoscientific Information System (GSIS) techniques. This study, funded by United States Department of Energy as a part of the Yucca Mountain Project, focuses on an area of approximately 100,000 square kilometers (three degrees of latitude by three degrees of longitude) and extends up to ten kilometers in depth. The geologic conditions are typical of the Basin and Range province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. GSIS techniques allow the synthesis of geologic, hydrologic and climatic information gathered from many sources, including satellite imagery and published maps and cross-sections. Construction of a 3-D hydrogeological model is possible with the combined use of software products available from several vendors, including traditional GIS products and sophisticated contouring, interpolation, visualization, and numerical modeling packages.

  13. Update of the hydrogeologic model of the Cerro Prieto field based on recent well data

    SciTech Connect

    Halfman, S.E.; Manon, A.; Lippmann, M.J.

    1986-01-01

    The hydrogeologic model of the Cerro Prieto geothermal field in Baja California, Mexico has been updated and modified on the basis of geologic and reservoir engineering data from 21 newly completed wells. Previously, only two reservoirs had been discovered: the shallow ..cap alpha.. reservoir and the deeper ..beta.. reservoir. Recently, three deep wells drilled east of the main wellfield penetrated a third geothermal reservoir (called the ..gamma.. reservoir) below the sandstones corresponding to the ..beta.. reservoir in the main part of the field. The new well data delimit the ..beta.. reservoir, confirm the important role of Fault H in controlling the flow of geothermal fluids, and enable us to refine the hydrogeologic model of the field.

  14. Hydrogeologic assessment of shallow flow systems in the Walnut Formation, central Texas

    SciTech Connect

    Feckley, D.L. . Geology Dept.)

    1993-02-01

    The Walnut Formation crops out in the limestone dominated terrain of the Grand Prairie in Central Texas. The Walnut is the only clay-rich member within this dominantly limestone section. Because of its clay-rich nature, agricultural landuse of the Walnut Formation is greater than on surrounding formations. The clay content also makes the Walnut a natural consideration for waste disposal sites. However, many drainages and streams receive baseflow from the Walnut, and the Walnut overlies the Paluxy Aquifer, a minor aquifer in the State of Texas. Therefore, understanding the hydrogeology of the Walnut becomes increasingly important in order to protect baseflow water quality, and the underlying Paluxy Aquifer. Evaluation of hydrogeologic properties includes well hydrograph analysis, slug tests, pumping tests and laboratory tests. Results strongly indicate the presence of shallow flow systems, which are influenced by geomorphology and stratigraphy. An understanding of the geomorphic evolution of the region greatly aids the groundwater investigations.

  15. Modeling of changing hydrogeological conditions during construction of pier foundations on the Kama river bank

    NASA Astrophysics Data System (ADS)

    Purgina, D.; Strokova, L.; Kuzevanov, K.

    2016-03-01

    The article presents the results of hydrogeological studies carried out within the area of the Kama river bank in Perm city. It proposes the hydrodynamic model by means of which a number of forecasting issues have been addressed. The possible scenarios of changes in filtration flow, i.e. water rise before the obstacle and water drop behind the obstacle due to groundwater filtration blockage, have been described [2]. The allowable changes of hydrodynamic conditions within the study area have been outlined.

  16. Site hydrogeologic/geotechnical characterization report for Site B new municipal solid waste landfill

    SciTech Connect

    Reynolds, R.; Nowacki, P.

    1991-04-01

    This Site Hydrogeologic/Geotechnical Characterization Report (SHCR) presents the results of a comprehensive study conducted on a proposed solid waste landfill site, identified herein as Site B, at the Savannah River Site (SRS). This report is intended to satisfy all requirements of the South Carolina Department of Health and Environmental Control (SCDHEC) with regard to landfill siting requirements and ground water and environmental protection. In addition, this report provides substantial geotechnical data pertinent to the landfill design process.

  17. Hydrogeologic framework and ground-water resources at Seymour Johnson Air Force Base, North Carolina

    USGS Publications Warehouse

    Cardinell, A.P.; Howe, S.S.

    1997-01-01

    A preliminary hydrogeologic framework of the Seymour Johnson Air Force Base was constructed from published data, available well data, and reports from Air Base files, City of Goldsboro and Wayne County records, and North Carolina Geological Survey files. Borehole geophysical logs were run in selected wells; and the surficial, Black Creek, and upper Cape Fear aquifers were mapped. Results indicate that the surficial aquifer appears to have the greatest lateral variability of clay units and aquifer material of the three aquifers. A surficial aquifer water-level surface map, constructed from selected monitoring wells screened exclusively in the surficial aquifer, indicates the general direction of ground-water movement in this mostly unconfined aquifer is toward the Neuse River and Stoney Creek. However, water-level gradient data from a few sites in the surficial aquifer did not reflect this trend, and there are insufficient hydrologic and hydrogeologic data to determine the cause of these few anamalous measurements. The Black Creek aquifer underlies the surficial aquifer and is believed to underlie most of Wayne County, including the Air Base where the aquifer and overlying confining unit are estimated from well log data to be as much as 100 feet thick. The Black Creek confining unit ranges in thickness from less than 8 feet to more than 20 feet. There are currently no accessible wells screened exclusively in the Black Creek aquifer from which to measure water levels. The upper Cape Fear aquifer and confining unit are generally found at depths greater than 80 feet below land surface at the Air Base, and are estimated to be as much as 70 feet thick. Hydrologic and hydrogeologic data are insufficient to determine localized surficial aquifer hydrogeology, ground-water movement at several sites, or hydraulic head differences between the three aquifers.

  18. Borehole Completion and Conceptual Hydrogeologic Model for the IFRC Well Field, 300 Area, Hanford Site

    SciTech Connect

    Bjornstad, Bruce N.; Horner, Jacob A.; Vermeul, Vincent R.; Lanigan, David C.; Thorne, Paul D.

    2009-04-20

    A tight cluster of 35 new wells was installed over a former waste site, the South Process Pond (316-1 waste site), in the Hanford Site 300 Area in summer 2008. This report documents the details of the drilling, sampling, and well construction for the new array and presents a summary of the site hydrogeology based on the results of drilling and preliminary geophysical logging.

  19. Evaluation of hydrogeologic aspects of proposed salinity control in Paradox Valley, Colorado

    USGS Publications Warehouse

    Konikow, Leonard F.; Bedinger, M.S.

    1978-01-01

    The salt load in the Dolores River increases by about 200,000 tons per year where it crosses Paradox Valley, Colorado, because of the discharge of a sodium chloride brine from an underlying aquifer. A ground-water management program to nearly eliminate this major source of salt, which eventually enters the Colorado River, can be designed on the basis of an accurate description of the hydrogeologic framework of Paradox Valley.

  20. Allocating risk capital for a brownfields redevelopment project under hydrogeological and financial uncertainty.

    PubMed

    Yu, Soonyoung; Unger, Andre J A; Parker, Beth; Kim, Taehee

    2012-06-15

    In this study, we defined risk capital as the contingency fee or insurance premium that a brownfields redeveloper needs to set aside from the sale of each house in case they need to repurchase it at a later date because the indoor air has been detrimentally affected by subsurface contamination. The likelihood that indoor air concentrations will exceed a regulatory level subject to subsurface heterogeneity and source zone location uncertainty is simulated by a physics-based hydrogeological model using Monte Carlo realizations, yielding the probability of failure. The cost of failure is the future value of the house indexed to the stochastic US National Housing index. The risk capital is essentially the probability of failure times the cost of failure with a surcharge to compensate the developer against hydrogeological and financial uncertainty, with the surcharge acting as safety loading reflecting the developers' level of risk aversion. We review five methodologies taken from the actuarial and financial literature to price the risk capital for a highly stylized brownfield redevelopment project, with each method specifically adapted to accommodate our notion of the probability of failure. The objective of this paper is to develop an actuarially consistent approach for combining the hydrogeological and financial uncertainty into a contingency fee that the brownfields developer should reserve (i.e. the risk capital) in order to hedge their risk exposure during the project. Results indicate that the price of the risk capital is much more sensitive to hydrogeological rather than financial uncertainty. We use the Capital Asset Pricing Model to estimate the risk-adjusted discount rate to depreciate all costs to present value for the brownfield redevelopment project. A key outcome of this work is that the presentation of our risk capital valuation methodology is sufficiently generalized for application to a wide variety of engineering projects. PMID:22366499

  1. Fractured rock hydrogeology (excluding modeling). (Latest citations from the Selected Water Resources abstracts database). Published Search

    SciTech Connect

    Not Available

    1994-01-01

    The bibliography contains citations concerning the nature and occurrence of groundwater in fractured crystalline and sedimentary rocks. Techniques for determining connectivity and hydraulic conductivity, pollutant distribution in fractures, and site studies in specific geologic environments are among the topics discussed. Citations pertaining to modeling studies of fractured rock hydrogeology are addressed in a separate bibliography. (Contains a minimum of 62 citations and includes a subject term index and title list.)

  2. Fractured rock hydrogeology (excluding modeling). (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1992-11-01

    The bibliography contains citations concerning the nature and occurrence of groundwater in fractured crystalline and sedimentary rocks. Techniques for determining connectivity and hydraulic conductivity, pollutant distribution in fractures, and site studies in specific geologic environments are among the topics discussed. Citations pertaining to modeling studies of fractured rock hydrogeology are addressed in a separate bibliography. (Contains a minimum of 54 citations and includes a subject term index and title list.)

  3. Aquifer sensitivity to pesticide leaching: Testing a soils and hydrogeologic index method

    USGS Publications Warehouse

    Mehnert, E.; Keefer, D.A.; Dey, W.S.; Wehrmann, H.A.; Wilson, S.D.; Ray, C.

    2005-01-01

    For years, researchers have sought index and other methods to predict aquifer sensitivity and vulnerability to nonpoint pesticide contamination. In 1995, an index method and map were developed to define aquifer sensitivity to pesticide leaching based on a combination of soil and hydrogeologic factors. The soil factor incorporated three soil properties: hydraulic conductivity, amount of organic matter within individual soil layers, and drainage class. These properties were obtained from a digital soil association map. The hydrogeologic factor was depth to uppermost aquifer material. To test this index method, a shallow ground water monitoring well network was designed, installed, and sampled in Illinois. The monitoring wells had a median depth of 7.6 m and were located adjacent to corn and soybean fields where the only known sources of pesticides were those used in normal agricultural production. From September 1998 through February 2001, 159 monitoring wells were sampled for 14 pesticides but no pesticide metabolites. Samples were collected and analyzed to assess the distribution of pesticide occurrence across three units of aquifer sensitivity. Pesticides were detected in 18% of all samples and nearly uniformly from samples from the three units of aquifer sensitivity. The new index method did not predict pesticide occurrence because occurrence was not dependent on the combined soil and hydrogeologic factors. However, pesticide occurrence was dependent on the tested hydrogeologic factor and was three times higher in areas where the depth to the uppermost aquifer was <6 m than in areas where the depth to the uppermost aquifer was 6 to <15 m. Copyright ?? 2005 National Ground Water Association.

  4. Geohydrodynamic properties of hydrogeological units in parts of Niger Delta, southern Nigeria

    NASA Astrophysics Data System (ADS)

    George, Nyakno J.; Emah, Joseph B.; Ekong, Ufot N.

    2015-05-01

    We used geophysical and laboratory techniques to study the geohydraulic properties of the geological units in the Niger Delta of southern Nigeria. Our main objective was to investigate the distribution of the geohydrodynamic parameters and to establish the interrelationships among them in the study area for effective characterisation of hydrogeological units. Measurements on the core samples aided in the estimation of effective porosities. The hydrogeological units' bulk resistivities measured from 1-D resistivity data constrained by nearby boreholes and the formation pore-water resistivities measured in the laboratory were used in computing the hydrogeological unit formation factor resistivity. Integration of field and laboratory measurements in conjunction with regression analysis of the data led to the determination of the hydrodynamic coefficients of the hydrogeological units. The graphs and the contour maps generated from the data show the variations and the interrelationships among the parameters. A theoretical model for the porosity-resistivity formation factor relation which conforms to Dakhnov's formulation, obtained for similar sediment with different grain sizes in another geological province has been developed based on the measured data. A good approximation with error of the mean square of 2.48 and standard deviation of 1.5 was obtained between the experimental aquifer formation factor F and the predicted aquifer formation factor Fm. Generally, the results of our study reveal good correlations with similar studies carried out in literatures at different places. The juxtaposition of contour maps which show variations of geohydraulic parameters in a continuum is worthwhile. The changes in geohydraulic parameters are influenced by size of grains, magnitude of pore sizes and shapes, pore-water and formation conductivities, facies changes and anisotropy of aquifer sediments. Our results have not really shown any interaction between freshwater and saltwater

  5. Teaching and learning hydrogeology using a physically-based modelling framework

    NASA Astrophysics Data System (ADS)

    Frampton, Andrew; Dessirier, Benoit; Pannetier, Romain

    2014-05-01

    Hydrogeology involves studying the occurrence, distribution, movement and quality of water in geological formations. Hydrogeology typically enters in the curriculum of physical geography as well as civil and environmental engineering courses, is a multidisciplinary subject which encompasses several scientific areas including mathematics, physics, geology, geochemistry and numerical analysis. For applications such as resource management, decision and policy making, and an understanding and interpretation of uncertainty and risk assessment is also necessary. Teaching hydrogeology is not only challenged by its multidisciplinary nature, but also since groundwater occurrence and movement is hidden from view in the subsurface, and is generally inaccessible to direct observation. Field experiments are often costly and time consuming, and laboratory experiments limited in scale. However, suitably designed computational systems can help address such issues by providing numerical modelling investigations of field conditions. This contribution presents results from a recent project dedicated to develop an open-source, interactive, visual numerical modelling tool for teaching/learning hydrogeology, based on current pedagogical understanding of learning in higher education. It provides physically-based groundwater flow solutions within an intuitive user-friendly interface, which does not require advanced technical skills to operate. The aim is to be able to improve student's learning by providing immediate and visual feedback on groundwater flow and contaminant transport problems. The development and implementation of the tool as part of a teaching framework to address subsurface flow concepts and phenomena is presented, discussed and evaluated. By linking theoretical problem-solving exercises with modelling tasks in a learn-by-doing approach, we further discuss how student's learning experiences can be enhanced.

  6. Hydrogeologic investigation of the Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama

    SciTech Connect

    Gardner, F.G.; Kearl, P.M.; Mumby, M.E.; Rogers, S.

    1996-09-01

    This document describes the geology and hydrogeology at the former Advanced Coal Liquefaction Research and Development (ACLR&D) facility in Wilsonville, Alabama. The work was conducted by personnel from the Oak Ridge National Laboratory Grand Junction office (ORNL/GJ) for the U.S. Department of Energy (DOE) Pittsburgh Energy Technology Center (PETC). Characterization information was requested by PETC to provide baseline environmental information for use in evaluating needs and in subsequent decision-making for further actions associated with the closeout of facility operations. The hydrogeologic conceptual model presented in this report provides significant insight regarding the potential for contaminant migration from the ACLR&D facility and may be useful during other characterization work in the region. The ACLR&D facility is no longer operational and has been dismantled. The site was characterized in three phases: the first two phases were an environmental assessment study and a sod sampling study (APCO 1991) and the third phase the hydraulic assessment. Currently, a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation (RI) to address the presence of contaminants on the site is underway and will be documented in an RI report. This technical memorandum addresses the hydrogeologic model only.

  7. The application of satellite differential SAR interferometry-derived ground displacements in hydrogeology

    USGS Publications Warehouse

    Galloway, D.L.; Hoffmann, J.

    2007-01-01

    The application of satellite differential synthetic aperture radar (SAR) interferometry, principally coherent (InSAR) and to a lesser extent, persistent-scatterer (PSI) techniques to hydrogeologic studies has improved capabilities to map, monitor, analyze, and simulate groundwater flow, aquifer-system compaction and land subsidence. A number of investigations over the previous decade show how the spatially detailed images of ground displacements measured with InSAR have advanced hydrogeologic understanding, especially when a time series of images is used in conjunction with histories of changes in water levels and management practices. Important advances include: (1) identifying structural or lithostratigraphic boundaries (e.g. faults or transitional facies) of groundwater flow and deformation; (2) defining the material and hydraulic heterogeneity of deforming aquifer-systems; (3) estimating system properties (e.g. storage coefficients and hydraulic conductivities); and (4) constraining numerical models of groundwater flow, aquifer-system compaction, and land subsidence. As a component of an integrated approach to hydrogeologic monitoring and characterization of unconsolidated alluvial groundwater basins differential SAR interferometry contributes unique information that can facilitate improved management of groundwater resources. Future satellite SAR missions specifically designed for differential interferometry will enhance these contributions. ?? Springer-Verlag 2006.

  8. The hydrogeological role of an aquitard in preventing drinkable water well contamination: a case study.

    PubMed

    Ponzini, G; Crosta, G; Giudici, M

    1989-11-01

    Groundwater pollution has become a worrisome phenomenon, mainly for aquifers underlying industrialized areas. In order to evaluate the risk of pollution, a model of the aquifer is needed. Herewith, we describe a quasi-tridimensional model, which we applied to a multilayered aquifer where a phreatic aquifer was coupled to a confined one by means of an aquitard. This hydrogeological scheme is often met in practice and, therefore, models a number of situations. Moreover, aquitards play and important role in the management of natural resources of this kind. The model we adopted contains some approximations: the flow within the aquifers is assumed to be horizontal, whereas leakage is assumed vertical. The effect of some wells drilled in these aquifers is also taken into account. In order to evaluate the leakage fluxes that correspond to different exploitation conditions, we numerically solve a system of quasilinear and time-dependent partial differential equations. This model has been calibrated by the hydrogeological data from a water supply station of the Milan Water Works, where water is polluted by some halocarbons. Our simulations account for several experimental facts, both from the hydrogeological and hydrogeochemical viewpoints. Maxima of computed downward leakage rates are found to correspond with measured pollutant concentration maxima. Other results show how the aquitard can help in minimizing the contamination of drinkable water. PMID:2620670

  9. Applying Time-Frequency Analysis to Assist Identification of Hydrogeological Structure of Groundwater Aquifers

    NASA Astrophysics Data System (ADS)

    shiuan, C. W.; Chang, L.

    2013-12-01

    Due to global warming, climate change, and economic development, the stability of water supply is challenged using only surface water resources. Hence, groundwater becomes an important water resource for increasing water supply reliability. However, groundwater extraction many introduce damages such as land subsidence and seawater intrusion. To accurately evaluate the response of groundwater aquifers, correct hydrogeological structure is a key factor. In the past, the evaluation of the hydrogeological structure relies on subjective judgment which is arbitrarily made based on available information of core sampling record, fossils, geological dating, etc. This study develops a quantitative method to provide objective information for improving the judgment. This method uses observed groundwater water level and time-frequency analysis. Precisely, the signal strength of the groundwater level is evaluated using Fast Fourier Transform (FFT) which is done by a commercially available software named Visual Signal. Two signal frequencies, daily and annual frequency, are studied. This method is applied to Lanyang Plain in Taiwan. The groundwater level record of shallow wells is selected for the signal processing. Therefore, higher signal strength of an annual signal indicates higher recharge which is an indicator of unconfined aquifer. In the case of Lanyang Plain, the low signal strength area includes fan top area and scatter areas at fan central and fantail areas. This signal information along with core sampling information can provide a complete picture of the hydrogeological structure and characteristics for the studied area Ilan shallow water wells in different frequencies

  10. Geologic framework and hydrogeologic characteristics of the Edwards Aquifer outcrop, Comal County, Texas

    USGS Publications Warehouse

    Small, T.A.; Hanson, J.A.

    1994-01-01

    All of the hydrogeologic subdivisions within the Edwards aquifer outcrop in Comal County have some porosity and permeability. The most porous and permeable appear to be hydrogeologic subdivision VI, the Kirschberg evaporite member of the Kainer Formation; hydrogeologic subdivision III, the leached and collapsed members, undivided; and hydro- geologic subdivision II, the cyclic and marine members, undivided, of the Person Formation. The two types of porosity in the Edwards aquifer outcrop are fabric selective, which is related to depositional or diagenetic elements and typically exists in specific stratigraphic horizons; and not fabric selective, which can exist in any litho- stratigraphic horizon. Two faults, Comal Springs and Hueco Springs, completely, or almost completely, offset the Edwards aquifer along much of their respective traces across Comal County. Porous and permeable Edwards aquifer limestones are juxtaposed against impermeable upper confining beds along all, or most of their traces across Comal County. These faults could be barriers, or partial barriers, to ground-water flow where the aquifer is offset. In Comal County, the Edwards aquifer is probably most vulnerable to surface contamination in the rapidly urbanizing areas on the Edwards aquifer outcrop. Possible contamination can result from spills, leakage of hazardous materials, or runoff onto the intensely faulted and fractured, karstic limestone outcrops characteristics of the recharge zone.

  11. Reconnaissance hydrogeologic investigation of the Defense Waste Processing Facility and Vicinity, Savannah River Plant, South Carolina

    SciTech Connect

    Dennehy, K.F.; Prowell, D.C.; McMahon, P.B.

    1989-01-01

    The purposes of this report are two-fold: (1) to define the hydrogeologic conditions in the vicinity of the defense waste processing facility (DWPF) and, (2) to evaluate the potential for movement of a concentrated salt-solution waste if released at or near the DWPF. These purposes were accomplished by assembling and evaluating existing hydrogeologic data; collecting additional geologic, hydrologic, and water-quality data; developing a local geologic framework; developing a conceptual model of the local ground-water flow system; and by performing laboratory experiments to determine the mobility of salt-solution waste in surface and near-surface sediments. Although the unconsolidated sediments are about 1000 ft thick in the study area, only the Tertiary age sediments, or upper 300 ft are discussed in this report. The top of the Ellenton Formation acts as the major confining unit between the overlying aquifers in Tertiary sediments and the underlying aquifers in Cretaceous sediments; therefore, the Ellenton Formation is the vertical limit of our hydrogeologic investigation. The majority of the hydrologic data for this study come from monitoring wells at the saltstone disposal site (SDS) in Z Area (fig. 3). No recent water-level data were collected in S Area owing to the removal of S Area monitoring wells prior to construction at the DWPF. 46 refs., 26 figs., 7 tabs.

  12. Hydrogeologic Architecture of the San Andreas Fault near the Logan Quarry

    NASA Astrophysics Data System (ADS)

    Xue, L.; Brodsky, E. E.; Erskine, J.; Fulton, P. M.; Carter, R.

    2015-12-01

    Hydrogeologic properties of fault zones are critical to the faulting processes; however, they are not well understood and difficult to measure in situ. Recording the tidal response of water level is a useful method to measure the in-situ properties. We utilize an array of wells near the San Andreas Fault zone in the Logan Quarry to study the fault zone hydrogeologic architecture by measuring the water tidal response. The measured specific storage and permeability show that there is a localized zone near the fault with higher specific storage and larger permeability than the surrounding region. This change of properties might be related to the fault zone fracture distribution. Surprisingly, the change of the specific storage is the clearest signal. The inferred compliance contrast is consistent with prior estimates of elastic moduli change in the near-fault environment, but the hydrogeologic effects of the compliance change have never before been measured on a major active fault. The observed specific storage structure implies that the fault zone plays an important role in permeability enhancement by seismic shaking. In addition, the measured diffusivity is about 10-2 m2/s, which is comparable to the post-earthquake hydraulic diffusivity measured on the Wenchuan Earthquake Fault. This observed high diffusivity with little variability inside the fault zone might suggest the accumulated pore pressure during interseismic period distributes over a broad region.

  13. Dynamic interactions between hydrogeological and exposure parameters in daily dose prediction under uncertainty and temporal variability.

    PubMed

    Kumar, Vikas; de Barros, Felipe P J; Schuhmacher, Marta; Fernàndez-Garcia, Daniel; Sanchez-Vila, Xavier

    2013-12-15

    We study the time dependent interaction between hydrogeological and exposure parameters in daily dose predictions due to exposure of humans to groundwater contamination. Dose predictions are treated stochastically to account for an incomplete hydrogeological and geochemical field characterization, and an incomplete knowledge of the physiological response. We used a nested Monte Carlo framework to account for uncertainty and variability arising from both hydrogeological and exposure variables. Our interest is in the temporal dynamics of the total dose and their effects on parametric uncertainty reduction. We illustrate the approach to a HCH (lindane) pollution problem at the Ebro River, Spain. The temporal distribution of lindane in the river water can have a strong impact in the evaluation of risk. The total dose displays a non-linear effect on different population cohorts, indicating the need to account for population variability. We then expand the concept of Comparative Information Yield Curves developed earlier (see de Barros et al. [29]) to evaluate parametric uncertainty reduction under temporally variable exposure dose. Results show that the importance of parametric uncertainty reduction varies according to the temporal dynamics of the lindane plume. The approach could be used for any chemical to aid decision makers to better allocate resources towards reducing uncertainty. PMID:24011618

  14. Structure and genesis of the Cubango Megafan in northern Namibia: implications for its hydrogeology

    NASA Astrophysics Data System (ADS)

    Lindenmaier, F.; Miller, R.; Fenner, J.; Christelis, G.; Dill, H. G.; Himmelsbach, T.; Kaufhold, S.; Lohe, C.; Quinger, M.; Schildknecht, F.; Symons, G.; Walzer, A.; van Wyk, B.

    2014-09-01

    An exploration strategy for groundwater was established and followed in the northern Namibian Cuvelai-Etosha Basin (CEB). The data derived from transient electromagnetics, rotary-drilling, coring and sample investigation were used to refine stratigraphy and hydrostratigraphy, and to develop a 3D map of aquifers within the Cubango Megafan. The results have delineated three major aquifers. The newly found, deep-seated Ohangwena II Aquifer (KOH-2) has the potential of providing significant additional water to the water supply of northern Namibia and Angola. While near-surface aquifers carry predominantly brackish water, freshwater in the deep-seated aquifer is further extended and features good hydraulic properties. To date, only a small part of the hydrogeological potential of arid CEB has been explored and an extension of exploration is needed, including southern Angola. The combination of structural, sedimentological and hydrogeological approaches greatly advanced both the geological and hydrogeological understanding. With regard to the deep-seated aquifer, strict measures need to be applied to ensure that the water in the KOH-2 reservoir is exploited sustainably. Water control areas need to be established to ensure long-term preservation of this newly explored aquifer.

  15. Hydrogeological aspects of groundwater drainage of the urban areas in Kuwait City

    NASA Astrophysics Data System (ADS)

    Al-Rashed, Muhammad F.; Sherif, Mohsen M.

    2001-04-01

    Residential areas in Kuwait City have witnessed a dramatic rise in subsurface water tables over the last three decades. This water rise phenomenon is attributed mainly to over irrigation practices of private gardens along with leakage from domestic and sewage networks. This paper presents a comprehensive study for urban drainage in two selected areas representing the two hydrogeological settings encountered in Kuwait City. In the first area, a vertical drainage scheme was applied successfully over an area of 1 km2. The system has been under continuous operation and monitoring for more than 4 years without problems, providing a permanent solution for the water rise problem in this area. The hydrogeological system has approached steady state conditions and the water levels have dropped to about 3·5 m below the ground surface. In the second area a dual drainage scheme, composing of horizontal and vertical elements, is proposed. Horizontal elements are suggested in the areas where the deep groundwater contains hazardous gases that may pose environmental problems. The proposed drainage scheme in the second area has not yet been implemented. Field tests were conducted to assess the aquifer parameters in both areas and a numerical model has been developed to predict the long-term response of the hydrogeological system in the two areas under consideration.

  16. Improvements in near-surface geophysical applications for hydrogeological parameter estimation

    NASA Astrophysics Data System (ADS)

    Addison, Adrian Demond

    One application of near-surface geophysical techniques is the hydrogeological parameter estimation. Hydrogeological estimated parameters such as volumetric water content, porosity, and hydraulic conductivity are useful in predicting groundwater flow. Therefore, any improvements in the field acquisition and data processing of the geophysical data will provide better results in estimating these parameters. This research examines the difficulties associated with processing and attribute analyses with shallow seismic P-wave reflection data, the application of the empirical mode decomposition (EMD) as a processing tool for ground-penetrating radar (GPR), and the use of GPR as tool in the assessment of bank filtration. Near-surface seismic reflection data are difficult to process because of the lack of reflections in the shot gathers; however, this research demonstrated that the application of certain steps such F-k filtering and velocity analysis can achieve the desired result, a more robust geologic model. The EMD technique was applied (removal of the WOW noise) to processing steps for GPR data in estimating hydrogeological parameters by providing significant stability during the calculation of dielectric constants. GPR techniques are widely known and diverse, but one rather different application of the GPR was to assess the suitability of bank filtration at a site in South Carolina. Finally, a multi-attribute analysis approach, a rather new application for near-surface seismic data, was used in predicting porosity from well logs and seismic data.

  17. A permeability and compliance contrast measured hydrogeologically on the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Xue, Lian; Brodsky, Emily E.; Erskine, Jon; Fulton, Patrick M.; Carter, Reed

    2016-03-01

    Hydrogeologic properties of fault zones are critical to faulting processes; however, they are not well understood and difficult to measure in situ, particularly in low-permeability fractured bedrock formations. Analysis of continuous water level response to Earth tides in monitoring wells provides a method to measure the in situ hydrogeologic properties. We utilize four monitoring wells within the San Andreas Fault zone near Logan Quarry to study the fault zone hydrogeologic architecture by measuring the water level tidal response. The specific storage and permeability inferred from the tidal response suggest that there is a difference in properties at different distances from the fault. The sites closer to the fault have higher specific storage and higher permeability than farther from the fault. This difference of properties might be related to the fault zone fracture distribution decreasing away from the fault. Although permeability channels near faults have been documented before, the difference in specific storage near the fault is a new observation. The inferred compliance contrast is consistent with prior estimates of elastic moduli in the near-fault environment, but the direct measurements are new. The combination of measured permeability and storage yields a diffusivity of about 10-2 m2/s at all the sites both near and far from the fault as a result of the competing effects of permeability and specific storage. This uniform diffusivity structure suggests that the permeability contrast might not efficiently trap fluids during the interseismic period.

  18. The influence of bedrock hydrogeology on catchment-scale nitrate fate and transport in fractured aquifers.

    PubMed

    Orr, Alison; Nitsche, Janka; Archbold, Marie; Deakin, Jenny; Ofterdinger, Ulrich; Flynn, Raymond

    2016-11-01

    Characterising catchment scale biogeochemical processes controlling nitrate fate in groundwater constitutes a fundamental consideration when applying programmes of measures to reduce risks posed by diffuse agricultural pollutants to water quality. Combining hydrochemical analyses with nitrate isotopic data and physical hydrogeological measurements permitted characterisation of biogeochemical processes influencing nitrogen fate and transport in the groundwater in two fractured bedrock aquifers with contrasting hydrogeology but comparable nutrient loads. Hydrochemical and isotopic analyses of groundwater samples collected from moderately fractured, diffusely karstified limestone indicated nitrification controlled dissolved nitrogen fate and delivery to aquatic receptors. By contrast nitrate concentrations in groundwater were considerably lower in a low transmissivity highly lithified sandstone and pyrite-bearing shale unit with patchy subsoil cover. Geophysical and hydrochemical investigations showed shallower intervals contained hydraulically active fractures where denitrification was reflected through lower nitrogen levels and an isotopic enrichment ratio of 1.7 between δ(15)N and δ(18)O. Study findings highlight the influence of bedrock hydrogeological conditions on aqueous nitrogen mobility. Investigation results demonstrate that bedrock conditions need to be considered when implementing catchment management plans to reduce the impact of agricultural practices on the quality of groundwater and baseflow in receiving rivers. Nitrate isotopic signatures in the groundwater of a freely draining catchment underlain by a karstified aquifer and a poorly draining aquifer with a low transmissivity aquifer. PMID:27432726

  19. Hydrogeology along the southern boundary of the Hanford Site between the Yakima and Columbia Rivers, Washington

    SciTech Connect

    Liikala, T.L.

    1994-09-01

    US Department of Energy (DOE) operations at the Hanford Site, located in southeastern Washington, have generated large volumes of hazardous and radioactive wastes since 1944. Some of the hazardous wastes were discharged to the ground in the 1100 and 3000 Areas, near the city of Richland. The specific waste types and quantities are unknown; however, they probably include battery acid, antifreeze, hydraulic fluids, waste oils, solvents, degreasers, paints, and paint thinners. Between the Yakima and Columbia rivers in support of future hazardous waste site investigations and ground-water and land-use management. The specific objectives were to collect and review existing hydrogeologic data for the study area and establish a water-level monitoring network; describe the regional and study area hydrogeology; develop a hydrogeologic conceptual model of the unconfined ground-water flow system beneath the study area, based on available data; describe the flow characteristics of the unconfined aquifer based on the spatial and temporal distribution of hydraulic head within the aquifer; use the results of this study to delineate additional data needs in support of future Remedial Investigation/Feasibility Studies (RI/FS), Fate and Transport modeling, Baseline Risk Assessments (BRA), and ground-water and land-use management.

  20. Hydrogeologic Framework Model for the Saturated Zone Site Scale flow and Transport Model

    SciTech Connect

    T. Miller

    2004-11-15

    The purpose of this report is to document the 19-unit, hydrogeologic framework model (19-layer version, output of this report) (HFM-19) with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results in accordance with AP-SIII.10Q, Models. The HFM-19 is developed as a conceptual model of the geometric extent of the hydrogeologic units at Yucca Mountain and is intended specifically for use in the development of the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]). Primary inputs to this model report include the GFM 3.1 (DTN: MO9901MWDGFM31.000 [DIRS 103769]), borehole lithologic logs, geologic maps, geologic cross sections, water level data, topographic information, and geophysical data as discussed in Section 4.1. Figure 1-1 shows the information flow among all of the saturated zone (SZ) reports and the relationship of this conceptual model in that flow. The HFM-19 is a three-dimensional (3-D) representation of the hydrogeologic units surrounding the location of the Yucca Mountain geologic repository for spent nuclear fuel and high-level radioactive waste. The HFM-19 represents the hydrogeologic setting for the Yucca Mountain area that covers about 1,350 km2 and includes a saturated thickness of about 2.75 km. The boundaries of the conceptual model were primarily chosen to be coincident with grid cells in the Death Valley regional groundwater flow model (DTN: GS960808312144.003 [DIRS 105121]) such that the base of the site-scale SZ flow model is consistent with the base of the regional model (2,750 meters below a smoothed version of the potentiometric surface), encompasses the exploratory boreholes, and provides a framework over the area of interest for groundwater flow and radionuclide transport modeling. In depth, the model domain extends from land surface to the base of the regional groundwater flow model (D'Agnese et al. 1997 [DIRS 100131], p 2). For the site-scale SZ flow model, the HFM

  1. Hydrogeophysics and remote sensing for the design of hydrogeological conceptual models in hard rocks - Sardón catchment (Spain)

    NASA Astrophysics Data System (ADS)

    Francés, Alain P.; Lubczynski, Maciek W.; Roy, Jean; Santos, Fernando A. M.; Mahmoudzadeh Ardekani, Mohammad R.

    2014-11-01

    Hard rock aquifers are highly heterogeneous and hydrogeologically complex. To contribute to the design of hydrogeological conceptual models of hard rock aquifers, we propose a multi-techniques methodology based on a downward approach that combines remote sensing (RS), non-invasive hydrogeophysics and hydrogeological field data acquisition. The proposed methodology is particularly suitable for data scarce areas. It was applied in the pilot research area of Sardón catchment (80 km2) located west of Salamanca (Spain). The area was selected because of hard-rock hydrogeology, semi-arid climate and scarcity of groundwater resources. The proposed methodology consisted of three main steps. First, we detected the main hydrogeological features at the catchment scale by processing: (i) a high resolution digital terrain model to map lineaments and to outline fault zones; and (ii) high-resolution, multispectral satellite QuickBird and WorldView-2 images to map the outcropping granite. Second, we characterized at the local scale the hydrogeological features identified at step one with: i) ground penetrating radar (GPR) to assess groundwater table depth complementing the available monitoring network data; ii) 2D electric resistivity tomography (ERT) and frequency domain electromagnetic (FDEM) to retrieve the hydrostratigraphy along selected survey transects; iii) magnetic resonance soundings (MRS) to retrieve the hydrostratigraphy and aquifer parameters at the selected survey sites. In the third step, we drilled 5 boreholes (25 to 48 m deep) and performed slug tests to verify the hydrogeophysical interpretation and to calibrate the MRS parameters. Finally, we compiled and integrated all acquired data to define the geometry and parameters of the Sardón aquifer at the catchment scale. In line with a general conceptual model of hard rock aquifers, we identified two main hydrostratigraphic layers: a saprolite layer and a fissured layer. Both layers were intersected and drained by

  2. Hydrogeologic and water-quality data for the explosive experimental area, Naval Surface Warfare Center, Dahlgren Site, Dahlgren, Virginia

    USGS Publications Warehouse

    Hammond, E.C.; Bell, C.F.

    1995-01-01

    Hydrogeologic and water-quality data were collected at the Explosive Experimental Area, Naval Surface Warfare Center, Dahlgren Site at Dahlgren, Virginia, as part of a hydrogeologic assessment of the shallow aquifer system begun in 1993. The U.S. Geological Survey conducted this study to provide the U.S. Navy with hydrogeologic data to aid in the evaluation of the effects from remediation of contaminated sites and to protect against additional contamination. This report describes the ground-water observation- well network, hydrogeologic, and water-quality data collected between October 1993 and April 1995. The report includes a description of the locations and construction of 28 observation wells on the Explosive Experimental Area. Hydrogeologic data include lithologic logs, geophysical logs, and vertical hydraulic conductivity measurements of selected core intervals. Hydrologic data include synoptic and hourly measurements of ground-water levels, and observation-well slug tests to determine horizontal hydraulic conductivity. Water-quality data include analyses of major dissolved constituents in ground water and surface water.

  3. Hydrogeological characterization on surface-based investigation phase in the Mizunami underground research laboratory project, in Japan

    SciTech Connect

    Saegusa, Hiromitsu; Onoe, Hironori; Takeuchi, Shinji; Takeuchi, Ryuji; Ohyama, Takuya

    2007-07-01

    The Mizunami Underground Research Laboratory (MIU) project is being carried out by Japan Atomic Energy Agency in the Cretaceous Toki granite in the Tono area, central Japan. The MIU project is a purpose-built generic underground research laboratory project that is planned for a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes. One of the main goals of the MIU project is to establish comprehensive techniques for investigation, analysis, and assessment of the deep geological environment. The MIU project has three overlapping phases: Surface-based Investigation (Phase I), Construction (Phase II) and Operation (Phase III). Hydrogeological investigations using a stepwise process in Phase I have been carried out in order to obtain information on important properties such as, location of water conducting features, hydraulic conductivity and so on. Hydrogeological modeling and groundwater flow simulations in Phase I have been carried out in order to synthesize these investigation results, to evaluate the uncertainty of the hydrogeological model and to identify the main issues for further investigations. Using the stepwise hydrogeological characterization approach and combining the investigation with modeling and simulation, understanding of the hydrogeological environment has been progressively improved. (authors)

  4. On the significance of contaminant plume-scale and dose-response models in defining hydrogeological characterization needs

    NASA Astrophysics Data System (ADS)

    de Barros, F.; Rubin, Y.; Maxwell, R.; Bai, H.

    2007-12-01

    Defining rational and effective hydrogeological data acquisition strategies is of crucial importance since financial resources available for such efforts are always limited. Usually such strategies are developed with the goal of reducing uncertainty, but less often they are developed in the context of the impacts of uncertainty. This paper presents an approach for determining site characterization needs based on human health risk factors. The main challenge is in striking a balance between improved definition of hydrogeological, behavioral and physiological parameters. Striking this balance can provide clear guidance on setting priorities for data acquisition and for better estimating adverse health effects in humans. This paper addresses this challenge through theoretical developments and numerical testing. We will report on a wide range of factors that affect the site characterization needs including contaminant plume's dimensions, travel distances and other length scales that characterize the transport problem, as well as health risk models. We introduce a new graphical tool that allows one to investigate the relative impact of hydrogeological and physiological parameters in risk. Results show that the impact of uncertainty reduction in the risk-related parameters decreases with increasing distances from the contaminant source. Also, results indicate that human health risk becomes less sensitive to hydrogeological measurements when dealing with ergodic plumes. This indicates that under ergodic conditions, uncertainty reduction in human health risk may benefit from better understanding of the physiological component as opposed to a detailed hydrogeological characterization

  5. Hydrogeologic framework and sampling design for an assessment of agricultural pesticides in ground water in Pennsylvania

    USGS Publications Warehouse

    Lindsey, Bruce D.; Bickford, Tammy M.

    1999-01-01

    State agencies responsible for regulating pesticides are required by the U.S. Environmental Protection Agency to develop state management plans for specific pesticides. A key part of these management plans includes assessing the potential for contamination of ground water by pesticides throughout the state. As an example of how a statewide assessment could be implemented, a plan is presented for the Commonwealth of Pennsylvania to illustrate how a hydrogeologic framework can be used as a basis for sampling areas within a state with the highest likelihood of having elevated pesticide concentrations in ground water. The framework was created by subdividing the state into 20 areas on the basis of physiography and aquifer type. Each of these 20 hydrogeologic settings is relatively homogeneous with respect to aquifer susceptibility and pesticide use?factors that would be likely to affect pesticide concentrations in ground water. Existing data on atrazine occurrence in ground water was analyzed to determine (1) which areas of the state already have suffi- cient samples collected to make statistical comparisons among hydrogeologic settings, and (2) the effect of factors such as land use and aquifer characteristics on pesticide occurrence. The theoretical vulnerability and the results of the data analysis were used to rank each of the 20 hydrogeologic settings on the basis of vulnerability of ground water to contamination by pesticides. Example sampling plans are presented for nine of the hydrogeologic settings that lack sufficient data to assess vulnerability to contamination. Of the highest priority areas of the state, two out of four have been adequately sampled, one of the three areas of moderate to high priority has been adequately sampled, four of the nine areas of moderate to low priority have been adequately sampled, and none of the three low priority areas have been sampled. Sampling to date has shown that, even in the most vulnerable hydrogeologic settings

  6. The KINDRA H2020 Project: a knowledge inventory for hydrogeology research

    NASA Astrophysics Data System (ADS)

    Petitta, Marco; Bodo, Balazs; Caschetto, Mariachiara; Correia, Victor; Cseko, Adrienn; Fernandez, Isabel; Hartai, Eva; Hinsby, Klaus; Madarasz, Tamas; Garcia Padilla, Mercedes; Szucs, Peter

    2015-04-01

    Hydrogeology-related research activities cover a wide spectrum of research areas at EU and national levels. This fact is due to the intrinsic nature of the "water" topic, representing a key-aspect of the modern society: water is not only necessary for human, biological and environmental requirements, but it is one basic "engine" of several interconnected research topics, including energy, health, climate, food, security and others as exemplified by the water-food-energy-climate nexus described by e.g. the World Economic Forum. With respect to the water cycle, the management of groundwater brings additional challenges to the implementation of the Water Framework Directive (WFD) and climate change adaptation (such as integrated transboundary management of groundwater resources). This fact is related to the nature of groundwater, which represents the "hidden" part of the water cycle, difficult to evaluate, communicate and appreciate, although it sustains the health of both humans and ecosystems as well as industrial and agricultural production. In general, groundwater has been considered mainly for its relationships with surface waters, influencing river flow, e-flows, GDE (groundwater-dependent ecosystems), pollutant fate, agricultural practices, water scarcity and others. In this framework, the importance of groundwater inside the WFD has been reinforced by the daughter directive on groundwater. In the last years, particular insights have been developed on surface waters/groundwater interactions and several related research projects have been carried out. Nevertheless, a specific focus on hydrogeology, the science branch studying groundwater, has not looked into until now, despite of its utmost importance as renewable, high-quality, naturally protected (but still vulnerable) resource. At the same time the European knowledge-base that has been acquired on this important topic is widespread into several projects, plans, actions, realized at national and fragmented

  7. What maintains the waters flowing in our rivers? - Rethinking hydrogeology to improve public policy

    NASA Astrophysics Data System (ADS)

    Vasconcelos, Vitor Vieira

    2016-01-01

    This article discusses how new contributions from hydrogeological science in the 20th and 21st centuries have allowed for a better understanding of the processes that affect the maintenance of river flows. Moreover, the way in which this knowledge has been conveyed beyond academia and has been gradually incorporated into public policy for natural resource management is also discussed. This article explains the development of several approaches used to understand the relationships among the management of aquifers, vegetation and river flows, including water balance, aquifer recharge, the piston effect, seasonal effects, and safe and sustainable yields. Additionally, the current challenges regarding the modeling of hydrological processes that integrate groundwater and surface waters are discussed. Examples of studies applied in Brazil that demonstrate these processes and stimulate thought regarding water management strategies are presented. In light of the case studies, it is possible to propose different strategies, each adapted for specific hydrogeological context to maximize aquifer recharge or base flow maintenance. Based on these strategies, the role of infiltration ponds and other artificial recharge techniques is re-evaluated in the context of the mitigation of environmental impacts on the maintenance of river flows. Proposals for the improvement of public policies regarding the payment of related environmental services to stimulate investment in aquifer recharge and the maintenance of base flow, for which the goal is to attain win-win-win situations for the environment, farmers and water users, while preventing land speculation, are discussed. Lastly, a conceptual model for the dissemination of hydrogeological knowledge in public policies is provided, and its challenges and possibilities are discussed.

  8. A discussion of issues related to hydrogeology of deep geologic systems

    NASA Astrophysics Data System (ADS)

    Tsang, C. F.; Niemi, A.

    2012-04-01

    The state of the deep hydrogeological system, including its hydraulic structures and flow patterns, distribution of permeability and porosity, and distribution of hydraulic head values, is very much an open research field. Much work needs to be done to obtain such data and to understand the current conditions at depth. Deep drilling projects worldwide have often been dominated by studies concerning the geological and geophysical processes, as well as the geochemical composition of the deep underground. Hydrogeological processes, on the other hand, have received relatively less attention. Yet many of the important chemical, thermal and mechanical processes of the deep underground are closely linked and cannot be properly addressed without an adequate understanding of fluid flow and solute migration. Hydrologic condition and its evolution may also play a significant role in long term geologic processes, such as orogenesis. Presently, intended to be part of the International Continental Drilling Program (ICDP), a deep drilling project is under preparation on the Swedish Caledonides (www.sddp.se/cosc), with the objective to address, among other things, issues related to fluid flow and solute migration. Partly prompted by this project, and partly by the desire to compile the existing knowledge, a workshop was convened in September 2011 in Uppsala, Sweden, to review the state-of-the-art of hydrogeological studies of deep systems, both from the point of view of available observations and data, and from the point of view of modeling and generic conceptual considerations. The discussions and presentations were structured around the following topics: (1) Spatial Extent and Dynamics of the Fluid Flow in the Deep Subsurface; (2) Fluid Flow in Coupled Thermo-Hydro-Mechanical-Chemical Processes occurring at depth; and (3) Monitoring and Modeling Methods. The present talk will aim to present the main outcomes and recommendations from this workshop.

  9. Hydrogeologic analysis of remedial alternatives for the solar ponds plume, RFETS

    SciTech Connect

    McLane, C.F. III; Whidden, J.A.; Hopkins, J.K.

    1998-07-01

    The focus of this paper is to develop a conceptual model and a hydrogeologic analysis plan for remedial alternatives being considered for the remediation of a ground water contaminant plume consisting of chiefly nitrate and uranium. The initial step in this process was to determine the adequacy of the existing data from the vast database of site information. Upon concluding that the existing database was sufficient to allow for the development of a conceptual model and then constructing the conceptual model, a hydrogeologic analysis plan was developed to evaluate several alternatives for plume remediation. The plan will be implemented using a combination of analytical and simple numerical ground water flow and contaminant transport models. This allows each portion of the study to be addressed using the appropriate tool, without having to develop a large three-dimensional numerical ground water flow and transport model, thereby reducing project costs. The analysis plan will consist of a preliminary phase of screening analyses for each of the remedial alternative scenarios, and a second phase of more comprehensive and in-depth analyses on a selected subset of remedial alternative scenarios. One of the alternatives which will be analyzed is phytoremediation (remediation of soil and ground water via uptake of chemicals by plants) because of the potential for relatively low capital and operation and maintenance costs, passive nature, and potential to provide long-term protection of the surface water. The results of these hydrogeological analyses will be factored into the selection of the preferred remedial alternative, or combination of alternatives, for the contaminant plume.

  10. Flow and transport in unsaturated fractured rock: effects of multiscale heterogeneity of hydrogeologic properties.

    PubMed

    Zhou, Quanlin; Liu, Hui-Hai; Bodvarsson, Gudmundur S; Oldenburg, Curtis M

    2003-01-01

    The heterogeneity of hydrogeologic properties at different scales may have different effects on flow and transport processes in a subsurface system. A model for the unsaturated zone of Yucca Mountain, Nevada, is developed to represent complex heterogeneity at two different scales: (1) layer scale corresponding to geologic layering and (2) local scale. The layer-scale hydrogeologic properties are obtained using inverse modeling, based on the available measurements collected from the Yucca Mountain site. Calibration results show a significant lateral and vertical variability in matrix and fracture properties. Hydrogeologic property distributions in a two-dimensional, vertical cross-section of the site are generated by combining the average layer-scale matrix and fracture properties with local-scale perturbations generated using a stochastic simulation method. The unsaturated water flow and conservative (nonsorbing) tracer transport through the cross-section are simulated for different sets of matrix and fracture property fields. Comparison of simulation results indicates that the local-scale heterogeneity of matrix and fracture properties has a considerable effect on unsaturated flow processes, leading to fast flow paths in fractures and the matrix. These paths shorten the travel time of a conservative tracer from the source (repository) horizon in the unsaturated zone to the water table for small fractions of total released tracer mass. As a result, the local-scale heterogeneity also has a noticeable effect on global tracer transport processes, characterized by an average breakthrough curve at the water table, especially at the early arrival time of tracer mass. However, the effect is not significant at the later time after 20% tracer mass reaches the water table. The simulation results also verify that matrix diffusion plays an important role in overall solute transport processes in the unsaturated zone at Yucca Mountain. PMID:12498572

  11. A review of non-invasive imaging methods and applications in contaminant hydrogeology research.

    PubMed

    Werth, Charles J; Zhang, Changyong; Brusseau, Mark L; Oostrom, Mart; Baumann, Thomas

    2010-04-01

    Contaminant hydrogeological processes occurring in porous media are typically not amenable to direct observation. As a result, indirect measurements (e.g., contaminant breakthrough at a fixed location) are often used to infer processes occurring at different scales, locations, or times. To overcome this limitation, non-invasive imaging methods are increasingly being used in contaminant hydrogeology research. Four of the most common methods, and the subjects of this review, are optical imaging using UV or visible light, dual-energy gamma radiation, X-ray microtomography, and magnetic resonance imaging (MRI). Non-invasive imaging techniques have provided valuable insights into a variety of complex systems and processes, including porous media characterization, multiphase fluid distribution, fluid flow, solute transport and mixing, colloidal transport and deposition, and reactions. In this paper we review the theory underlying these methods, applications of these methods to contaminant hydrogeology research, and methods' advantages and disadvantages. As expected, there is no perfect method or tool for non-invasive imaging. However, optical methods generally present the least expensive and easiest options for imaging fluid distribution, solute and fluid flow, colloid transport, and reactions in artificial two-dimensional (2D) porous media. Gamma radiation methods present the best opportunity for characterization of fluid distributions in 2D at the Darcy scale. X-ray methods present the highest resolution and flexibility for three-dimensional (3D) natural porous media characterization, and 3D characterization of fluid distributions in natural porous media. And MRI presents the best option for 3D characterization of fluid distribution, fluid flow, colloid transport, and reaction in artificial porous media. Obvious deficiencies ripe for method development are the ability to image transient processes such as fluid flow and colloid transport in natural porous media in three

  12. Hydrogeologic facies characterization of an alluvial fan near Fresno, California, using geophysical techniques

    USGS Publications Warehouse

    Burow, Karen R.; Weissmann, G.S.; Miller, R.D.; Placzek, Gary

    1997-01-01

    DBCP (1,2-dibromo-3-chloropropane) contamination in the sole source aquifer near Fresno, California, has significantly affected drinking-water supplies. Borehole and surface geophysical data were integrated with borehole textural data to characterize the Kings River alluvial fan sediments and to provide a framework for computer modeling of pesticide transport in ground water. Primary hydrogeologic facies units, such as gravel, coarse sand or gravel, fine sand, and silt and clay, were identified in cores collected from three borings located on a 4.6-kilometer transect of multilevel monitoring wells. Borehole geophysical logs collected from seven wells and surface geophysical surveys were used to extrapolate hydrogeologic facies to depths of about 82meters and to correlate the facies units with neighboring drilling sites. Thickness ranged from 0.3to 13 meters for sand and gravel units, and from 0.3 to 17 meters for silt and clay. The lateral extent of distinct silt and clay layers was mapped using shallow seismic reflection and ground-penetrating radar techniques. About 3.6 kilometers of seismic reflection data were collected; at least three distinct fine-grained layers were mapped. The depth of investigation of the seismic survey ranged from 34 to 107 meters below land surface, and vertical resolution was about 3.5 meters. The ground-penetrating radar survey covered 3.6kilometers and imaged a 1.5-meters thick, continuous fine-grained layer located at a depth of about 8 meters. Integrated results from the borehole sediment descriptions and geophysical surveys provided a detailed characterization over a larger areal extent than traditional hydrogeologic methods alone.

  13. The Impact of Hsueh-Shan Tunnel Construction on the Hydrogeological Environment in Northern Taiwan

    NASA Astrophysics Data System (ADS)

    Chiu, Y.; Chia, Y.

    2010-12-01

    The Hsueh-Shan tunnel, the fourth longest tunnel in the world, was suffered many collapses due to huge groundwater ingression and was ultimately opened to the public in June, 2006, after 15-year construction. Since the commencement of construction of tunnel, a long-term monitoring project to measure the groundwater ingression into the tunnel was conducted to ensure the safety of tunnel structure. According to the measured data obtained from the monitoring project, the average total flux of ingressive groundwater is about 450 l/sec. In order to assess the influence of this huge amount of ingressive groundwater on the regional hydrogeology near the tunnel area, a hydrogeological conceptual model was developed. We use MODFLOW-2005 to simulate groundwater flow and use the automated parameter estimation method to calibrate the model. The data on geography, geological structure, and groundwater hydrology are compiled to develop the conceptual model and the measured flux of ingressive groundwater is used to calibrate the model. The regional hydrogeological characteristics, before and after the tunnel excavation, and the water resources are evaluated by this calibrated conceptual model. The result shows that the ingression of groundwater into the tunnel is almost reach the steady state and the total amount of water is mainly contributed by about 2% loss of the total inflow of the Feitsui Reservoir. Besides, the condition of linings in the tunnel plays an important role in the safety of tunnel structure. Therefore, the long-term monitoring project should be continuously conducted to ensure the distribution of water resources and the safety of tunnel structure.

  14. A REVIEW OF NON-INVASIVE IMAGING METHODS AND APPLICATIONS IN CONTAMINANT HYDROGEOLOGY RESEARCH

    SciTech Connect

    Werth, Charles J.; Zhang, Changyong; Brusseau, M. L.; Oostrom, Martinus; Baumann, T.

    2010-03-08

    Contaminant hydrogeological processes occurring in porous media are typically not amenable to direct observation. As a result, indirect measurements (e.g., contaminant breakthrough at a fixed location) are often used to infer processes occurring at different scales, locations, or times. To overcome this limitation, non-invasive imaging methods are increasingly being used in contaminant hydrogeology research. The most common methods, and the subjects of this review, are optical imaging using UV or visible light, dual-energy gamma-radiation, X-ray microtomography, and magnetic resonance imaging (MRI). Non-invasive imaging techniques have provided valuable insights into a variety of complex systems and processes, including porous media characterization, multiphase fluid distribution, fluid flow, solute transport and mixing, colloidal transport and deposition, and reactions. In this paper we review the theory underlying these methods, applications of these methods to contaminant hydrogeology research, and methods’ advantages and disadvantages. As expected, there is no perfect method or tool for non-invasive imaging. However, optical methods generally present the least expensive and easiest options for imaging fluid distribution, solute and fluid flow, colloid transport, and reactions in artificial two-dimensional (2D) porous media. Gamma radiation methods present the best opportunity for characterization of fluid distributions in 2D at the Darcy scale. X-ray methods present the highest resolution and flexibility for three-dimensional (3D) natural porous media characterization, and 3D characterization of fluid distributions in natural porous media. And MRI presents the best option for 3D characterization of fluid distribution, fluid flow, colloid transport, and reaction in artificial porous media. Obvious deficiencies ripe for method development are the ability to image transient processes such as fluid flow and colloid transport in natural porous media in three

  15. The use of ecohydrological groundwater indicator plants in hydrogeological conceptual models

    NASA Astrophysics Data System (ADS)

    Lewis, J.

    2011-12-01

    Many plant species have been used for millennia as indicators of subsurface water. Under favorable circumstances, such ecohydrological indicators can suggest groundwater discharge areas, the depth to groundwater and the degree of mineralization. This information is available at virtually no expense and therefore has the potential to cost-effectively contribute to hydrogeological conceptual site models. However, very few hydrogeological studies take advantage of this inexpensive source of data. This review focuses on woody plants that are easily identified by earth scientists with little botanical training. Both facultative and obligate phreatophyte species are discussed. Riparian vegetation, being often found in groundwater discharge areas is covered in depth. The majority of published research concerning phreatophytes comes from the arid and semi-arid environments of the southwestern United States. However, this paper makes an effort to draw on data from several regions of the world and several fields of study. This includes a substantial body of research into geobotany from the former Soviet Union which has been largely overlooked by Western scholars. One of the most significant obstacles to using ecohydrological indicators in hydrogeological conceptual models is simply locating relevant information. Little has been published concerning indicator species in temperate, boreal and tropical zones. As a result, there is less useful information that can be deduced from groundwater indicator species in these climates. This article reviews both the state of the art and the potential for appliying ecohydrological groundwater indicator species to groundwater conceptual models. We conclude that ecohydrological groundwater indicators currently have the potential to cost effectively contribute to groundwater conceptual models in arid and semi-arid riparian zones. In climates that have an excess of moisture, extracting useful information from indicator species may require

  16. Validating the regional hydrogeological models with stable isotope data in precipitation

    NASA Astrophysics Data System (ADS)

    Kalvāns, Andis; Babre, Alise; Popovs, Konārds; Timuhins, Andrejs; Spalviņš, Aivars

    2016-04-01

    Stable isotopes 18O and 2H are a conservative tracer in the subsurface flow. The precipitation is the primary input in the groundwater systems, hens' there should be a positive regional correlation of the stable isotope values in the groundwater and precipitation. The local recharge peculiarities should modulate the precipitation isotope signal and introduce some noise but not eliminate the correlation completely. Modelled isotope values in the precipitation (Terzer et al. 2013) were compared to the actually observed values in the groundwater (Babre et al, in print) in the Baltic Artesian Basin, located at the South-East cost of the Baltic Sea. But positive and significant correlation was not found. Two regional hydrogeological models LAMO (Spalvins et al. 2015) and MOSYS (Virbulis et al. 2013) were used to trace the likely recharge area of the considered groundwater samples. A simple particle tracing of the LAMO produced a statistically significant, positive correlation between observed δ18O values in the relatively young groundwater (modelled residence time <7500 years) and precipitation at the location of the recharge. More complicated modelling system MOSYS with coarser resolution allowed to simulate the large scale downward depletion of the δ18O values in the groundwater. It is concluded that observed stable isotope values in the groundwater can be compared to the precipitation values in the recharge areas to validate the modelled regional flow patterns. This research is supported by Latvian National Research Programme EVIDENnT project "Groundwater and climate scenarios". References Babre, A., Kalv¯a ns, K., Popovs, K., Retiķe, I., D¯e liņa, A., Vaikmäe, R., Martma, T. (in print) New isotope data in groundwater from Latvia, central part of the Baltic Basin. Isotopes in Environmental & Health Studies Spalvins, A., Slangens j., L¯a ce I., Aleks¯a ns, O., Krauklis, K., 2015. Improvement of Hydrogeological Models: A Case Study. In International Review on

  17. The Evolution of the Hydrogeologic System in the Taipei Basin, Northern Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, M.; Chia, Y.

    2011-12-01

    Taipei basin is the largest metropolitain area in Taiwan, and thus the change of its hydrogeologic system is closely associated with the economic development of the urban area. In this study, we integrated the core data and groundwater level data to construct the hydrogeologic framework of the Taipei basin. Then the long-term elevation data and groundwater data were analyzed to understand the impact of urban development on the hydrogeologic system. By analyzing the long-term change of groundwater level in the Taipei basin, we found two groups of wells with a different range of water level and pattern of water level variation. The first group of wells is relatively shallow. Their hydraulic heads fluctuated between 0 and 5m. Generally the water level is rarely affected by pumping, but sensitive to the rainfall. These wells were placed in sand layers of the Songshan formation. However, the second group of wells, where the hydraulic head ranges from -40m to 0m, is relatively deep. They were installed in the Jingmei formation and Wugu formation. Pumping activities have significantly influenced the change in groundwater level. For these reasons, we proposed two hydrogeologic units in the Taipei basin. One is the Songshan aquifer characterized by interbeded local aquifer and aquitard. The other is the Taipei aquifer which combines the lower Songshan formation, Jingmei formation, and Wugu formation. Extensive pumping from the Taipei aquifer has caused serious land subsidence since the rapid expansion of the urban area in 1950s. The cumulative amount of settlement in the Taipei basin is about 2.2 m by 1983. The subsidence appeared to be inelastic with little recovery. The groundwater level has declined approximately 50 m by 1976. The decline was followed by a rapid recovery in the Taipei aquifer starting from late 1970s. In the past two decades, however, small subsidence ranging from 3~5 cm have been induced by the extensive pumping during the construction of Metro system

  18. Hydrogeology of closed basins and deserts of South America, ERTS-1 interpretations

    NASA Technical Reports Server (NTRS)

    Stoertz, G. E.; Carter, W. D.

    1973-01-01

    Images from the Earth Resources Technology Satellite (ERTS-1) contain data useful in studies of hydrogeology, geomorphology, and paleoclimatology. Sixteen Return Beam Vidicon (RBV) images and 15 Multi-Spectral Scanner (MSS) images were studied. These covered deserts and semidesert areas in southwestern Bolivia, northwestern Argentina, northern Chile, and southeastern Peru from July 30 to November 17, 1972. During the first 3 months after launching, high-quality cloud-free imagery was obtained over approximately 90 percent of the region of interior drainage, or an area of 170,000 square miles.

  19. Development of hydrogeological modelling approaches for assessment of consequences of hazardous accidents at nuclear power plants

    SciTech Connect

    Rumynin, V.G.; Mironenko, V.A.; Konosavsky, P.K.; Pereverzeva, S.A.

    1994-07-01

    This paper introduces some modeling approaches for predicting the influence of hazardous accidents at nuclear reactors on groundwater quality. Possible pathways for radioactive releases from nuclear power plants were considered to conceptualize boundary conditions for solving the subsurface radionuclides transport problems. Some approaches to incorporate physical-and-chemical interactions into transport simulators have been developed. The hydrogeological forecasts were based on numerical and semi-analytical scale-dependent models. They have been applied to assess the possible impact of the nuclear power plants designed in Russia on groundwater reservoirs.

  20. MODFLOW-2000, the U.S. Geological Survey modular ground-water model -- Three additions to the Hydrogeologic-Unit Flow (HUF) Package: Alternative storage for the uppermost active cells, Flows in hydrogeologic units, and the Hydraulic-coductivity depth-dependence (KDEP) capability

    USGS Publications Warehouse

    Anderman, Evan R.; Hill, Mary C.

    2003-01-01

    The Hydrogeologic-Unit Flow (HUF) Package is an internal flow package for MODFLOW-2000 that allows the vertical geometry of the system hydrogeology to be defined differently than the definition of model layers. Effective hydraulic properties for the model layers are calculated using the hydraulic properties of the hydrogeologic units. The HUF Package can be used instead of the Block-Centered Flow (BCF) or the Layer Property Flow (LPF) Packages. This report documents three additions to the HUF Package.

  1. Delineating small karst watersheds based on digital elevation model and eco-hydrogeological principles

    NASA Astrophysics Data System (ADS)

    Jie Luo, Guang; Jie Wang, Shi; Bai, Xiao Yong; Liu, Xiu Ming; Cheng, An Yun

    2016-03-01

    Dominated by specific eco-hydrogeological backgrounds, a small watershed delineated by using the traditional method is always inauthentic in karst regions because it cannot accurately reflect the eco-hydrological process of the dual structure of the surface and subsurface. This study proposes a new method for the delineation of small watersheds based on digital elevation models (DEMs) and eco-hydrogeological principles in karst regions. This method is applied to one section of the tributary area (Sancha River) of the Yangtze River in China. By comparing the quantity, shape, superimposition, and characteristics of the internal hydrological process of a small watershed extracted by using the digital elevation model with that extracted by using the proposed method of this study, we conclude that the small karst watersheds extracted by the new method accurately reflect the hydrological process of the river basin. Furthermore, we propose that the minimum unit of the river basin in karst regions should be the watershed, whose exit is the corrosion and corrasion baselevel and a further division of watershed may cause a significant inconsistency with the true eco-hydrological process.

  2. Using hydrochemistry, tracers and isotopes to analyze hydrogeological dynamics and eutrophication processes in coastal lagoons

    NASA Astrophysics Data System (ADS)

    Menció, Anna; Mas-Pla, Josep; Quintana, Xavier D.

    2016-04-01

    Wetlands and coastal lagoons in Mediterranean areas have recently been the focus of an increasing interest due to the degradation of their ecological status in terms of declining biodiversity, alteration of ecological functioning and limitation of the ecosystem services they provide. Accordingly, the Horizon 2020 Programme of the European Union has set, as one of its priorities, to prevent a further degradation of these ecosystems and to recover their ecological functioning. The aim of this project is to analyze the hydrogeological dynamics in the Pletera coastal lagoons (NE, Spain) as a basis to propose guidelines for their sustainable management. Thus, monthly hydrochemical (with major ions, nutrients and tracers) and isotopic (δ18OH2O and δD) campaigns have been conducted, from November 2014 to October 2015, to determine the hydrogeological dynamics of the Pletera lagoons. In addition, in some of the sampling campaigns δ34SSO4, δ18OSO4, δ15NNO3 and δ18ONO3 have also been analyzed to determine the origin of eutrophication problems observed in these lagoons, mainly caused by nitrogen compounds. Project founded by MEC CGL-2014-57215-C4-2R and LIFE 13 NAT/ES/001001

  3. Hydrogeologic controls on groundwater discharge and nitrogen loads in a coastal watershed

    NASA Astrophysics Data System (ADS)

    Russoniello, Christopher J.; Konikow, Leonard F.; Kroeger, Kevin D.; Fernandez, Cristina; Andres, A. Scott; Michael, Holly A.

    2016-07-01

    Submarine groundwater discharge (SGD) is a small portion of the global water budget, but a potentially large contributor to coastal nutrient budgets due to high concentrations relative to stream discharge. A numerical groundwater flow model of the Inland Bays Watershed, Delaware, USA, was developed to identify the primary hydrogeologic factors that affect groundwater discharge rates and transit times to streams and bays. The distribution of groundwater discharge between streams and bays is sensitive to the depth of the water table below land surface. Higher recharge and reduced hydraulic conductivity raised the water table and increased discharge to streams relative to bays compared to the Reference case (in which 66% of recharge is discharged to streams). Increases to either factor decreased transit times for discharge to both streams and bays compared to the Reference case (in which mean transit times are 56.5 and 94.3 years, respectively), though sensitivity to recharge is greater. Groundwater-borne nitrogen loads were calculated from nitrogen concentrations measured in discharging fresh groundwater and modeled SGD rates. These loads combined with long SGD transit times suggest groundwater-borne nitrogen reductions and estuarine water quality improvements will lag decades behind implementation of efforts to manage nutrient sources. This work enhances understanding of the hydrogeologic controls on and uncertainties in absolute and relative rates and transit times of groundwater discharge to streams and bays in coastal watersheds.

  4. Hydrogeology and soil gas at J-Field, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Hughes, W.B.

    1993-01-01

    Disposal of chemical warfare agents, munitions, and industrial chemicals in J-Field, Aberdeen Proving Ground, Maryland, has contaminated soil, groundwater and surface water. Seven exploratory borings and 38 observation wells were drilled to define the hydrogeologic framework at J-Field and to determine the type, extent, and movement of contaminants. The geologic units beneath J-Field consist of Coastal Plain sediments of the Cretaceous Patapsco Formation and Pleistocene Talbot Formation. The Patapsco Formation contains several laterally discontinuous aquifers and confining units. The Pleistocene deposits were divided into 3 hydrogeologic units--a surficial aquifer, a confining unit, and a confined aquifer. Water in the surficial aquifer flows laterally from topographically high areas to discharge areas in marshes and streams, and vertically to the underlying confined aquifer. In offshore areas, water flows from the deeper confined aquifers upward toward discharge areas in the Gunpowder River and Chesapeake Bay. Analyses of soil-gas samples showed high relative-flux values of chlorinated solvents, phthalates, and hydrocarbons at the toxic-materials disposal area, white-phosphorus disposal area, and riot-control-agent disposal area. The highest flux values were located downgradient of the toxic materials and white phosphorus disposal areas, indicating that groundwater contaminants are moving from source areas beneath the disposal pits toward discharge points in the marshes and estuaries. Elevated relative-flux values were measured upgradient and downgradient of the riot-control agent disposal area, and possibly result from soil and (or) groundwater contamination.

  5. Hydrogeologic characterization of the cretaceous-tertiary Coastal Plain sequence at the Savannah River Site

    SciTech Connect

    Aadland, R.K.

    1990-01-01

    Several hydrostratigraphic classification schemes have been devised to describe the hydrogeology at the Savannah River Site SRS. Central to these schemes is the one-to-one fixed relationship between the hydrostratigraphic units and the lithostratigraphic units currently favored for the Site. This fixed relationship has proven difficult to apply in studies of widely separated locations at the Site due to the various facies observed in the updip Coastal Plain sequence. A detailed analysis and synthesis of the geophysical, core, and hydrologic data available from more than 164 deep wells from 23 cluster locations both on the Site and in the surrounding region was conducted to provide the basis for a hydrostratigraphic classification scheme which could be applied to the entire SRS region. As a result, an interim hydrostratigraphic classification was developed that defines the regional hydrogeologic characteristics of the aquifers underlying the Site (Aadland et al., 1990). The hydrostratigraphic code accounts for and accommodates the rapid lateral variation in lithofacies observed in the region, and eliminates all formal'' connection between the hydrostratigraphic nomenclature and the lithostratigraphic nomenclature. The code is robust and can be made as detailed as is needed to characterize the aquifer units and aquifer zones described in Site-specific studies. 15 refs., 2 figs.

  6. Relationship between the environmental and hydrogeological elements characterizing groundwater-dependent ecosystems in central Poland

    NASA Astrophysics Data System (ADS)

    Krogulec, Ewa; Zabłocki, Sebastian

    2015-11-01

    Results are presented for a quantitative and qualitative analysis of the relationship between hydrogeological and environmental elements characterizing the areas of groundwater-dependent ecosytems (GDEs) located in the Kampinos National Park in central Poland. Statistical analysis was used to assess the seasonal and long-term variability of groundwater conditions. A geographic information system (GIS)-based model enabled the visualization of the test results. Objectification of spatial relationships between hydrogeological and environmental elements was carried out using factor analysis. The statistical analysis of groundwater levels in the period 1999-2013 confirmed the sequence of wet and dry years. The calculation enabled the determination of the range of groundwater-level changes, but no specific trends were observed with respect to these changes. Moreover, the widespread belief that the lowering of the water table in presented GDEs is due to anthropogenic pressure and climate change was not confirmed. The factor analysis showed that GDE areas are characterized by a considerable homogeneity of abiotic elements and locally occurring heterogeneous regions, mainly related to anthropogenic pressure. Dependency between the type of plant community and depth to the water table in the typical GDEs was not defined by the delimiting factors.

  7. Hydrogeological Conditions of a Crystalline Aquifer: Simulation of Optimal Abstraction Rates under Scenarios of Reduced Recharge

    PubMed Central

    Fynn, Obed Fiifi; Chegbeleh, Larry Pax; Nude, Prosper M.; Asiedu, Daniel K.

    2013-01-01

    A steady state numerical groundwater flow model has been calibrated to characterize the spatial distribution of a key hydraulic parameter in a crystalline aquifer in southwestern Ghana. This was to provide an initial basis for characterizing the hydrogeology of the terrain with a view to assisting in the large scale development of groundwater resources for various uses. The results suggest that the structural entities that control groundwater occurrence in the area are quite heterogeneous in their nature and orientation, ascribing hydraulic conductivity values in the range of 4.5 m/d to over 70 m/d to the simulated aquifer. Aquifer heterogeneities, coupled possibly with topographical trends, have led to the development of five prominent groundwater flowpaths in the area. Estimated groundwater recharge at calibration ranges between 0.25% and 9.13% of the total annual rainfall and appears to hold significant promise for large-scale groundwater development to support irrigation schemes. However, the model suggests that with reduced recharge by up to 30% of the current rates, the system can only sustain increased groundwater abstraction by up to 150% of the current abstraction rates. Prudent management of the resource will require a much more detailed hydrogeological study that identifies all the aquifers in the basin for the assessment of sustainable basin yield. PMID:24453882

  8. Environmental and hydrogeological problems in karstic terrains crossed by tunnels: a case study

    NASA Astrophysics Data System (ADS)

    Gisbert, J.; Vallejos, A.; González, A.; Pulido-Bosch, A.

    2009-07-01

    The construction of one of the high-speed railway tunnels between Malaga and Córdoba (South Spain) beneath the Abdalajís mountains occasioned a series of hydrogeological problems with geotechnical and environmental impacts. The double tunnel, 7,300 m in length, runs south to north across several lines of small, calcareous mountains that have a highly complex structure. Beneath the Jurassic limestones lie Triassic clays and evaporites. Overlying the limestones is an essentially marly and limestone-marl Cretaceous series, which culminates with Miocene marls containing some organic matter. These mountains have generated springs that are used for urban water supply and irrigation, as well as drinking fountains in the surrounding villages. The initial water level in the aquifer series varied from 400 to 650 m above sea level. After drilling approximately 2,900 m, and intercepting a fracture zone within the carbonate rocks, a sudden water eruption occurred that reached a peak flow of 800 L/s. After a short while, spring discharges dried up, leading to a public protest. In this paper, we describe the geological and hydrogeological settings, the development of the aquifer as the drilling operation proceeded, the measures adopted and the responses subsequent to completion of the tunnel, including the effect of rainfall on the recovery of water levels. Lastly, a generalized estimate is made of how the system functions, and a forecast is made for recovery of its equilibrium.

  9. The geology and hydrogeology of Bear Creek Valley Waste Disposal Areas A and B

    SciTech Connect

    1984-05-01

    A study was undertaken of the Oil Landfarm and Burial Grounds A and B, which are three disposal sites within the Bear Creek Waste Disposal Area. The area is located west of the Y-12 plant, about 3 miles southwest of Oak Ridge, Tennessee. The purpose of this interim report is to present data collected at the Burial Grounds A and B, and to provide the results of hydrogeologic analyses. The Oil Landfarm geologic and hydrogeologic data and analyses have been submitted in a January 1984 interim report. The overall objectives of the study were to characterize the types and extent of wastes present and to define the occurrence and movement of ground water beneath the sites. The intention of this work is to provide criteria on which a design for containing the waste can be developed. Specific activities performed by Bechtel included: drilling for subsurface geologic data; installing monitoring wells; measuring permeability and ground-water flow directions; and collecting soil, sediment, surface- and ground-water, and liquid-waste samples for chemical analysis. Results are presented on the geology and ground waters.

  10. Actualization of the Hydrogeological Model of the Ojos Negros VALLEY\\'{ }s Aquifer

    NASA Astrophysics Data System (ADS)

    Campos-Gaytan, J.; Vazquez Gonzalez, R.

    2002-12-01

    A regional groundwater flow model is actualized in order to study the water table behavior in the zone of the Ojos Negros valley, which is located in the state of Baja California, Mexico. In the actualization process of the Ojos Negros valley's hydrogeological model, is used all the information proportionate for the National Commission of Water, as well as that information obtained from academic and research works achieved in the study zone, about the hydrogeological conditions that present the Ojos Negros and Real del Castillo aquifers. In addition, a groundwater flow simulator is modified and improved from the numerical point of view. The actualized simulator solves numerically the Boussinesq equation, using centrals finite-differences techniques, the "fully implicit" approximation for the temporary variation, and the iterative method of successive over relaxation. Also it counts with the structure to considering the temporary variation of the different variables and geohydrologics conditions that has influence upon the groundwater system, and with programming subroutines in MATLAB (2000) for the graphic display of results. The simulation results are appropriate for determining the phreatic surface and the flow directions in different time intervals. The phreatic surface information can be used for studying the behavior (temporary evolution) of water table in the aquifers.

  11. Tritium/3He measurements in young groundwater: Progress in applications to complex hydrogeological systems

    USGS Publications Warehouse

    Schlosser, P.; Shapiro, S.D.; Stute, M.; Plummer, N.

    2000-01-01

    Tritium/3He dating has been applied to many problems in groundwater hydrology including, for example, determination of circulation patterns, mean residence times, recharge rates, or bank infiltration. Here, we discuss recent progress in the application of the tritium/3He dating method to sites with complex hydrogeological settings. Specifically, we report on tritium/3He dating at sites with (a) river infiltration into the basaltic fractured rock aquifer of the Eastern Snake River Plain, and (b) river infiltration through sinkholes into the karstic limestone Upper Floridian aquifer near Valdosta, Georgia.Tritium/3He dating has been applied to many problems in groundwater hydrology including, for example, determination of circulation patterns, mean residence times, recharge rates, or bank infiltration. Here, we discuss recent progress in the application of the tritium/3He dating method to sites with complex hydrogeological settings. Specifically, we report on tritium/3He dating at sites with (a) river infiltration into the basaltic fractured rock aquifer of the Eastern Snake River Plain, and (b) river infiltration through sinkholes into the karstic limestone Upper Floridian aquifer near Valdosta, Georgia.

  12. The hydrogeology of the military inundation at the 1914-1918 Yser front (Belgium)

    NASA Astrophysics Data System (ADS)

    Vandenbohede, Alexander

    2016-03-01

    Protection against flooding by the sea, drainage of rainwater and integrated management of groundwater and surface-water resources are key issues in low-lying coastal areas. However, under exceptional circumstances, knowledge to keep coastal areas dry and habitable can be used otherwise. Inundation for military purposes is such an example. The hydrogeology of the inundation at the Yser River, Belgium, during the Great War is studied. The inundation started in October 1914 to stop the German advance and lasted until 1918. A water balance and groundwater model are combined to derive the water balance before and during the inundation and to study the impact on the groundwater system. It is concluded that a number of hydrogeological factors contributed to the effectiveness of the inundation. Most importantly, the low-permeability subsoil facilitated loss of inundation water mainly by evaporation. Further, the normal water management strategy of the area (aimed at evacuating excess water towards the sea) was reversed to keep water between the opposing armies. However, the duration of the inundation meant a reorganization of the drainage of areas not inundated; truly an exercise in integrated water management.

  13. Waterborne toxoplasmosis investigated and analysed under hydrogeological assessment: new data and perspectives for further research

    PubMed Central

    Vieira, Flávia Pereira; Alves, Maria da Glória; Martins, Livia Mattos; Rangel, Alba Lucínia Peixoto; Dubey, Jitender Prakash; Hill, Dolores; Bahia-Oliveira/, Lilian Maria Garcia

    2015-01-01

    We present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondii oocyst testing and for collecting blood from free-range chickens and humans for anti-T. gondii serologic testing. Serologic testing of human specimens was done using conventional commercial tests and a sporozoite-specific embryogenesis-related protein (TgERP), which is able to differentiate whether infection resulted from tissue cysts or oocysts. Water specimens were negative for the presence of viable T. gondii oocysts. However, seroprevalence in free-range chickens was significantly associated with vulnerability of groundwater to surface contamination (p < 0.0001; odds ratio: 4.73, 95% confidence interval: 2.18-10.2). Surprisingly, a high prevalence of antibodies against TgERP was detected in human specimens, suggesting the possibility of a continuous contamination of drinking water with T. gondii oocysts in this endemic setting. These findings and the new proposed approach to investigate and analyse endemic toxoplasmosis in light of groundwater vulnerability information associated with prevalence in humans estimated by oocyst antigens recognition have implications for the potential role of hydrogeological assessment in researching waterborne toxoplasmosis at a global scale. PMID:26560984

  14. Hydrogeological impacts of a railway tunnel in fractured Precambrian gneiss rocks (south-eastern Norway)

    NASA Astrophysics Data System (ADS)

    Kværner, Jens; Snilsberg, Petter

    2013-11-01

    Groundwater monitoring along the Romeriksporten tunnel, south-eastern Norway, provided an opportunity for studying the impacts of tunnelling on groundwater in fractured Precambrian gneiss rocks, and examining relations between bedrock hydrology, tectonic weakness zones and catchments. Tunnel leakage resulted in groundwater drawdown up to 35 m in weakness zones, converted groundwater discharge zones into recharge zones, and affected groundwater chemistry. The magnitude of drawdown and fluctuations in groundwater level differed between weakness zones, and varied with distance from the tunnel route, tunnel leakage, and recharge from catchments. Clear differences in groundwater level and fluctuation patterns indicated restricted groundwater flow between weakness zones. The groundwater drawdowns demonstrated coherent water-bearing networks to 180-m depth in faults and fracture zones. Similar groundwater levels with highly correlated fluctuations demonstrated hydraulic connectivity within fracture zones. Different groundwater drawdown and leakage in weakness zones with different appearance and influence of tectonic events demonstrated the importance of the geological history for bedrock hydrogeology. Water injection into the bedrock counteracted groundwater drawdowns. Even moderate leakage to underground constructions may lead to large groundwater drawdown in areas with small groundwater recharge. Hydrogeological interpretation of tectonic weakness zones should occur in the context of geological history and local catchment hydrology.

  15. Hydrogeologic framework of Antelope Valley and Bedell Flat, Washoe County, west-central Nevada

    USGS Publications Warehouse

    Berger, D.L.; Ponce, D.A.; Ross, W.C.

    2001-01-01

    Description of the hydrogeologic framework of Antelope Valley and Bedell Flat in west-central Nevada adds to the general knowledge of regional ground-water flow north of the Reno-Sparks metropolitan area. The hydrogeologic framework is defined by the rocks and deposits that transmit ground water or impede its movement and by the combined thickness of Cenozoic deposits. When data are lacking about the subsurface geology of an area, geophysical methods can be used to provide additional information. In this study, gravimetric and seismic-refraction methods were used to infer the form of structural features and to estimate the thickness of Cenozoic deposits in each of the two valleys. In Antelope Valley, the thickness of these deposits probably does not exceed about 300 feet, suggesting that ground-water storage in the basin-fill aquifer is limited. Beneath Bedell Flat is an elongated, northeast-trending structural depression in the pre-Cenozoic basement; the maximum thickness of Cenozoic deposits is about 2,500 feet beneath the south-central part of the valley. Shallow ground water in the northwest corner of Bedell Flat may be a result of decreasing depth to the pre-Cenozoic basement.

  16. Hydrogeology of a low-level radioactive-waste disposal site near Sheffield, Illinois

    USGS Publications Warehouse

    Foster, J.B.; Erickson, J.R.; Healy, R.W.

    1984-01-01

    The Sheffield low-level radioactive-waste facility is located on 20 acres of rolling terrain 3 miles southwest of Sheffield, Illinois. The shallow hydrogeologic system is composed of glacial sediments. Pennsylvania shale and mudstone bedrock isolate the regional aquifers below from the hydrogeologic system in the overlying glacial deposits. Pebbly sand underlies 67 percent of the site. Two ground-water flow paths were identified. The primary path conveys ground water from the site to the east through the pebbly-sand unit; a secondary path conveys ground water to the south and east through less permeable material. The pebbly-sand unit provides an underdrain that eliminates the risk of water rising into the trenches. Digital computer model results indicate that the pebbly-sand unit controls ground-water movement. Tritium found migrating in ground water in the southeast corner of the site travels approximately 25 feet per year. A group of water samples from wells which contained the highest tritium concentrations had specific conductivities, alkalinities, hardness, and chloride, sulfate, calcium, and magnesium contents higher than normal for local shallow ground water. (USGS)

  17. Waterborne toxoplasmosis investigated and analysed under hydrogeological assessment: new data and perspectives for further research.

    PubMed

    Vieira, Flávia Pereira; Alves, Maria da Glória; Martins, Livia Mattos; Rangel, Alba Lucínia Peixoto; Dubey, Jitender Prakash; Hill, Dolores; Bahia-Oliveira, Lilian Maria Garcia

    2015-11-01

    We present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondii oocyst testing and for collecting blood from free-range chickens and humans for anti-T. gondii serologic testing. Serologic testing of human specimens was done using conventional commercial tests and a sporozoite-specific embryogenesis-related protein (TgERP), which is able to differentiate whether infection resulted from tissue cysts or oocysts. Water specimens were negative for the presence of viable T. gondii oocysts. However, seroprevalence in free-range chickens was significantly associated with vulnerability of groundwater to surface contamination (p < 0.0001; odds ratio: 4.73, 95% confidence interval: 2.18-10.2). Surprisingly, a high prevalence of antibodies against TgERP was detected in human specimens, suggesting the possibility of a continuous contamination of drinking water with T. gondii oocysts in this endemic setting. These findings and the new proposed approach to investigate and analyse endemic toxoplasmosis in light of groundwater vulnerability information associated with prevalence in humans estimated by oocyst antigens recognition have implications for the potential role of hydrogeological assessment in researching waterborne toxoplasmosis at a global scale. PMID:26560984

  18. Hydrogeologic framework, groundwater movement, and water budget of the Kitsap Peninsula, west-central Washington

    USGS Publications Warehouse

    Welch, Wendy B.; Frans, Lonna M.; Olsen, Theresa D.

    2014-01-01

    This report presents information used to characterize the groundwater-flow system on the Kitsap Peninsula, and includes descriptions of the geology and hydrogeologic framework, groundwater recharge and discharge, groundwater levels and flow directions, seasonal groundwater-level fluctuations, interactions between aquifers and the surface‑water system, and a water budget. The Kitsap Peninsula is in the Puget Sound lowland of west-central Washington, is bounded by Puget Sound on the east and by Hood Canal on the west, and covers an area of about 575 square miles. The peninsula encompasses all of Kitsap County, the part of Mason County north of Hood Canal, and part of Pierce County west of Puget Sound. The peninsula is surrounded by saltwater and the hydrologic setting is similar to that of an island. The study area is underlain by a thick sequence of unconsolidated glacial and interglacial deposits that overlie sedimentary and volcanic bedrock units that crop out in the central part of the study area. Geologic units were grouped into 12 hydrogeologic units consisting of aquifers, confining units, and an underlying bedrock unit. A surficial hydrogeologic unit map was developed and used with well information from 2,116 drillers’ logs to construct 6 hydrogeologic sections and unit extent and thickness maps. Unconsolidated aquifers typically consist of moderately to well-sorted alluvial and glacial outwash deposits of sand, gravel, and cobbles, with minor lenses of silt and clay. These units often are discontinuous or isolated bodies and are of highly variable thickness. Unconfined conditions occur in areas where aquifer units are at land surface; however, much of the study area is mantled by glacial till, and confined aquifer conditions are common. Groundwater in the unconsolidated aquifers generally flows radially off the peninsula in the direction of Puget Sound and Hood Canal. These generalized flow patterns likely are complicated by the presence of low

  19. Arsenic in groundwater of Licking County, Ohio, 2012—Occurrence and relation to hydrogeology

    USGS Publications Warehouse

    Thomas, Mary Ann

    2016-01-01

    Arsenic concentrations were measured in samples from 168 domestic wells in Licking County, Ohio, to document arsenic concentrations in a wide variety of wells and to identify hydrogeologic factors associated with arsenic concentrations in groundwater. Elevated concentrations of arsenic (greater than 10.0 micrograms per liter [µg/L]) were detected in 12 percent of the wells (about 1 in 8). The maximum arsenic concentration of about 44 µg/L was detected in two wells in the same township.A subset of 102 wells was also sampled for iron, sulfate, manganese, and nitrate, which were used to estimate redox conditions of the groundwater. Elevated arsenic concentrations were detected only in strongly reducing groundwater. Almost 20 percent of the samples with iron concentrations high enough to produce iron staining (greater than 300 µg/L) also had elevated concentrations of arsenic.In groundwater, arsenic primarily occurs as two inorganic species—arsenite and arsenate. Arsenic speciation was determined for a subset of nine samples, and arsenite was the predominant species. Of the two species, arsenite is more difficult to remove from water, and is generally considered to be more toxic to humans.Aquifer and well-construction characteristics were compiled from 99 well logs. Elevated concentrations of arsenic (and iron) were detected in glacial and bedrock aquifers but were more prevalent in glacial aquifers. The reason may be that the glacial deposits typically contain more organic carbon than the Paleozoic bedrock. Organic carbon plays a role in the redox reactions that cause arsenic (and iron) to be released from the aquifer matrix. Arsenic concentrations were not significantly different for different types of bedrock (sandstone, shale, sandstone/shale, or other). However, arsenic concentrations in bedrock wells were correlated with two well-construction characteristics; higher arsenic concentrations in bedrock wells were associated with (1) shorter open intervals and

  20. Extraterrestrial hydrogeology

    NASA Astrophysics Data System (ADS)

    Baker, Victor R.; Dohm, James M.; Fairén, Alberto G.; Ferré, Ty P. A.; Ferris, Justin C.; Miyamoto, Hideaki; Schulze-Makuch, Dirk

    2005-03-01

    Subsurface water processes are common for planetary bodies in the solar system and are highly probable for exoplanets (planets outside the solar system). For many solar system objects, the subsurface water exists as ice. For Earth and Mars, subsurface saturated zones have occurred throughout their planetary histories. Earth is mostly clement with the recharge of most groundwater reservoirs from ample precipitation during transient ice- and hot-house conditions, as recorded through the geologic and fossilized records. On the other hand, Mars is mostly in an ice-house stage, which is interrupted by endogenic-driven activity. This activity catastrophically drives short-lived hydrological cycling and associated climatic perturbations. Regional aquifers in the Martian highlands that developed during past, more Earth-like conditions delivered water to the northern plains. Water was also cycled to the South Polar Region during changes in climate induced by endogenic activity and/or by changes in Mars' orbital parameters. Venus very likely had a warm hydrosphere for hundreds of millions of years, before the development of its current extremely hot atmosphere and surface. Subsequently, Venus lost its hydrosphere as solar luminosity increased and a run-away moist greenhouse took effect. Subsurface oceans of water or ammonia-water composition, induced by tidal forces and radiogenic heating, probably occur on the larger satellites Europa, Ganymede, Callisto, Titan, and Triton. Tidal forces operating between some of the small bodies of the outer solar system could also promote the fusion of ice and the stability of inner liquid-water oceans. Les processus de subsurface impliquant l'eau sont communs pour les corps planétaires du système solaire et sont très probables sur les exoplanètes (planètes en dehors du système solaire). Pour plusieurs objets du systèmes solaire, l'eau de subsurface est présente sous forme de glace. Pour la Terre et Mars, les zones saturées de subsurface apparaissent à travers toute leur histoire planétaire. La Terre est particulièrement clémente avec la recharge des réservoirs, avec de amples précipitations, des conditions glaciaires et de fortes chaleurs, comme l'atteste les enregistrements géologiques et paléontologiques. D'un autre côté, Mars se trouve dans une phase essentiellement glaciaire, qui est interrompue par des activités contraintes par les phénomènes endogéniques. Cette activité conduit de manière catastrophique à des cycles hydrologiques et à des perturbations climatiques brutaux. Les aquifères régionaux dans les haute terres martiennes qui se sont formés dans des conditions similaires aux conditions terrestres, alimentent les plaines du Nord. L'eau a également été déplacée vers le Pôle Sud martien durant des changements marqués par une forte activité endogénique et une modification des paramètres de l'orbite de Mars. Venus possèdait vrais emblablement une hydrosphère chaude durant des millions d'année, avant le développement de son atmosphère et sa surface particulièrement chaude. Par après Venus a perdit son hydrosphère alors que la luminosité solaire augmentait et qu'une humidité liée à un effet de serre s'installait. Les océans de subsurface d'eau ou d'eau ammoniacale, induits par les forces de marée et le chauffage radiogénique, apparaissent probablement sur les satellites les plus importants (Europa, Ganymede, Callisto, Titan, Triton). Les forces de marée entre les petits corps externes du système solaire peuvent également occasionner la fusion de glace et la stabilité des océans internes d'eau liquide. Los procesos hídricos subsuperficiales son comunes en cuerpos planetarios del sistema solar y son altamente probables para exoplanetas (planetas fuera del sistema solar). Para muchos cuerpos del sistema solar, el agua subsuperficial existe como hielo. Para la Tierra y Marte han ocurrido zonas saturadas subsuperficiales a través de sus historias planetarias. La Tierra es principalmente generosa con la recarga de la mayoría de rese

  1. Extraterrestrial hydrogeology

    NASA Astrophysics Data System (ADS)

    Baker, Victor R.; Dohm, James M.; Fairén, Alberto G.; Ferré, Ty P. A.; Ferris, Justin C.; Miyamoto, Hideaki; Schulze-Makuch, Dirk

    2005-03-01

    Subsurface water processes are common for planetary bodies in the solar system and are highly probable for exoplanets (planets outside the solar system). For many solar system objects, the subsurface water exists as ice. For Earth and Mars, subsurface saturated zones have occurred throughout their planetary histories. Earth is mostly clement with the recharge of most groundwater reservoirs from ample precipitation during transient ice- and hot-house conditions, as recorded through the geologic and fossilized records. On the other hand, Mars is mostly in an ice-house stage, which is interrupted by endogenic-driven activity. This activity catastrophically drives short-lived hydrological cycling and associated climatic perturbations. Regional aquifers in the Martian highlands that developed during past, more Earth-like conditions delivered water to the northern plains. Water was also cycled to the South Polar Region during changes in climate induced by endogenic activity and/or by changes in Mars' orbital parameters. Venus very likely had a warm hydrosphere for hundreds of millions of years, before the development of its current extremely hot atmosphere and surface. Subsequently, Venus lost its hydrosphere as solar luminosity increased and a run-away moist greenhouse took effect. Subsurface oceans of water or ammonia-water composition, induced by tidal forces and radiogenic heating, probably occur on the larger satellites Europa, Ganymede, Callisto, Titan, and Triton. Tidal forces operating between some of the small bodies of the outer solar system could also promote the fusion of ice and the stability of inner liquid-water oceans. Les processus de subsurface impliquant l'eau sont communs pour les corps planétaires du système solaire et sont très probables sur les exoplanètes (planètes en dehors du système solaire). Pour plusieurs objets du systèmes solaire, l'eau de subsurface est présente sous forme de glace. Pour la Terre et Mars, les zones saturées de subsurface apparaissent à travers toute leur histoire planétaire. La Terre est particulièrement clémente avec la recharge des réservoirs, avec de amples précipitations, des conditions glaciaires et de fortes chaleurs, comme l'atteste les enregistrements géologiques et paléontologiques. D'un autre côté, Mars se trouve dans une phase essentiellement glaciaire, qui est interrompue par des activités contraintes par les phénomènes endogéniques. Cette activité conduit de manière catastrophique à des cycles hydrologiques et à des perturbations climatiques brutaux. Les aquifères régionaux dans les haute terres martiennes qui se sont formés dans des conditions similaires aux conditions terrestres, alimentent les plaines du Nord. L'eau a également été déplacée vers le Pôle Sud martien durant des changements marqués par une forte activité endogénique et une modification des paramètres de l'orbite de Mars. Venus possèdait vrais emblablement une hydrosphère chaude durant des millions d'année, avant le développement de son atmosphère et sa surface particulièrement chaude. Par après Venus a perdit son hydrosphère alors que la luminosité solaire augmentait et qu'une humidité liée à un effet de serre s'installait. Les océans de subsurface d'eau ou d'eau ammoniacale, induits par les forces de marée et le chauffage radiogénique, apparaissent probablement sur les satellites les plus importants (Europa, Ganymede, Callisto, Titan, Triton). Les forces de marée entre les petits corps externes du système solaire peuvent également occasionner la fusion de glace et la stabilité des océans internes d'eau liquide. Los procesos hídricos subsuperficiales son comunes en cuerpos planetarios del sistema solar y son altamente probables para exoplanetas (planetas fuera del sistema solar). Para muchos cuerpos del sistema solar, el agua subsuperficial existe como hielo. Para la Tierra y Marte han ocurrido zonas saturadas subsuperficiales a través de sus historias planetarias. La Tierra es principalmente generosa con la recarga de la mayoría de reservorios de aguas subterráneas a partir de amplia precipitación reconocida en condiciones transitorias calientes y heladas, tal y como aparece en los registros fósiles y geológicos. Por otro lado, Marte se encuentra principalmente en una etapade cámara de hielo la cual es interrumpida por actividad de tipo endogénico. Esta actividad pone en funcionamiento catastróficamente ciclos hidrológicos de vida corta y perturbaciones climáticas asociadas. Acuíferos regionales en las montañas de Marte que se desarrollaron en el pasado en condiciones similares a la Tierra distribuyen agua a las planicies del norte. El agua ha sido transportada hacia el sur de la región polar durante cambios en el clima inducidos por actividad endogénica y/o cambios en los parámetros orbitales de Marte. Venus muy probablemente tuvo una hidrósfera caliente durante cientos de millones de años, antes de que se desarrollara su atmósfera y superficie actual extremadamente caliente. Subsecuentemente, Venus perdió su hidrósfera a medida que la luminosidad solar aumentó y un efecto de invernadero húmedo escapatorio se llevó a cabo. Océanos subsuperficiales de composición agua o amoniaco-agua, inducidos por fuerzas de marea y calentamiento radiogénico, probablemente ocurren en los satélites más grandes como Europa, Ganimeda, Callisto, Titan y Triton. Las fuerzas de marea que operan entre los cuerpos pequeños del sistema solar externo podrían también promover la fusión de hielo y la estabilidad de líquido interno-aguas de los océanos.

  2. User Guide for HUFPrint, A Tabulation and Visualization Utility for the Hydrogeologic-Unit Flow (HUF) Package of MODFLOW

    USGS Publications Warehouse

    Banta, Edward R.; Provost, Alden M.

    2008-01-01

    This report documents HUFPrint, a computer program that extracts and displays information about model structure and hydraulic properties from the input data for a model built using the Hydrogeologic-Unit Flow (HUF) Package of the U.S. Geological Survey's MODFLOW program for modeling ground-water flow. HUFPrint reads the HUF Package and other MODFLOW input files, processes the data by hydrogeologic unit and by model layer, and generates text and graphics files useful for visualizing the data or for further processing. For hydrogeologic units, HUFPrint outputs such hydraulic properties as horizontal hydraulic conductivity along rows, horizontal hydraulic conductivity along columns, horizontal anisotropy, vertical hydraulic conductivity or anisotropy, specific storage, specific yield, and hydraulic-conductivity depth-dependence coefficient. For model layers, HUFPrint outputs such effective hydraulic properties as horizontal hydraulic conductivity along rows, horizontal hydraulic conductivity along columns, horizontal anisotropy, specific storage, primary direction of anisotropy, and vertical conductance. Text files tabulating hydraulic properties by hydrogeologic unit, by model layer, or in a specified vertical section may be generated. Graphics showing two-dimensional cross sections and one-dimensional vertical sections at specified locations also may be generated. HUFPrint reads input files designed for MODFLOW-2000 or MODFLOW-2005.

  3. Calendar year 1995 groundwater quality report for the Bear Creek Hydrogeologic Regime, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1996-02-01

    This annual groundwater quality report (GWQR) contains groundwater and surface water quality data obtained during the 1995 calendar year (CY) at several hazardous and nonhazardous waste management facilities associated with the Y-12 Plant located on the DOE Oak Ridge Reservation (ORR) southeast of Oak Ridge, Tennessee. The sites addressed by this document are located in Bear Creek Valley (BCV) west of the Y-12 Plant complex within the Bear Creek Hydrogeologic Regime. The Bear Creek Regime is one of three hydrogeologic regimes defined for the purposes of groundwater and surface water quality monitoring at the Y-12 Plant. The purpose of the Groundwater Protection Program (GWPP) is to characterize the hydrogeology and to monitor groundwater quality at the Y-12 Plant and surrounding area to provide for protection of groundwater resources consistent with federal, state, and local requirements. Part 1 (this report) consists primarily of data appendices and serves as a reference for the groundwater quality data obtained each CY under the lead of the Y-12 Plant GWPP. Part 2 of the report, to be issued mid-year, will contain an evaluation of the data with respect to regime-wide groundwater quality, present the findings and status of ongoing hydrogeologic studies, describe changes in monitoring priorities, and present planned modifications to the groundwater sampling and analysis program for the following CY.

  4. Geologic and hydrogeologic information for a geodatabase for the Brazos River Alluvium Aquifer, Bosque County to Fort Bend County, Texas

    USGS Publications Warehouse

    Shah, Sachin D.; Houston, Natalie A.

    2007-01-01

    During July-October 2006, the U.S. Geological Survey (USGS), in cooperation with the Texas Water Development Board (TWDB), developed geologic and hydrogeologic information for a geodatabase for use in development of a Groundwater Availability Model (GAM) of the Brazos River alluvium aquifer along the Brazos River from Bosque County to Fort Bend County, Texas. The report provides geologic and hydrogeologic information for a study area that encompasses the Brazos River alluvium aquifer, a 1/2-mile-wide lateral buffer surrounding the aquifer, and the rocks immediately underlying the aquifer. The geodatabase involves use of a thematic approach to create layers of feature data using a geographic information system. Feature classes represent the various types of data that are keyed to spatial location and related to one another within the geodatabase. The 1/2-mile-wide buffer surrounding the aquifer was applied to include data from wells constructed primarily in alluvium but outside the boundary of the Brazos River alluvium aquifer. A 1/2- by 1/2-mile grid was generated on the study area to facilitate uniform distribution of data for eventual input into the GAM. Data were compiled primarily from drillers and borehole geophysical logs from government agencies and universities, hydrogeologic sections and maps from published reports, and agency files. The geodatabase contains 450 points with geologic data and 280 points with hydrogeologic data.

  5. Selected hydrogeologic data for the Inyan Kara, Minnekahta, Minnelusa, Madison, and Deadwood aquifers in the Black Hills area, South Dakota

    USGS Publications Warehouse

    Galloway, J.M.

    1999-01-01

    This report presents selected hydrogeologic data on wells and springs in the Inyan Kara, Minnekahta, Minnelusa, Madison, and Deadwood aquifers in the Black Hills area of western South Dakota. The data were used to create potentiometric maps for these five aquifers.

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

    USGS Publications Warehouse

    Gendaszek, Andrew S.

    2011-01-01

    The Chehalis River has the largest drainage basin of any river entirely contained within the State of Washington with a watershed of approximately 2,700 mi2 and has correspondingly diverse geology and land use. Demands for water resources have prompted the local citizens and governments of the Chehalis River basin to coordinate with Federal, State and Tribal agencies through the Chehalis Basin Partnership to develop a long-term watershed management plan. The recognition of the interdependence of groundwater and surface-water resources of the Chehalis River basin became the impetus for this study, the purpose of which is to describe the hydrogeologic framework and groundwater/surface-water interactions of the Chehalis River basin. Surficial geologic maps and 372 drillers' lithostratigraphic logs were used to generalize the basin-wide hydrogeologic framework. Five hydrogeologic units that include aquifers within unconsolidated glacial and alluvial sediments separated by discontinuous confining units were identified. These five units are bounded by a low permeability unit comprised of Tertiary bedrock. A water table map, and generalized groundwater-flow directions in the surficial aquifers, were delineated from water levels measured in wells between July and September 2009. Groundwater generally follows landsurface-topography from the uplands to the alluvial valley of the Chehalis River. Groundwater gradients are highest in tributary valleys such as the Newaukum River valley (approximately 23 cubic feet per mile), relatively flat in the central Chehalis River valley (approximately 6 cubic feet per mile), and become tidally influenced near the outlet of the Chehalis River to Grays Harbor. The dynamic interaction between groundwater and surface-water was observed through the synoptic streamflow measurements, termed a seepage run, made during August 2010, and monitoring of water levels in wells during the 2010 Water Year. The seepage run revealed an overall gain of 56

  7. An Attempt of Hydrogeological Classification of Fault Zones in Karst Areas

    NASA Astrophysics Data System (ADS)

    Bauer, Helene; Decker, Kurt

    2014-05-01

    Around 60% of Vienna`s drinking water originates in the Hochschwab plateau (Eastern Alps, Austria). The hydrogeology (groundwater storage and flow) of the Hochschwab is essentially governed by karstified, large-scale faults. Previous work has shown that faults that formed during the Oligocene/L. Miocene lateral extrusion of the Eastern Alps act as groundwater pathways draining the karst massif preferably in E-W-direction. However, further analysis of flow processes in karstified aquifers requires hydrogeological relevant data from natural fault zones. We investigated E- to ENE- striking strike-slip faults in limestones and dolomites of the Wetterstein Fm. in terms of potential permeability properties that result from structural composition and fault rock content. Using the standard fault core-damage zone model, we analyzed fault rock characteristics and volumes at the fault cores and connective fracture networks surrounding faults in the damage zones. Special attention has been drawn to fracture densities and the spatial extent of fracture networks. Small-scale fractures are generally assumed to carry most of the effective porosity and have a great influence on the permeability of a fault zone. Therefore, we established a classification scheme and measuring method that provides semi-quantitative estimates of the density and abundance of small-scale fractures by using scanning line techniques to quantify the total joint surface in a volume of rock (m² joint surfaces per m³ rock). This easily applicable method allows to generate fracture density data for the entire damage zones (over tens of meters) and thus to enhance the understanding of permeability properties of damage zones. The field based data is supported by effective porosity and permeability measurements of fractured wall rock and fault rock samples. Different fault rock categories turned out to have complex poro/perm properties due to differences in grain sizes, matrix content, cementation and fracturing

  8. The hydrological and the hydrogeological framework of the Lottenbachtal, Bochum, Germany

    NASA Astrophysics Data System (ADS)

    Alhamed, Mohammad

    2014-11-01

    This study was performed to investigate the hydrological and the hydrogeological framework of the Lottenbachtal, Germany. Long-term climatic data were statistically analyzed, water and soil samples were collected and analyzed, stream flow discharge was measured and separated, the hydrological balance of this catchment was calculated and a hydrological and hydrogeological conceptual model was constructed. The study area is characterized mainly by the precipitation value ranged between 0.1 and 5 mm/day. The actual evapotranspiration constitutes 31.90 % of the total precipitation, the direct surface runoff constitutes 61.04 %, the soil storage constitutes 3 % and the groundwater recharge of the Lottenbachtal constitutes only 4 % of the total precipitation. The Lottenbachtal has largely affected the diversity of the land use, which includes forests, arable areas, abandoned coal mines and settlement areas. The soil of the forested area is represented by relatively high acidic conditions and relatively high sulfate concentrations, while the soil of the arable areas is represented by near-neutral conditions associated with relatively high concentrations of nutrients and other chemical elements (calcium, magnesium, sodium, potassium, chloride, sulfate, nitrate). The settlement areas are characterized by huge blocks of concrete and backfills, which are rich in calcium and magnesium carbonates. The effects of this diversity in the land use on groundwater and surface water quality resulting by leaching the chemical elements from the soil covers and the other materials. These effects are represented by the following complex water types of Ca-Na-Mg-Cl-SO4-HCO3, Ca-Mg-HCO3-SO4, Ca-Na-Mg-Cl-SO4, Ca-Na-Mg-Cl-SO4 and Ca-HCO3, which represent the diversity of the flow paths of the water as well as to mixing processes. The diversity of the land use also affected the physical hydrological-hydrogeological characteristics of the study area by increasing the direct surface runoff and

  9. Estimation of regional hydrogeological properties for use in a hydrologic model of the Chesapeake Bay watershed

    NASA Astrophysics Data System (ADS)

    Seck, A.; Welty, C.

    2012-12-01

    Characterization of subsurface hydrogeologic properties in three dimensions and at large scales for use in groundwater flow models can remain a challenge owing to the lack of regional data sets and scatter in coverage, type, and format of existing small-scale data sets. This is the case for the Chesapeake Bay watershed, where numerous studies have been carried out to quantify groundwater processes at small scales but limited information is available on subsurface characteristics and groundwater fluxes at regional scales. One goal of this work is to synthesize disparate information on subsurface properties for the Chesapeake Bay watershed for use in a 3D integrated ParFlow model over an area of 400,000 km2 with a horizontal resolution of 1 km and a vertical resolution of 5 m. We combined different types of data at various scales to characterize hydrostratigraphy and hydrogeological properties. The conceptual hydrogeologic model of the study area is composed of two major regions. One region extends from the Valley and Ridge physiographic province south of New York to the Piedmont physiographic province in Maryland and Virginia. This region is generally characterized by fractured rock overlain by a mantle of regolith. Soil thickness and hydraulic conductivity values were obtained from the U.S. General Soil Map (STATSGO2). Saprolite thickness was evaluated using casing depth information from well completion reports from four state agencies. Geostatistical methods were used to generalize point data to the model extent and resolution. A three-dimensional hydraulic conductivity field for fractured bedrock was estimated using a published national map of permeability and depth- varying functions from literature. The Coastal Plain of Maryland, Virginia, Delaware and New Jersey constitutes the second region and is characterized by layered sediments. In this region, the geometry of 20 aquifers and confining units was constructed using interpolation of published contour maps of

  10. Overview of the Hydrogeologic Systems of the Former Homestake Mine, Lead, SD (Invited)

    NASA Astrophysics Data System (ADS)

    Roggenthen, B.

    2013-12-01

    The hydrogeology of the former Homestake Gold Mine is an important consideration, both from a scientific as well as an operational standpoint, because the facility is being converted into an operating underground research laboratory. The long history of mining provided much information about the sources and amounts of the water, as did studies performed during mine closure and subsequent evaluations for the construction of the laboratory. Over 600 km of drifts and shafts were excavated during the 135 year life of the facility, but the water inflow averages only ~44 l/s. All of this water must be either captured at high levels in the facility or pumped from the deeper sumps. Hydrogeologic systems operate on several scales in the Homestake underground. The Precambrian phyllites, schists, quartzites, and amphibolites of the subsurface have nearly no matrix permeability. Water flow is confined to fractures, most of which are quite small, but larger fractures and shear zones have been encountered at depth that produced significant amounts of water. In general, fractures tend to be vertical with few horizontal connections in the areas studied during more recent times. Much of the water inflow in the upper part of the facility originates from surface waters that are introduced into the underground through runoff into an adjacent and overlying open pit. At the 4850 Level, which is the location of the current laboratory (depth of 1.5 km), water chemistry suggests that most of the water is part of a ground water system and impact from surface waters is less. Although deeper portions of the facility are not currently accessible, previous reports indicated that water chemistry in these areas was substantially different from that found at the 4850 Level or from the surface waters. Within the flooded portion of the underground it appears that a circulation system was established involving the mine waters themselves and resulted from geothermal heating in the deeper parts of the

  11. Natural and Artificial (fluorescent) Tracers to Characterise Hydrogeological Functioning and to Protect Karst Aquifers

    NASA Astrophysics Data System (ADS)

    Andreo, B.

    2013-12-01

    Bartolomé Andreo; andreo@uma.es Co-workers: Matías Mudarra, Ana Isabel Marín and Juan Antonio Barberá Centre of Hydrogeology and Department of Geology. University of Malaga. http://cehiuma.uma.es/ The hydrogeological functioning and response of karst aquifers can be determined by the combined use of natural hydrogeochemical tracers, especially Total Organic Carbon (TOC) and intrinsic fluorescence of water, together with artificial (fluorescent) tracers; all them under the same hydrodynamic conditions. Sharp and rapid variations in discharge, temperature, electrical conductivity and water chemistry, particularly of natural tracers of infiltration (TOC, intrinsic fluorescence and NO3-) recorded in karst spring waters suggest the existence of a conduit flow system, with rapid flows and very short transit times from the surface to the springs. This is in agreement with the evidences obtained from breakthrough curves of fluorescent dye tracers. However, each type of tracer provides information about different aspects of the system in response to rainfall: natural tracers show the global response of the entire recharge area, while dye tracers reflect the response to concentrated recharge from specific points on the surface (karst swallow holes). Recent experiences on time lags between maximum concentrations of natural (especially TOC and intrinsic fluorescence) and artificial tracers has demonstrated that the global system response is faster and more sensitive than that produced from infiltration concentrated at a single point on the surface, even in karst sinkholes. Both natural and dye tracers permit to estimate response and transit times of water through the karst, but flow velocities can only be quantified using artificial tracers. These findings are crucial for water resources management and protection, with particular emphasis in the functioning of the aquifer and the different rates of response to input signals. Analysis of the responses obtained by natural

  12. Geology, ground-water flow, and dissolved-solids concentrations in ground water along hydrogeologic sections through Wisconsin aquifers

    USGS Publications Warehouse

    Kammerer, P.A.

    1998-01-01

    A cooperative project between the U.S. Geological Survey (USGS) and the Wisconsin Department of Natural Resources (DNR) was begun with the objectives of describing water quality and its relation to the hydrology of Wisconsin's principal aquifers and summarizing instances of ground-water contamination and quality problems from information available in DNR files. The first objective was met by a hydrologic investigation done by the USGS, and the second, by preparation of a report by the DNR, for their internal use, that describes the State's water resources and known ground-water quality and contamination problems and makes policy recommendations for ground-water management.The USGS investigation was divided into two phases. The first phase consisted of compiling available water-quality and hydrogeologic data and collecting new data to describe general regional water-quality and hydrogeologic relations within and between Wisconsin aquifers. The second phase began concurrently with the later part of the first phase and consisted of an areal description of water quality and flow in the State's shallow aquifer system (Kammerer, 1995). The overall purpose of this investigation was to provide a regional framework that could serve as a basis for intensive local and site specific ground-water investigations by State and local government agencies.This report presents the results of the first phase of the USGS investigation. Regional hydrogeologic and water-quality relations within and between aquifers are shown along 15 hydrogeologic sections that traverse the State. Maps are used to show surficial geology of bedrock and unconsolidated deposits and horizontal direction of ground-water flow. Interpretations on the maps and hydrogeologic sections are based on data from a variety of sources and provide the basis for the areal appraisal of water quality in the State's shallow aquifer system in the second phase of the investigation.

  13. Geologic framework and hydrogeologic characteristics of the Edwards aquifer outcrop (Barton Springs segment), northeastern Hays and southwestern Travis Counties, Texas

    USGS Publications Warehouse

    Small, Ted A.; Hanson, John A.; Hauwert, Nico M.

    1996-01-01

    The hydrogeologic subdivisions within the Barton Springs segment of the Edwards aquifer outcrop in northeastern Hays and southwestern Travis Counties generally are porous and permeable. The most porous and permeable appear to be hydrogeologic subdivision VI, the Kirschberg evaporite member of the Kainer Formation; and hydrogeologic subdivision III, the leached and collapsed members, undivided, of the Person Formation. Hydrogeologic subdivision II, the cyclic and marine members, undivided, of the Person Formation, also is quite porous and permeable in Hays County. The porosity of the rocks in the Edwards aquifer outcrop is related to depositional or diagenetic elements along specific stratigraphic horizons (fabric selective) and to dissolution and structural elements that can occur in any lithostratigraphic horizon (not fabric selective). Permeability depends on the physical properties of the rock such as pore size, shape, distribution, fissuring, dissolution, and interconnection of pores and vugs. The Edwards aquifer rocks that crop out in the Barton Springs segment of the Edwards aquifer generally have the same lithologic characteristics as the Edwards aquifer rocks that crop out in Comal and southwestern Hays Counties. However, in the northeastern part of the segment in Travis County, the rock unit that is apparently equivalent to the basal nodular member of the Kainer Formation is called the Walnut Formation. Because the units appear to be stratigraphically and lithologically equivalent, the basal nodular member is used instead of the Walnut Formation for this report. Essentially all of hydrogeologic subdivision II, which is about 70 feet thick in Hays County, is missing in Travis County. In the Barton Springs segment of the Edwards aquifer, the aquifer probably is most vulnerable to surface contamination in the rapidly urbanizing areas on the Edwards aquifer outcrop. Contamination can result from spills or leakage of hazardous materials; or runoff on the

  14. Digital Elevations and Extents of Regional Hydrogeologic Units in the Northern Atlantic Coastal Plain Aquifer System From Long Island, New York, to North Carolina

    USGS Publications Warehouse

    Pope, Jason P.; David C. Andreasen; Mcfarland, E. Randolph; Watt, Martha K.

    2016-01-01

    Digital geospatial datasets of the extents and top elevations of the regional hydrogeologic units of the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to northeastern North Carolina were developed to provide an updated hydrogeologic framework to support analysis of groundwater resources. The 19 regional hydrogeologic units were delineated by elevation grids and extent polygons for 20 layers: the land and bathymetric surface at the top of the unconfined surficial aquifer, the upper surfaces of 9 confined aquifers and 9 confining units, and the bedrock surface that defines the base of all Northern Atlantic Coastal Plain sediments. The delineation of the regional hydrogeologic units relied on the interpretive work from source reports for New York, New Jersey, Delaware and Maryland, Virginia, and North Carolina rather than from re-analysis of fundamental hydrogeologic data. This model of regional hydrogeologic unit geometries represents interpolation, extrapolation, and generalization of the earlier interpretive work. Regional units were constructed from available digital data layers from the source studies in order to extend units consistently across political boundaries and approximate units in offshore areas.Though many of the Northern Atlantic Coastal Plain hydrogeologic units may extend eastward as far as the edge of the Atlantic Continental Shelf, the modeled boundaries of all regional hydrogeologic units in this study were clipped to an area approximately defined by the furthest offshore extent of fresh to brackish water in any part of the aquifer system, as indicated by chloride concentrations of 10,000 milligrams per liter. Elevations and extents of units that do not exist onshore in Long Island, New York, were not included north of New Jersey. Hydrogeologic units in North Carolina were included primarily to provide continuity across the Virginia-North Carolina State boundary, which was important for defining the southern edge of

  15. Geophysical Interpretations of the Southern Espanola Basin, New Mexico, That Contribute to Understanding Its Hydrogeologic Framework

    USGS Publications Warehouse

    Grauch, V.J.S.; Phillips, Jeffrey D.; Koning, Daniel J.; Johnson, Peggy S.; Bankey, Viki

    2009-01-01

    The southern Espanola basin consists of a westward- and northward-thickening wedge of rift fill, composed primarily of Santa Fe Group sediments, that serves as an important aquifer for the city of Santa Fe and surrounding areas. Detailed aeromagnetic surveys were flown to better understand ground-water resources in this aquifer. This report presents a synthesis of these data with gravity data and other constraints. The interpretations were accomplished using qualitative interpretation, state-of-art data analysis techniques, and two- and three-dimensional modeling. The results depict the presence of and depth to many geologic features that have hydrogeologic significance, including shallow faults, different types of igneous units, and basement rocks. The results are presented as map interpretations, geophysical profile models, and a digital surface that represents the base and thickness of Santa Fe Group sediments, as well as vector files of some volcanic features and faults.

  16. Hydrogeology of parts of the Central Platte and Lower Loup Natural Resources Districts, Nebraska

    SciTech Connect

    Peckenpaugh, J.M.; Dugan, J.T.

    1983-01-01

    Water-level declines of at least 15 feet have occurred in this heavily irrigated area of central Nebraska since the early 1930's, and potential for additional declines is high. To test the effects of additional irrigation development on water levels and streamflow in the area, computer programs were developed that represent the surface-water system, soil zone, and saturated zone of the hydrogeologic system. A two-dimensional, finite difference ground-water flow model of the 3374 square-mile study area was developed and calibrated using steady-state and transient conditions, and three management alternatives were examined. Results indicate that significant additional water-level declines will occur even if there is no additional ground-water development. 35 refs., 18 figs., 22 tabs.

  17. Hydrogeologic and geochemical precursors of earthquakes: an assessment for possible applications

    NASA Astrophysics Data System (ADS)

    Martinelli, G.

    2015-06-01

    Groundwaters and gaseous emissions have been analyzed in the past with the purpose to contribute to earthquake prediction researches. Main test sites were Japan, U.S.A., former U.S.S.R., China and Turkey. Catalogues of presumed precursory episodes have been compiled over the years and allowed to reach preliminary conclusions about site selection techniques. Controlled experimental sites have recently given the opportunity to better investigate the physical mechanisms originating recorded pre-seismic anomalies. Main characteristics and limitations of hydrogeologic and geochemical parameters are discussed. An in-depth review of results obtained in most relevant test site areas allow to project future instrumental networks oriented to hazard reduction policies

  18. Hydrogeologic and Ground-Water-Quality Data for Belvidere, Illinois, and Vicinity, 2001-02

    USGS Publications Warehouse

    Mills, P.C.; Kay, R.T.

    2003-01-01

    This report presents miscellaneous geologic, hydrologic, and ground-water-quality data collected in and near Belvidere, Ill. during May 2001-November 2002. The data were collected for two studies conducted by the U.S. Geological Survey during 1990-2002, but subsequent to publication of the final interpretive reports for the studies. The cooperative studies with the U.S. Environmental Protection Agency and Illinois Environmental Protection Agency evaluated the hydrogeology, ground-water-flow system, and distribution of contaminants in the glacial drift and bedrock (primarily Galena-Platteville) aquifers underlying the vicinity of Belvidere, including the Parson?s Casket Hardware Superfund site. Data presented in the report include lithologic descriptions, geophysical logs, water levels, hydraulic characteristics, field-measured characteristics of water quality, and laboratory analyses of volatile organic compounds, major ions, trace elements, nutrients, and herbicides.

  19. Hydrogeology and simulation of ground-water flow in the aquifers underlying Belvidere, Illinois

    USGS Publications Warehouse

    Mills, Patrick C.; Nazimek, J.E.; Halford, K.J.; Yeskis, D.J.

    2002-01-01

    The U.S. Geological Survey investigated the ground-water-flow system and distribution of contaminants in the vicinity of Belvidere, Illinois, during 1992?2000. The study included the compilation, collection, and analyses of hydrogeologic and water-quality data and simulation of the ground-water-flow system. Hydrogeologic data include lithologic, stratigraphic, geophysical, hydraulic-property, water-level, ground-water withdrawal, and streamflow data. Water-quality data include analyses of water samples primarily for volatile organic compounds (VOC?s) and selectively for tritium and inorganic constituents. Data were collected from about 250 wells and 21 surfacewater sites. These data were used (1) to describe the hydrogeologic framework of the ground-waterflow system, preferential pathways and directions of ground-water movement and contaminant distribution, ground-water/surface-water relations, and the water budget and (2) to develop and calibrate the ground-water-flow model. The glacial drift (sand and gravel with some clay) and Galena-Platteville (fractured dolomite) aquifers and the sandstone aquifers of the Cambrian-Ordovician aquifer system compose the ground-water-flow system underlying Belvidere and vicinity. The Glenwood confining unit separates the Galena-Platteville aquifer from the underlying sandstone aquifers. The Galena- Platteville aquifer and confining unit may be absent in parts of the Troy Bedrock Valley, about 1.5 miles west of Belvidere. Throughout the study area, the Kishwaukee River and its tributaries seem to be gaining flow from shallow ground-water discharge. Potentiometric levels in the glacial drift and Galena-Platteville aquifers range from about 900 feet above sea level in the upland areas to 740 feet along the Kishwaukee River. Estimated horizontal hydraulic conductivity of the glacial drift aquifer ranges from about 0.13 to 280 feet per day. The Galena-Platteville aquifer is a dual-porosity unit with the greatest percentage of flow

  20. Hydrogeology of Puerto Rico and the outlying islands of Vieques, Culebra, and Mona

    USGS Publications Warehouse

    Gómez-Gómez, Fernando; Rodríguez-Martínez, Jesús; Santiago, Marilyn

    2014-01-01

    The availability of hydrogeologic maps for Puerto Rico and the outlying islands of Vieques, Culebra, and Mona are important to hydrogeologists, groundwater specialists, and water resource managers and planners. These maps, in combination with the report, serve as a source of information to all users by providing basic hydrogeologic and hydrologic knowledge in a concise illustrated format. Puerto Rico and the outlying islands cover a total area of 8,927 square kilometers (km2). Of this total area, about 3,500 km2 are underlain by hydrogeologic units that are classified as intergranular or fissured. These hydrogeologic units form the principal aquifer systems throughout Puerto Rico and the outlying islands. In Puerto Rico, the most extensive and intensely developed aquifers are the North Coast Limestone aquifer system and the South Coastal Alluvial Plain aquifer system. Withdrawals from these two aquifer systems constitute nearly 70 percent of the total groundwater withdrawn in Puerto Rico. The spatial extent of the North Coast Limestone aquifer system is about 2,000 km2. Within this aquifer system, groundwater development is greatest in the 800-km2 area between the Río Grande de Arecibo and the Río de la Plata. This also is the area for which concern is the highest regarding the future use of groundwater as a primary source of water for domestic and industrial use. With an estimated withdrawal of 280,000 cubic meters per day (m3/d), groundwater constituted the principal source of water within this area providing 100 percent of the water for self-supplied industries and about 85 percent for public water supplies in 1985. By 2005, groundwater withdrawals decreased to 150,000 m3/d. The spatial extent of the South Coastal Alluvial Plain aquifer system is about 470 km2. The estimated consumptive groundwater withdrawal from the aquifer system was 190,000 m3/d in 1980 and 170,000 m3/d in 2005. About 60 percent and 40 percent of the groundwater withdrawal from the South

  1. Hydrogeologic characterization of the Coldwater Spring recharge area, Calhoun County, Alabama

    USGS Publications Warehouse

    Kidd, Robert E.

    2001-01-01

    The complex ground-water flow in the Coldwater Spring aquifer system is the result of complicated geologic structures, porous media flow within the shallow unconsolidated zone, conduit flow in the karst bedrock aquifers, and discontinuities in hydrogeologic units caused by faulting. Recharge water in the unconsolidated zone percolates slowly to the underlying bedrock aquifer. The bedrock aquifer includes fractured zones in the Chilhowee Group and solution features in the Shady Dolomite, Conasauga Formation, Knox Groud, and Newala and Little Oak Limestones. Ground-water movement in the shallow unconsolidated zone roughly follows the topographic surface as it moves deeper into the ground-water system. Ground water flowing south through the bedrock aquifers is bloced by less permeable rocks in the area of the Jacksonville Fault; and possibly moves south and west along the fault to discharge at Coldwater Spring. The recharge area for Coldwater Spring encompasses the recharge areas of the shallow unconsolidated zone and the bedrock aquifers.

  2. Karst hydrogeology within a subarctic peatland: Attawapiskat River, Hudson Bay lowland, Canada

    NASA Astrophysics Data System (ADS)

    Cowell, Daryl W.

    1983-02-01

    The Attawapiskat River has cut through 30 m of mid-Silurian limestone ˜90 km west of James Bay in the Hudson Bay Lowland. Limestone cliffs of 12-15 m provide local relief along the river but inland the terrain is flat, covered by 1.5 m or more of peat. The area emerged from the Tyrrell Sea ˜4400 yr. B.P. Since that time two karst hydrogeological zones have become established. These are: (1) a vadose fluvio-karst zone in the exposed limestone along the river represented by disappearing lakes and streams; and (2) an organo-karst zone represented by sinkholes on or next to limestone bioherms within the peat mantle. They occupy 16% and 13% of the study area, respectively.

  3. Combined geophysical and petrophysical characterization to support a hydrogeological model of a coastal environment

    NASA Astrophysics Data System (ADS)

    Burschil, Thomas; Wiederhold, Helga; Scheer, Wolfgang; Kirsch, Reinhard; Krawczyk, Charlotte M.

    2014-05-01

    Global warming affects the water cycle by changing precipitation/evaporation and raising sea level. Especially groundwater systems in sensitive environments, such as coastal areas or barrier islands, have to be evaluated with respect to the potential reduction of water quality, e.g. salinization by saltwater intrusion (Hinsby et al., 2012). To assess these hazards using groundwater modeling we need a strong base of hydraulic and hydrogeological information. The use of integrated geophysical methods, in combination with a petrophysical characterization, provides a reliable architecture for groundwater modeling. Within the EU-project CLIWAT, we investigated the hydrogeological situation of the North Sea island of Föhr in Schleswig-Holstein (Germany). The island was mainly formed during glaciations in Pleistocene Series, especially Saalian and Weichselian Stages. These deposits remain as a Geest core in the southern central part, and house a freshwater lens that is used for the local water supply. To investigate the architecture of the fresh water lens, we carried out several surveys with airborne electromagnetic (AEM), seismic reflection, and borehole methods. To enhance the AEM resistivity model we inverted the data with a-priori constraints from seismic reflections (Burschil et al., 2012a). This constrained inversion leads to, among other things, a separation of two aquifers by resistivity data. Additionally, from borehole logs, vertical seismic profiles (VSP), and nearby AEM inversion point models we are able to petrophysically characterize different lithological categories regarding resistivity and seismic velocity. Subsurface glacial structures, e.g. buried valleys and a push moraine complex, are mapped down to 150 m below sea level. Below this rather horizontal features indicate Tertiary layers. Geophysically determined petrophysical values were correlated with lithological categories to enhance the interpretation of geophysical data. In this way, we expose

  4. East Chestnut Ridge hydrogeologic characterization: A geophysical study of two karst features

    SciTech Connect

    Not Available

    1991-01-01

    Permitting and site selection activities for the proposed East Chestnut Ridge landfill, located on the Oak Ridge Reservation, have required additional hydrogeologic studies of two karst features. Geophysical testing methods were utilized for investigating these karst features. The objectives of the geophysical testing was to determine the feasibility of geophysical techniques for locating subsurface karst features and to determine if subsurface anomalies exist at the proposed landfill site. Two karst features, one lacking surface expression (sinkhole) but with a known solution cavity at depth (from previous hydrologic studies), and the other with surface expression were tested with surface geophysical methods. Four geophysical profiles, two crossing and centered over each karst feature were collected using both gravimetric and electrical resistivity techniques.

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

    USGS Publications Warehouse

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

    2012-01-01

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

  6. Hydrogeologic maps of proposed flood detention area, Green Swamp area, Florida

    USGS Publications Warehouse

    Rutledge, A.T.; Grubb, Hayes F.

    1978-01-01

    Information about the hydrogeology of that part of the Green Swamp area which has been designated by Southwest Florida Water Management District as the Flood Detention Area is given on seven maps. The maps show (1) core-hole numbers, (2) sand thickness, (3) clay thickness, (4) clay vertical hydraulic conductivity, (5) clay leakance, (6) depth to Floridan aquifer, and (7) altitude of top of Floridan aquifer. The data were obtained from 85 core holes drilled in 1977 and from 24 core hole drilled previously. The 127 square-mile study area is part of the headwaters of the Withlacooche River and the Little Wthlacoochee River. The data will be useful in future water-resources planning and in a concurrent interpretive study of the Green Swamp area. (Woodard-USGS)

  7. Identification of rainfall triggering damaging hydrogeological events: a methodological approach applied to Calabria (Italy)

    NASA Astrophysics Data System (ADS)

    Aceto, L.; Petrucci, O.

    2014-09-01

    The paper deals with Damaging Hydrogeological Events (DHEs), defined as periods of severe weather affecting wide regions for several days, and during which landslides and floods cause economic damage and there are victims. The great variability of DHEs in both space and time is the cause of one of the main problems to solve in performing analyses of these events. Dealing with events affecting wide areas for several days, it is problematic to isolate the rainy days that can be considered as factors triggering the observed damaging phenomena. We develop a methodological approach aiming to select and analyse rainfall events that triggered damage. The analysis allows the highlighting of some seasonal characteristics of Calabrian DHEs. The approach can be used for an in-depth analysis leading to the identification of both rainfall thresholds for DHE triggering and rain/damage relationships.

  8. Field Trip 5: HYDROGEOLOGY OF BEER AND WINE IN THE YAKIMA VALLEY

    SciTech Connect

    Last, George V.; Bachmann, Matthew P.; Bjornstad, Bruce N.

    2011-05-05

    The climate and geology of eastern Washington are ideally suited to the production of hops and wine grapes. Nearly all of Washington’s hop and wine-grape production is located in the lower Yakima River Basin , which is one of the most intensively irrigated areas in the United States. Most of this irrigation water has been supplied by surface water reservoirs and canal systems drawing from the Yakima River. However, increasing demands for water has spurred the increased use of groundwater resources. This field trip guide explores many aspects of the geology and hydrogeology in the lower Yakima River Basin, particularly as they relate to water resources that support the local beer and wine industries.

  9. Selected Hydrogeologic Data for the High Plains Aquifer in Southwestern Laramie County, Wyoming, 1931-2006

    USGS Publications Warehouse

    Hallberg, Laura L.; Mason, Jon P.

    2007-01-01

    The U.S. Geological Survey, in cooperation with the Wyoming State Engineer's Office, created a hydrogeologic database for southwestern Laramie County, Wyoming. The database contains records from 166 wells and test holes drilled during 1931-2006. Several types of information, including well construction; well or test hole locations; lithologic logs; gamma, neutron, spontaneous-potential, and single-point resistivity logs; water levels; and transmissivities and storativities estimated from aquifer tests, are available in the database. Most wells and test holes in the database have records containing information about construction, location, and lithology; 77 wells and test holes have geophysical logs; 70 wells have tabulated water-level data; and 60 wells have records of aquifer-test results.

  10. A hydrogeological conceptual approach to study urban groundwater flow in Bucharest city, Romania

    NASA Astrophysics Data System (ADS)

    Boukhemacha, Mohamed Amine; Gogu, Constantin Radu; Serpescu, Irina; Gaitanaru, Dragos; Bica, Ioan

    2015-05-01

    Management of groundwater systems in urban areas is necessary and can be reliably performed by means of mathematical modeling combined with geospatial analysis. A conceptual approach for the study of urban hydrogeological systems is presented. The proposed approach is based on the features of Bucharest city (Romania) and can be adapted to other urban areas showing similar characteristics. It takes into account the interaction between groundwater and significant urban infrastructure elements that can be encountered in modern cities such as subway tunnels and water-supply networks, and gives special attention to the sewer system. In this respect, an adaptation of the leakage factor approach is proposed, which uses a sewer-system zoning function related to the conduits' location in the aquifer system and a sewer-conduits classification function related to their structural and/or hydraulic properties. The approach was used to elaborate a single-layered steady state groundwater flow model for a pilot zone of Bucharest city.

  11. Index-based groundwater vulnerability mapping models using hydrogeological settings: A critical evaluation

    SciTech Connect

    Kumar, Prashant; Bansod, Baban K.S.; Debnath, Sanjit K.; Thakur, Praveen Kumar; Ghanshyam, C.

    2015-02-15

    Groundwater vulnerability maps are useful for decision making in land use planning and water resource management. This paper reviews the various groundwater vulnerability assessment models developed across the world. Each model has been evaluated in terms of its pros and cons and the environmental conditions of its application. The paper further discusses the validation techniques used for the generated vulnerability maps by various models. Implicit challenges associated with the development of the groundwater vulnerability assessment models have also been identified with scientific considerations to the parameter relations and their selections. - Highlights: • Various index-based groundwater vulnerability assessment models have been discussed. • A comparative analysis of the models and its applicability in different hydrogeological settings has been discussed. • Research problems of underlying vulnerability assessment models are also reported in this review paper.

  12. Hydrogeologic data from a shallow flooding demonstration project, Twitchell Island, California, 1997-2001

    USGS Publications Warehouse

    Gamble, James M.; Burow, Karen R.; Wheeler, Gail A.; Hilditch, Robert; Drexler, Judy Z.

    2003-01-01

    Data were collected during a study to determine the effects of continuous shallow flooding on ground-water discharge to an agricultural drainage ditch on Twitchell Island, California. The conceptual model of the hydrogeologic setting was detailed with soil coring and borehole-geophysical logs. Twenty-two monitoring wells were installed to observe hydraulic head. Ten aquifer slug tests were done in peat and mineral sediments. Ground-water and surface-water temperature was monitored at 14 locations. Flow to and from the pond was monitored through direct measurement of flows and through the calculation of a water budget. These data were gathered to support the development of a two-dimensional ground-water flow model. The model will be used to estimate subsurface discharge to the drainage ditch as a result of the pond. The estimated discharge will be used to estimate the concentrations of DOC that can be expected in the ditch.

  13. Hydrogeology of the Tully Lakes area in southern Onondaga and Cortland counties, New York

    USGS Publications Warehouse

    Kappel, William M.; Miller, Todd S.; Hetcher, Kari K.

    2001-01-01

    Glacial processes created the many kettlehole lakes, ponds, and depressions in the Tully Lakes area, as well as the Valley Heads Moraine, which forms the drainage divide between the St. Lawrence River drainage to the north and the Susquehanna River drainage to the south. The first hydrogeologic studies of the Tully Lakes area began in the 1870's, when the lakes were considered as a possible water supply for the city of Syracuse. Water was diverted from some of the northwestern lakes and ponds into the Tully Valley; these diversions occurred as early as the 1840's and ceased in the early 1960's, with the closure of the eastern Tully Valley brinefield. In 1998, the USGS began a 2-year hydrogeologic study of the aquifer system underlying the Tully Lakes area that included monitoring water levels in five of the Tully Lakes and more than 50 wells. The average annual water-level fluctuations in the three western lakes ranged from about 2.5 feet to 6 feet. Water-level fluctuations in the eastern lakes, near the center of the valley, were much less--about 1.5 feet, because these lakes have natural outlets. Three sets of ground-water-level measurements were made from the spring recharge period through the fall dry period of 2000. The resulting potentiometric-surface maps indicate that the water-level declines from the spring to the fall ranged from 1.5 to 8 feet. The ground-water divide is about 1 mile south of the Valley Heads Moraine crest in the spring and migrates southward in response to declining water levels in the surficial aquifer during the fall. Water-surface altitudes in the kettlehole lakes and ponds respond slowly to seasonal water-level changes in the surrounding aquifer and often differ from water levels in the aquifer because the poorly permeable lakebed sediments impede the exchange of water.

  14. Gravimetry contributions to the study of the complex western Haouz aquifer (Morocco): Structural and hydrogeological implications

    NASA Astrophysics Data System (ADS)

    Chouikri, Ibtissam; el Mandour, Abdennabi; Jaffal, Mohammed; Baudron, Paul; García-Aróstegui, José-Luis; Manar, Ahmed; Casas, Albert

    2016-03-01

    This study provides new elements that illustrate the benefits of combining gravity, structural, stratigraphic and piezometric data for hydrogeological purposes. A combined methodology was applied to the western Haouz aquifer (Morocco), one of the main sources of water for irrigation and human consumption in the Marrakech region. First, a residual anomaly map was calculated from the Bouguer anomaly data. The computed map provided information on the ground density variation, revealing a strong control by a regional gradient. We then used various filtering techniques to delineate the major geological structures such as faults and basins: vertical and horizontal derivatives and upward continuation. This technique highlighted news structures and provided information on their dip. The gravity anomalies perfectly delineated the basement uplifts and the sedimentary thickening in depressions and grabens. The interpretation of gravimetric filtering, geological and hydrogeological data then highlighted two types of groundwater reservoirs, an unconfined aquifer hosted in conglomeratic mio-pliocene and quaternary rocks, covering the entire western Haouz and a deep confined aquifer contained in cenomanian-turonian limestone and eocene dolomitic formations in the south. Combining piezometric and residual anomaly maps revealed that groundwater flow and storage was in perfect agreement with the structures showing a negative anomaly, while structures with positive anomalies corresponded to groundwater divides. The study of gravity gradient zones by contact analysis enhanced the existing structural pattern of the study area and highlighted new structures, mainly oriented N70 and N130. The results of this study present a common framework and provide a notable step forward in the knowledge of the geometry and the groundwater flow pattern of the western Haouz aquifer, and will serve as a solid basis for a better water resource management.

  15. Karst system vadose zone hydrodynamics highlighted by an integrative geophysical and hydrogeological monitoring

    NASA Astrophysics Data System (ADS)

    Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Rochez, G.; Kaufmann, O.

    2015-12-01

    The vadose zone of karst systems plays an important role on the water dynamics. In particular, temporary perched aquifers can appear in the subsurface due to changes of climate conditions, diminished evapotranspiration and differences of porosity relative to deeper layers. It is therefore crucial, but challenging, to separate the hydrological signature of the vadose zone from the one of the saturated zone for understanding hydrological processes that occur in the vadose zone. Although many difficulties are usually encountered when studying karst environments due to their heterogeneities, cave systems offer an outstanding opportunity to investigate vadose zone from the inside with various techniques. We present results covering two years of hydrogeological and geophysical monitoring at the Rochefort Cave Laboratory (RCL), located in the Variscan fold-and-thrust belt (Belgium), a region that shows many karstic networks within Devonian limestone units. Hydrogeological data such as flows and levels monitoring or tracer tests performed in both vadose and saturated zones bring valuable information on the hydrological context of the studied area. Combining those results with geophysical measurements allows validating and imaging them with more integrative techniques. A microgravimetric monitoring involves a superconducting gravimeter continuously measuring at the surface of the RCL. Early in 2015, a second relative gravimeter was installed in the underlying cave system located 35 meters below the surface. This set up allows highlighting vadose gravity changes. These relative measurements are calibrated using an absolute gravimeter. 12 additional stations (7 at the surface, 5 in the cave) are monitored on a monthly basis by a spring gravimeter. To complete these gravimetric measurements, the site has been equipped with a permanent Electrical Resistivity Tomography (ERT) monitoring system comprising an uncommon array of surface, borehole and cave electrodes. Although such

  16. Multi-scale hydrogeological and hydrogeophysical approach to monitor vadose zone hydrodynamics of a karst system

    NASA Astrophysics Data System (ADS)

    Watlet, Arnaud; Poulain, Amaël; Van Camp, Michel; Francis, Olivier; Triantafyllou, Antoine; Rochez, Gaëtan; Hallet, Vincent; Kaufmann, Olivier

    2016-04-01

    The vadose zone of karst systems plays an important role on the water dynamics. In particular, temporary perched aquifers can appear in the subsurface due to changes of weather conditions, reduced evapotranspiration and the vertical gradients of porosity and permeability. Although many difficulties are usually encountered when studying karst environments due to their heterogeneities, cave systems offer an outstanding opportunity to investigate vadose zone from the inside. We present a multi-scale study covering two years of hydrogeological and geophysical monitoring of the Lomme Karst System (LKS) located in the Variscan fold-and-thrust belt (Belgium), a region (~ 3000 ha) that shows many karstic networks within Devonian limestone units. Hydrogeological data cover the whole LKS and involve e.g. flows and levels monitoring or tracer tests performed in both vadose and saturated zones. Such data bring valuable information on the hydrological context of the studied area at the catchment scale. Combining those results with geophysical measurements allows validating and imaging them at a smaller scale, with more integrative techniques. Hydrogeophysical measurements are focused on only one cave system of the LKS, at the Rochefort site (~ 40 ha), taking benefit of the Rochefort Cave Laboratory (RCL) infrastructures. In this study, a microgravimetric monitoring and an Electrical Resistivity Tomography (ERT) monitoring are involved. The microgravimetric monitoring consists in a superconducting gravimeter continuously measuring gravity changes at the surface of the RCL and an additional relative gravimeter installed in the underlying cave located 35 meters below the surface. While gravimeters are sensible to changes that occur in both the vadose zone and the saturated zone of the whole cave system, combining their recorded signals allows enhancing vadose zone's gravity changes. Finally, the surface ERT monitoring provide valuable information at the (sub)-meter scale on the

  17. Hydrogeology and tritium transport in Chicken Creek Canyon,Lawrence Berkeley National Laboratory, Berkeley, California

    SciTech Connect

    Jordan, Preston D.; Javandel, Iraj

    2007-10-31

    This study of the hydrogeology of Chicken Creek Canyon wasconducted by the Environmental Restoration Program (ERP) at LawrenceBerkeley National Laboratory (LBNL). This canyon extends downhill fromBuilding 31 at LBNL to Centennial Road below. The leading edge of agroundwater tritium plume at LBNL is located at the top of the canyon.Tritium activities measured in this portion of the plume during thisstudy were approximately 3,000 picocuries/liter (pCi/L), which issignificantly less than the maximum contaminant level (MCL) for drinkingwaterof 20,000 pCi/L established by the Environmental ProtectionAgency.There are three main pathways for tritium migration beyond theLaboratory s boundary: air, surface water and groundwater flow. Thepurpose of this report is to evaluate the groundwater pathway.Hydrogeologic investigation commenced with review of historicalgeotechnical reports including 35 bore logs and 27 test pit/trench logsas well as existing ERP information from 9 bore logs. This was followedby field mapping of bedrock outcrops along Chicken Creek as well asbedrock exposures in road cuts on the north and east walls of the canyon.Water levels and tritium activities from 6 wells were also considered.Electrical-resistivity profiles and cone penetration test (CPT) data werecollected to investigate the extent of an interpreted alluvial sandencountered in one of the wells drilled in this area. Subsequent loggingof 7 additional borings indicated that this sand was actually anunusually well-sorted and typically deeply weathered sandstone of theOrinda Formation. Wells were installed in 6 of the new borings to allowwater level measurement and analysis of groundwater tritium activity. Aslug test and pumping tests were also performed in the wellfield.

  18. Applications of ichnology to hydrogeology, with examples from the Cape Fear Formation (Cretaceous), South Carolina

    SciTech Connect

    Martin, A.J. . Geosciences Program); Simones, G.C. )

    1992-01-01

    Ichnology, the study of modern and ancient traces left by organisms, has provided supplemental information to geologic subdisciplines such as sedimentology and stratigraphy. The major objective of the authors paper is to emphasize the valuable information that can be conveyed by trace fossils in the investigation of hydrogeologic units. Bioturbation has a net effect of mixing different types and layers of sediments, such as introducing clays into sands and vice versa. This mixing can decrease porosity and permeability of sandy units, thus changing potential aquifers into confining units. For example, a sandy fluvial deposit will contain distinctive nonmarine trace fossils, thus defining channel sands that may serve as permeable conduits for ground-water flow. In contrast, a sandy shelf deposit will contain marine trace fossils in a sand body geometry that will be markedly different from aquifers produced in nonmarine environments. Bioturbation also causes geochemical and diagenetic changes in sediments, causing irrigation of previously anoxic sediments and precipitation of ion oxides. The Cretaceous Cape Fear Formation of the Atlantic Coastal Plain, in the subsurface of South Carolina, is presented as an example of a hydrogeologic unit that has been reinterpreted using ichnologic data. Extensive bioturbation caused mixing of clays and sands in Cape Fear sediments, which resulted in the Cape Fear becoming a regional confining system. Trace fossil assemblages indicate a brackish water environment, perhaps estuarine, for the Cape Fear, as opposed to previous interpretations of fluvial and deltaic environments. Bioturbated zones also have significantly more oxidized iron than unbioturbated zones, highlighting potential effects on ground-water quality.

  19. Hydrogeologic controls on induced seismicity in crystalline basement rocks due to fluid injection into basal reservoirs.

    PubMed

    Zhang, Yipeng; Person, Mark; Rupp, John; Ellett, Kevin; Celia, Michael A; Gable, Carl W; Bowen, Brenda; Evans, James; Bandilla, Karl; Mozley, Peter; Dewers, Thomas; Elliot, Thomas

    2013-01-01

    A series of Mb 3.8-5.5 induced seismic events in the midcontinent region, United States, resulted from injection of fluid either into a basal sedimentary reservoir with no underlying confining unit or directly into the underlying crystalline basement complex. The earthquakes probably occurred along faults that were likely critically stressed within the crystalline basement. These faults were located at a considerable distance (up to 10 km) from the injection wells and head increases at the hypocenters were likely relatively small (∼70-150 m). We present a suite of simulations that use a simple hydrogeologic-geomechanical model to assess what hydrogeologic conditions promote or deter induced seismic events within the crystalline basement across the midcontinent. The presence of a confining unit beneath the injection reservoir horizon had the single largest effect in preventing induced seismicity within the underlying crystalline basement. For a crystalline basement having a permeability of 2 × 10(-17)  m(2) and specific storage coefficient of 10(-7) /m, injection at a rate of 5455 m(3) /d into the basal aquifer with no underlying basal seal over 10 years resulted in probable brittle failure to depths of about 0.6 km below the injection reservoir. Including a permeable (kz  = 10(-13)  m(2) ) Precambrian normal fault, located 20 m from the injection well, increased the depth of the failure region below the reservoir to 3 km. For a large permeability contrast between a Precambrian thrust fault (10(-12)  m(2) ) and the surrounding crystalline basement (10(-18)  m(2) ), the failure region can extend laterally 10 km away from the injection well. PMID:23745958

  20. Effects of hydrogeological properties on sea-derived benzene transport in unconfined coastal aquifers.

    PubMed

    Li, Wei-Ci; Ni, Chuen-Fa; Tsai, Chia-Hsing; Wei, Yi-Ming

    2016-05-01

    This paper presents numerical investigations on quantifying the hydrodynamic effects of coastal environment factors, including tidal fluctuations, beach slopes, hydraulic conductivity, and hydraulic gradients on sea-derived benzene transport in unconfined coastal aquifers. A hydrologic transport and mixed geochemical kinetic/equilibrium reactions in saturated-unsaturated media model was used to simulate the spatial and temporal behaviors of the density flow and benzene transport for various hydrogeological conditions. Simulation results indicated that the tidal fluctuations lead to upper saline plumes (USPs) near the groundwater and seawater interfaces. Such local circulation zones trapped the seaward benzene plumes and carried them down in aquifers to the depth depending on the tide amplitudes and beach slopes across the coastal lines. Comparisons based on different tidal fluctuations, beach slopes, hydraulic conductivity, and hydraulic gradient were systematically conducted and quantified. The results indicated that areas with USPs increased with the tidal amplitude and decreased with the increasing beach slope. However, the variation of hydraulic conductivity and hydraulic gradient has relatively small influence on the patterns of flow fields in the study. The increase of the USP depths was linearly correlated with the increase of the tidal amplitudes. The benzene reactive transport simulations revealed that the plume migrations are mainly controlled by the local flow dynamics and constrained in the USP circulation zones. The self-cleaning process of a coastal aquifer is time-consuming, typically requiring double the time of the contamination process that the benzene plume reach the bottom of a USP circulation zone. The presented systematic analysis can provide useful information for rapidly evaluating seaward contaminants along a coastal line with available hydrogeological properties. PMID:27106208

  1. Fault zone hydrogeologic properties and processes revealed by borehole temperature monitoring

    NASA Astrophysics Data System (ADS)

    Fulton, P. M.; Brodsky, E. E.

    2015-12-01

    High-resolution borehole temperature monitoring can provide valuable insight into the hydrogeologic structure of fault zones and transient processes that affect fault zone stability. Here we report on results from a subseafloor temperature observatory within the Japan Trench plate boundary fault. In our efforts to interpret this unusual dataset, we have developed several new methods for probing hydrogeologic properties and processes. We illustrate how spatial variations in the thermal recovery of the borehole after drilling and other spectral characteristics provide a measure of the subsurface permeability architecture. More permeable zones allow for greater infiltration of cool drilling fluids, are more greatly thermally disturbed, and take longer to recover. The results from the JFAST (Japan Trench Fast Drilling Project) observatory are consistent with geophysical logs, core data, and other hydrologic observations and suggest a permeable damage zone consisting of steeply dipping faults and fractures overlays a low-permeability clay-rich plate boundary fault. Using high-resolution time series data, we have also developed methods to map out when and where fluid advection occurs in the subsurface over time. In the JFAST data, these techniques reveal dozens of transient earthquake-driven fluid pulses that are spatially correlated and consistently located around inferred permeable areas of the fault damage zone. These observations are suspected to reflect transient fluid flow driven by pore pressure changes in response to dynamic and/or static stresses associated with nearby earthquakes. This newly recognized hydrologic phenomenon has implications for understanding subduction zone heat and chemical transport as well as the redistribution of pore fluid pressure which influences fault stability and can trigger other earthquakes.

  2. Quantification of Submarine Groundwater Discharge Using a Radon (222-Rn) Mass Balance and Hydrogeological Modelling

    NASA Astrophysics Data System (ADS)

    Petermann, Eric; Stollberg, Reiner; Scholten, Jan; Knöller, Kay; Schubert, Michael

    2016-04-01

    Apart from river and surface water runoff subsurface discharge of groundwater plays a key role in coastal water and matter budgets. Two major forms of submarine groundwater discharge (SGD) can be distinguished: (i) pure freshwater discharge from continental aquifers that are connected to the coastal sea driven by a positive hydraulic gradient (fresh SGD) and (ii) re-circulation of seawater that has penetrated permeable coastal sediments (re-circulated SGD), e.g. driven by tidal pumping. The localization of SGD zones and the quantification of SGD fluxes is of high interest for coastal water management due to potential threats related to SGD, namely (i) the detrimental impact of discharging nutrient- or contaminant-laden groundwater on coastal seawater quality, an aspect that is of relevance along coastlines which are impacted by agriculture, industry or intense urbanization, and (ii) the loss of freshwater to the ocean, an issue that is of major relevance in all coastal areas with (seasonally) limited freshwater availability. In this work, we discuss estimates for the total (fresh + re-circulated) SGD fluxes derived from a mass balance of the radioactive noble gas radon (222-Rn) with estimates of fresh SGD fluxes derived by hydrogeological modelling. The precision of the mass balance results depends on the adequate determination of the mass balance source and sink terms. These terms are calculated based on field observations of environmental tracers (salinity, δ18O, 222-Rn, 223-Ra, 224-Ra, 226-Ra) in seawater and porewater, as well as on meteorological data. The numerical hydrogeological model estimates groundwater flow based on groundwater monitoring data, river flow data, groundwater recharge estimates, tidal dynamics, and density effects along the freshwater/seawater interface. We compare these two independent methodological approaches of SGD flux estimation, discuss results regarding their relevance for the regional water balance and reason the implications of

  3. Methods for assessing hydrogeological similarity and for classification of groundwater systems on the regional scale

    NASA Astrophysics Data System (ADS)

    Haaf, Ezra; Barthel, Roland

    2015-04-01

    Conducting groundwater modelling and resource analysis on the regional scale is often complicated by the scarcity and uneven distribution of observations over space and time, the uncertainty of structures, inputs and processes as well as the inherent heterogeneity and variability of hydrogeological conditions. In order to improve modelling and prediction of poorly-observed groundwater systems, information could be transferred from similar, but more well-explored and better understood systems analogous to PUB (Prediction in ungauged catchments). To achieve this, the overarching goal of this study is to develop an approach to statistically extract relevant information on structure and state from observed and well characterized locations in order to derive a classification scheme of functionally similar groups. At the core of the approach will be the classification of (i) static hydrogeological characteristics (such as aquifer geometry and hydraulic properties) (ii) dynamic changes of the boundary conditions (such as recharge) and (iii) dynamic groundwater system responses (groundwater head and chemical parameters) as well as the systematic use of the dependencies of system responses on explanatory factors. With a classification framework in place, insight can be gained into the behavior of less well-observed groundwater systems and underlying processes can be better understood. Furthermore, it is expected that regional conceptual models can be checked without the need of numerical groundwater models as well as that missing values in time series can be filled. Apart from illustrating the general approach and the main ideas of groundwater systems classification, we show a number of promising methods that can be used to establish a classification framework for groundwater systems assessment. The focus at the current stage is on finding relevant statistical methods that can be used for identifying and quantifying similarities/dissimilarities of groundwater hydrographs

  4. An approach for classification of hydrogeological systems at the regional scale based on groundwater hydrographs

    NASA Astrophysics Data System (ADS)

    Haaf, Ezra; Barthel, Roland

    2016-04-01

    When assessing hydrogeological conditions at the regional scale, the analyst is often confronted with uncertainty of structures, inputs and processes while having to base inference on scarce and patchy data. Haaf and Barthel (2015) proposed a concept for handling this predicament by developing a groundwater systems classification framework, where information is transferred from similar, but well-explored and better understood to poorly described systems. The concept is based on the central hypothesis that similar systems react similarly to the same inputs and vice versa. It is conceptually related to PUB (Prediction in ungauged basins) where organization of systems and processes by quantitative methods is intended and used to improve understanding and prediction. Furthermore, using the framework it is expected that regional conceptual and numerical models can be checked or enriched by ensemble generated data from neighborhood-based estimators. In a first step, groundwater hydrographs from a large dataset in Southern Germany are compared in an effort to identify structural similarity in groundwater dynamics. A number of approaches to group hydrographs, mostly based on a similarity measure - which have previously only been used in local-scale studies, can be found in the literature. These are tested alongside different global feature extraction techniques. The resulting classifications are then compared to a visual "expert assessment"-based classification which serves as a reference. A ranking of the classification methods is carried out and differences shown. Selected groups from the classifications are related to geological descriptors. Here we present the most promising results from a comparison of classifications based on series correlation, different series distances and series features, such as the coefficients of the discrete Fourier transform and the intrinsic mode functions of empirical mode decomposition. Additionally, we show examples of classes

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  6. An Analysis Platform for Multiscale Hydrogeologic Modeling with Emphasis on Hybrid Multiscale Methods

    SciTech Connect

    Scheibe, Timothy D.; Murphy, Ellyn M.; Chen, Xingyuan; Rice, Amy K.; Carroll, Kenneth C.; Palmer, Bruce J.; Tartakovsky, Alexandre M.; Battiato, Ilenia; Wood, Brian D.

    2015-01-01

    One of the most significant challenges facing hydrogeologic modelers is the disparity between those spatial and temporal scales at which fundamental flow, transport and reaction processes can best be understood and quantified (e.g., microscopic to pore scales, seconds to days) and those at which practical model predictions are needed (e.g., plume to aquifer scales, years to centuries). While the multiscale nature of hydrogeologic problems is widely recognized, technological limitations in computational and characterization restrict most practical modeling efforts to fairly coarse representations of heterogeneous properties and processes. For some modern problems, the necessary level of simplification is such that model parameters may lose physical meaning and model predictive ability is questionable for any conditions other than those to which the model was calibrated. Recently, there has been broad interest across a wide range of scientific and engineering disciplines in simulation approaches that more rigorously account for the multiscale nature of systems of interest. In this paper, we review a number of such approaches and propose a classification scheme for defining different types of multiscale simulation methods and those classes of problems to which they are most applicable. Our classification scheme is presented in terms of a flow chart (Multiscale Analysis Platform or MAP), and defines several different motifs of multiscale simulation. Within each motif, the member methods are reviewed and example applications are discussed. We focus attention on hybrid multiscale methods, in which two or more models with different physics described at fundamentally different scales are directly coupled within a single simulation. Very recently these methods have begun to be applied to groundwater flow and transport simulations, and we discuss these applications in the context of our classification scheme. As computational and characterization capabilities continue to

  7. Mitigation of the surficial hydrogeological impact induced by the construction of the Pajares Tunnels (NW Spain).

    NASA Astrophysics Data System (ADS)

    Valenzuela, Pablo; Sáenz de Santa María, José Antonio; José Domínguez-Cuesta, María; López Fernández, Carlos; Meléndez-Asensio, Mónica; Jiménez-Sánchez, Montserrat

    2016-04-01

    Pajares Tunnels are railway tunnels 24.5 km long and 700 m depth drilled in Paleozoic rocks of the Cantabrian Range (NW Spain). The construction of these tunnels is the cause of a very important surficial hydrogeological impact on the Alcedo Valley consisting on: i) the strong alteration of its natural hydrogeological regime; ii) the development of 25 sinkholes from 2007 to 2014 in calcareous rocks covered by alluvial deposits; iii) the transformation of the Alcedo stream into an influent, losing all the surficial water flow by infiltration trough 7 active ponors developed at the stream bed. The estimated mean water volume infiltration across these sinkholes was around 0.4 Hm3/year (10 ls-1). Previous studies proved the infiltration of this runoff towards the new base level established by the tunnels, which would affect the operation and safety conditions required in a high-speed railway line. In order to minimize this situation, several geotechnical works have been performed from July 2014 to November 2015. These works consist on: (i) geological research, (ii) borehole drilling, (iii) geophysical prospecting, (iv) sealing of sinkholes and ponors, (v) construction of a concrete channel covered with geotextile and completely buried with original removed alluvial materials, and (vi) environmental restoration. After the completion of these actions, the first observations have allowed to note a total elimination of the infiltration from the Alcedo Valley to the tunnels. This involves an 8% reduction of total drainage in Pajares Tunnels (from average 350 l s-1 to 325 l s-1).

  8. Open-Source Semantic and Schematic Mediation in Hydrogeologic Spatial Data Infrastructures

    NASA Astrophysics Data System (ADS)

    Boisvert, E.; Brodaric, B.

    2008-12-01

    A common task in cyber-based data environments, hydrogeologic or otherwise, is an initial search for data amongst distributed heterogeneous sources, followed by amalgamation of the multiple results into a single file organized using a common structure and perhaps standard content. For example, querying water well databases to obtain a list of the rock materials that occur beyond a certain ground depth, represented in some specific XML dialect. This task is often achieved with the aid of open geospatial technologies (OGC), which conveniently enable interoperability at the system and syntax levels by providing standard web service interfaces (WMS, WFS, WCS) and a standard data transfer language (GML). However, at present such technologies, which are mainly non-open source, provide minimal support for interoperating at the schematic and semantic levels, meaning it is difficult to query the data sources and obtain results in a common data structure populated with standard content. Classical data integration systems provide mediator and wrapper middleware to address this issue: mediators dispatch queries to distributed data repositories and integrate query results, while wrappers perform translation to common standards for both queries and results, and these actions are typically supported by ontologies. Under this classical scenario existing open geospatial services can be considered wrappers with minimal translation capacity, thus requiring a mediator to both integrate and translate. Consequently, we have used open source components to develop a re-usable mediator that operates as a virtual open geospatial web service (WFS), one that integrates and translates both query requests and results from OGC-wrapped data sources to common standards. The mediator is designed as a customizable XML processing pipeline that operates on declarative descriptions that support schematic and semantic translation. It is being implemented in virtual environments for hydrogeology to

  9. Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications

    SciTech Connect

    Grauch, V.J.S.; Sawyer, D.A.; Fridrich, C.J.; Hudson, M.R.

    2000-06-08

    Gravity and magnetic data, when integrated with other geophysical, geological, and rock-property data, provide a regional framework to view the subsurface geology in the southwestern Nevada volcanic field. The authors have loosely divided the region into six domains based on structural style and overall geophysical character. For each domain, they review the subsurface tectonic and magmatic features that have been inferred or interpreted from previous geophysical work. Where possible, they note abrupt changes in geophysical fields as evidence for potential structural or lithologic control on ground-water flow. They use inferred lithology to suggest associated hydrogeologic units in the subsurface. The resulting framework provides a basis for investigators to develop hypotheses for regional ground-water pathways where no drill-hole information exists. The authors discuss subsurface features in the northwestern part of the Nevada Test Site and west of the Nevada Test Site in more detail to address potential controls on regional ground-water flow away from areas of underground nuclear-weapons testing at Pahute Mesa. Subsurface features of hydrogeologic importance in these areas are (1) the resurgent intrusion below Timber Mountain, (2) a NNE-trending fault system coinciding with western margins of the Silent Canyon and Timber Mountain caldera complexes, (3) a north-striking, buried fault east of Oasis Mountain extending for 15 km, which they call the Hogback fault, and (4) an east-striking transverse fault or accommodation zone that, in part, bounds Oasis Valley basin on the south, which they call the Hot Springs fault. In addition, there is no geophysical nor geologic evidence for a substantial change in subsurface physical properties within a corridor extending from the northwestern corner of the Rainier Mesa caldera to Oasis Valley basin (east of Oasis Valley discharge area). This observation supports the hypothesis of other investigators that regional ground water

  10. Hydrogeological characterization of the South Oyster bacterial transport site using geophysical data

    NASA Astrophysics Data System (ADS)

    Hubbard, Susan S.; Chen, Jinsong; Peterson, John; Majer, Ernest L.; Williams, Kenneth H.; Swift, Donald J.; Mailloux, Brian; Rubin, Yoram

    2001-10-01

    A multidisciplinary research team has conducted a field-scale bacterial transport study within an uncontaminated sandy Pleistocene aquifer near Oyster, Virginia. The overall goal of the project was to evaluate the importance of heterogeneities in controlling the field-scale transport of bacteria that are injected into the ground for remediation purposes. Geochemical, hydrological, geological, and geophysical data were collected to characterize the site prior to conducting chemical and bacterial injection experiments. In this paper we focus on results of a hydrogeological characterization effort using geophysical data collected across a range of spatial scales. The geophysical data employed include surface ground-penetrating radar, radar cross-hole tomography, seismic cross-hole tomography, cone penetrometer, and borehole electromagnetic flowmeter. These data were used to interpret the subregional and local stratigraphy, to provide high-resolution hydraulic conductivity estimates, and to provide information about the log conductivity spatial correlation function. The information from geophysical data was used to guide and assist the field operations and to constrain the numerical bacterial transport model. Although more field work of this nature is necessary to validate the usefulness and cost-effectiveness of including geophysical data in the characterization effort, qualitative and quantitative comparisons between tomographically obtained flow and transport parameter estimates with hydraulic well bore and bromide breakthrough measurements suggest that geophysical data can provide valuable, high-resolution information. This information, traditionally only partially obtainable by performing extensive and intrusive well bore sampling, may help to reduce the ambiguity associated with hydrogeological heterogeneity that is often encountered when interpreting field-scale bacterial transport data.

  11. Modelling hyporheic processes for regulated rivers under transient hydrological and hydrogeological conditions

    NASA Astrophysics Data System (ADS)

    Siergieiev, D.; Ehlert, L.; Reimann, T.; Lundberg, A.; Liedl, R.

    2015-01-01

    Understanding the effects of major hydrogeological controls on hyporheic exchange and bank storage is essential for river water management, groundwater abstraction, restoration and ecosystem sustainability. Analytical models cannot adequately represent complex settings with, for example, transient boundary conditions, varying geometry of surface water-groundwater interface, unsaturated and overland flow, etc. To understand the influence of parameters such as (1) sloping river banks, (2) varying hydraulic conductivity of the riverbed and (3) different river discharge wave scenarios on hyporheic exchange characteristics such as (a) bank storage, (b) return flows and (c) residence time, a 2-D hydrogeological conceptual model and, subsequently, an adequate numerical model were developed. The numerical model was calibrated against observations in the aquifer adjacent to the hydropower-regulated Lule River, northern Sweden, which has predominantly diurnal discharge fluctuations during summer and long-lasting discharge peaks during autumn and winter. Modelling results revealed that bank storage increased with river wave amplitude, wave duration and smaller slope of the river bank, while maximum exchange flux decreased with wave duration. When a homogeneous clogging layer covered the entire river-aquifer interface, hydraulic conductivity positively affected bank storage. The presence of a clogging layer with hydraulic conductivity < 0.001 m d-1 significantly reduced the exchange flows and virtually eliminated bank storage. The bank storage return/fill time ratio was positively related to wave amplitude and the hydraulic conductivity of the interface and negatively to wave duration and bank slope. Discharge oscillations with short duration and small amplitude decreased bank storage and, therefore, the hyporheic exchange, which has implications for solute fluxes, redox conditions and the potential of riverbeds as fish-spawning locations. Based on these results, river

  12. UNDERSTANDING HARD ROCK HYDROGEOLOGY THROUGH AN EXPERIMENTAL HYDROGEOLOGICAL PARK IN SOUTH INDIA: Site development and investigations on the major role of the fractured zone in crystalline aquifers

    NASA Astrophysics Data System (ADS)

    Ahmed, S.; Guiheneuf, N.; Boisson, A.; Marechal, J.; Chandra, S.; Dewandel, B.; Perrin, J.

    2012-12-01

    In water stressed south India most of the groundwater used for irrigation is pumped from crystalline rocks aquifers. In those structures groundwater flow dominantly occur in a shallow higher-permeability zone that overlies a deeper lower-permeability zone hosting little flow. The fractured zone of the weathering profile plays an important role for groundwater. In order to understand clearly this impact on water availability and quality changes the Experimental Hydrogeological Park at Choutuppal, Andhra Pradesh, India is developed in the framework of the SORE H+ network. Several hydraulic tests (injection, flowmeter profiles, single-packer tests…) and geophysical measurements (ERT, Borehole logging…) are carried out on the site in order to characterize the depth-dependence of hydrodynamic parameters in the Indian Archean granite. Specific investigation on a borewell through packer tests demonstrate that the most conductive part of the aquifer corresponds to the upper part of the fractured layer, located just below the saprolite bottom, between 15 meters and 20 meters depth. There is no highly conductive fracture beyond 20 meters depth and no indication for any conductive fracture beyond 25 meters depth. Packer tests show that the upper part of the fractured layer (15-20 m depth) is characterized by a good vertical connectivity. On the contrary, the tests carried out below 20 m depth show no vertical connectivity at all. The geometry of the fracture network and associated hydrodynamic parameters are in agreement with the conceptual model of hard-rock aquifers that derive its properties from weathering processes. The general existence of such a highly conductive structure at the top of the fractured zone has a great impact on water prospection and exploitation in such crystalline aquifers.

  13. Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina

    USGS Publications Warehouse

    Williams, Lester J.; Dixon, Joann F.

    2015-01-01

    Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part of the U.S. Geological Survey Groundwater Resources Program. The dataset contains structural surfaces depicting the top and base of the aquifer system, its major and minor hydrogeologic units and zones, geophysical marker horizons, and the altitude of the 10,000-milligram-per-liter total dissolved solids boundary that defines the approximate fresh and saline parts of the aquifer system. The thicknesses of selected major and minor units or zones were determined by interpolating points of known thickness or from raster surface subtraction of the structural surfaces. Additional data contained include clipping polygons; regional polygon features that represent geologic or hydrogeologic aspects of the aquifers and the minor units or zones; data points used in the interpolation; and polygon and line features that represent faults, boundaries, and other features in the aquifer system.

  14. Characterisation of the hydrogeology of the Augustus River catchment, Western Australia

    NASA Astrophysics Data System (ADS)

    Wilkes, Shane M.; Clement, T. Prabhakar; Otto, Claus J.

    Understanding the hydrogeology of weathered rock catchments is integral for the management of various problems related to increased salinity within the many towns of Western Australia. This paper presents the results of site characterisation investigations aimed at improving the overall understanding of the hydrogeology of the southern portion of the Augustus River catchment, an example of a weathered rock catchment. Site data have highlighted the presence of both porous media aquifers within the weathered profile and fractured rock aquifers within the basement rocks. Geophysical airborne surveys and other drilling data have identified a large number of dolerite dykes which crosscut the site. Fractured quartz veins have been found along the margins of these dolerite dykes. Detailed groundwater-level measurements and barometric efficiency estimates indicate that these dolerite dykes and fractured quartz veins are affecting groundwater flow directions, promoting a strong hydraulic connection between all aquifers, and also influencing recharge mechanisms. The hydrogeological significance of the dolerite dykes and fractured quartz veins has been assessed using a combination of high-frequency groundwater-level measurements (30-min sampling interval), rainfall measurements (5-min sampling interval) and barometric pressure fluctuations (30-min sampling interval). A conceptual model was developed for describing various hydrogeological features of the study area. The model indicates that fractured quartz veins along the margins of dolerite dykes are an important component of the hydrogeology of the weathered rock catchments. Comprendre l'hydrogéologie des bassins en roches altérées est essentiel pour la gestion de différents problèmes liés à l'augmentation de la salinité dans de nombreuses villes d'Australie occidentale. Cet article présente les résultats d'études de caractérisation de sites conduites pour améliorer la compréhension de l'hydrogéologie de la

  15. Integrating Multiple Subsurface Exploration Technologies in Slope Hydrogeologic Investigation: A Case Study in Taiwan

    NASA Astrophysics Data System (ADS)

    Lo, H.-C.; Hsu, S.-M.; Jeng, D.-I.; Ku, C.-Y.

    2009-04-01

    Taiwan is an island located at a tectonically active collision zone between the Eurasian Plate and the Pacific Plate. Also, the island is in the subtropical climate region with frequent typhoon events that are always accompanied by intense rainfalls within a short period of time. These seismic and climatic elements frequently trigger, directly or indirectly, natural disasters such as landslides on the island with casualties and property damages. Prompted by the urge for minimizing the detrimental effects of such natural disasters, Taiwan government has initiated and funded a series of investigations and studies aimed at better understanding the causes of the natural disasters that may lead to the formulation of more effective disaster contingency plans and possibly some forecasts system. The hydrogeology of a landslide site can help unveil the detention condition of storm water entering the aquifer system of the slope as well as its groundwater condition which, in turn, plays a critical role in slope stability. In this study, a hydrogeologic investigation employing a series of subsurface exploration technologies was conducted at an active landslide site in the vicinity of Hwa Yuan Village in northern Taiwan. The site, which covers an area of approximately 0.14 km2 (35 acres) and generally ranges between 25 to 36 degree in slope, was initially investigated with ground resistivity image profiling (RIP) and electrical logging in order to determine the lithology and possibly the water-bearing capacity of the geologic units beneath the slope surface. Subsequently, both acoustic and optical borehole loggings were then applied to identify potentially significant fracture features at depth and their hydrogeologic implications. In addition, flowmeter loggings and hydraulic packer tests were conducted to further characterize the hydrogeologic system of the site and quantitatively determine the hydraulic properties of major hydrogeologic units. According to the ground

  16. Hydrogeologic data related to the potential for stock-water development on federally owned rangeland near Dillon, Montana

    USGS Publications Warehouse

    Levings, J.F.

    1985-01-01

    Existing hydrogeologic data and information were synthesized for 20 sites on federally owned rangeland near Dillon, Montana. The purpose was to assist the U.S. Bureau of Land Management in evaluating the potential for developing additional stock-water supplies. Hydrologic and geologic conditions at most of the sites were verified by onsite inspection during the summer of 1984. Each site is described in terms of location, altitude of land surface, inferred aquifer(s), estimated depth to water, estimated drilling depth, estimated yield, estimated dissolved-solids concentration, hydrogeologic setting, and development. A plate shows the location of wells and springs, dissolved-solids concentrations and chemical-constituent diagrams for water samples, ownership status for selected rangeland areas near Dillon. (USGS)

  17. Hydrogeologic framework and geologic structure of the Floridan aquifer system and intermediate confining unit in the Lake Okeechobee area, Florida

    USGS Publications Warehouse

    Reese, Ronald S.

    2014-01-01

    The successful implementation of aquifer storage and recovery (ASR) as a water-management tool requires detailed information on the hydrologic and hydraulic properties of the potential water storage zones. This report presents stratigraphic and hydrogeologic sections of the upper part of the Floridan aquifer system and the overlying confining unit or aquifer system in the Lake Okeechobee area, and contour maps of the upper contacts of the Ocala Limestone and the Arcadia Formation, which are represented in the sections. The sections and maps illustrate hydrogeologic factors such as confinement of potential storage zones, the distribution of permeability within the zones, and geologic features that may control the efficiency of injection, storage, and recovery of water, and thus may influence decisions on ASR activities in areas of interest to the Comprehensive Everglades Restoration Plan.

  18. Hydrogeology characterization of roto-translational slides in flysch rock masses

    NASA Astrophysics Data System (ADS)

    Ronchetti, F.; Borgatti, L.; Cervi, F.; Corsini, A.; Piccinini, L.; Vincenzi, V.; Truffelli, G.

    2009-04-01

    The hydrogeological characteristics of roto-traslational slides in flysch are complex, due to the inherent anisotropy and heterogeneity of such rock masses. The paper deals with the hydrogeological characterization of a reactivated roto-translational slide affecting Cretaceous flysch, located in the Northern Apennines of Italy. In situ permeability and pumping test, continuous monitoring of groundwater levels, hydrochemical and isotope analyses, and finally uranine tracers were the adopted prospecting methods. The landslide sector classified as rock slide extends for about 0.5 km2 and is characterized by a marked active sliding surface at 40 m depth. Borehole cores showed an upper 10-20 m landslide layer made of clayey debris, and a lower 20 m landslide layer made of highly fractured sandstone-rich flysch. Below sliding surface the flysch is much less fractured and it is overlying a clayey mélange. The hydraulic conductivity of both layers of the rock slide body was estimated with more than ten borehole permeability tests and by 5 slug-tests in open-pipe piezometers. Results highlighted a variability of permeability at different depths and locations, between 10-6 to 10-8 m/s, linked to fracturing of rock masses and to clay fraction. Groundwater levels were monitored for more than 3 years by means of transducers in 5 standpipe piezometers, fissured above or below the sliding surface. Results showed that two overlaying aquifers exist at the slope scale: an unconfined one, in the fractured flysch of the rock slide; a confined one, in the undisturbed flysch below sliding surface. Pore pressure in the unconfined aquifer is controlled by rainfall, with fluctuation of several meters occurring hours or days from onset of precipitation. On the contrary, pore pressure in the confined aquifer shows little response to precipitation events, has fluctuations of few meters related to seasonal trends, and maintains pressure head higher than that in the unconfined one. This makes

  19. Hydrogeologic framework, groundwater movement, and water budget in the Chimacum Creek basin and vicinity, Jefferson County, Washington

    USGS Publications Warehouse

    Jones, Joseph L.; Welch, Wendy B.; Frans, Lonna M.; Olsen, Theresa D.

    2011-01-01

    This report presents information used to characterize the groundwater flow system in the Chimacum Creek basin. It includes descriptions of the geology and hydrogeologic framework; groundwater recharge and discharge; groundwater levels and flow directions; seasonal fluctuations in groundwater level; interactions between aquifers and the surface-water system; and a groundwater budget. The study area covers 124 square miles in northeastern Jefferson County, Washington, and includes the Chimacum Creek basin, which drains an area of about 37 square miles. The area is underlain by a north-thickening sequence of unconsolidated glacial and interglacial deposits that overlie sedimentary and igneous bedrock units that crop out along the margins and western interior of the study area. Six hydrogeologic units consisting of unconsolidated aquifers and confining units, along with an underlying bedrock unit, were identified. A surficial hydrogeologic map was developed and used with well information from 187 drillers' logs to construct 4 hydrogeologic sections, and maps showing the extent and thickness of the units. Natural recharge was estimated using precipitation-recharge relation regression equations developed for western Washington, and estimates were calculated for return flow from data on domestic indoor and outdoor use and irrigated agriculture. Results from synoptic streamflow measurements and water table elevations determined from monthly measurements at monitoring wells are presented and compared with those from a study conducted during 2002-03. A water budget was calculated comprising long-term average recharge, domestic public-supply withdrawals and return flow, self-supplied domestic withdrawals and return flow, and irrigated agricultural withdrawals and return flow.

  20. Review and reconnaissance of the hydrogeology of Tertiary sedimentary rocks in the vicinity of Frenchman Flat, Nevada Test Site

    SciTech Connect

    Prothro, L.B.; Drellack, S.L. Jr.

    1997-09-01

    Work is currently underway within the Underground Test Area (UGTA) subproject of the US Department of Energy/Nevada Operations Office Environmental Restoration Program to develop corrective action plans in support of the overall corrective action strategy for the Nevada Test Site (NTS) as established in the Federal Facility Agreement and Consent Order (FFACO, 1996). A closure plan is currently being developed for Frenchman Flat, which has been identified in the FFACO as a Corrective Action Unit (CAU). Part of this effort requires that hydrogeologic data be compiled for inclusion in a CAU-specific hydrologic flow and transport model that will be used to predict contaminant boundaries. Hydrogeologic maps and cross sections are currently being prepared for use in the model to define the nature and extent of aquifers and confining units that might influence the flow of contaminated groundwater from underground nuclear tests conducted in Frenchman Flat. During this effort, it has been found that older Tertiary-age sediments might be hydrogeologically important in the Frenchman Flat model area. Although the character and extent of these units are poorly known, there is reason to believe that in some parts of Frenchman Flat they may lie between the regional Lower Carbonate Aquifer (LCA) and the younger Tertiary saturated alluvium and volcanic units in which several underground nuclear tests were conducted. It was not possible to quickly determine their extent, or ascertain whether or not these units might act as confining units or aquifers. The work described in this report was done to gain a better understanding of the hydrogeology of these rocks.

  1. [The contents of radon in deep borehole water of hydro-geological region of Gdańsk].

    PubMed

    Pachocki, K A; Gorzkowski, B; Rózycki, Z; Majle, T

    1999-01-01

    Radon 222Rn in deep borehole water of Gdańsk Hydrogeological Region has been quantitative determined. This region is located in east part of Gdańsk Voivodship and in west part of Elblag Voivodship including Zuławy. The measurements were performed using alpha liquid scintillation counting method. Only in some case the concentrations of 222Rn in investigated samples exceed recommended limit 11 Bq/l. PMID:10523933

  2. The Supporting Role of Mesocosm-Scale Laboratory Experiments in Solving Critical Issues at Hydrogeological Research Sites

    NASA Astrophysics Data System (ADS)

    Schincariol, R.; Nagare, R.; Quinton, W.; Hayashi, M.

    2008-12-01

    Hydrogeological research sites provide a unique opportunity to study parameters and processes at the field scale. However, the most successful long-term research sites have been coupled with laboratory-scale experiments and numerical modeling studies. Mesocosm-scale laboratory experiments allow the investigation of local-scale hydrogeological processes often with sensors that exceed the spatial, temporal, and accuracy of field based monitoring. After over two years of design and construction a unique mesocosm-scale hydrogeological climate chamber was emplaced at the University of Western Ontario Biotron facility in April 2008. What makes this chamber different from other ecohydrological chambers is the ability to reproduce the subarctic solar and atmospheric environment and house soil monoliths up to 1.5 m in diameter and 4 m in height. Of particular importance is the ability to subject soil monoliths, inclusive of vegetation, to climate forcing experiments (varying solar energy, air temperature, precipitation, wind, CO2) while continuously monitoring liquid, gas, and energy fluxes. At present, experiments on 60 cm diameter by 90 cm deep peat / permafrost cores from our central Mackenzie River basin long-term field site are being conducted to better elucidate moisture and carbon transport processes occurring in the active layer. These climate forcing laboratory based experiments will be closely integrated with on-going field studies in the basin. Through this research we will be able to develop a physically-based numerical model to estimate the volume and timing of runoff from wetland-dominated basins in discontinuous permafrost. The experiments will answer critical questions, not addressable by field data alone, on how subarctic ecosystems will respond to climate change. We would also like to foster collaborations to address other scientific questions utilizing the climate chamber. In particular, experiments in support of pilot scale remediation efforts in cold

  3. Calendar Year 1994 Groundwater Quality Report for the Bear Creek Hydrogeologic Regime Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1995-02-01

    This annual groundwater quality report (GWQR) contains groundwater and surface water quality data obtained during the 1994 calendar year (CY) at several hazardous and non-hazardous waste-management facilities associated with the U.S. Department of Energy (DOE) Y-12 Plant located on the DOE Oak Ridge Reservation (ORR) southeast of Oak Ridge, Tennessee. The sites addressed by this document are located in Bear Creek Valley (BCV) west of the Y-12 Plant complex (directions in this report are in reference to the Y-12 administrative grid system) within the Bear Creek Hydrogeologic Regime (Bear Creek Regime), one of three hydrogeologic regimes defined for the purposes of groundwater and surface water quality monitoring at the Y-12 Plant. The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Organization manages the groundwater monitoring activities in the Bear Creek Regime under the auspices of the Y-12 Plant Groundwater Protection Program (GWPP). The purpose of the GWPP is to characterize the hydrogeology and to monitor groundwater quality at the Y-12 Plant and surrounding area to provide for protection of groundwater resources consistent with federal, state, and local requirements and in accordance with DOE Orders and Martin Marietta Energy Systems, Inc. (Energy Systems) corporate policy. The annual GWQR for the Bear Creek Regime is completed in two parts. Part 1 (this report) consists primarily of data appendices and serves as a reference for the groundwater quality data obtained each CY under the lead of the Y-12 Plant GWPP. Part 2 of the report, to be issued mid-year, will contain an evaluation of the data with respect to regime-wide groundwater quality, present the findings and status of ongoing hydrogeologic studies, describe changes in monitoring priorities, and present planned modifications to the groundwater sampling and analysis program for the following CY.

  4. Hydrogeologic inferences from geophysical and geologic investigation of the Standard Mine site, Elk Basin, Colorado

    NASA Astrophysics Data System (ADS)

    Minsley, B. J.; Caine, J. S.; Ball, L. B.; Burton, B.; Curry-Elrod, E.; Manning, A. H.; Verplanck, P. L.

    2009-12-01

    Geophysical and geologic data were collected at the Standard Mine in Elk Basin near Crested Butte, CO, to improve our understanding of the hydrogeologic controls in the basin and how they influence surface and groundwater interactions with nearby mine workings. The Tertiary Ohio Creek and Wasatch formations are the bedrock geologic units; both are primarily sandstones, but with differences in weathering and fracturing. Dikes, near-vertical normal faults, and polymetallic quartz veins with varying degrees of lateral continuity cut the sedimentary units. The net impact of these features, along with basin topography, makes it difficult to predict the behavior of the surface and groundwater systems. This integrated study utilizes geologic observations to help constrain subsurface information obtained from the analysis of surface geophysical measurements. This is a critical step toward using the geophysical data in a meaningful hydrogeologic framework. The approach combines the benefit of direct, but sparse, field observations with spatially continuous, but indirect, measurements of physical properties through the use of geophysics. Surface geophysical data includes electrical resistivity profiles aimed at imaging variability in subsurface structural properties and fluid content; self-potentials, which are sensitive to mineralized zones at this site and, to a lesser extent, shallow flow patterns; and magnetic measurements, which provide information on lateral variability in near-surface geologic features, although the minerals at this site are not strongly magnetized. Downhole caliper and optical televiewer logs were acquired in one well and provide valuable information on fracture properties. Field geologic observations include hand sample mineralogy and detailed mapping and characterization of faults, joints, and veins. Analyses of representative rock samples include magnetic susceptibility, mercury injection capillary pressure, semi-quantitative x-ray diffraction

  5. The flood event of November 2013 in Calabria (southern Italy): damage and hydrogeological characteristics

    NASA Astrophysics Data System (ADS)

    Petrucci, Olga; Caloiero, Tommaso; Aurora Pasqua, Angela

    2014-05-01

    On November 19th, 2013, Calabria region (southern Italy) has been affected by a flood event which caused numerous damages in particular in the Ionian side of the region. In this work, the event is analyzed in terms of damage and hydrologic features. Beside rainfall, the event has been characterized by intense sea storms which, increased by Sirocco gusts, obstructed the outlet of the floods toward the sea. As a result, river overflowing was amplified and caused the breaking of either natural or artificial embankments. Damage affected 49 municipalities located in the mid-east sector, on a surface of 1898 km2 (12.6% of the Calabrian area). Roads (damaged in 86% of the affected municipalities) and private buildings (39%) were the most heavily damaged elements: in many cases the water level reached 1m. People were directly involved in risky situations but they managed to save their lives: only two people were injured. Return periods of daily rain can be classified as ordinary (between 2 and 13 years) with the only exception of a gauge located in the northern east sector, which showed a return period of more than 100 years. On the contrary, 3-hour rain shows peak values of 160 mm and return period higher than 200 years. As a result, the event can be considered an "impulsive" one, powered by intense hourly rain, and its dangerousness was mainly related to the "flash" character of the triggered floods. The analysis of circumstances in which people were directly threatened confirms floods as the main source of risk, both indoors (65% of cases) and outdoors (35%); in the latter case, the majority of people involved were on board of vehicles (26%). Differently from the past Calabrian damaging hydrogeological events, people did not adopt unnecessary risky behaviors, and in 26% of cases they managed to save their life without any help. Probably this is the factor that lead to low damage to people, since only two people were slightly injured. These results could be proficiently

  6. Hydrogeologic framework and salinity distribution of the Floridan aquifer system of Broward County, Florida

    USGS Publications Warehouse

    Reese, Ronald S.; Cunningham, Kevin J.

    2014-01-01

    Concerns about water-level decline and seawater intrusion in the surficial Biscayne aquifer, currently the principal source of water supply to Broward County, prompted a study to refine the hydrogeologic framework of the underlying Floridan aquifer system to evaluate its potential as an alternative source of supply. This report presents cross sections that illustrate the stratigraphy and hydrogeology in eastern Broward County; maps of the upper surfaces and thicknesses of several geologic formations or units within the Floridan aquifer system; and maps of two of the potentially productive water-bearing zones within the system, the Upper Floridan aquifer and the Avon Park permeable zone. An analysis of data on rock depositional textures, associated pore networks, and flow zones in the Floridan aquifer system shows that groundwater moves through the system in two ways. These data support a conceptual, dual-porosity model of the system wherein groundwater moves either as concentrated flow in discrete, thin bedding-plane vugs or zones of vuggy megaporosity, or as diffuse flow through rocks with primarily interparticle and moldic-particle porosity. Because considerable exchange of groundwater may occur between the zones of vuggy and matrix-dominated porosity, understanding the distribution of that porosity and flow zone types is important to evaluating the suitability of the several units within the Floridan aquifer system for managing the water through practices such as aquifer storage and recovery (ASR). The salinity of the water in the Floridan aquifer system is highest in the central part of the study area, and lower toward the north and south. Although salinity generally increases with depth, in the western part of the study area a zone of relatively high saline water is perched above water of lower salinity in the underlying Avon Park permeable zone. Overall, the areas of highest salinity in the aquifer system coincide with those with the lowest estimated

  7. Estimating the Prospectivity of Geothermal Resources Using the Concept of Hydrogeologic Windows

    NASA Astrophysics Data System (ADS)

    Bielicki, Jeffrey; Blackwell, David; Harp, Dylan; Karra, Satish; Kelley, Richard; Kelley, Shari; Middleton, Richard; Person, Mark; Sutula, Glenn; Witcher, James

    2016-04-01

    In this Geothermal Play Fairways Analysis project we sought to develop new ways to analyze geologic, geochemical, and geophysical data to reduce the risk and increase the prospects of successful geothermal exploration and development. We collected, organized, and analyzed data from southwest New Mexico in the context of an integrated framework that combines the data for various signatures of a geothermal resource into a cohesive analysis of the presence of heat, fluid, and permeability. We incorporated data on structural characteristics (earthquakes, geophysical logs, fault location and age, basement depth), topographic and water table elevations, conservative ion concentrations, and thermal information (heat flow, bottom hole temperature, discharge temperature, and basement heat generation). These data were combined to create maps that indicate structural analysis, slope, geothermometry, and heat. We also mapped discharge areas (to constrain elevations where groundwater may be discharged through modern thermal springs or paleo-thermal springs) and subcrops: possible erosionally- or structurally-controlled breaches in regional-scale aquitards that form the basis of our hydrogeologic windows concept. These two maps were particularly useful in identifying known geothermal systems and narrowing the search for unknown geothermal prospects. We further refined the "prospectivity" of the areas within the subcrops and discharge areas by developing and applying a new method for spatial association analysis to data on known and inferred faults, earthquakes, geochemical thermometers, and heat flow. This new methodology determines the relationships of the location and magnitudes of observations of these data with known geothermal sites. The results of each of the six spatial association analyses were weighted between 0 and 1 and summed to produce a prospectivity score between 0 and 6, with 6 indicating highest geothermal potential. The mean value of prospectivity for all

  8. Evaluation of geochemical and hydrogeological processes by geochemical modeling in an area affected by evaporite karstification

    NASA Astrophysics Data System (ADS)

    Acero, P.; Auqué, L. F.; Galve, J. P.; Gutiérrez, F.; Carbonel, D.; Gimeno, M. J.; Yechieli, Y.; Asta, M. P.; Gómez, J. B.

    2015-10-01

    The Ebro Valley in the outskirts of Zaragoza (NE Spain) is severely affected by evaporite karstification, leading to multiple problems related to subsidence and sinkhole formation. In this work, a combination of inverse (mixing + mass-balance) and forward (reaction-path) geochemical calculations is applied for the quantification of the main karstification processes and seasonal variations in this area. The obtained results prove the suitability of the applied methodology for the characterization of similar problems in other areas with scarce geological and hydrogeological information. The hydrogeology and hydrochemistry of the system can be mainly attributed to the mixing of variable proportions of concentrated groundwater from the evaporitic aquifer and more dilute water from the overlying alluvial aquifer. The existence of a good connection between these aquifers is supported by: (1) the fast changes in the hydrochemistry of the karst aquifer related to recharge by irrigation, and (2) the deduced input of evaporitic groundwater in the alluvial materials. The evolution in some parts of the alluvial/evaporitic aquifer system is clearly dominated by the seasonal variations in the recharge by dilute irrigation waters (up to 95% of water volume in some sinkhole ponds), whereas other points seem to be clearly determined by the hydrochemistry of the concentrated evaporitic aquifer groundwater (up to 50% of the water volume in some springs). The following reactions, previous or superimposed to mixing processes, explain the observed hydrochemistry in the studied area: dissolution of halite (NaCl), gypsum (CaSO4ṡ2H2O)/anhydrite (CaSO4) and dolomite (CaMg(CO3)2), CO2(g) input and degassing and calcite (CaCO3) dissolution/precipitation. The modeling results suggest the existence of a large spatial variability in the composition of the evaporitic groundwater, mainly caused by large differences in the availability of halite in contact with the groundwater. Active subsidence

  9. Hydrogeologic controls on baseflow temperature distributions: Implications for stream temperature response to climate variability

    NASA Astrophysics Data System (ADS)

    Boutt, D. F.; Smith, Z.

    2012-12-01

    Ground water temperature distributions in the near surface are not uniform and are the complex result of a variety of near- and sub-surface processes. Heat from the atmosphere is input into the ground via conduction at the ground surface and advection of infiltrating water. These processes produce predictable distributions of temperature that have been used to investigate current and past climatic conditions, determine ground water velocities, and assess basin-scale heat transport in sedimentary systems. The purpose of this investigation is to test a hypothesis that timing and nature of ground water recharge (advection of heat into the subsurface) is a significant control on the temporal and spatial distribution of heat in the shallow subsurface. The advective movement of heat imposes a dominant control on the 3-dimensional subsurface temperature distribution and strongly affects stream baseflow temperatures. We present observational data supporting a strong hydrogeologic control on subsurface water temperatures. These temperature distributions are modified by advection and are significantly different than theoretical distributions in a conduction-dominated environment. The temperature distributions with depth and space are controlled by the aquifers internal hydrogeologic structure and connections to recharge areas. Synthetic modeling is used to address the following questions: (1) how quickly do ground water temperatures respond to a changing climate, and how quickly do they reach a new equilibrium following perturbation; (2) what is the role of recharge water temperature and timing on subsurface temperature distributions; and (3) how do these factors influence baseflow temperatures in stream systems of varying size. Two-dimensional numerical models are developed using Comsol Multiphysics to perform a sensitivity analysis of basin-scale temperature response and coupling to surface water. In nested ground water flow systems, discharge areas farther down the

  10. Hydrogeology and analysis of ground-water-flow system, Sagamore Marsh area, southeastern Massachusetts

    USGS Publications Warehouse

    Walter, D.A.; Masterson, J.P.; Barlow, P.M.

    1996-01-01

    A study of the hydrogeology and an analysis of the ground-water-flow system near Sagamore Marsh, southeastern Massachusetts, was undertaken with the cooperation of the U.S. Army Corps of Engineers. The purpose of the study was to improve the understanding of the current (1994-95) hydrogeologic conditions near the marsh and how the ground-water system might respond to proposed changes in the tidal-stage regime of streams that flood and drain the marsh. A 5-day aquifer test at a public-supply well adjacent to the marsh gave a transmissivity of the regional aquifer of 9,300 to 10,900 feet squared per day and a hydraulic conductivity of 181 to 213 feet per day, assuming a saturated thickness of the aquifer of 51.3 feet. The regional aquifer became unconfined near the pumped well during the test. The ratio of tidal ranges in the tidal channel to the ranges in the underlying aquifer at two sites (the lower and upper marsh) indicated aquifer diffusivities for the marsh sediments of 380 and 170 feet squared per day; these values correspond to hydraulic conductivities of 2.5 x 10-3 and 1.7 x 10-3 feet per day, respectively. The maximum distances from the tidal channel at the lower and upper marsh sites where tidal ranges would exceed 0.01 foot, as calculated from aquifer diffusivities and current (1995) tidal ranges in the tidal channels, were 24.4 and 26.7 feet, respectively. The maximum distances from the tidal channel where tidal pulses in the ground water would exceed 0.01 foot, using potential increased tidal stages resulting from proposed tidal-stage modifications and predicted by the U.S. Army Corps of Engineers, were 37.1 and 42.0 feet, respectively. A numerical model of the marsh and surrounding aquifer system indicated that the contributing area for the supply well adjacent to the marsh, for current (1994) pumping conditions, extends toward Great Herring Pond, about 2 miles northwest (upgradient) of the well, and does not extend beneath the marsh. The model also

  11. Hydrogeological studies in high mountains karst environment: the example of Picos de Europa (Spain)

    NASA Astrophysics Data System (ADS)

    Meléndez, Mónica; Ballesteros, Daniel; Jiménez-Sanchez, Montserrat; García-Sansegundo, Joaquín

    2015-04-01

    Karst aquifers are very vulnerable to contamination due their high infiltration coefficient, elevated hydraulic conductivity, high speed of circulation, and very low self-purification capacities. The functioning of that type of aquifer is quite complicated by the high heterogeneity and anisotropy of the karst and the presence of three different types of porosity. It is necessary to understand the functioning of a karst aquifer in order to protect and manage them properly. Therefore, it is necessary to develop working methods to establish the aquifer hydrodynamics, especially in high mountain areas with many methodological constrains (e. g. difficulty to access). The Picos de Europa karst aquifer, located in theNational Park of Picos de Europa (North Spain), presents a high environmental, geomorphological and hydrogeological value; it is included in the "Spanish geological contexts with global relevance" by the Law of Natural Heritage and Biodiversity of Spain, being considered as a Global Geosite by the Geological and Mining Institute of Spain. In addition, the karst massif is included in several figures of environmental protection, both at global and national levels. Hydrogeological and geomorphological research is developed together in this area under the GEOCAVE project (MAGRAMA-580/12 OAPN) and the "Investigación hidrogeológica en las masas de agua subterránea 012.014 Picos de Europa-Panes y 012.018 Alto Deva-Alto Cares. (IGME-73.3.00.41.00/2013)". The aim of this study is to characterize the hydrodynamics of the karst aquifer, considering the snow as an important component of the aquifer recharge. The proposed methodology includes the installation of an integrated pressure sensor and data logger for level and temperature measurement in two karst spring related to two groundwater bodies (GWB) with 86 and 14 km2 extension. The store of data to regular intervals with punctual values of discharge measures has provided, at least, an annual series of data in

  12. Efficiency Evaluation of Open-Loop GHPS Operation Under Various Hydrogeological Conditions

    NASA Astrophysics Data System (ADS)

    Lee, S.; Kim, S.; Bae, G.; Lee, K.

    2008-12-01

    Geothermal heat pump system (GHPS) can be cost-effective renewable energy sources. In order to develop the GHPS which has certain hydrogeological characteristics, understanding the thermohydraulic process of an aquifer is necessary for effective usage of open-loop GHPS. Experimental and numerical tests are performed for two concepts of open-loop GHPS: simple open-loop and energy storage concept. In simple open-loop sets, tests were performed fixing the locations of pumping and injection wells. In contrast, tests in energy storage sets were conducted by changing the locations of wells in a seasonal cycle. Experimental test using sand tank was performed only for the simple open-loop concept, while numerical tests were performed for the both concepts. Numerical modeling results using FEFLOW were compatible with the experimental results. In the simple open-loop sets, the temporal temperature change in a pumping well was measured. Effective operation conditions are obtained with high hydraulic conductivity (3X10-3 m/s) and long distance (60 cm) between wells on hydraulic gradient 0.025 because the effect of injected water temperature must be minimized. In the energy storage sets, thermal recovery factors (R) under various conditions were calculated to evaluate the efficiency. Low hydraulic conductivity (3X10-5 m/s), hydraulic gradient 0.0 and long well distance (more than 20 m) are the best conditions for operation efficiency (R=37.92) because faster groundwater flow lead to advection or down-gradient `drift' of stored energy beyond potential recovery regions. In the case of two-layered aquifer, the porosity and groundwater flow characteristics of each layer sensitively affected the migration of thermal plume. Two-layered aquifer with the top-layer of low hydraulic conductivity (3X10-5 m/s) and porosity (0.2) is profitable for the effective open-loop GHPS operation under hydraulic gradient 0.0 and well distance (20 m). The results from experimental and numerical tests

  13. Hydrogeology and simulation of ground-water flow, Picatinny Arsenal and vicinity, Morris County, New Jersey

    USGS Publications Warehouse

    Voronin, L.M.; Rice, D.E.

    1996-01-01

    Ground-water flow in glacial sediments and bedrock at Picatinny Arsenal, N.J., was simulated by use of a three-dimensional finite-difference ground- water-flow model. The modeled area includes a 4.3-square-mile area that extends from Picatinny Lake to the Rockaway River. Most of the study area is bounded by the natural hydrologic boundaries of the ground-water system. eophysical logs, lithologic logs, particle-size data, and core data from selected wells and surface geophysical data were analyzed to define the hydrogeologic framework. Hydrogeologic sections and thickness maps define six permeable and three low-permeability layers that are represented in the model as aquifers and confining units, respectively. Hydrologic data incorporated in the model include a rate of recharge from precipitation of 22 inches per year, estimated from long-term precipitation records and estimates of evapotranspiration. Additional recharge from infiltration along valleys was estimated from measured discharge of springs along the adjacent valley walls and from estimates of runoff from upland drainage that flows to the valley floor. Horizontal and vertical hydraulic conductivities of permeable and low-permeability layers were estimated from examination of aquifer-test data, gamma-ray logs, borehole cuttings, and previously published data. Horizontal hydraulic conductivities in glacial sediments range from 10 to 380 feet per day. Vertical hydraulic conductivities of the low-permeability layers range from 0.01 to 0.7 feet per day. The model was calibrated by simulating steady-state conditions during 1989-93 and by closely matching simulated and measured ground-water levels, vertical ground-water-head differences, and streamflow gain and loss. Simulated steady-state potentiometric- surface maps produced for the six permeable layers indicate that ground water in the unconfined material within Picatinny Arsenal flows predominantly toward the center of the valley, where it discharges to Green

  14. Canadian groundwater inventory: Regional hydrogeological characterization of the south-central part of the maritimes basin

    USGS Publications Warehouse

    Rivard, C.; Michaud, Y.; Deblonde, C.; Boisvert, V.; Carrier, C.; Morin, R.H.; Calvert, T.; Vigneault, H.; Conohan, D.; Castonguay, S.; Lefebvre, R.; Rivera, A.; Parent, M.

    2008-01-01

    The Maritimes Groundwater Initiative (MGWI) is a large, integrated, regional hydrogeological study focusing on a representative area of the Maritimes Basin in eastern Canada. The study area covers a land surface of 10 500 km2, of which 9 400 km2 are underlain by sedimentary rocks. This sedimentary bedrock is composed of a sequence of discontinuous strata of highly variable hydraulic properties, and is generally overlain by a thin layer of glacial till(mostly 4-8 m thick, but can reach 20 m). Depending on the area, 46 to 100% of the population relieson groundwater for water supply, either from municipal wells or from private residential wells. The main objectives of this project were to improve the general understanding of groundwater-flow dynamics and to provide baseline information and tools for a regional groundwater-resource assessment. This bulletin presents the current state of understanding of this hydrogeological system, along with the methodology used to characterize and analyze its distinct behaviour at three different scales. This regional bedrock aquifer system contains confined and unconfined zones, and each of its lenticular permeable strata extends only a few kilometres. Preferential groundwater recharge occurs where sandy till is present. The mean annual recharge rate to the bedrock is estimated to range between 130 and 165 mm/a. Several geological formations of this basin provide good aquifers, with hydraulic conductivity in the range 5x10-6 to 10-4m/s. Based on results of numerical flow modelling, faults were interpreted to have a key role in the regional flow. Pumping-test results revealed that the fractured aquifers can locally be very heterogeneous and anisotropic, but behave similarly to porous media. Work performed at the local scale indicated that most water-producing fractures seem to be subhorizontal and generally oriented in a northeasterly direction, in agreement with regional structures and pumping-test results. Almost all residential

  15. Hydrogeological characterization of the Heletz Sands Reservoir, Heletz (Israel) as a preliminary step towards CO2 injection experiments

    NASA Astrophysics Data System (ADS)

    Bensabat, Jacob; Niemi, Auli; Tsang, Chin-Fu; Sharma, Prabhakar; Carrera, Jesus; Sauter, Martin; Tatomir, Alexandru; Ghergut, Julia; Pezard, Philippe; Edlman, Katriona; Brauchler, Ralf

    2013-04-01

    Hydrogeological characterization of the Heletz Sands Reservoir, Heletz (Israel) as a preliminary step towards CO2 injection experiments One the major components of the EU-FP7 funded MUSTANG project is to conduct a highly controlled series of CO2 injection experiments, aimed at determining field values of key CO2 trapping mechanisms such as dissolution and residual trapping and to establish a comprehensive and consistent dataset for model validation. Prior to injecting CO2 there is a need to achieve a sufficient degree of hydrogeological characterization of the reservoir. In what follows we present a sequence of hydrologic tests to be conducted at Heletz and their expected contribution to the understanding relevant hydrogeology. These include: 1) Chemical characterization of the formation fluid; 2) Flowing Fluid Electrical Conductivity log, aimed at determining the vertical variability of the reservoir permeability in the near well vicinity; 3) Water pulse and pumping tests, aimed at determining the reservoir scale hydraulic properties; 4) Thermal test, aimed at determining the value of the heat transfer coefficient from the reservoir to the borehole fluid, which is responsible for the heating of injected fluid in the borehole; 5) two-well injection and pumping of water and tracers test, in order to determine the impact of heterogeneity on the hydraulic parameters and to identify preferential flow paths in the reservoir. This paper presents the design and planning of the experiments, the results obtained in field and a preliminary interpretation.

  16. Application of ground-penetrating radar methods in determining hydrogeologic conditions in a karst area, west-central Florida

    USGS Publications Warehouse

    Barr, G.L.

    1993-01-01

    Ground-penetrating radar (GPR) is useful as a surface geophysical method for exploring geology and subsurface features in karst settings. Interpretation of GPR data was used to infer lithology and hydrogeologic conditions in west-central Florida. This study demonstrates how GPR methods can be used to investigate the hydrogeology of an area. GPR transmits radio- frequency electromagnetic waves into the ground and receives reflected energy waves from subsurface interfaces. Subsurface profiles showing sediment thickness, depth to water table and clay beds, karst development, buried objects, and lake-bottom structure were produced from GPR traverses obtained during December 1987 and March 1990 in Pinellas, Hillsborough, and Hardee Counties in west-central Florida. Performance of the GPR method is site specific, and data collected are principally affected by the sediment and pore fluids, conductances and dielectric constants. Effective exploration depths of the GPR surveys through predominately unsaturated and saturated sand and clay sediments at five study sites ranged from a few feet to greater than 50 feet below land surface. Exploration depths were limited when high conductivity clay was encountered, whereas greater exploration depths were possible in material composed of sand. Application of GPR is useful in profiling subsurface conditions, but proper interpretation depends upon the user's knowledge of the equipment and the local hydrogeological setting, as well as the ability to interpret the graphic profile.

  17. Hydrogeologic evaluation and numerical simulation of the Death Valley regional ground-water flow system, Nevada and California

    SciTech Connect

    D`Agnese, F.A.; Faunt, C.C.; Turner, A.K.; Hill, M.C.

    1997-12-31

    Yucca Mountain is being studied as a potential site for a high-level radioactive waste repository. In cooperation with the U.S. Department of Energy, the U.S. Geological Survey is evaluating the geologic and hydrologic characteristics of the ground-water system. The study area covers approximately 100,000 square kilometers between lat 35{degrees}N., long 115{degrees}W and lat 38{degrees}N., long 118{degrees}W and encompasses the Death Valley regional ground-water flow system. Hydrology in the region is a result of both the and climatic conditions and the complex described as dominated by interbasinal flow and may be conceptualized as having two main components: a series of relatively shallow and localized flow paths that are superimposed on deeper regional flow paths. A significant component of the regional ground-water flow is through a thick Paleozoic carbonate rock sequence. Throughout the regional flow system, ground-water flow is probably controlled by extensive and prevalent structural features that result from regional faulting and fracturing. Hydrogeologic investigations over a large and hydrogeologically complex area impose severe demands on data management. This study utilized geographic information systems and geoscientific information systems to develop, store, manipulate, and analyze regional hydrogeologic data sets describing various components of the ground-water flow system.

  18. Geophysical borehole logging for control of driller's records: hydrogeological case study from Voltaian sedimentary rocks in northern Ghana

    NASA Astrophysics Data System (ADS)

    Agyekum, William; Klitten, Kurt; Armah, Thomas; Banoeng-Yakubo, Bruce; Amartey, Edmund Okoe

    2013-06-01

    The low borehole yielding potential and the high drilling failure rate of the Voltaian sedimentary rocks of Northern Ghana have been of concern to many local hydrogeologists and international donors. Consequently, several donor-supported projects have been instituted within the last few years with the view to study the hydrogeological characteristics of this `difficult' rock system. One such project is the geophysical borehole logging of 13 boreholes drilled into the Voltaian sedimentary rocks of Northern Ghana to enhance detailed hydrogeological assessment. Natural gamma detectors embedded in the five exploratory logging tools employed for the study ensured depth control by comparing their individual gamma log signatures. The combined gamma and formation resistivity/conductivity response logs provided more detailed lithological information than were shown in the driller's/geologist's logs. Significant discrepancies between the logging results and the reported drilled depths, construction depths, and screen settings were observed in seven of the thirteen investigated boreholes. Thus, the reliability of driller's borehole records seems questionable, which will hamper hydrogeological studies and the mapping of groundwater resources. Further, it may be supposed that the productivity of most wells in Ghana is compromised by poor depth control of screen placement.

  19. Characterization of Spatial Variability of Hydrogeologic Properties for Unsaturated Flow in the Fractured Rocks at Yucca Mountain, Nevada

    SciTech Connect

    Zhou, Quanlin; Bodvarsson, Gudmundur S.; Liu, Hui-Hai; Oldenburg, Curtis M.

    2002-05-21

    The spatial variability of layer-scale hydrogeologic properties of the unsaturated zone (UZ) at Yucca Mountain, Nevada, is investigated using inverse modeling. The thick UZ is grouped into five hydrostratigraphic units and further into 35 hydrogeologic layers. For each layer, lateral variability is represented by the variations in calibrated values of layer-scale properties at different individual deep boreholes. In the calibration model, matrix and fracture properties are calibrated for the one-dimensional vertical column at each individual borehole using the ITOUGH2 code. The objective function is the summation of the weighted misfits between the ambient unsaturated flow (represented by measured state variables: water saturation, water potential, and pneumatic pressure) and the simulated one in the one-dimensional flow system. The objective function also includes the weighted misfits between the calibrated properties and their prior information. Layer-scale state variables and prior rock properties are obtained from their core-scale measurements. Because of limited data, the lateral variability of three most sensitive properties (matrix permeability, matrix of the van Genuchten characterization, and fracture permeability) is calibrated, while all other properties are fixed at their calibrated layer-averaged values. Considerable lateral variability of hydrogeologic properties is obtained. For example, the lateral variability of is two to three orders of magnitude and that of and is one order of magnitude. The effect of lateral variability on site-scale flow and transport will be investigated in a future study.

  20. Karst connections between unconfined aquifers and the Upper Floridan aquifer in south Georgia: geophysical evidence and hydrogeological models

    NASA Astrophysics Data System (ADS)

    Thieme, D. M.; Denizman, C.

    2011-12-01

    Buried karst features in sedimentary rocks of the south Georgia Coastal Plain present a challenge for hydrogeological models of recharge and confined flow within the underlying Upper Floridan aquifer. The Withlacoochee River, the trunk stream for the area, frequently disappears into subsurface caverns as it makes its way south to join the Suwannee River in northern Florida. The Withlacoochee also receives inputs from small ponds and bays which in turn receive spring and seep groundwater inputs. We have mapped karst topography at the "top of rock" using ground-penetrating radar (GPR). Up to seven meters of relief is indicated for the paleotopography on Miocene to Pliocene rocks, contrasting with the more subdued relief of the modern landscape. Current stratigraphic and hydrogeological reconstructions do not incorporate this amount of relief or lateral variation in the confining beds. One "pipe" which is approximately four meters in diameter is being mapped in detail. We have field evidence at this location for rapid movement of surficial pond and river water with a meteoric signature through several separate strata of sedimentary rock into an aquifer in the Hawthorn formation. We use our geophysical and hydrological field evidence to constrain quantitative hydrogeological models for the flow rates into and out of both this upper aquifer and the underlying Upper Floridan aquifer, which is generally considered to be confined by the clays of the Hawthorn.

  1. Hydrogeologic factors in the selection of shallow land burial sites for the disposal of low-level radioactive waste

    USGS Publications Warehouse

    Fischer, John N.

    1986-01-01

    In the United States, low-level radioactive waste is disposed of by shallow land burial. Commercial low-level radioactive waste has been buried at six sites, and low-level radioactive waste generated by the Federal Government has been buried at nine major and several minor sites. Several existing low-level radioactive waste sites have not provided expected protection of the environment. These shortcomings are related, at least in part, to an inadequate understanding of site hydrogeology at the time the sites were selected. To better understand the natural systems and the effect of hydrogeologic factors on long-term site performance, the U.S. Geological Survey has conducted investigations at five of the six commercial low-level radioactive waste sites and at three Federal sites. These studies, combined with those of other Federal and State agencies, have identified and confirmed important hydrogeologic factors in the effective disposal of low-level radioactive waste by shallow land burial. These factors include precipitation, surface drainage, topography, site stability, geology, thickness of the host soil-rock horizon, soil and sediment permeability, soil and water chemistry, and depth to the water table.

  2. Detailed hydrogeological investigation and conceptual modelling of an Alpine Main Valley crossed by the Brenner Bases tunnel

    NASA Astrophysics Data System (ADS)

    Burger, Ulrich; San Nicolo, Lorenz; Zurlo, Raffaele

    2014-05-01

    The Brenner Base Tunnel (BBT) will cross the Isarco Valley near the village of Fortezza (BZ) at a depth of approximately 20 m below the riverbed of the Isarco river. The design of this roughly 1 km long stretch through alluvial sediments and below groundwater level required detailed knowledge of the prevailing hydrogeological conditions. In particular, it was necessary to determine if dewatering procedures were feasible and what the impacts on natural water flows in the aquifer after completion of the infrastructure will be. The study area is a typical Alpine valley, filled with alluvial sediments to a maximum depth of approximately 120m. The valley is bounded by granitic rocks with regional, water saturated main fault zones. In addition to the Isarco River, the area is shaped by two lateral rivers. The deposits of these lateral rivers form main alluvial fans. The aim of the study was to study the geological structure and the hydrogeological behaviour of this alpine valley. Therefor a detailed geological and hydrogeological investigation program was carried out, including a geological detailed mapping, construction of 40 boreholes (max. depth 120m; 35 are equipped to groundwater monitoring wells) and 5 large wells (55m - 87m). In order to determine the hydrodynamic characteristics of the aquifer in the valley, several pumping tests were carried out in different study stages: Stage 1: preliminary hydrogeological characterization of the area based on a pumping test carried out in the first well (100l/s pumping for 14 days). Stage 2: individual step tests and constant rate tests in additional four wells Stage 3: main pumping test including all the five wells with a maximum pumping rate of 450l/s for 14 days. The main topics oh the presentation are: - Overview of the BBT-project, the investigation area and investigation program - Description of the validated geological model of the main alpine valley - Results of the various hydraulic tests performed in the individual

  3. Groundwater protection of minimal water supply systems integrating simple hydrogeological information

    NASA Astrophysics Data System (ADS)

    Rodrigo-Ilarri, Javier; Rodrigo-Clavero, María Elena

    2016-04-01

    According to the current EU environmental legislation, groundwater protection is one of the key issues to be addressed when new industrial activities have to be authorised. This work shows a simple methodology that could be used by local and environmental authorities in order to analyse the potential risk caused by an industrial spill on a natural environment. The methodology leads to the determination of the protection area around an extraction well system using the information given by: i) a set of local piezometers, ii) the chemical nature of the industrial spill and iii) the hydrogeological parameters of the local aquifer. The exact location of the contaminant source is not needed for the analysis. The flow equation is afterwards solved using a finite-difference approximation scheme under stationary conditions. Finally, the capture zones for different times are computed by a simple upstream advective transport model. Results on the determination of the perimeter protection area definition of a water supply system in the municipality of L'Alcora (Castellón) in Spain are shown.

  4. A spatial DB model to simulate the road network efficiency in hydrogeological emergency

    NASA Astrophysics Data System (ADS)

    Michele, Mangiameli; Giuseppe, Mussumeci

    2015-12-01

    We deal with the theme of the simulation of risk analysis using a technological approach based on the integration of exclusively free and open source tools: PostgreSQL as Database Management System (DBMS) and Quantum GIS-GRASS as Geographic Information System (GIS) platform. The case study is represented by a seismic land in Sicily characterized by steep slopes and frequent instability phenomena. This area includes a city of about 30.000 inhabitants (Enna) that lies on the top of a mountain at about 990 m a.s.l.. The access to the city is assured by few and very winding roads that are also highly vulnerable to seismic and hydrogeological hazards. When exceptional rainfall events occur, the loss of efficiency of these roads should compromise timeliness and effectiveness of rescue operations. The data of the sample area have been structured into the adopted DBMS, and the connection to the GIS functionalities allows simulating the exceptional events. We analyzed the hazard, vulnerability and exposure related to these events and calculated the final risk defining three classes for each scenario: low (L), medium (M) and high (H). This study can be a valuable tool to prioritize risk levels and set priorities for intervention to the main road networks..

  5. Critical zone study in Korea: integration of hydrogeology, mineralogy, sedimentology and molecular biogeochemistry

    NASA Astrophysics Data System (ADS)

    Lee, J. Y.; Kwon, K.; Jo, K. N.; Lee, J. S.

    2015-12-01

    Critical Zone (CZ) is the topmost layer of the Earth ranging from the vegetation canopy down to the soil, groundwater, and bedrock that sustains our ecosystem including human life. This CZ is being greatly influenced by the climate change and anthropogenic forces. We introduce the Critical Zone Frontier Research Laboratory (CFRL), a critical zone research lab recently funded by the Korean government for 2015-2020. The objective of CFRL is to unravel the relationships between climate and CZ changes to propose a prediction model for future responses of CZ to climate change. For this ultimate goal, we establish multiple CZ observatories in Kangwon areas and investigate soil, groundwater, and cave environments by integration of hydrogeology, mineralogy, sedimentology and molecular biogeochemistry. This study will enhance our understanding about CZ and local resolution of a climate change model. This research is financially supported by the Basic Research Laboratory Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning.

  6. Hydrogeology and leachate movement near two chemical-waste sites in Oswego County, New York

    USGS Publications Warehouse

    Anderson, H.R.; Miller, Todd S.

    1986-01-01

    Forty-five observation wells and test holes were installed at two chemical waste disposal sites in Oswego County, New York, to evaluate the hydrogeologic conditions and the rate and direction of leachate migration. At the site near Oswego groundwater moves northward at an average velocity of 0.4 ft/day through unconsolidated glacial deposits and discharges into White Creek and Wine Creek, which border the site and discharge to Lake Ontario. Leaking barrels by chemical wastes have contaminated the groundwater within the site, as evidenced by detection of 10 ' priority pollutant ' organic compounds, and elevated values of specific conductance, chloride, arsenic, lead, and mercury. At the site near Fulton, where 8,000 barrels of chemical wastes are buried, groundwater in the sandy surficial aquifer bordering the landfill on the south and east moves southward and eastward at an average velocity of 2.8 ft/day and discharges to Bell Creek, which discharges to the Oswego River, or moves beneath the landfill. Leachate is migrating eastward, southeastward, and southwestward, as evidenced by elevated values of specific conductance, temperature, and concentrations of several trace metals at wells east, southeast, and southwest of the site. (USGS)

  7. Selected hydrogeologic and water-quality data from Jones Beach Island, Long Island, New York

    USGS Publications Warehouse

    Scorca, M.P.; Reilly, T.E.; Franke, O.L.

    1995-01-01

    A data-collection site was instrumented on Jones Beach Island, a barrier island south of Long Island, N.Y., to study local freshwater/ saltwater relations in the shallow ground-water system. A geologic test boring revealed about 88 feet of well-sorted glacial outwash sand above about 15 feet of Gardiners Clay, which directly overlies silty sand of the Magothy Formation. Tidal effects on water levels in Great South Bay, the upper glacial aquifer, and the Magothy aquifer were observed and quantified with a tidal gage in the bay and analog water-level recorders in the wells.Chloride concentrations in the upper Magothy aquifer were higher than expected--about 270 mg/L (milligrams per liter), and those in the upper glacial aquifer were 17,000 to 19,000 mg/L, about the same as in Great South Bay. Estimates of pressure and freshwater equivalent heads indicate that, at the data-collection site, freshwater is discharging upward from the Magothy aquifer into the salty upper glacial aquifer, but dilution by this freshwater is undetectable. The reason for the elevated chloride concentration in the Magothy aquifer cannot be determined from available hydrogeologic information.

  8. Hydrogeological properties of fault zones in a karstified carbonate aquifer (Northern Calcareous Alps, Austria)

    NASA Astrophysics Data System (ADS)

    Bauer, H.; Schröckenfuchs, T. C.; Decker, K.

    2016-08-01

    This study presents a comparative, field-based hydrogeological characterization of exhumed, inactive fault zones in low-porosity Triassic dolostones and limestones of the Hochschwab massif, a carbonate unit of high economic importance supplying 60 % of the drinking water of Austria's capital, Vienna. Cataclastic rocks and sheared, strongly cemented breccias form low-permeability (<1 mD) domains along faults. Fractured rocks with fracture densities varying by a factor of 10 and fracture porosities varying by a factor of 3, and dilation breccias with average porosities >3 % and permeabilities >1,000 mD form high-permeability domains. With respect to fault-zone architecture and rock content, which is demonstrated to be different for dolostone and limestone, four types of faults are presented. Faults with single-stranded minor fault cores, faults with single-stranded permeable fault cores, and faults with multiple-stranded fault cores are seen as conduits. Faults with single-stranded impermeable fault cores are seen as conduit-barrier systems. Karstic carbonate dissolution occurs along fault cores in limestones and, to a lesser degree, dolostones and creates superposed high-permeability conduits. On a regional scale, faults of a particular deformation event have to be viewed as forming a network of flow conduits directing recharge more or less rapidly towards the water table and the springs. Sections of impermeable fault cores only very locally have the potential to create barriers.

  9. Review: Some low-frequency electrical methods for subsurface characterization and monitoring in hydrogeology

    SciTech Connect

    Revil, Andre; Karaoulis, M.; Johnson, Timothy C.; Kemna, Andreas

    2012-02-10

    Low-frequency geoelectrical methods include mainly self-potential, resistivity, and induced polarization techniques, which have potential inmany environmental and hydrogeological applications. They provide complementary information to each other and to in-situ measurements. The self-potential method is a passive measurement of the electrical response associated with the in-situ generation of electrical current due to the flow of pore water in porous media, a salinity gradient, and/or the concentration of redoxactive species. Under some conditions, this method can be used to visualize groundwater flow, to determine permeability, and to detect preferential flow paths. Electrical resistivity is dependent on the water content, the temperature, the salinity of the pore water, and the clay content and mineralogy. Time-lapse resistivity can be used to assess the permeability and dispersivity distributions and to monitor contaminant plumes. Induced polarization characterizes the ability of rocks to reversibly store electrical energy. It can be used to image permeability and to monitor chemistry of the pore water-minerals interface. These geophysical methods, reviewed in this paper, should always be used in concert with additional in-situ measurements (e.g. in-situ pumping tests, chemical measurements of the pore water), for instance through joint inversion schemes, which is an area of fertile on-going research.

  10. Development of a Micro-UAV Hyperspectral Imaging Platform for Assessing Hydrogeological Hazards

    NASA Astrophysics Data System (ADS)

    Chen, Z.; Alabsi, M.

    2015-12-01

    The exacerbating global weather changes have cast significant impacts upon the proportion of water supplied to agriculture. Therefore, one of the 21stCentury Grant Challenges faced by global population is securing water for food. However, the soil-water behavior in an agricultural environment is complex; among others, one of the key properties we recognize is water repellence or hydrophobicity, which affects many hydrogeological and hazardous conditions such as excessive water infiltration, runoff, and soil erosion. Under a US-Israel research program funded by USDA and BARD at Israel, we have proposed the development of a novel micro-unmanned aerial vehicle (micro-UAV or drone) based hyperspectral imaging platform for identifying and assessing soil repellence at low altitudes with enhanced flexibility, much reduced cost, and ultimately easy use. This aerial imaging system consists of a generic micro-UAV, hyperspectral sensor aided by GPS/IMU, on-board computing units, and a ground station. The target benefits of this system include: (1) programmable waypoint navigation and robotic control for multi-view imaging; (2) ability of two- or three-dimensional scene reconstruction for complex terrains; and (3) fusion with other sensors to realize real-time diagnosis (e.g., humidity and solar irradiation that may affect soil-water sensing). In this talk we present our methodology and processes in integration of hyperspectral imaging, on-board sensing and computing, hyperspectral data modeling, and preliminary field demonstration and verification of the developed prototype.

  11. Limitations of pump and treat remediation in a common New England hydrogeologic environment

    SciTech Connect

    Maclean, D.A.; Marin, P.A. )

    1993-03-01

    A common hydrogeologic setting in New England consists of a thin layer of permeable glacial outwash (0--20 ft.) which overlays dense contact till deposited directly by glacial ice. These settings provide quite a challenge for hydrogeologists attempting to contain and remediate ground water contamination. Average linear migration velocities are often high because of the high permeability of the outwash (ranging from 1 to 100 ft/day or more). Spills in these environments can quickly create contaminated ground water plumes of large size threatening drinking water wells and other sensitive receptors. Pump and treat'' systems (consisting of a pumped recovery well with a treatment system to clean pumped water prior to discharge) are commonly installed in these environments, but they often fail to contain and remediate ground water contamination. Data from several case studies and from analytical models used to evaluate pump and treat options demonstrate that pumping rates are limited by the available drawdown in the shallow outwash unit and by the low hydraulic conductivity of the lower till unit. Therefore, pump and treat systems often fail to develop effective capture zones in these environments even though highly permeable outwash sands are present. Combined air sparging and soil venting techniques (AS/SV) may provide an effective alternative to pump and treat remediation systems in these environments. Data from cases studies show that AS/SV can remove more contaminant mass than pump and treat while treating soil and ground water in place.

  12. Development of analytical and numerical models for the assessment and interpretation of hydrogeological field tests

    SciTech Connect

    Mironenko, V.A.; Rumynin, V.G.; Konosavsky, P.K.; Pozdniakov, S.P.; Shestakov, V.M.; Roshal, A.A.

    1994-07-01

    Mathematical models of the flow and tracer tests in fractured aquifers are being developed for the further study of radioactive wastes migration in round water at the Lake Area, which is associated with one of the waste disposal site in Russia. The choice of testing methods, tracer types (chemical or thermal) and the appropriate models are determined by the nature of the ongoing ground-water pollution processes and the hydrogeological features of the site under consideration. Special importance is attached to the increased density of wastes as well as to the possible redistribution of solutes both in the liquid phase and in the absorbed state (largely, on fracture surfaces). This allows for studying physical-and-chemical (hydrogeochemical) interaction parameters which are hard to obtain (considering a fractured structure of the rock mass) in laboratory. Moreover, a theoretical substantiation is being given to the field methods of studying the properties of a fractured stratum aimed at the further construction of the drainage system or the subsurface flow barrier (cutoff wall), as well as the monitoring system that will evaluate the reliability of these ground-water protection measures. The proposed mathematical models are based on a tight combination of analytical and numerical methods, the former being preferred in solving the principal (2D axisymmetrical) class of the problems. The choice of appropriate problems is based on the close feedback with subsequent field tests in the Lake Area. 63 refs.

  13. Reliability, sensitivity, and uncertainty of reservoir performance under climate variability in basins with different hydrogeologic settings

    NASA Astrophysics Data System (ADS)

    Mateus, C.; Tullos, D.

    2014-12-01

    This study investigated how reservoir performance varied across different hydrogeologic settings and under plausible future climate scenarios. The study was conducted in the Santiam River basin, OR, USA, comparing the North Santiam basin (NSB), with high permeability and extensive groundwater storage, and the South Santiam basin (SSB), with low permeability, little groundwater storage, and rapid runoff response. We applied projections of future temperature and precipitation from global climate models to a rainfall-runoff model, coupled with a formal Bayesian uncertainty analysis, to project future inflow hydrographs as inputs to a reservoir operations model. The performance of reservoir operations was evaluated as the reliability in meeting flood management, spring and summer environmental flows, and hydropower generation objectives. Despite projected increases in winter flows and decreases in summer flows, results suggested little evidence of a response in reservoir operation performance to a warming climate, with the exception of summer flow targets in the SSB. Independent of climate impacts, historical prioritization of reservoir operations appeared to impact reliability, suggesting areas where operation performance may be improved. Results also highlighted how hydrologic uncertainty is likely to complicate planning for climate change in basins with substantial groundwater interactions.

  14. Hydrogeology and Physical Characteristics of Water Samples at the Red River Aluminum Site, Stamps, Arkansas

    NASA Astrophysics Data System (ADS)

    Czarnecki, J. B.; Stanton, G. P.; Freiwald, D. A.

    2001-12-01

    The Red River Aluminum site near Stamps, Arkansas, contains waste piles of salt cake and metal byproducts from the smelting of aluminum. The waste piles are subjected to about 50 inches of rainfall a year, resulting in the dissolution of the salts and metal. To assess the potential threat to underlying ground-water resources at the site, its hydrogeology was characterized by measuring water levels and field parameters of water quality in 23 wells and at 2 surface-water sites. Seventeen of these monitor wells were constructed at various depths for this study to allow for the separate characterization of the shallow and deep ground-water systems, the calculation of vertical gradients, and the collection of water samples at different depths within the flow system. Lithologic descriptions from drill-hole cuttings and geophysical logs indicate the presence of interbedded sands, gravels, silts, and clays to depths of 65 feet. The regionally important Sparta aquifer underlies the site. Water levels in shallow wells indicate radial flow away from the salt-cake pile located near the center of the site. Flow in the deep system is to the west and southwest toward Bodcau Creek. Water-level data from eight piezometer nests indicate a downward hydraulic gradient from the shallow to deep systems across the site. Values of specific conductance (an indicator of dissolved salts) ranged from 215 to 196,200 microsiemens per centimeter and indicate that saline waters are being transported horizontally and vertically downward away from the site.

  15. Design of monitor wells, hydrogeology, and ground-water quality beneath Country Pond, Kingston, New Hampshire

    USGS Publications Warehouse

    Mack, Thomas J.

    1995-01-01

    Ten monitoring well were installed in May 1993 to collect data on the hydrogeology and ground-water quality beneath Country Pond, in Kingston, New Hampshire. Monitoring wells were installed 4 to 48 feet beneath the pond surface in stratified drift that was up to 40 feet thick. The stratified drift is overlain by up to 35 feet of fine-grained, predominantly organic, lake-bottom sediment. The potentiometric head in the aquifer was at or above the pond surface and up to 0.8 foot above the pond surface at one location. Water-quality analyses detected numerous volatile organic compounds including chloroethane, benzene, dichlorobenzenes, and 1,1-dichloroethane at maximum concentrations of 110, 43, 54, and 92 mg/L, respectively. The maximum concentration of total volatile organic compounds detected in ground water from a monitoring well was 550 mg/L in November 1993. Ground-water samples with high concentrations of volatile organic compounds also had elevated specific conductances indicating the presence of other non-organic contaminants. Water-quality analyses indicate that a plume of contaminated ground water extends at least 300 feet in a northeast direction beneath the pond.

  16. Hydrogeology and chemical quality of water and soil at Carroll Island, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Tenbus, F.J.; Phillips, S.W.

    1996-01-01

    Carroll Island was used for open-air testing of chemical warfare agents from the late 1940's until 1971. Testing and disposal activities weresuspected of causing environmental contamination at 16 sites on the island. The hydrogeology and chemical quality of ground water, surface water, and soil at these sites were investigated with borehole logs, environmental samples, water-level measurements, and hydrologic tests. A surficial aquifer, upper confining unit, and upper confined aquifer were defined. Ground water in the surficial aquifer generally flows from the east-central part of the island toward the surface-water bodies, butgradient reversals caused by evapotranspiration can occur during dry seasons. In the confined aquifer, hydraulic gradients are low, and hydraulic head is affected by tidal loading and by seasonal pumpage from the west. Inorganic chemistry in the aquifers is affected by brackish-water intrusion from gradient reversals and by dissolution ofcarboniferous shell material in the confining unit.The concentrations of most inorganic constituents probably resulted from natural processes, but some concentrations exceeded Federal water-quality regulations and criteria. Organic compounds were detected in water and soil samples at maximum concentrations of 138 micrograms per liter (thiodiglycol in surface water) and 12 micrograms per gram (octadecanoic acid in soil).Concentrations of organic compounds in ground water exceeded Federal drinking-water regulations at two sites. The organic compounds that weredetected in environmental samples were variously attributed to natural processes, laboratory or field- sampling contamination, fallout from industrial air pollution, and historical military activities.

  17. Hydrogeologic Processes Impacting Storage, Fate, and Transport of Chloride from Road Salt in Urban Riparian Aquifers.

    PubMed

    Ledford, Sarah H; Lautz, Laura K; Stella, John C

    2016-05-17

    Detrimental effects of road salt runoff on urban streams are compounded by its facilitated routing via storm drains, ditches, and flood channels. Elevated in-stream salinity may also result from seasonal storage and discharge of chloride in groundwater, and previous work has hypothesized that groundwater discharge to streams may have the effect of diluting stream chloride concentrations in winter and enriching them in summer. However, the hydrogeological processes controlling these patterns have not been thoroughly investigated. Our research focuses on an urban stream and floodplain system in Syracuse, NY, to understand how groundwater and surface water exchange impacts chloride storage, fate, and transport. We created a 3D groundwater flow and solute transport model of the floodplain, calibrated to the distributions of floodplain hydraulic heads and groundwater fluxes to the stream throughout the reach. We used a sensitivity analysis to calibrate and evaluate the influence of model parameters, and compared model outputs to field observations. The main source mechanism of chloride to the floodplain aquifer was high-concentration, overbank flood events in winter that directly recharged groundwater. The modeled residence time and storage capacity of the aquifer indicate that restoration projects designed to promote floodplain reconnection and the frequency of overbank flooding in winter have the potential to temporarily store chloride in groundwater, buffer surface water concentrations, and reduce stream concentrations following periods of road salting. PMID:27077530

  18. Structural and hydrogeological features of a Lias carbonate aquifer in the Triffa Plain, NE Morocco

    NASA Astrophysics Data System (ADS)

    Sardinha, J.; Carneiro, J. F.; Zarhloule, Y.; Barkaoui, A.; Correia, A.; Boughriba, M.; Rimi, A.; El Houadi, B.

    2012-09-01

    The rising demand for water and the contamination of shallow water table aquifers has led authorities in NE Morocco to look for deeper groundwater resources in the Triffa Plain, namely in Lower Jurassic (Lias) dolomitic limestones. The liassic aquifer is of strategic importance for the development of the region, however, its hydrodynamic behaviour is poorly understood due to lack of hydrogeological data and block structure. This article presents a first effort towards understanding the structure and hydraulic behaviour of the aquifer. Exploration borehole data and results from geophysical campaigns were integrated into a GIS environment to build a preliminary model of the aquifer structure. The aquifer behaves as an unconfined aquifer in the northern part of the Béni Snassen Mountains (the recharge area), but as it dips to the north, it becomes confined by marls and shales of the Middle/Upper Jurassic. Even though piezometric level data are scarce, a tentative piezometric map was produced. Three blocks separated by NW-SE trending faults in a horst and graben structure, with distinct flow behaviours were identified: Berkane, Fezouane and Sidi Rahmoun blocks. Those blocks also show differences in hydraulic conductivity distribution. As a result of the reaction with the dolomitic limestones, the groundwater is of calcium-magnesium bicarbonate type. Groundwater temperature as measured in springs ranges from 29 °C to 37 °C in springs and constitutes a potential low enthalpy geothermal resource.

  19. An integrated model for simulating nitrogen trading in an agricultural catchment with complex hydrogeology.

    PubMed

    Cox, T J; Rutherford, J C; Kerr, S C; Smeaton, D C; Palliser, C C

    2013-09-30

    Nitrogen loads to several New Zealand lakes are dominated by nonpoint runoff from pastoral farmland which adversely affects lake water quality. A 'cap and trade' scheme is being considered to help meet targets set for nitrogen loads to Lake Rotorua, and a numerical model, NTRADER, has been developed to simulate and compare alternative schemes. NTRADER models both the geophysics of nitrogen generation and transport, including groundwater lag times, and the economics of 'cap and trade' schemes. It integrates the output from several existing models, including a farm-scale nitrogen leaching and abatement model, a farm-scale management economic model, and a catchment-scale nitrogen transport model. This paper details modeling methods and compares possible trading program design features for the Lake Rotorua catchment. Model simulations demonstrate how a cap and trade program could be used to effectively achieve challenging environmental goals in the targeted catchment. However, results also show that, due to complex hydrogeology, satisfactory environmental outcomes may be not achieved unless groundwater lag times are incorporated into the regulatory scheme. One way to do this, as demonstrated here, would be to explicitly include lag times in the cap and trade program. The utility of the model is further demonstrated by quantifying relative differences in abatement costs across potential regulatory schemes. PMID:23771202

  20. Reconnaissance hydrogeologic investigation of the Defense Waste Processing Facility and vicinity, Savannah River Plant, South Carolina

    USGS Publications Warehouse

    Dennehy, K.F.; Prowell, D.C.; McMahon, P.B.

    1989-01-01

    The hydrogeologic framework of the area around the Savannah River Plant, South Carolina consists of 2 to 3 separate water bearing units. In the northern half of the study area, the Barnwell and underlying McBean aquifers are considered one aquifer owing to the absence of the tan clay-confining unit between them. In the southern half of the study area they are separated by the tan clay into two aquifers. Underlying these aquifers, and separated from them by the green clay-confining unit, is the Congaree aquifer. Hydraulic conductivities of the aquifers range from 0.00000001 to 0.0001 ft/sec. Directions of groundwater flow in the Barnwell and McBean aquifers are to the north, with a component of flow directed downward across the green clay and into the Congaree aquifer. The direction of flow in the Congaree aquifer is to the northwest. Water in these aquifers evolves from an acidic (pH < 6.5) mixed-cation type in the Barnwell aquifer to an alkaline (pH > 8) calcium bicarbonate water in the Congaree aquifer. Laboratory experiments indicate that reactions between sediments of the Barnwell aquifer and a salt-solution waste to be stored at the study area would significantly reduce the permeability of the sediment, thereby limiting the movement of the waste in groundwater at the site. (USGS)

  1. Description and hydrogeologic evaluation of nine hazardous-waste sites in Kansas, 1984-86

    USGS Publications Warehouse

    Hart, R.J.; Spruill, T.B.

    1988-01-01

    Wastes generated at nine hazardous-waste sites in Kansas were disposed in open pits, 55-gal drums, or large storage tanks. These disposal methods have the potential to contaminate groundwater beneath the sites, the soil on the sites, and nearby surface water bodies. Various activities on the nine sites included production of diborane, transformer oil waste, production of soda ash, use of solvents for the manufacture of farm implements, reclamation of solvents and paints, oil-refinery wastes, meat packaging, and the manufacture and cleaning of tanker-truck tanks. Monitoring wells were installed upgradient and downgradient from the potential contamination source on each site. Strict decontamination procedures were followed to prevent cross contamination between well installations. Air-quality surveys were made on each site before other investigative procedures started. Hydrogeologic investigative techniques, such as terrain geophysical surveys, gamma-ray logs, and laboratory permeameter tests, were used. Groundwater level measurements provide data to determine the direction of flow. Groundwater contamination detected under the sites posed the greatest threat to the environment because of possible migration of contaminants by groundwater flow. Concentrations of volatile organic compounds, polynuclear aromatic hydrocarbons, and trace metals were detected in the groundwater at several of the sites. Many of the same compounds detected in the groundwater also were detected in soil and bed-material samples collected onsite or adjacent to the sites. Several contaminants were detected in background samples of groundwater and soil. (USGS)

  2. Geologic and hydrogeologic frameworks of the Biscayne aquifer in central Miami-Dade County, Florida

    USGS Publications Warehouse

    Wacker, Michael A.; Cunningham, Kevin J.; Williams, John H.

    2014-01-01

    Evaluations of the lithostratigraphy, lithofacies, paleontology, ichnology, depositional environments, and cyclostratigraphy from 11 test coreholes were linked to geophysical interpretations, and to results of hydraulic slug tests of six test coreholes at the Snapper Creek Well Field (SCWF), to construct geologic and hydrogeologic frameworks for the study area in central Miami-Dade County, Florida. The resulting geologic and hydrogeologic frameworks are consistent with those recently described for the Biscayne aquifer in the nearby Lake Belt area in Miami-Dade County and link the Lake Belt area frameworks with those developed for the SCWF study area. The hydrogeologic framework is characterized by a triple-porosity pore system of (1) matrix porosity (mainly mesoporous interparticle porosity, moldic porosity, and mesoporous to megaporous separate vugs), which under dynamic conditions, produces limited flow; (2) megaporous, touching-vug porosity that commonly forms stratiform groundwater passageways; and (3) conduit porosity, including bedding-plane vugs, decimeter-scale diameter vertical solution pipes, and meter-scale cavernous vugs. The various pore types and associated permeabilities generally have a predictable vertical spatial distribution related to the cyclostratigraphy. The Biscayne aquifer within the study area can be described as two major flow units separated by a single middle semiconfining unit. The upper Biscayne aquifer flow unit is present mainly within the Miami Limestone at the top of the aquifer and has the greatest hydraulic conductivity values, with a mean of 8,200 feet per day. The middle semiconfining unit, mainly within the upper Fort Thompson Formation, comprises continuous to discontinuous zones with (1) matrix porosity; (2) leaky, low permeability layers that may have up to centimeter-scale vuggy porosity with higher vertical permeability than horizontal permeability; and (3) stratiform flow zones composed of fossil moldic porosity, burrow

  3. Hydrogeologic framework of U.S. Marine Corps Base at Camp Lejeune, North Carolina

    USGS Publications Warehouse

    Cardinell, A.P., Jr.; Berg, S.A.; Lloyd, O.B., Jr.

    1993-01-01

    The hydrogeologic framework at Camp Lejeune consists of the surficial, Castle Hayne, Beaufort, and Peedee aquifers and intervening confining units. The Castle Hayne aquifer furnishes about 7 million gallons of water per day to Camp Lejeune, but the surficial, Beaufort, and Peedee aquifers, which contain freshwater in places, are not used for supply. The Castle Hayne aquifer is composed of 60 to 90 percent sand and limestone with clay and silt beds, and ranges from 156 to 400 feet thick. Hydraulic conductivity of the aquifer ranges from 14 to 91 feet per day. The Castle Hayne confining unit, which overlies the Castle Hayne aquifer, is composed of silt and sandy clay and averages 9 feet thick where present. This confining unit is incised by the New River and its tributaries, as well as some paleochannels. The effects of pumping from the Castle Hayne aquifer have not significantly affected natural head gradients in the aquifer. However, the potential exists for lateral migration of saltwater where wells are located near streams or paleochannels that have incised the confining unit. Except for one measurement of 960 milligrams per liter chloride in a water sample from the bottom of the Castle Hayne aquifer, dissolved-chloride concentrations in water samples from the Castle Hayne aquifer were less than 120 milligrams per liter. It is not known whether this occurrence of saltwater in the Castle Hayne aquifer is widespread or localized, but its presence indicates a potential for upward movement of saltwater beneath pumped wells.

  4. Hydrogeological properties of fault zones in a karstified carbonate aquifer (Northern Calcareous Alps, Austria)

    NASA Astrophysics Data System (ADS)

    Bauer, H.; Schröckenfuchs, T. C.; Decker, K.

    2016-03-01

    This study presents a comparative, field-based hydrogeological characterization of exhumed, inactive fault zones in low-porosity Triassic dolostones and limestones of the Hochschwab massif, a carbonate unit of high economic importance supplying 60 % of the drinking water of Austria's capital, Vienna. Cataclastic rocks and sheared, strongly cemented breccias form low-permeability (<1 mD) domains along faults. Fractured rocks with fracture densities varying by a factor of 10 and fracture porosities varying by a factor of 3, and dilation breccias with average porosities >3 % and permeabilities >1,000 mD form high-permeability domains. With respect to fault-zone architecture and rock content, which is demonstrated to be different for dolostone and limestone, four types of faults are presented. Faults with single-stranded minor fault cores, faults with single-stranded permeable fault cores, and faults with multiple-stranded fault cores are seen as conduits. Faults with single-stranded impermeable fault cores are seen as conduit-barrier systems. Karstic carbonate dissolution occurs along fault cores in limestones and, to a lesser degree, dolostones and creates superposed high-permeability conduits. On a regional scale, faults of a particular deformation event have to be viewed as forming a network of flow conduits directing recharge more or less rapidly towards the water table and the springs. Sections of impermeable fault cores only very locally have the potential to create barriers.

  5. Coupled semivariogram uncertainty of hydrogeological and geophysical data on capture zone uncertainty analysis

    USGS Publications Warehouse

    Rahman, A.; Tsai, F.T.-C.; White, C.D.; Willson, C.S.

    2008-01-01

    This study investigates capture zone uncertainty that relates to the coupled semivariogram uncertainty of hydrogeological and geophysical data. Semivariogram uncertainty is represented by the uncertainty in structural parameters (range, sill, and nugget). We used the beta distribution function to derive the prior distributions of structural parameters. The probability distributions of structural parameters were further updated through the Bayesian approach with the Gaussian likelihood functions. Cokriging of noncollocated pumping test data and electrical resistivity data was conducted to better estimate hydraulic conductivity through autosemivariograms and pseudo-cross-semivariogram. Sensitivities of capture zone variability with respect to the spatial variability of hydraulic conductivity, porosity and aquifer thickness were analyzed using ANOVA. The proposed methodology was applied to the analysis of capture zone uncertainty at the Chicot aquifer in Southwestern Louisiana, where a regional groundwater flow model was developed. MODFLOW-MODPATH was adopted to delineate the capture zone. The ANOVA results showed that both capture zone area and compactness were sensitive to hydraulic conductivity variation. We concluded that the capture zone uncertainty due to the semivariogram uncertainty is much higher than that due to the kriging uncertainty for given semivariograms. In other words, the sole use of conditional variances of kriging may greatly underestimate the flow response uncertainty. Semivariogram uncertainty should also be taken into account in the uncertainty analysis. ?? 2008 ASCE.

  6. Beyond hydrogeologic evidence: challenging the current assumptions about salinity processes in the Corangamite region, Australia

    NASA Astrophysics Data System (ADS)

    Dahlhaus, P. G.; Cox, J. W.; Simmons, C. T.; Smitt, C. M.

    2008-11-01

    In keeping with the standard scientific methods, investigations of salinity processes focus on the collection and interpretation of contemporary scientific data. However, using multiple lines of evidence from non-hydrogeologic sources such as geomorphic, archaeological and historical records can substantially add value to the scientific investigations. By using such evidence, the validity of the assumptions about salinity processes in Australian landscapes is challenged, especially the assumption that the clearing of native vegetation has resulted in rising saline groundwater in all landscapes. In the Corangamite region of south-west Victoria, salinity has been an episodic feature of the landscapes throughout the Quaternary and was present at the time of the Aboriginal inhabitants and the first pastoral settlement by Europeans. Although surface-water salinity has increased in some waterways and the area of salinised land has expanded in some landscapes, there is no recorded evidence found which supports significant rises in groundwater following widespread land-use change. In many areas, salinity is an inherent component of the region’s landscapes, and sustains world-class environmental assets that require appropriate salinity levels for their ecological health. Managing salinity requires understanding the specific salinity processes in each landscape.

  7. Hydrogeological relationships of sandy deposits: modeling of two-dimensional unsaturated water and pesticide transport.

    PubMed

    Iversen, Bo V; van der Keur, Peter; Vosgerau, Henrik

    2008-01-01

    Prediction of the movement of water and solutes in the vadose zone requires information on the distribution of spatial trends and heterogeneities in porous media. The present study describes different lithofacies origination mainly from glaciofluvial deposits. Among different lithofacies, hydrological relationships were investigated. By means of a two-dimensional hydrological model it was evaluated how the flow of water and leaching of metribuzin (4-amino-6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazin-5-one) was affected. Two selected large outcrop sections consisting of glacial outwash deposits were used in the modeling study. Eleven different lithofacies were distinguished and described in terms of texture distribution, sorting, bedding style, and external boundaries based on excavated soil profiles from 27 locations representing seven predominantly sandy landforms in Denmark. Undisturbed soil columns were sampled from each of the lithofacies and brought to the laboratory to be analyzed. With respect to their soil hydraulic properties, the different lithofacies formed four different hydrofacies having relatively homogeneous, hydrogeological properties. Two large outcrop sections from one of the locations (a gravel pit) located near the terminal moraine of the former Weichsel glacier were used for the HYDRUS-2D modeling. Modeling results revealed that the spatial distribution of sedimentary bodies affected water flow and the leaching of metribuzin. PMID:18689752

  8. Hydrogeologic factors that influence ground water movement in the desert southwest United States

    USGS Publications Warehouse

    Chuang, Frank C.; McKee, Edwin H.; Howard, Keith A.

    2003-01-01

    A project to study ground-water and surface-water interactions in the desert southwestern United States was initiated in 2001 by the Tucson, Arizona office of the Water Resources Division, U.S. Geological Survey (USGS). One of the goals of the Southwest Ground-water Resources Project was to develop a regional synthesis that includes the use of available digital geologic data, which is growing rapidly due to the increasing use of Geographic Information Systems (GIS). Included in this report are the digital maps and databases of geologic information that should have a direct impact on the studies of ground-water flow and surface-water interaction. Ground-water flow is governed by many geologic factors or elements including rock and soil permeability, stratigraphy and structural features. These elements directly influence ground-water flow, which is key to understanding the possible inter-connectivity of aquifer systems in desert basins of the southwestern United States. We derive these elements from the evaluation of regional geology and localized studies of hydrogeologic basins. These elements can then be applied to other unstudied areas throughout the desert southwest. This report presents a regional perspective of the geologic elements controlling ground-water systems in the desert southwest that may eventually lead to greater focus on smaller sub-regions and ultimately, to individual ground-water basins.

  9. Review: Some Low-Frequency Electrical Methods for Subsurface Characterization and Monitoring in Hydrogeology

    SciTech Connect

    Revil, Andre; Karaoulis, M.; Johnson, Timothy C.; Kemna, Andreas

    2011-01-01

    Low-frequency geoelectrical methods include mainly self-potential, resistivity, and induced polarization. These methods are commonly used to solve hydrogeological problems in the shallow subsurface and provide complementary information to each other and to in-situ measurements. The self-potential method is a passive measurement of the electrical response associated with the in-situ generation of current mainly due to the flow of pore water in porous media, a salinity gradient, and/or the concentration of redox-active species. It can be used to visualize groundwater flow patterns, to determine permeability, and to detect preferential flow paths. Electrical resistivity is dependent on the water content, the temperature, the salinity of the pore water, and the clay content and mineralogy. Induced polarization characterizes the ability of rocks to store electrical energy in terms of ion accumulations in the pore water. Electrical resistivity, time-domain and frequency-domain induced polarization methods can be used to image the permeability and the distribution of contaminants in the ground.

  10. The typology of Irish hard-rock aquifers based on an integrated hydrogeological and geophysical approach

    NASA Astrophysics Data System (ADS)

    Comte, Jean-Christophe; Cassidy, Rachel; Nitsche, Janka; Ofterdinger, Ulrich; Pilatova, Katarina; Flynn, Raymond

    2012-12-01

    Groundwater flow in hard-rock aquifers is strongly controlled by the characteristics and distribution of structural heterogeneity. A methodology for catchment-scale characterisation is presented, based on the integration of complementary, multi-scale hydrogeological, geophysical and geological approaches. This was applied to three contrasting catchments underlain by metamorphic rocks in the northern parts of Ireland (Republic of Ireland and Northern Ireland, UK). Cross-validated surface and borehole geophysical investigations confirm the discontinuous overburden, lithological compartmentalisation of the bedrock and important spatial variations of the weathered bedrock profiles at macro-scale. Fracture analysis suggests that the recent (Alpine) tectonic fabric exerts strong control on the internal aquifer structure at meso-scale, which is likely to impact on the anisotropy of aquifer properties. The combination of the interpretation of depth-specific hydraulic-test data with the structural information provided by geophysical tests allows characterisation of the hydrodynamic properties of the identified aquifer units. Regionally, the distribution of hydraulic conductivities can be described by inverse power laws specific to the aquifer litho-type. Observed groundwater flow directions reflect this multi-scale structure. The proposed integrated approach applies widely available investigative tools to identify key dominant structures controlling groundwater flow, characterising the aquifer type for each catchment and resolving the spatial distribution of relevant aquifer units and associated hydrodynamic parameters.

  11. Borehole Fluid Logging Methods for Hydrogeologic Characterization: What Have We Learned in Twenty-Five Years?

    NASA Astrophysics Data System (ADS)

    Pedler, W. H.

    2012-12-01

    Over the past twenty-five years, several methods have been developed and enhanced to improve the capability to characterize hydraulically conductive intervals in wellbores. The principal, and most commonly employed, methods include the heat pulse flow meter, the electromagnetic flow meter, and hydrophysical (or FEC) logging. The primary objective of each of these methods is to identify the depth of the water bearing (conductive) intervals and estimate the volumetric flow rate of each conductive interval under one or more pressure conditions. The pressure conditions under which measurements are taken include ambient (native), pumping or injection of the subject well and/or pumping a well proximate to the subject (cross-hole testing). During this period, these methods have been applied in effectively all of the hydrogeologic systems including fractured bedrock, fractured sandstones, porous alluvium, massive and fractured clays, karst, and volcanics. Project applications range from contaminant fate and transport, geotechnical, mining and water supply. These methods evaluate flow in the wellbore fluid column by applying either stationary and/or profile-type logging measurements. Each of these methods evaluates flow in a distinct and unique way and, as such, there are limitations associated with each measurement method. The analytical methods to reduce the field data to the stated objectives also vary in complexity between the different methods. Numerous field and laboratory comparative studies have been conducted to evaluate, compare and verify the results of these methods. This poster will present a summary of these methods, recent updates, variety of applications and associated limitations.

  12. Hydrogeology of the 200 Areas low-level burial grounds: An interim report: Volume 1, Text

    SciTech Connect

    Last, G.V.; Bjornstad, B.N.; Bergeron, M.P.; Wallace, D.W.; Newcomer, D.R.; Schramke, J.A.; Chamness, M.A.; Cline, C.S.; Airhart, S.P.; Wilbur, J.S.

    1989-01-01

    This report presents information derived from the installation of 35 ground-water monitoring wells around six low-level radioactive/hazardous waste burial grounds located in the 200 Areas of the Hanford Site in southeastern Washington State. This information was collected between May 20, 1987 and August 1, 1988. The contents of this report have been divided into two volumes. This volume contains the main text. Volume 2 contains the appendixes, including data and supporting information that verify content and results found in the main text. This report documents information collected by the Pacific Northwest Laboratory at the request of Westinghouse Hanford Company. Presented in this report are the preliminary interpretations of the hydrogeologic environment of six low-level burial grounds, which comprise four waste management areas (WMAs) located in the 200 Areas of the Hanford Site. This information and its accompanying interpretations were derived from sampling and testing activities associated with the construction of 35 ground-water monitoring wells as well as a multitude of previously existing boreholes. The new monitoring wells were installed as part of a ground-water monitoring program initiated in 1986. This ground-water monitoring program is based on requirements for interim status facilities in compliance with the Resource Conservation and Recovery Act (1976).

  13. Structural geology and geophysics as a support to build a hydrogeologic model of granite rock

    NASA Astrophysics Data System (ADS)

    Martinez-Landa, Lurdes; Carrera, Jesús; Pérez-Estaún, Andrés; Gómez, Paloma; Bajos, Carmen

    2016-06-01

    A method developed for low-permeability fractured media was applied to understand the hydrogeology of a mine excavated in a granitic pluton. This method includes (1) identifying the main groundwater-conducting features of the medium, such as the mine, dykes, and large fractures, (2) implementing this factors as discrete elements into a three-dimensional numerical model, and (3) calibrating these factors against hydraulic data . A key question is how to identify preferential flow paths in the first step. Here, we propose a combination of several techniques. Structural geology, together with borehole sampling, geophysics, hydrogeochemistry, and local hydraulic tests aided in locating all structures. Integration of these data yielded a conceptual model of the site. A preliminary calibration of the model was performed against short-term (< 1 day) pumping tests, which facilitated the characterization of some of the fractures. The hydraulic properties were then used for other fractures that, according to geophysics and structural geology, belonged to the same families. Model validity was tested by blind prediction of a long-term (4 months) large-scale (1 km) pumping test from the mine, which yielded excellent agreement with the observations. Model results confirmed the sparsely fractured nature of the pluton, which has not been subjected to glacial loading-unloading cycles and whose waters are of Na-HCO3 type.

  14. Development of a hydrogeologic framework using tidally influenced groundwater levels, Hawaii

    NASA Astrophysics Data System (ADS)

    Rotzoll, K.; Oki, D. S.; El-Kadi, A. I.

    2013-12-01

    Aquifer hydraulic properties can be estimated from commonly available water-level data from tidally influenced wells because the tidal signal attenuation depends on the aquifer's regional hydraulic diffusivity. Estimates of hydraulic properties are required for models that are used to manage groundwater availability and quality. A few localized studies of tidal attenuation in Hawaii have been published, but many water-level records have not been analyzed and no regional synthesis of tidal attenuation information in Hawaii exists. Therefore, we estimate aquifer properties from tidal attenuation for Hawaii using groundwater-level records from more than 350 wells. Filtering methods to separate water-level fluctuations caused by ocean tides from other environmental stresses such as barometric pressure and long-period ocean-level variations are explored. For short-term records, several approaches to identify tidal components are examined. The estimated aquifer properties are combined in a regional context with respect to the hydrogeologic framework of each island. The results help to better understand conceptual models of groundwater flow in Hawaii aquifers and facilitate the development of regional numerical groundwater flow and transport models aimed at sustainable water-resource management.

  15. Hydrogeologic controls on lake level: a case study at Mountain Lake, Virginia, USA

    NASA Astrophysics Data System (ADS)

    Roningen, Jeanne M.; Burbey, Thomas J.

    2012-09-01

    Mountain Lake in Giles County, Virginia, USA, has a documented history of severe natural lake-level changes involving groundwater seepage that extends over the past 4,200 years. The natural lake was full during a large part of the twentieth century but dried up completely in September 2008 and levels have yet to recover. The objective of the study was to understand the hydrogeologic factors that influence lake-level changes using a daily water balance, electrical resistivity, water sampling and geochemical analysis, and well logging. Results from the water balance demonstrate the seasonal response to precipitation of a forested first-order drainage system in fractured rock. The resistivity surveys suggest discrete high-permeability areas may provide pathways for lake drainage. Imagery, well logs, and field observations appear to confirm the presence of a fault which crosses the Eastern Continental Divide to the east of the lake that had not previously been discussed in literature on the lake; the position of the lake within local and intermediate groundwater flow systems is considered. Historical data suggest that either significant precipitation or artificial intervention to mitigate seepage would be required for lake-level recovery in the near future.

  16. Hydrogeological factors affecting the multiple plumes of chlorinated contaminants in an industrial complex, Wonju, Korea

    NASA Astrophysics Data System (ADS)

    Yang, J.; Kaown, D.; Lee, H.; Lee, K.

    2010-12-01

    Apparent plume attenuations of multiple chlorinated contaminants such as TCE, carbon tetrachloride, and its daughter products at an industrial complex, Wonju, Korea were examined through various hydraulic tests and six rounds of groundwater quality analyses. Aquifer media properties and hydrogeologic factors affecting the distribution and attenuation of multiple contaminants were investigated and key attributes were evaluated. The study area has vertically heterogeneous properties from top alluvial layer to crystalline rocks while the weathered fractured layer above intact Jurassic biotite granite acts as the main layer for groundwater flow and aqueous phase multiple contaminants migration. Aerial heterogeneity in surface conditions plays an important role for groundwater recharge because the industrial complex is mostly paved by asphalt and concrete. Due to limited recharge area and concentrated precipitation in summer season, seasonal effects of contaminant plume distribution diminish as the distance increase from the area of recharge. This study analyzed how differently the solute and contaminant concentrations response to the seasonal recharge. For the analyses, the study site was divided into three zones and four transects were established. Groundwater and solute mass balances were estimated by computing groundwater and solute mass flux through transects. The effects of groundwater pumping, groundwater flow and contaminant degradation were examined to simulate the solutes and contaminant concentrations. General tendency of the water quality and contaminant concentration were reproducible with the effects of major components such as groundwater recharge, pumping and estimated degradation rate.

  17. Detailed hydrogeological analysis of a deep-seated rockslide at the Gepatsch reservoir (Klasgarten, Austria)

    NASA Astrophysics Data System (ADS)

    Strauhal, Thomas; Loew, Simon; Holzmann, Michael; Zangerl, Christian

    2016-03-01

    The hydrogeology of the deep-seated, slowly creeping Klasgarten rockslide in Austria is investigated in this study based on detailed surface and subsurface field data, laboratory analyses, and analytical and numerical simulations. Field data are derived from several deep exploration and monitoring boreholes, an exploration drift located within the rockslide, and geological and geomorphological mapping. Particular attention is given to the pore pressure measurements and their temporal and spatial variability. These pore pressure variations are controlled by a thin layer of clayey fault gouge (representing the basal shear zone of the rockslide), a high-permeability rockslide mass, and moderately fractured paragneissic bedrock. Variably saturated equivalent-continuum hydraulic conductivities and storage properties are derived from packer tests, laboratory tests and optical televiewer images. These data sets are used for two-dimensional numerical groundwater models to study the flow-field and pore-pressure variations caused by the reservoir water-level fluctuations, the transient groundwater infiltration from snowmelt and precipitation along the slope, and the exploration drift. The strongest pressure transients in the rockslide are caused by reservoir level fluctuations and not the natural groundwater recharge, even at substantial distances from the reservoir. The response times are very short and only a minor distance-dependent attenuation is observed. The results of this study are essential to analyse the hydromechanical control of the deformation behaviour of rockslides adjacent to hydropower reservoirs. Further, it helps to understand how the formation of a rockslide can change the original bedrock aquifer.

  18. Hydrogeology of the upper and middle Verde River watersheds, central Arizona

    USGS Publications Warehouse

    Blasch, Kyle W.; Hoffmann, John P.; Graser, Leslie F.; Bryson, Jeannie R.; Flint, Alan L.

    2006-01-01

    The upper and middle Verde River watersheds in central Arizona are primarily in Yavapai County, which in 1999 was determined to be the fastest growing rural county in the United States; by 2050 the population is projected to more than double its current size (132,000 in 2000). This study combines climatic, surface-water, ground-water, water-chemistry, and geologic data to describe the hydrogeologic systems within the upper and middle Verde River watersheds and to provide a conceptual understanding of the ground-water flow system. The study area includes the Big Chino and Little Chino subbasins in the upper Verde River watershed and the Verde Valley subbasin in the middle Verde Rive watershed...more...A geochemical mixing model was used to quantify fractions of ground-water sources to the Verde River from various parts of the study area. Most of the water in the uppermost 0.2 mile of the Verde River is from the Little Chino subbasin, and the remainder is from the Big Chino subbasin. Discharge from a system of springs increases base flow to about 17 cubic feet per second within the next 2 miles of the river. Ground water that discharges at these springs is derived from the western part of the Coconino Plateau, from the Big Chino subbasin, and from the Little Chino subbasin. More...

  19. Transport properties of iodide in a sandy aquifer: Hydrogeological modelling and field tracer tests

    NASA Astrophysics Data System (ADS)

    Razafindratsima, Stephen; Péron, Olivier; Piscitelli, Anne; Gégout, Claire; Schneider, Vincent; Barbecot, Florent; Giffaut, Eric; Robinet, Jean-Charles; Le Cointe, Pierre; Montavon, Gilles

    2015-01-01

    The release of radioactive iodine into geological media from nuclear waste disposal is an issue that has to be considered since iodine is a biophilic element. 129I is, with 99Tc, one of the two long-lived radionuclides that have the highest mobility in radioactive waste disposal. Within this context, iodide retardation is still a matter of debate. A low value of the retardation factor is generally accepted in soils without organic matter, but the possibility for sorption cannot be completely ruled out. Since isotopic exchange with naturally occurring iodine is one of the main potential sorption mechanisms, site-specific retention parameters are needed. In the present paper, we study iodide transport in a sandy aquifer. A hydrogeological model was built to fit deuterium, bromide and iodide breakthrough data from in situ tracer test experiments. Within the precision range of the fitting, iodide is excluded from 2.5% of the effective porosity by anionic exclusion and presents a field retention factor (Kd) lower than 0.025 L/kg.

  20. Hydrogeology of the unsaturated zone, North Ramp area of the Exploratory Studies Facility, Yucca Mountain, Nevada

    SciTech Connect

    Rousseau, J.P.; Kwicklis, E.M.; Gillies, D.C.

    1999-03-01

    Yucca Mountain, in southern Nevada, is being investigated by the US Department of Energy as a potential site for a repository for high-level radioactive waste. This report documents the results of surface-based geologic, pneumatic, hydrologic, and geochemical studies conducted during 1992 to 1996 by the US Geological Survey in the vicinity of the North Ramp of the Exploratory Studies Facility (ESF) that are pertinent to understanding multiphase fluid flow within the deep unsaturated zone. Detailed stratigraphic and structural characteristics of the study area provided the hydrogeologic framework for these investigations. Shallow infiltration is not discussed in detail in this report because the focus in on three major aspects of the deep unsaturated-zone system: geologic framework, the gaseous-phase system, and the aqueous-phase system. However, because the relation between shallow infiltration and deep percolation is important to an overall understanding of the unsaturated-zone flow system, a summary of infiltration studies conducted to date at Yucca Mountain is provided in the section titled Shallow Infiltration. This report describes results of several Site Characterization Plan studies that were ongoing at the time excavation of the ESF North Ramp began and that continued as excavation proceeded.

  1. Towards identifying data needs for a regional hydrogeologic contamination study using multiple realization simulations

    SciTech Connect

    McCord, J.; Treadway, A.

    1993-11-01

    This paper describes a stochastic, distributed parameter simulation approach which is being used to identify/prioritize data collection activities for a 250 km{sup 2} region containing numerous potential contamination sites. The region is located in the southeast part of the Albuquerque Basin in central New Mexico, USA. The Basin is part of the Rio Grande Trough, a large graben with large vertical displacements between the central basin and the adjacent highlands. Numerous potential human receptors are located around the periphery of the region, and it is the desired to have a groundwater monitoring well network.which can help provide early detection of contamination plumes as well as provide relevant data on the regional hydrogeologic framework. A 2D numerical model of the regional basin-fill aquifer is developed with explicit recognition of uncertainties in flow parameter spatial distributions. We account for uncertainty in the parameter field through Monte Carlo simulation. To reduce the computational burden of multiple realization simulation, we employ a linearized stochastic model which permits cosimulation of transmissivity and head fields, conditioning on both transmissivity and head. The locations of selected contamination sites within the region then are overlaid on the simulation results, and flow paths and groundwater travel times from the contamination sites are assessed using sensitivity analysis to identify preferred locations for collection of additional data and the types of data which should be collected (e.g., head, transmissivity, or geologic cores).

  2. The Influence of Subsurface Karst Terrain on Hydrology and Hydrogeology in Southwestern Victoria, Australia

    NASA Astrophysics Data System (ADS)

    Perveen, F.; Webb, J.; Dresel, E.; Hekmeijer, P.; Zydor, H.

    2012-12-01

    A detailed study, in collaboration with Department of Primary Industries (DPI), Victoria, has been carried out in three small subcatchments of southwestern Victoria (total area 8.4 km2), which are characterised by varying degrees of influence of a subsurface karst terrain. Lithological logs and downhole geophysics (gamma and bulk conductivity - EM39) on 15 bores within the catchments were supplemented by 2D electrical resistivity vertical profiling, and showed that the middle to late Miocene Port Campbell Limestone is present at shallow depths (~5 m) in two catchments, and somewhat deeper (>70 m) in the third catchment. The limestone is overlain by early Pliocene clay-rich Dorodong Sands. The topography of the third catchment is characterised by shallow closed depressions. Detailed hydrogeological cross-sections using groundwater levels in the bores show closed depressions within the potentiometric surface, that are attributed to the presence of subsurface conduits within the highly permeable limestone, verified by the variable hydraulic conductivity values ( 0.005 - 0.545m/day) obtained from single borehole recovery tests. Stream hydrographs reveal that there is virtually no surface runoff from one subcatchment, due to leakage into a conduit in the underlying limestone. A perched water table is also found in the same area. Thus the study area shows the typical karst features of a highly heterogeneous terrain with massive connectivity between surface water and groundwater regimes, despite the fact that the limestone is overlain by the clay-rich Dorodong Sands.

  3. Hydrogeology and groundwater flow in a basalt-capped Mesozoic sedimentary series of the Ethiopian highlands

    NASA Astrophysics Data System (ADS)

    Vandecasteele, Ine; Nyssen, Jan; Clymans, Wim; Moeyersons, Jan; Martens, Kristine; van Camp, Marc; Gebreyohannes, Tesfamichael; Desmedt, Florimond; Deckers, Jozef; Walraevens, Kristine

    2011-05-01

    A hydrogeological study was undertaken in the Zenako-Argaka catchment, near Hagere Selam in Tigray, northern Ethiopia, during the rainy season of 2006. A geological map was produced through geophysical measurements and field observations, and a fracture zone identified in the north west of the catchment. A perched water table was found within the Trap Basalt series above the laterized upper Aram Aradam Sandstones. A map of this water table was compiled. Water-level variation during the measurement period was at least 4.5 m. Variation in basal flow for the whole catchment for the measurement period was between 12 and 276 m3/day. A groundwater flow model was produced using Visual MODFLOW, indicating the general direction of flow to be towards the south, and illustrating that the waterways have only a limited influence on groundwater flow. The soil water budget was calculated for the period 1995-2006, which showed the important influence of the distribution of rainfall in time. Although Hagere Selam received some 724 mm of rainfall per year over this period, the strong seasonal variation in rainfall meant there was a water deficit for on average 10 months per year.

  4. A spatial DB model to simulate the road network efficiency in hydrogeological emergency

    SciTech Connect

    Michele, Mangiameli Giuseppe, Mussumeci

    2015-12-31

    We deal with the theme of the simulation of risk analysis using a technological approach based on the integration of exclusively free and open source tools: PostgreSQL as Database Management System (DBMS) and Quantum GIS-GRASS as Geographic Information System (GIS) platform. The case study is represented by a seismic land in Sicily characterized by steep slopes and frequent instability phenomena. This area includes a city of about 30.000 inhabitants (Enna) that lies on the top of a mountain at about 990 m a.s.l.. The access to the city is assured by few and very winding roads that are also highly vulnerable to seismic and hydrogeological hazards. When exceptional rainfall events occur, the loss of efficiency of these roads should compromise timeliness and effectiveness of rescue operations. The data of the sample area have been structured into the adopted DBMS, and the connection to the GIS functionalities allows simulating the exceptional events. We analyzed the hazard, vulnerability and exposure related to these events and calculated the final risk defining three classes for each scenario: low (L), medium (M) and high (H). This study can be a valuable tool to prioritize risk levels and set priorities for intervention to the main road networks.

  5. Hydrogeology of an alpine rockfall aquifer system and its role in flood attenuation and maintaining baseflow

    NASA Astrophysics Data System (ADS)

    Lauber, U.; Kotyla, P.; Morche, D.; Goldscheider, N.

    2014-06-01

    The frequency and intensity of extreme hydrological events in alpine regions is projected to increase with climate change. The goal of this study was to better understand the functioning of aquifers composed of complex alluvial and rockfall deposits in alpine valleys and to quantify the role of these natural storage spaces in flood attenuation and baseflow maintenance. Geomorphological and hydrogeological mapping, tracer tests, and continuous flow measurements were conducted in the Reintal valley (German Alps), where runoff from a karst spring infiltrates into a series of postglacial alluvial/rockfall aquifers. During high-flow conditions, groundwater velocities of 30 m h-1 were determined along 500 m; hydrograph analyses revealed short lag times (5 h) between discharge peaks upstream and downstream from the aquifer series; the maximum discharge ratio downstream (22) and the peak recession coefficient (0.196 d-1) are low compared with other alpine catchments. During low-flow conditions, the underground flow path length increased to 2 km and groundwater velocities decreased to 13 m h-1. Downstream hydrographs revealed a delayed discharge response after 101 h and peaks dampened by a factor of 1.5. These results indicate that alluvial/rockfall aquifers might play an important role in the flow regime and attenuation of floods in alpine regions.

  6. Hydrogeology of an Alpine rockfall aquifer system and its role in flood attenuation and maintaining baseflow

    NASA Astrophysics Data System (ADS)

    Lauber, U.; Kotyla, P.; Morche, D.; Goldscheider, N.

    2014-11-01

    The frequency and intensity of extreme hydrological events in Alpine regions is projected to increase with climate change. The goal of this study is to better understand the functioning of aquifers composed of complex alluvial and rockfall deposits in Alpine valleys and to quantify the role of these natural storage spaces in flood attenuation and baseflow maintenance. Geomorphological and hydrogeological mapping, tracer tests, and continuous flow measurements were conducted in the Reintal (German Alps), where runoff from a karst spring infiltrates a series of postglacial alluvial/rockfall aquifers. During high-flow conditions, groundwater velocities of 30 m h-1 were determined along 500 m; hydrograph analyses revealed short lag times (5 h) between discharge peaks upstream and downstream from the aquifer series; the maximum discharge ratio downstream (22) and the peak recession coefficient (0.196 d-1) are low compared with other Alpine catchments. During low-flow conditions, the underground flow path length increased to 2 km and groundwater velocities decreased to 13 m h-1. Downstream hydrographs revealed a delayed discharge response after 101 h and peaks damped by a factor of 1.5. These results indicate that alluvial/rockfall aquifers might play an important role in the flow regime and attenuation of floods in Alpine regions.

  7. The influence of hydrogeological disturbance and mining on coal seam microbial communities.

    PubMed

    Raudsepp, M J; Gagen, E J; Evans, P; Tyson, G W; Golding, S D; Southam, G

    2016-03-01

    The microbial communities present in two underground coal mines in the Bowen Basin, Queensland, Australia, were investigated to deduce the effect of pumping and mining on subsurface methanogens and methanotrophs. The micro-organisms in pumped water from the actively mined areas, as well as, pre- and post-mining formation waters were analyzed using 16S rRNA gene amplicon sequencing. The methane stable isotope composition of Bowen Basin coal seam indicates that methanogenesis has occurred in the geological past. More recently at the mine site, changing groundwater flow dynamics and the introduction of oxygen in the subsurface has increased microbial biomass and diversity. Consistent with microbial communities found in other coal seam environments, pumped coal mine waters from the subsurface were dominated by bacteria belonging to the genera Pseudomonas and the family Rhodocyclaceae. These environments and bacterial communities supported a methanogen population, including Methanobacteriaceae, Methanococcaceae and Methanosaeta. However, one of the most ubiquitous micro-organisms in anoxic coal mine waters belonged to the family 'Candidatus Methanoperedenaceae'. As the Archaeal family 'Candidatus Methanoperedenaceae' has not been extensively defined, the one studied species in the family is capable of anaerobic methane oxidation coupled to nitrate reduction. This introduces the possibility that a methane cycle between archaeal methanogenesis and methanotrophy may exist in the anoxic waters of the coal seam after hydrogeological disturbance. PMID:26541089

  8. Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada

    USGS Publications Warehouse

    Nastev, Miroslav; Morin, R.; Godin, Rejean; Rouleau, Alain

    2008-01-01

    A hydrogeological study was conducted in Potsdam sandstones on the international border between Canada (Quebec) and the USA (New York). Two sandstone formations, arkose and conglomerate (base) and well-cemented quartz arenite (upper), underlie the study area and form the major regional aquifer unit. Glacial till, littoral sand and gravel, and marine silt and clay discontinuously overlie the aquifer. In both sandstone formations, sub-horizontal bedding planes are ubiquitous and display significant hydraulic conductivities that are orders of magnitude more permeable than the intact rock matrix. Aquifer tests demonstrate that the two formations have similar bulk hydrologic properties, with average hydraulic conductivities ranging from 2 ?? 10-5 to 4 ?? 10-5 m/s. However, due to their different lithologic and structural characteristics, these two sandstones impose rather different controls on groundwater flow patterns in the study area. Flow is sustained through two types of fracture networks: sub-horizontal, laterally extensive fractures in the basal sandstone, where hydraulic connectivity is very good horizontally but very poor vertically and each of the water-bearing bedding planes can be considered as a separate planar two-dimensional aquifer unit; and the more fractured and vertically jointed system found in the upper sandstone that promotes a more dispersed, three-dimensional movement of groundwater. ?? Springer-Verlag 2007.

  9. The hydrogeology of the Condamine River Alluvial Aquifer, Australia: a critical assessment

    NASA Astrophysics Data System (ADS)

    Dafny, Elad; Silburn, D. Mark

    2014-05-01

    The Condamine plain is an important agricultural zone in Australia with prominent irrigated cotton and grain crops. About one third of the irrigation water is pumped from the shallow alluvial aquifer, causing gross aquifer depletion over time. Over the last few decades, various hydrological, hydrochemical, and geological aspects of this aquifer and the overlying floodplain (including soil properties) have been investigated and used to construct the conceptual understanding and numerical models for management of this resource. Yet, the water balance of the aquifer is still far from resolved, and the geological contact between the alluvial sediments and underlying bedrock is yet to be categorically defined, to mention two major uncertainties. This report collates up-to-date knowledge of different disciplines, critically evaluates the accepted hydrogeological conventions, highlights key knowledge gaps, and suggests strategies for future research. Among recommendations are (1) development of numerical flow and solute transport models for the natural (i.e. pre-developed) period, (2) analysis of groundwater for isotopic composition and presence of pesticides, CFCs and PPCPs, and (3) use of stochastic approaches to characterize the hydraulic properties of the alluvial sediments. These and other proposed measures are relevant also to other alluvial aquifers which suffer from similar fundamental uncertainties.

  10. A new quasi-3D unsaturated-saturated hydrogeologic model of the Plateau de Saclay (France)

    NASA Astrophysics Data System (ADS)

    Renard, François; Tognelli, Antoine

    2016-04-01

    A new hydrogeologic model is developed for the Plateau de Saclay (20 km south-west of Paris, France), which covers an area of 74 km2. It is based on a 2D model of the Fontainebleau Sands aquifer, combined with a 1D model of the unsaturated zone, taking into account the spatial variability of the groundwater permeability field and the thickness of the unsaturated zone. The paper focuses on the estimation of a triplet of parameters (permeability, infiltration and effective porosity), based on transient flow simulations. First, the permeability is obtained by inversion of mean hydraulic head data for different values of infiltration. Then, infiltration and effective porosity are determined by using transient flow simulations and fitting the hydraulic head measurements at several piezometers over the 1970-2014 period. The infiltration is estimated at between 125 and 150 mm/yr, the mean permeability between 2 · 10-5 and 6 · 10-5 m/s, and the effective porosity between 20% and 30%. Furthermore, the role of the unsaturated zone is quantified and the induced delay is estimated at about 20 years in the case of the transport of a tracer.

  11. Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Nastev, M.; Morin, R.; Godin, R.; Rouleau, A.

    2008-03-01

    A hydrogeological study was conducted in Potsdam sandstones on the international border between Canada (Quebec) and the USA (New York). Two sandstone formations, arkose and conglomerate (base) and well-cemented quartz arenite (upper), underlie the study area and form the major regional aquifer unit. Glacial till, littoral sand and gravel, and marine silt and clay discontinuously overlie the aquifer. In both sandstone formations, sub-horizontal bedding planes are ubiquitous and display significant hydraulic conductivities that are orders of magnitude more permeable than the intact rock matrix. Aquifer tests demonstrate that the two formations have similar bulk hydrologic properties, with average hydraulic conductivities ranging from 2 × 10-5 to 4 × 10-5 m/s. However, due to their different lithologic and structural characteristics, these two sandstones impose rather different controls on groundwater flow patterns in the study area. Flow is sustained through two types of fracture networks: sub-horizontal, laterally extensive fractures in the basal sandstone, where hydraulic connectivity is very good horizontally but very poor vertically and each of the water-bearing bedding planes can be considered as a separate planar two-dimensional aquifer unit; and the more fractured and vertically jointed system found in the upper sandstone that promotes a more dispersed, three-dimensional movement of groundwater.

  12. Preliminary Test Results of Heshe Hydrogeological Experimental Well Station in Taiwan

    NASA Astrophysics Data System (ADS)

    Chuang, P.; Liu, C.; Lin, M.; Chan, W.; Lee, T.; Chia, Y.; Teng, M.; Liu, C.

    2013-12-01

    Safe disposal of radioactive waste is a critical issue for the development of nuclear energy. The design of final disposal system is based on the concept of multiple barriers which integrate the natural barriers and engineering barriers for long-term isolation of radioactive wastes. As groundwater is the major medium that can transport radionuclides to our living environment, it is essential to characterize groundwater flow at the disposal site. Taiwan is located at the boundary between the Eurasian plate and the Philippine Sea plate. Geologic formations are often fractured due to tectonic compression and extension. In this study, a well station for the research and development of hydrogeological techniques was established at the Experimental Forest of the National Taiwan University in central Taiwan. There are 10 testing wells, ranging in depth from 25 m to 100 m, at the station. The bedrock beneath the regolith is highly fractured mudstone. As fracture is the preferential pathway of the groundwater flow, the focus of in-situ tests is to investigate the location of permeable fractures and the connection of permeable fractures. Several field tests have been conducted, including geophysical logging, heat-pulse flowmeter, hydraulic test, tracer test and double packer test, for the development of advanced technologies to detect the preferential groundwater flow in fractured rocks.

  13. The Geologic and Hydrogeologic Setting of the Waste Isolation Pilot Plant

    SciTech Connect

    Swift, P.N.; Corbet, T.F.

    1999-03-04

    The Waste Isolation Pilot Plant (WIPP) is a mined repository constructed by the US Department of Energy for the permanent disposal of transuranic wastes generated since 1970 by activities related to national defense. The WIPP is located 42 km east of Carlsbad, New Mexico, in bedded salt (primarily halite) of the Late Permian (approximately 255 million years old) Salado Formation 655 m below the land surface. Characterization of the site began in the mid-1970s. Construction of the underground disposal facilities began in the early 1980s, and the facility received final certification from the US Environmental Protection Agency in May 1998. Disposal operations are planned to begin following receipt of a final permit from the State of New Mexico and resolution of legal issues. Like other proposed geologic repositories for radioactive waste, the WIPP relies on a combination of engineered and natural barriers to isolate the waste from the biosphere. Engineered barriers at the WIPP, including the seals that will be emplaced in the access shafts when the facility is decommissioned, are discussed in the context of facility design elsewhere in this volume. Physical properties of the natural barriers that contribute to the isolation of radionuclides are discussed here in the context of the physiographic, geologic, and hydrogeologic setting of the site.

  14. Hydrogeologic and hydrogeochemical assessment of geothermal fluids in the Pyramid Lake area, Washoe country, Nevada

    SciTech Connect

    Ojiambo, S. Bwire

    1992-01-01

    This paper evaluates the hydrogeological and hydrogeochemical characteristics of the geothermal fluids in the Pyramid Lake area using data from existing published and unpublished reports on springs, challow and deep wells in the area. Four geochemical provinces, namely, chloride, bicarbonate, suphate and nixed chloride-bicarbonate have been identified. Chloride waters are found in known geothermal areas. Two subsurface water recharge zones which reed the shallow and deep geothermal systems are proposed. These are the Virginia Mountains and their Northern extension and the Fox and Lake Ranges. Tertiary and Quaternary faulting systems in these mountains and Ranges act as heat conduits for geothermal fluids. The Needle Rocks geothermal system is postulated to be deeper than the San Emidio system. A connection between the Needle Rocks system and the Pyramid and Anaho islands warm springs is not clear from this study because of lack of chemical data from these islands. More systematic measurements of static water levels, temperatures, well lithology, water chemistry and isotopes data are recommended to enable better understanding of the geothermal systems in the area.

  15. Model evaluation of the hydrogeology of the Cypress Creek well field : in west-central Florida

    USGS Publications Warehouse

    Ryder, Paul D.

    1978-01-01

    The Cypress Creek well field is being developed to help supply a rapidly growing population in west-central Florida. The ground-water system in the Cypress Creek well-field area consists of a surficial sand aquifer, a semiconfining clay layer ranging from 2 to 25 feet in thickness, and a sequence of carbonate rocks, approximately 1,000 feet thick, called the Floridan aquifer. All recharge to the Floridan aquifer in the local area is derived from the overlying surficial sand aquifer by downward percolation through the semiconfining clay bed. The major proportion of water supplied to municipal wells open to the Floridan aquifer comes from a dolomitic section of the Avon Park Limestone containing two major cavernous zones. The hydrogeology of the well-field area was evaluated by digital model simulation. Model runs were made to analyze sensitivity of the model to variations in selected hydrologic parameters. The model was tested further by attempting to simulate the potentiometric surface of the Floridan aquifer under actual pumping stresses during the January 1976 dry period. (Woodard-USGS).

  16. Hydrogeology of the unsaturated zone, North Ramp area of the Exploratory Studies Facility, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Rousseau, Joseph P., (Edited By); Kwicklis, Edward M.; Gillies, Daniel C.

    1999-01-01

    Yucca Mountain, in southern Nevada, is being investigated by the U.S. Department of Energy as a potential site for a repository for high-level radioactive waste. This report documents the results of surface-based geologic, pneumatic, hydrologic, and geochemical studies conducted during 1992 to 1996 by the U.S. Geological Survey in the vicinity of the North Ramp of the Exploratory Studies Facility (ESF) that are pertinent to understanding multiphase fluid flow within the deep unsaturated zone. Detailed stratigraphic and structural characteristics of the study area provided the hydrogeologic framework for these investigations. Multiple lines of evidence indicate that gas flow and liquid flow within the welded tuffs of the unsaturated zone occur primarily through fractures. Fracture densities are highest in the Tiva Canyon welded (TCw) and Topopah Spring welded (TSw) hydrogeologic units. Although fracture density is much lower in the intervening nonwelded and bedded tuffs of the Paintbrush nonwelded hydrogeologic unit (PTn), pneumatic and aqueous-phase isotopic evidence indicates that substantial secondary permeability is present locally in the PTn, especially in the vicinity of faults. Borehole air-injection tests indicate that bulk air-permeability ranges from 3.5x10-14 to 5.4x10-11 square meters for the welded tuffs and from 1.2x10-13 to 3.0x10-12 square meters for the non welded and bedded tuffs of the PTn. Analyses of in-situ pneumatic-pressure data from monitored boreholes produced estimates of bulk permeability that were comparable to those determined from the air-injection tests. In many cases, both sets of estimates are two to three orders of magnitude larger than estimates based on laboratory analyses of unfractured core samples. The in-situ pneumatic-pressure records also indicate that the unsaturated-zone pneumatic system consists of four subsystems that coincide with the four major hydrogeologic units of the unsaturated zone at Yucca Mountain. In

  17. Probability distributions of hydraulic conductivity for the hydrogeologic units of the Death Valley regional ground-water flow system, Nevada and California

    SciTech Connect

    Belcher, W.R.; Sweetkind, D.S.; Elliott, P.E.

    2002-11-19

    The use of geologic information such as lithology and rock properties is important to constrain conceptual and numerical hydrogeologic models. This geologic information is difficult to apply explicitly to numerical modeling and analyses because it tends to be qualitative rather than quantitative. This study uses a compilation of hydraulic-conductivity measurements to derive estimates of the probability distributions for several hydrogeologic units within the Death Valley regional ground-water flow system, a geologically and hydrologicaly complex region underlain by basin-fill sediments, volcanic, intrusive, sedimentary, and metamorphic rocks. Probability distributions of hydraulic conductivity for general rock types have been studied previously; however, this study provides more detailed definition of hydrogeologic units based on lithostratigraphy, lithology, alteration, and fracturing and compares the probability distributions to the aquifer test data. Results suggest that these probability distributions can be used for studies involving, for example, numerical flow modeling, recharge, evapotranspiration, and rainfall runoff. These probability distributions can be used for such studies involving the hydrogeologic units in the region, as well as for similar rock types elsewhere. Within the study area, fracturing appears to have the greatest influence on the hydraulic conductivity of carbonate bedrock hydrogeologic units. Similar to earlier studies, we find that alteration and welding in the Tertiary volcanic rocks greatly influence conductivity. As alteration increases, hydraulic conductivity tends to decrease. Increasing degrees of welding appears to increase hydraulic conductivity because welding increases the brittleness of the volcanic rocks, thus increasing the amount of fracturing.

  18. MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model -Documentation of the Hydrogeologic-Unit Flow (HUF) Package

    USGS Publications Warehouse

    Anderman, E.R.; Hill, M.C.

    2000-01-01

    This report documents the Hydrogeologic-Unit Flow (HUF) Package for the groundwater modeling computer program MODFLOW-2000. The HUF Package is an alternative internal flow package that allows the vertical geometry of the system hydrogeology to be defined explicitly within the model using hydrogeologic units that can be different than the definition of the model layers. The HUF Package works with all the processes of MODFLOW-2000. For the Ground-Water Flow Process, the HUF Package calculates effective hydraulic properties for the model layers based on the hydraulic properties of the hydrogeologic units, which are defined by the user using parameters. The hydraulic properties are used to calculate the conductance coefficients and other terms needed to solve the ground-water flow equation. The sensitivity of the model to the parameters defined within the HUF Package input file can be calculated using the Sensitivity Process, using observations defined with the Observation Process. Optimal values of the parameters can be estimated by using the Parameter-Estimation Process. The HUF Package is nearly identical to the Layer-Property Flow (LPF) Package, the major difference being the definition of the vertical geometry of the system hydrogeology. Use of the HUF Package is illustrated in two test cases, which also serve to verify the performance of the package by showing that the Parameter-Estimation Process produces the true parameter values when exact observations are used.

  19. Identification and Characterization of Hydrogeologic Units at the Nevada Test Site Using Geophysical Logs: Examples from the Underground Test Area Project

    SciTech Connect

    Lance Prothro; Drellack, Sigmund; Townsend, Margaret

    2009-03-25

    The diverse and complex geology of the Nevada Test Site region makes for a challenging environment for identifying and characterizing hydrogeologic units penetrated by wells drilled for the U.S. Department of Energy, National Nuclear Security Administration, Underground Test Area (UGTA) Environmental Restoration Sub-Project. Fortunately, UGTA geoscientists have access to large and robust sets of subsurface geologic data, as well as a large historical knowledge base of subsurface geological analyses acquired mainly during the underground nuclear weapons testing program. Of particular importance to the accurate identification and characterization of hydrogeologic units in UGTA boreholes are the data and interpretation principles associated with geophysical well logs. Although most UGTA participants and stakeholders are probably familiar with drill hole data such as drill core and cuttings, they may be less familiar with the use of geophysical logs; this document is meant to serve as a primer on the use of geophysical logs in the UGTA project. Standard geophysical logging tools used in the UGTA project to identify and characterize hydrogeologic units are described, and basic interpretation principles and techniques are explained. Numerous examples of geophysical log data from a variety of hydrogeologic units encountered in UGTA wells are presented to highlight the use and value of geophysical logs in the accurate hydrogeologic characterization of UGTA wells.

  20. Conceptual hydrogeologic framework of the shallow aquifer system at Virginia Beach, Virginia

    USGS Publications Warehouse

    Smith, Barry S.; Harlow,, George E., Jr.

    2002-01-01

    The hydrogeologic framework of the shallow aquifer system at Virginia Beach was revised to provide a better understanding of the distribution of fresh ground water, its potential use, and its susceptibility to contamination. The revised conceptual framework is based primarily on analyses of continuous cores and downhole geophysical logs collected at 7 sites to depths of approximately 200 ft.The shallow aquifer system at Virginia Beach is composed of the Columbia aquifer, the Yorktown confining unit, and the Yorktown-East-over aquifer. The shallow aquifer system is separated from deeper units by the continuous St. Marys confining unit.The Columbia aquifer is defined as the predominantly sandy surficial deposits above the Yorktown confining unit. The Yorktown confining unit is composed of a series of very fine sandy to silty clay units of various colors at or near the top of the Yorktown Formation. The Yorktown confining unit varies in thickness and in composition, but on a regional scale is a leaky confining unit. The Yorktown-Eastover aquifer is defined as the predominantly sandy deposits of the Yorktown Formation and the upper part of the Eastover Formation above the confining clays of the St. Marys Formation. The limited areal extent of highly permeable deposits containing freshwater in the Yorktown-Eastover aquifer precludes the installation of highly productive freshwater wells over most of the city. Some deposits of biofragmental sand or shell hashes in the Yorktown-Eastover aquifer can support high-capacity wells.A water sample was collected from each of 10 wells installed at 5 of the 7 core sites to determine the basic chemistry of the aquifer system. One shallow well and one deep well was installed at each site. Concentrations of chloride were higher in the water from the deeper well at each site. Concentrations of dissolved iron in all of the water samples were higher than the U.S. Environmental Protection Agency Secondary Drinking Water Regulations

  1. Hydrogeological and isotope mapping of the karstic Savica River (NW Slovenia)

    NASA Astrophysics Data System (ADS)

    Brenčič, Mihael; Vreča, Polona

    2015-04-01

    Mapping is important part of the hydrogeological terrain investigations, especially when spatial and temporal relations are not known precisely. There are many different methods available; among them not least important is careful visual inspection of the stream and its stream bed at regular intervals with the aim to detect phenomena which reflect surface water groundwater interactions. In parallel with the inspection various measurements can be performed. Together with usual water electro conductivity and water temperature we tested complimentary information which can be obtained with the concomitant regular sampling for δ18O determination in the river water course. Combination of all these information proved to be very useful in obtaining spatial trends in river characteristics and to determine relations between its water balance components. Testing of the methodology of hydrogeological mapping with the means of isotopes on the karstic Savica River during low flow period where water balance relations between its tributaries were not known before demonstrate the usefulness of the applied approach. Savica River is positioned in the north-west part of Slovenia in the centre of Triglav national Park which covers large part of East Julian Alps. River represents the main recharge of the Bohinj Lake, largest Slovenian natural lake. Savica River is short with the length of only 4.0 km and consists of two tributaries in the upper part; Mala Savica coming from the west and Velika Savica coming from the north-west. The first is recharged from several water caves of various lengths in which water level depends on hydrological conditions, consequently terminal end of the water in its riverbed part changes during the year. The second tributary is recharged from the 510 m long karstic cave with the entrance at 836 m a.s.l. where water disappears over 75 m high famous and picturesque waterfall. Geology of the catchment is predominantly formed by Dachstein limestone of Upper

  2. Mineral water discharges at the Azores archipelago (Portugal): hydrogeological setting, chemical composition and mapping

    NASA Astrophysics Data System (ADS)

    Freire, P.; Cruz, J.; Coutinho, R.; Costa, A.; Antunes, P.

    2009-04-01

    , which presents a large range of water types and mineralization magnitude. Several groups of waters are defined: (1) Na-HCO3 and Na-HCO3-Cl type waters, to which almost all the thermal and CO2-rich waters belong, (2) Na-Cl type waters, to which discharges from the basal aquifer system belong and (3) acid-SO4 type waters, to which some of the boiling waters of São Miguel island belong. A few samples show intermediate facies between these main water types. The pH range between 2.2 and 7.82, discharge temperature between 15°C and 99.5°C (median=35°C), and conductivity varies between 139 and 43100 S/cm (median=906 S/cm). The main hydrogeochemical processes are the CO2-dominated volatile absorption, water-rock interaction and mixture with hydrothermal fluids. Sulfate dominated composition is explained by the influence of steam heating, and the Na-Cl water type result from mixture with sea salts. For the purpose of mapping mineral water discharges at the Azores a geochemical atlas was made using ESRI ArcGis 9.1 software. Data was divided in classes according to quartile values and spatial analysis was made through thematic mapping, for several features, as hydrogeological setting, water types and variables as discharge temperature, pH, conductivity, free CO2 and major elements content. In the present contribution several examples of the hydrogeological maps are shown.

  3. Hydrogeologic characteristics of four public drinking-water supply springs in northern Arkansas

    USGS Publications Warehouse

    Galloway, Joel M.

    2004-01-01

    In October 2000, a study was undertaken by the U.S. Geological Survey (USGS) in cooperation with the Arkansas Department of Health to determine the hydrogeologic characteristics, including the extent of the recharge areas, for Hughes Spring, Stark Spring, Evening Shade Spring, and Roaring Spring, which are used for public-water supply in northern Arkansas. Information pertaining to each spring can be used to enable development of effective management plans to protect these water resources and public health. An integrated approach to determine the ground-water characteristics and the extent of the local recharge areas of the four springs incorporated tools and methods of hydrology, structural geology, geomorphology, geophysics, and geochemistry. Analyses of discharge, temperature, and water quality were completed to describe ground-water flow characteristics, source-water characteristics, and connectivity of the ground-water system with surface runoff. Water-level contour maps were constructed to determine ground-water flow directions and ground-water tracer tests were conducted to determine the extent of the recharge areas and ground-water flow velocities. Hughes Spring supplies water for the city of Marshall, Arkansas, and the surrounding area. The mean annual discharge for Hughes Spring was 2.9 and 5.2 cubic feet per second for water years 2001 and 2002, respectively. Recharge to the spring occurs mainly from the Boone Formation (Springfield Plateau aquifer). Ground-water tracer tests indicate the recharge area for Hughes Spring generally coincides with the surface drainage area (15.8 square miles) and that Hughes Spring is connected directly to the surface flow in Brush Creek. The geochemistry of Hughes Spring demonstrated variations with flow conditions and the influence of surface-runoff in the recharge area. Calcite saturation indices, total dissolved solids concentrations, and hardness demonstrate noticeable differences with flow conditions reflecting the

  4. A near real time scenario at regional scale for the hydrogeological risk

    NASA Astrophysics Data System (ADS)

    Ponziani, F.; Stelluti, M.; Zauri, R.; Berni, N.; Brocca, L.; Moramarco, T.; Salciarini, D.; Tamagnini, C.

    2012-04-01

    The early warning systems dedicated to landslides and floods represent the Umbria Region Civil Protection Service new generation tools for hydraulic and hydrogeological risk reduction. Following past analyses performed by the Functional Centre (part of the civil protection service dedicated to the monitoring and the evaluation of natural hazards) on the relationship between saturated soil conditions and rainfall thresholds, we have developed an automated early warning system for the landslide risk, called LANDWARN, which generates daily and 72h forecast risk matrix with a dense mesh of 100 x 100m, throughout the region. The system is based on: (a) the 20 days -observed and 72h -predicted rainfall, provided by the local meteorological network and the Local scale Meteorological Model COSMO ME, (b) the assessment of the saturation of soils by: daily extraction of ASCAT satellite data, data from a network of 16 TDR sensors, and a water balance model (developed by the Research Institute for Geo-Hydrological Protection, CNR, Perugia, Italy) that allows for the prediction of a saturation index for each point of the analysis grid up to a window of 72 h, (c) a Web-GIS platform that combines the data grids of calculated hazard indicators with layers of landslide susceptibility and vulnerability of the territory, in order to produce dynamic risk scenarios. The system is still under development and it's implemented at different scales: the entire region, and a set of known high-risk landslides in Umbria. The system is monitored and regularly reviewed through the back analysis of landslide reports for which the activation date is available. Up to now, the development of the system involves: a) the improvement of the reliability assessment of the condition of soil saturation, a key parameter which is used to dynamically adjust the values of rainfall thresholds used for the declaration of levels of landslide hazard. For this purpose, a procedure was created for the ASCAT

  5. Hydrogeologic Conditions at the DUSEL Mid-level Campus and Implications for Large Cavern Design

    NASA Astrophysics Data System (ADS)

    Weinig, W. T.; Popielak, R. S.; Stetler, L. D.

    2010-12-01

    conceptual hydrogeologic model for the mid-level campus including poorly connected fractures, medium to high pressures, and low flow rates was postulated based on the 2009 data combined with historical inflow and hydraulic conductivity measurements. Ongoing data collection in late 2009 and 2010 support this conceptual model. The conceptual hydrogeologic model indicates that inflows to the planned large excavations will be relatively low, although groundwater pressure approaching 14 MPa may be encountered. The drainage systems for the new excavations will primarily serve as pressure relief, with additional diffusion of potential high pressures and low groundwater fluxes provided by micro-fractured yield zones around the perimeters of the excavations. The drainage systems are not expected to handle large flow rates, consistent with the experience during Homestake operational days and conditions observed in the chamber that housed the Davis neutrino experiment for nearly 40 years.

  6. Hydrogeology and Aquifer Storage and Recovery Performance in the Upper Floridan Aquifer, Southern Florida

    USGS Publications Warehouse

    Reese, Ronald S.; Alvarez-Zarikian, Carlos A.

    2007-01-01

    Well construction, hydraulic well test, ambient water-quality, and cycle test data were inventoried and compiled for 30 aquifer storage and recovery facilities constructed in the Floridan aquifer system in southern Florida. Most of the facilities are operated by local municipalities or counties in coastal areas, but five sites are currently being evaluated as part of the Comprehensive Everglades Restoration Plan. The relative performance of all sites with adequate cycle test data was determined, and compared with four hydrogeologic and design factors that may affect recovery efficiency. Testing or operational cycles include recharge, storage, and recovery periods that each last days or months. Cycle test data calculations were made including the potable water (chloride concentration of less than 250 milligrams per liter) recovery efficiency per cycle, total recovery efficiency per cycle, and cumulative potable water recovery efficiencies for all of the cycles at each site. The potable water recovery efficiency is the percentage of the total amount of potable water recharged for each cycle that is recovered; potable water recovery efficiency calculations (per cycle and cumulative) were the primary measures used to evaluate site performance in this study. Total recovery efficiency, which is the percent recovery at the end of each cycle, however, can be substantially higher and is the performance measure normally used in the operation of water-treatment plants. The Upper Floridan aquifer of the Floridan aquifer system currently is being used, or planned for use, at 29 of the aquifer storage and recovery sites. The Upper Floridan aquifer is continuous throughout southern Florida, and its overlying confinement is generally good; however, the aquifer contains brackish to saline ground water that can greatly affect freshwater storage and recovery due to dispersive mixing within the aquifer. The hydrogeology of the Upper Floridan varies in southern Florida; confinement

  7. The water cycle in a bottle: simulation of a hydrogeological basin

    NASA Astrophysics Data System (ADS)

    Nebot Castelló, M. R.; Leiva Hevia, S.

    2012-04-01

    THE WATER CYCLE IN A BOTTLE: simulation of a hydrogeological basin Author: Mª Roser Nebot (Institut Manuel Blancafort, La Garriga, Barcelona, Spain) Co-author: Sílvia Leiva Hevia (Institut Llicà d'Amunt, Lliça d'Amunt, Barcelona, Spain) The activity can be implemented in a great range of ages, because it has many different levels of depth. It is based on the construction of an analogical model of a hydrogeological basin using a 5L or 8L empty bottle. There are also other hands-on experiences that can be done in relation to the central one, such as creating a fountain, making a cloud, fog, a breeze… The use of a model that the students have to build and interact with enhances the possibility of cooperative and dialogic learning. The set of activities begins with an introduction to see what the students know about the water cycle and to focus on what they are going to work on. It also makes them think about underground water, which is frequently forgotten when drawing and studying the water cycle. Then, the building of the water cycle simulation from an empty bottle is presented, see http://www.xtec.cat/cirel/pla_le/nottingham/roser_nebot/index.htm (Unit 5). You will also find other activities related to the water cycle at the site. The students build the model, water the soil, and observe infiltration and the formation of a lake. Using a syringe they overexploit the well and dry the lake. By making the students label the underground water level and observe how water percolates through the holes in the aquifer we are making them aware that underground water doesn't circulate in rivers inside underground tunnels, but through the interconnected holes and crevices. Inside the bottle there is a little plant to observe evapotranspiration but, because it is very difficult to see the water droplets in the small plant that is inside the set-up, it is advisable to do a parallel experiment using bigger plants in a pot, covering them with a plastic bag tied around the

  8. Fractured-aquifer hydrogeology from geophysical logs: Brunswick group and Lockatong Formation, Pennsylvania

    USGS Publications Warehouse

    Morin, R.H.; Senior, L.A.; Decker, E.R.

    2000-01-01

    The Brunswick Group and the underlying Lockatong Formation are composed of lithified Mesozoic sediments that constitute part of the Newark Basin in southeastern Pennsylvania. These fractured rocks form an important regional aquifer that consists of gradational sequences of shale, siltstone, and sandstone, with fluid transport occurring primarily in fractures. An extensive suite of geophysical logs was obtained in seven wells located at the borough of Lansdale, Pennsylvania, in order to better characterize the areal hydrogeologic system and provide guidelines for the refinement of numerical ground water models. Six of the seven wells are approximately 120 m deep and the seventh extends to a depth of 335 m. Temperature, fluid conductivity, and flowmeter logs are used to locate zones of fluid exchange and to quantify transmissivities. Electrical resistivity and natural gamma logs together yield detailed stratigraphic information, and digital acoustic televiewer data provide magnetically oriented images of the borehole wall from which almost 900 fractures are identified. Analyses of the geophysical data indicate that the aquifer penetrated by the deep well can be separated into two distinct structural domains, which may, in turn, reflect different mechanical responses to basin extension by different sedimentary units: 1. In the shallow zone (above 125 m), the dominant fracture population consists of gently dipping bedding plane partings that strike N46??E and dip to the northwest at about 11 degrees. Fluid flow is concentrated in the upper 80 m along these subhorizontal fractures, with transmissivities rapidly diminishing in magnitude with depth. 2. The zone below 125 m marks the appearance of numerous high-angle fractures that are orthogonal to the bedding planes, striking parallel but dipping steeply southeast at 77 degrees. This secondary set of fractures is associated with a fairly thick (approximately 60 m) high-resistivity, low-transmissivity sandstone unit that

  9. Hydrogeological and isotope mapping of the karstic Savica River (NW Slovenia)

    NASA Astrophysics Data System (ADS)

    Brenčič, Mihael; Vreča, Polona

    2015-04-01

    Mapping is important part of the hydrogeological terrain investigations, especially when spatial and temporal relations are not known precisely. There are many different methods available; among them not least important is careful visual inspection of the stream and its stream bed at regular intervals with the aim to detect phenomena which reflect surface water groundwater interactions. In parallel with the inspection various measurements can be performed. Together with usual water electro conductivity and water temperature we tested complimentary information which can be obtained with the concomitant regular sampling for δ18O determination in the river water course. Combination of all these information proved to be very useful in obtaining spatial trends in river characteristics and to determine relations between its water balance components. Testing of the methodology of hydrogeological mapping with the means of isotopes on the karstic Savica River during low flow period where water balance relations between its tributaries were not known before demonstrate the usefulness of the applied approach. Savica River is positioned in the north-west part of Slovenia in the centre of Triglav national Park which covers large part of East Julian Alps. River represents the main recharge of the Bohinj Lake, largest Slovenian natural lake. Savica River is short with the length of only 4.0 km and consists of two tributaries in the upper part; Mala Savica coming from the west and Velika Savica coming from the north-west. The first is recharged from several water caves of various lengths in which water level depends on hydrological conditions, consequently terminal end of the water in its riverbed part changes during the year. The second tributary is recharged from the 510 m long karstic cave with the entrance at 836 m a.s.l. where water disappears over 75 m high famous and picturesque waterfall. Geology of the catchment is predominantly formed by Dachstein limestone of Upper

  10. Hydrogeologic investigations of the Miocene Nogales Formation in the Nogales Area, Upper Santa Cruz Basin, Arizona

    USGS Publications Warehouse

    Page, William R.; Gray, Floyd; Bultman, Mark W.; Menges, Christopher M.

    2016-01-01

    Hydrogeologic investigations were conducted to evaluate the groundwater resource potential for the Miocene Nogales Formation in the Nogales area, southern Arizona. Results indicate that parts of the formation may provide new, deeper sources of groundwater for the area. Geologic mapping determined the hydrogeologic framework of the formation by defining lithologic, mineralogic, and stratigraphic characteristics; identifying potential aquifers and confining units; and mapping faults and fractures which likely influence groundwater flow. Geophysical modeling was used to determine the basin geometry and thickness of the Nogales Formation and younger alluvial aquifers and to identify target areas (deep subbasins) which may prove to be productive aquifers.Volcaniclastic sandstone samples from the formation were analyzed for porosity, bulk density, saturated hydraulic conductivity, and fabric. Effective porosity ranges from 16 to 42 percent, bulk density from 1.6 to 2.47 grams per cubic centimeter, and saturated hydraulic conductivity (SHC) from 4 to 57 centimeters per day (4.9×10-5 to 6.7×10-4 centimeters per second). Thin sections show that sandstone framework grains consist of quartz, feldspar, biotite, hornblende, pumice, volcanic glass, and opaque minerals. The matrix in most samples consists of pumice fragments, and some contain predominantly silt and clay. Samples with a mostly silt and clay matrix have lower porosity and SHC compared to samples with mostly pumice, which have higher and wider ranges of porosity and SHC. Pore space in the Nogales Formation sediments includes moldic, intercrystalline, and fracture porosity. Some intercrystalline pore space is partially filled with calcite cement. About one third of the samples contain fractures, which correspond to fractures noted in outcrops in all members of the formation.Scanning electron microscope (SEM) and x-ray diffraction (XRD) analyses indicate that most of the samples contained the zeolite clinoptilolite

  11. Natural and Artificial (fluorescent) Tracers to Characterise Hydrogeological Functioning and to Protect Karst Aquifers

    NASA Astrophysics Data System (ADS)

    Andreo, B.; Mudarra, M.; Marin, A. I.; Barberá, J. A.

    2012-12-01

    The hydrogeological functioning and response of karst aquifers can be determined by the joint use of natural hydrogeochemical tracers, especially total organic carbon (TOC) and intrinsic fluorescence of water, together with artificial (fluorescent) tracers, under the same hydrodynamic conditions. Sharp and rapid variations in discharge, temperature, electrical conductivity and water chemistry, particularly of natural tracers of infiltration (TOC, intrinsic fluorescence and NO3-) recorded in karst spring water, confirm the existence of well developed karst conduits in the sector of the aquifer being drained, with rapid flows and very short water transit times from the surface to the springs (Mudarra et al., 2011). This is in agreement with the evidence obtained from breakthrough curves of fluorescent dye tracers (uranine, eosine, etc.). However, time lags between maximum concentrations of natural (especially TOC and intrinsic fluorescence) and artificial tracers show that the global system response is faster than that produced from a recharge concentrated at a point on the surface, even in karst sinkholes. Response and transit times of water through the karst can be calculated using both natural and artificial tracers, but flow velocities can really only be quantified using artificial tracers. Analysis of the responses obtained by natural tracers of infiltration (global system response) and artificial tracers (single response) in karst waters has revealed the usefulness and complementarity of both techniques for characterising the hydrogeological functioning of karst aquifers and, even more important, for validating contamination vulnerability mapping in these medium (Zwahlen, 2004; Andreo et al., 2006). In recent decades, several methods have been developed for such vulnerability mapping, but little progress has been made in validating their results. This validation is essential for the adequate protection of water resources in karst media, as has been shown in

  12. Automatic Multi-Scale Calibration Procedure for Nested Hydrological-Hydrogeological Regional Models

    NASA Astrophysics Data System (ADS)

    Labarthe, B.; Abasq, L.; Flipo, N.; de Fouquet, C. D.

    2014-12-01

    Large hydrosystem modelling and understanding is a complex process depending on regional and local processes. A nested interface concept has been implemented in the hydrosystem modelling platform for a large alluvial plain model (300 km2) part of a 11000 km2 multi-layer aquifer system, included in the Seine basin (65000 km2, France). The platform couples hydrological and hydrogeological processes through four spatially distributed modules (Mass balance, Unsaturated Zone, River and Groundwater). An automatic multi-scale calibration procedure is proposed. Using different data sets from regional scale (117 gauging stations and 183 piezometers over the 65000 km2) to the intermediate scale(dense past piezometric snapshot), it permits the calibration and homogenization of model parameters over scales.The stepwise procedure starts with the optimisation of the water mass balance parameters at regional scale using a conceptual 7 parameters bucket model coupled with the inverse modelling tool PEST. The multi-objective function is derived from river discharges and their de-composition by hydrograph separation. The separation is performed at each gauging station using an automatic procedure based one Chapman filter. Then, the model is run at the regional scale to provide recharge estimate and regional fluxes to the groundwater local model. Another inversion method is then used to determine the local hydrodynamic parameters. This procedure used an initial kriged transmissivity field which is successively updated until the simulated hydraulic head distribution equals a reference one obtained by krigging. Then, the local parameters are upscaled to the regional model by renormalisation procedure.This multi-scale automatic calibration procedure enhances both the local and regional processes representation. Indeed, it permits a better description of local heterogeneities and of the associated processes which are transposed into the regional model, improving the overall performances

  13. Combining Airbone geophysics and hydrogeologic modeling to determine the hydrologic boundary condition below the sea.

    NASA Astrophysics Data System (ADS)

    Schaars, Frans; Viezzoli, Andrea; Rolf, Harry; Groen, Michel; Auken, Esben; Bjergsted Pedersen, Jesper

    2013-04-01

    Groundwater models in coastal aquifers are often used to predict the effect of hydrological changes (climate change, sea level rise, and etcetera) on groundwater heads and seawater intrusion. The results can be very sensitive to the boundary condition that is used for the coastal edge of the model, even when the main interest is in groundwater heads only. This is especially the case when models are calibrated, because groundwater heads from monitoring wells are often the only calibration data available. The lack of offshore data is a complicating factor that consequently decreases the reliability of the entire model. Using Airborne electromagnetic geophysics (e.g., SkyTEM) we can determine the extent of the fresh groundwater wedge below the sea. However, the low resistive seawater and subsequent geo-electrical equivalence makes it difficult to determine the thickness and resistivity of the resistive zone. Furthermore, it can be impossible to separate lithology and water-quality based on the resistivity model only, for example in concurrent presence of clays and saline aquifers. In this study we combined the resistivity model and the hydrological model in a number of cross sections perpendicular to the coast. We use data from the SKYTEM survey that was done in 2011 along the coast at the dune area of PWN water supply. Additionally we have continuous vertical electrical sounding (CVES) profiles and electrical cone penetration (CPT) tests on the beach. We will show the benefits of combining both hydrogeological modeling and airborne geophysical measurements to determine a good boundary condition and the matching lithology and water quality. We will also determine the effect of commonly used boundary conditions that were derived without the geophysical information. Comparing these results we demonstrate the benefit of the combination and give practical recommendations for future applications.

  14. Hydrogeology of the Beaver Kill basin in Sullivan, Delaware, and Ulster Counties, New York

    USGS Publications Warehouse

    Reynolds, Richard J.

    2000-01-01

    The hydrogeology of the 299-square-mile Beaver Kill basin in the southwestern Catskill Mountains of southeastern New York is depicted in a surficial geologic map and five geologic sections, and is summarized through an analysis of low-flow statistics for the Beaver Kill and its major tributary, Willowemoc Creek. Surficial geologic data indicate that the most widespread geologic units within the basin are ablation and lodgment till. Large masses of ablation till as much as 450 feet thick were deposited as lateral embankments within the narrow Beaver Kill and Willowemoc Creek valleys and have displaced the modern stream courses by as much as 1,000 feet from the preglacial bedrock-valley axis. Low-flow statistics for the Beaver Kill and Willowemoc Creeks indicate that the base flows (discharges that are exceeded 90 percent of the time) of these two streams--0.36 and 0.39 cubic feet per square mile,respectively--are the highest of 13 Catskill Mountain streams studied. High base flows elsewhere in the glaciated northeastern United States are generally associated with large stratified-drift aquifers, however, stratified drift in these two basins accounts for only about 5 percent and 4.4 percent of their respective surface areas, respectively. The high base flows in these two basins appear to correlate with an equally high percentage of massive sandstone members of the Catskill Formation, which underlies the entire region. Ground-water seepage from these sandstone members may be responsible for the high base flows of these two streams.

  15. Hydrochemistry and hydrogeologic conditions within the Hanford Site upper basalt confined aquifer system

    SciTech Connect

    Spane, F.A. Jr.; Webber, W.D.

    1995-09-01

    As part of the Hanford Site Ground-Water Surveillance Project, Flow System Characterization Task. Pacific Northwest Laboratory examines the potential for offsite migration of contamination within the upper basalt confined aquifer system for the US Department of Energy (DOE). As part of this activity, groundwater samples were collected over the past 2 years from selected wells completed in the upper Saddle Mountains Basalt. The hydrochemical and isotopic information obtained from these groundwater samples provides hydrologic information concerning the aquifer-flow system. Ideally, when combined with other hydrologic property information, hydrochemical and isotopic data can be used to evaluate the origin and source of groundwater, areal groundwater-flow patterns, residence and groundwater travel time, rock/groundwater reactions, and aquifer intercommunication for the upper basalt confined aquifer system. This report presents the first comprehensive Hanford Site-wide summary of hydrochemical properties for the upper basalt confined aquifer system. This report provides the hydrogeologic characteristics (Section 2.0) and hydrochemical properties (Section 3.0) for groundwater within this system. A detailed description of the range of the identified hydrochemical parameter subgroups for groundwater in the upper basalt confined aquifer system is also presented in Section 3.0. Evidence that is indicative of aquifer contamination/aquifer intercommunication and an assessment of the potential for offsite migration of contaminants in groundwater within the upper basalt aquifer is provided in Section 4.0. The references cited throughout the report are given in Section 5.0. Tables that summarize groundwater sample analysis results for individual test interval/well sites are included in the Appendix.

  16. Hydrogeology and Ground-Water Quality, Chippewa Township, Isabella County, Michigan, 2002-05

    USGS Publications Warehouse

    Westjohn, David B.; Hoard, Chris J.

    2006-01-01

    The ground-water resource potential of Chippewa Township, Isabella County, Mich. was characterized on the basis of existing hydrogeologic data, water-level records, analyses of water samples, and interpretation of geophysical survey data. Eight ground-water samples were collected and analyzed for major ions, nutrients, and trace-metal composition. In addition, 10 direct current-resistivity soundings were collected throughout Chippewa and Coe Townships to identify potential freshwater in the aquifer system. The aquifer system includes complexly interbedded glaciofluvial, glaciolacustrine, and basal-lodgment tills, which overlie Jurassic or Pennsylvanian sedimentary rocks. In parts of the township, freshwater is present in all geologic units, but in most areas saline water is encountered near the base of Pleistocene glacial deposits and in the Jurassic or Pennsylvanian bedrock. A near-surface sheet of relatively dense basal-lodgment till likely prevents, or substantially retards, significant direct recharge of ground water to glacial and bedrock aquifers in Chippewa and adjacent townships. Glacial sands and gravels form the principal aquifer for domestic wells (97.5 percent of wells in the township). The single community water supply in the township has wells screened in glacial deposits near the base of the glacial drift. Increased withdrawals of ground water in response to increasing demand has led to a slight decline in water quality from this supply. This water-quality decline is related primarily to an increase of dissolved sulfate, which is probably a function of well depth and dissolution of gypsum, a common mineral constituent in the Jurassic 'red beds,' which form the uppermost bedrock unit throughout most of the township. One explanation for the increase in sulfate is upconing of saline water from bedrock sources, which may contain saline water.

  17. Data requirements for simulation of hydrogeologic effects of liquid waste injection, Harrison and Jackson Counties, Mississippi

    USGS Publications Warehouse

    Rebich, Richard A.

    1994-01-01

    Available literature and data were reviewed to quantify data requirements for computer simulation of hydrogeologic effects of liquid waste injection in southeastern Mississippi. Emphasis of each review was placed on quantifying physical properties of current Class I injection zones in Harrison and Jackson Counties. Class I injection zones are zones that are used for injection of hazardous or non-hazardous liquid waste below a formation containing the lowermost underground source of drinking water located within one-quarter of a mile of the injection well. Several mathematical models have been developed to simulate injection effects. The Basic Plume Method was selected because it is commonly used in permit applications, and the Intercomp model was selected because it is generally accepted and used in injection-related research. The input data requirements of the two models were combined into a single data requirement list inclusive of physical properties of injection zones only; injected waste and well properties are not included because such information is site-specific by industry, which is beyond the scope of this report. Results of the reviews of available literature and data indicated that Class I permit applications and standard-reference chemistry and physics texts were the primary sources of information to quantify physical properties of injection zones in Harrison and Jackson Counties. With the exception of a few reports and supplementary data for one injection zone in Jackson County, very little additional information pertaining to physical properties of the injection zones was available in sources other than permit applications and standard-reference texts.

  18. Hydrogeologic factors affecting cavern morphology within rocks of Mississippian age in northwestern Arkansas

    SciTech Connect

    Fanning, B.J. . Dept. of Geology); Brahana, J.V. . Geological Survey)

    1993-02-01

    Cavern development within rocks of Mississippian age in northwestern Arkansas is associated with two Pleistocene erosional features, the Boston Mountains Plateau and the Springfield Plateau. Each plateau is characterized by a distinct stratigraphic sequence with unique lithologies. Cavern morphology (both cross-sectional and planimetric) in each plateau is the result of the complex interaction of numerous hydrogeologic factors. Four of the most dominant factors which affect cavern morphology appear to be: (1) composition and continuity of the confining units; (2) percentage of noncarbonate components in rocks of the cavern-forming interval; (3) nature and distribution of ground-water recharge to the cavern-forming interval; and (4) nature and distribution of fractures within the cavern-forming interval. Network maze patterns typically develop in the Pitkin Limestone, the formation in which most caverns form beneath the Boston Mountains Plateau. The Pitkin, a bioclastic limestone, is confined above by siltstones of the Cane Hill member of the Hale Formation and below by shales of the Fayetteville Formation. The maze pattern indicates that these caverns probably were formed by dissolution of the rock matrix by diffuse recharge moving vertically through leaky confining units. Single rooms are the dominant cavern morphology in the chert-dominated Boone Formation of the Springfield Plateau. Where the concentration of chert is greater than 50 percent, the Boone lacks structural integrity and fails to develop well-integrated conduit networks. Point recharge features in outcrop areas of the Boone Formation are not visible in most of the Springfield Plateau because the insoluble residuum masks the upper bedrock surface. Where the Boone Formation is less than 7 meters thick, surface karst features are more prevalent.

  19. Correlation of Miocene sequences and hydrogeologic units, New Jersey Coastal Plain

    NASA Astrophysics Data System (ADS)

    Sugarman, Peter J.; Miller, Kenneth G.

    1997-02-01

    We have developed a Miocene sequence stratigraphic framework using data from recently drilled boreholes in the New Jersey Coastal Plain. Sequences are shallowing upward, unconformity-bounded units; fine-grained shelf and prodelta sediments grade upward to delta front and shallow-marine sands, corresponding to confining bed—aquifer couplets. By dating Miocene sequences using Sr-isotope stratigraphy, and mapping with borehole data and geophysical logs, we can predict the continuity and effectiveness of the confining beds and aquifers. The following are illustrated on a 90-km basinward dip section: (1) the composite confining bed is comprised of the Kw0 and lower Kw1a (ca. 23.8-20.5 Ma) sequences downdip at Atlantic City, and the Kw1b, Kw1a and older sequences updip (ca. 69.3-20.6 Ma), and is continuous throughout most of the coastal plain; (2) the major confined aquifer, the Atlantic City 800-foot sand, is comprised of the upper Kw1a and Kw1b sequences (ca. 20.5-20.2 Ma) and is an areally continuous sand that is interconnected with the Kirkwood-Cohansey aquifer system updip of Mays Landing; (3) the confining bed above the Atlantic City 800-foot sand is comprised of the Kw2a, Kw2b, and Kw3 sequences (18.1-13.3 Ma) and is an extensive confining bed that pinches out updip. These sequences and aquifer-confining bed couplets are linked to global sea-level changes evinced by the δ18O record. We conclude that sequence stratigraphy is a powerful tool when applied to regional hydrogeologic problems, although basinal tectonic differences and localized variations in sediment supply can affect aquifer thickness and permeability.

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

    USGS Publications Warehouse

    Grannemann, N.G.

    1984-01-01

    A hydrogeological study of Sands Plain, a sandy outwash area in the north-central part of Michigan 's Upper Peninsula, was conducted during 1979-82. Parts of the area are being considered as possible sites for construction and operation of iron mining tailings basins. Gribben Basin, an existing tailings basin in the western part of Sands Plains, covers 2.5 square miles; hypothetical tailings basins may cover as much as 11 square miles. Glacial deposits are the area 's principal aquifer. The general direction of ground-water flow is from the outwash area toward Lake Superior. Before reaching Lake Superior, however, most ground water is discharged in a series of nearly parallel streams. Ground water accounts for 95 percent of the discharge of these streams. Precipitation collected at two sites had average pH values of 4.0. Dissolved solids concentrations in water from wells ranged from 41 to 246 milligrams per liter; in water from streams, they ranged from 82 to 143 milligrams per liter. Calcium and bicarbonate were the principal dissolved ions. A two-dimensional digital model of ground-water flow was used to simulate ground-water levels and runoff. The predictive computer simulations indicate that construction and operation of Gribben tailings basin, located in the western part of the study area, decreased ground-water flow to Goose Lake Outlet by 0.9 to 1.6 cubic feet per second. Construction and operation of four hypothetical tailings basins covering a total of 11 square miles is estimated to reduce ground-water flow to the area 's streams by 7 to 18 cubic feet per second depending on the hydraulic properties of material comprising the basin boundaries. Leakage from all of the basins is estimated to range from 0.7 to 7 cubic feet per second. (USGS)

  1. Groundwater protection and unconventional gas extraction: the critical need for field-based hydrogeological research.

    PubMed

    Jackson, R E; Gorody, A W; Mayer, B; Roy, J W; Ryan, M C; Van Stempvoort, D R

    2013-01-01

    Unconventional natural gas extraction from tight sandstones, shales, and some coal-beds is typically accomplished by horizontal drilling and hydraulic fracturing that is necessary for economic development of these new hydrocarbon resources. Concerns have been raised regarding the potential for contamination of shallow groundwater by stray gases, formation waters, and fracturing chemicals associated with unconventional gas exploration. A lack of sound scientific hydrogeological field observations and a scarcity of published peer-reviewed articles on the effects of both conventional and unconventional oil and gas activities on shallow groundwater make it difficult to address these issues. Here, we discuss several case studies related to both conventional and unconventional oil and gas activities illustrating how under some circumstances stray or fugitive gas from deep gas-rich formations has migrated from the subsurface into shallow aquifers and how it has affected groundwater quality. Examples include impacts of uncemented well annuli in areas of historic drilling operations, effects related to poor cement bonding in both new and old hydrocarbon wells, and ineffective cementing practices. We also summarize studies describing how structural features influence the role of natural and induced fractures as contaminant fluid migration pathways. On the basis of these studies, we identify two areas where field-focused research is urgently needed to fill current science gaps related to unconventional gas extraction: (1) baseline geochemical mapping (with time series sampling from a sufficient network of groundwater monitoring wells) and (2) field testing of potential mechanisms and pathways by which hydrocarbon gases, reservoir fluids, and fracturing chemicals might potentially invade and contaminate useable groundwater. PMID:23745972

  2. Hydrogeology and water quality of the North Canadian River alluvium, Concho Reserve, Canadian County, Oklahoma

    USGS Publications Warehouse

    Becker, C.J.

    1998-01-01

    A growing user population within the Concho Reserve in Canadian County, Oklahoma, has increased the need for drinking water. The North Canadian River alluvium is a reliable source of ground water for agriculture, industry, and cities in Canadian County and is the only ground-water source capable of meeting large demands. This study was undertaken to collect and analyze data to describe the hydrogeology and ground-water quality of the North Canadian River alluvium within the Concho Reserve. The alluvium forms a band about 2 miles long and 0.5 mile wide along the southern edge of the Concho Reserve. Thickness of the alluvium ranges from 19 to 75 feet thick and averages about 45 feet in the study area. Well cuttings and natural gamma-ray logs indicate the alluvium consists of interfingering lenses of clay, silt, and sand. The increase of coarse-grained sand and the decrease of clay and silt with depth suggests that the water-bearing properties of the aquifer within the study area improve with depth. A clay layer in the upper part of the aquifer may be partially responsible for surface water ponding in low areas after above normal precipitation and may delay the infiltration of potentially contaminated water from land surface. Specific conductance measurements indicate the ground-water quality improves in a northern direction towards the terrace. Water-quality properties, bacteria counts, major ion and nutrient concentrations, trace-element and radionuclide concentrations, and organic compound concentrations were measured in one ground-water sample at the southern edge of the Concho Reserve and comply with the primary drinking-water standards. Measured concentrations of iron, manganese, sulfate, and total dissolved solids exceed the secondary maximum contaminant levels set for drinking water. The ground water is a calcium sulfate bicarbonate type and is considered very hard, with a hardness of 570 milligrams per liter as calcium carbonate.

  3. Comprehensive principles of quantitative hydrogeology established by Darcy (1856) and Dupuit (1857)

    NASA Astrophysics Data System (ADS)

    Ritzi, Robert W.; Bobeck, Patricia

    2008-10-01

    Henry Darcy and Jules Dupuit were born 1 year apart, were classmates during their undergraduate and graduate education in civil engineering, and were colleagues in the French corps of civil engineers, with overlapping appointments as inspector general in the early 1850s. At that time Darcy turned over, to Dupuit, his position as Director of Water and Bridges in Paris and the research on pipe flow he had begun there in 1849. In these pipe flow experiments, Darcy discovered what he referred to as a "law" of fluid mechanics, which is that above a certain velocity threshold, the head loss is proportional to velocity squared, and below that threshold, the head loss is linearly proportional to velocity. During the remainder of their careers, Darcy and Dupuit applied this law with their collective, extensive, prior knowledge of fluid mechanics, geology, aquifers, wells, and springs to quantitative studies of fluid flow in the subsurface (and also in pipes, aqueducts, rivers, and sand filters). Two monographs by Darcy (1856) and Dupuit (1857) are mutually cited retrospectives on much of this research, submitted at nearly the same time, to the same Corps des Ponts et Chaussées publisher, near the end of their careers. Between these two monographs, many of the fundamentals of quantitative hydrogeology were established, including the equation for groundwater motion, average linear velocity, average travel time, effective hydraulic conductivity for layered heterogeneity, conservation of mass in confined and unconfined flow, the nature of the regional pieziometric surface, porous flow versus flow through discrete fractures and karst conduits, the equation for a cone of depression around flowing wells, superposition of the effects of multiple wells, and capture zone geometries of wells within a regional flow field.

  4. Hydrogeologic Testing During Drilling of COSC-1 Borehole: Application of FFEC Logging Method

    NASA Astrophysics Data System (ADS)

    Tsang, Chin-Fu; Rosberg, Jan-Erik; Sharma, Prabhakar; Niemi, Auli; Juhlin, Christopher

    2015-04-01

    Drilling of a deep borehole does not normally allow for hydrogeologic testing during the drilling period. The only time hydraulic testing is done during the drilling operations is when drilling experiences a large loss (or high return) of drilling fluid representing encountering of a large-transmissivity zone. Then, either the zone is cemented for drilling to continue or drilling is stopped for conducting, for example, a drill-stem test (DST), which involves installation of a packer above the drilling depth and performing a pressure or flow transient test. The first alternative means loss of critical information on in-situ hydraulic transmissivities and the second option enables the study of only the one high-transmissivity zone, with a significant delay of the drilling schedule. The drilling of the COSC-1 borehole at Åre, Northern Sweden, presented an opportunity of conducting a particular hydraulic testing with negligible impact on drilling schedule, yet providing important and accurate information on in-situ hydraulic conductivities on both high- and low-transmissivity zones, already during the drilling period. This information can be used to guide downhole fluid sampling programs and future detailed borehole testing. The particular testing method used is the Flowing Fluid Electric Conductivity (FFEC) Logging Method, which has the capability of identifying large and small hydraulically active zones and providing data for estimating their transmissivity values and local formation water salinity. In this paper, the method will be described and its application to the drilling of COSC-1 borehole presented. Results show that from 300 m to the borehole bottom at 2500 m, there are eight hydraulic active zones in COSC-1, with very low transmissivity values which range over one order of magnitude.

  5. Collaborative research: Hydrogeological-geophysical methods for subsurface site characterization. 1997 annual progress report

    SciTech Connect

    Rubin, Y.; Morrison, F.; Rector, J.

    1997-10-31

    'In the first year of the project progress has been made in several areas which are central to the project. Development of Joint Hydrogcological-Geophysical Co-Interpretation Procedure A strong effort was invested in developing the concepts and the algorithm of the joint hydrogeological-geophysical co-interpretation approach. The reason for the concerted effort in that direction is the large amount of time the authors expect this task will take before completion, and also by the need to direct the data collection efforts. They are currently testing several ideas for co-interpretation, but they are at a quite advanced stage. They are testing these ideas using synthetic studies as well as some preliminary data that has been collected at the Lawrence Livermore National Lab site. Part of the efforts is in developing methods for estimation of the semi-variograms of the logconductivity based on direct measurements as well as on seimsic velocity measurements as obtained from cross-well tomography. Preliminary tests show that these two sources of data complement each other quite well: the direct measurements supply the medium to small wave number portion of the logconductivity spectra, while a high resolution seismic survey supplies a good coverage of the large wave number part of the spectra. They advanced significantly with formulating their approach for using Ground Penetrating Radar (GPR) imaging techniques in shallow subsurface surveys. Synthetic surveys show that GPR maybe very suitable for mapping spatial variations in saturations. They have access to field data and are analyzing it. Some additional issues that were investigated are also listed.'

  6. Hydrogeology and groundwater evaluation of a shallow coastal aquifer, southern Akwa Ibom State (Nigeria)

    NASA Astrophysics Data System (ADS)

    Edet, Aniekan

    2016-06-01

    The rapid expansion of economic activities in coastal parts of Nigeria has triggered an uncoordinated development of groundwater leading to stress on the resource. Hence a study was conducted to assess the hydrogeological characteristics of the shallow coastal aquifer of southern Akwa Ibom State, Nigeria. Emphasis was on the hydraulic characteristics, quality with respect to domestic and irrigation purposes and influence of seawater. The study result revealed that the aquifer consist of intercalations of clayey sand and sand. The aquifer is characterized by high hydraulic conductivity and transmissivity values. The groundwater flow direction is southwards with higher groundwater depletion in the dry season. Groundwater samples from hand dug wells and boreholes were evaluated based on World Health Organization standard and some indices, respectively, for drinking and irrigation uses. The groundwaters are fit for drinking and domestic uses. However, more than 70 % of the pH values are not within the allowable limits of between 6.5 and 9.2 for drinking and domestic use. Therefore, it is recommended that neutralizing filter containing calcite or ground limestone should be applied to raise the pH of the groundwater. Of the 10 parameters used to assess the water for irrigation use, only sodium adsorption ratio (SAR), magnesium hazard (MH) and magnesium ratio indicated the excellent quality of these waters. Na+-K+-HCO3 - constitute the dominant water type. Total dissolved solids and ratios of Na+/Cl-, Mg2+/Cl-, and Ca2+/SO4 2- and saltwater mixing index (SMI) suggest some level of seawater intrusion in the area.

  7. Palaeo-hydrogeology of the Cretaceous Sediments of the Williston Basin using Stable Isotopes of Water

    NASA Astrophysics Data System (ADS)

    Hendry, Michael J.; Barbour, S. Lee; Novakowski, Kent; Wassenaar, Len I.

    2013-04-01

    Hydraulic and isotopic data collected from aquifers are typically used to characterize hydrogeological conditions within sedimentary basins. Similar data from confining units are generally not collected despite their ability to provide insights into important water/solute transport controls. In this study, we characterized palaeo-groundwater flow and solute transport mechanisms across 384 m of a Cretaceous shale aquitard in the Williston Basin, Canada, using high-resolution depth profiles of water isotopes (δ18O and δ2H). Water samples were also collected from wells installed in the underlying regional aquifer (Mannville Fm; 93 m thick) and from seepage inflows into potash mine shafts (to 825 m below ground). 1-D numerical transport modeling of isotopic profiles yielded insight into large-scale/long-term solute transport in both Cretaceous sediments and the Basin. Molecular diffusion was determined to be the dominant solute transport mechanism through the aquitard. Transport model simulations suggest average vertical groundwater velocities of <0.05 m/10 ka and an average excess hydraulic head of <10 m. These values are less than anticipated by successive glaciations. The dominant palaeo-event reflected in present-day profiles is introduction during the Pleistocene of glaciogenic meteoric water to the aquifer underlying the aquitard, likely along an aquifer outcrop area east of the site or through local vertical conduits in the aquitard. Simulations suggest these recharge events occurred during one or more glacial periods. The isotopic profile over the upper 25 m of Pleistocene till and shale is consistent with glacial deposition and transport processes within these units during the Holocene (past 10 ka).

  8. A hydrogeologic framework for characterizing summer streamflow sensitivity to climate warming in the Pacific Northwest, USA

    NASA Astrophysics Data System (ADS)

    Safeeq, M.; Grant, G. E.; Lewis, S. L.; Kramer, M. G.; Staab, B.

    2014-09-01

    Summer streamflows in the Pacific Northwest are largely derived from melting snow and groundwater discharge. As the climate warms, diminishing snowpack and earlier snowmelt will cause reductions in summer streamflow. Most regional-scale assessments of climate change impacts on streamflow use downscaled temperature and precipitation projections from general circulation models (GCMs) coupled with large-scale hydrologic models. Here we develop and apply an analytical hydrogeologic framework for characterizing summer streamflow sensitivity to a change in the timing and magnitude of recharge in a spatially explicit fashion. In particular, we incorporate the role of deep groundwater, which large-scale hydrologic models generally fail to capture, into streamflow sensitivity assessments. We validate our analytical streamflow sensitivities against two empirical measures of sensitivity derived using historical observations of temperature, precipitation, and streamflow from 217 watersheds. In general, empirically and analytically derived streamflow sensitivity values correspond. Although the selected watersheds cover a range of hydrologic regimes (e.g., rain-dominated, mixture of rain and snow, and snow-dominated), sensitivity validation was primarily driven by the snow-dominated watersheds, which are subjected to a wider range of change in recharge timing and magnitude as a result of increased temperature. Overall, two patterns emerge from this analysis: first, areas with high streamflow sensitivity also have higher summer streamflows as compared to low-sensitivity areas. Second, the level of sensitivity and spatial extent of highly sensitive areas diminishes over time as the summer progresses. Results of this analysis point to a robust, practical, and scalable approach that can help assess risk at the landscape scale, complement the downscaling approach, be applied to any climate scenario of interest, and provide a framework to assist land and water managers in adapting to

  9. A hydrogeological study of the Nhandugue River, Mozambique - A major groundwater recharge zone

    NASA Astrophysics Data System (ADS)

    Arvidsson, K.; Stenberg, L.; Chirindja, F.; Dahlin, T.; Owen, R.; Steinbruch, F.

    The Nhandugue River flows over the western margin of the Urema Rift, the southernmost extension of the East African Rift System, and marks the north-western border of Gorongosa National Park, Mozambique. It constitutes one of the major indispensable water resources for the ecosystem that the park protects. Our study focused on the hydrogeological conditions at the western rift margin by resistivity measurements, soil sampling and discharge measurements. The resistivity results suggest that the area is heavily faulted and constitutes a major groundwater recharge zone. East of the rift margin the resistivity indicate that solid gneiss is fractured and weathered, and is overlain by sandstone and alluvial sediments. The top 10-15 m of the alluvial sequence is interpreted as sand. The sand layer extends back to the rift margin thus also covering the gneiss. The sandstone outcrops a few kilometers from the rift margin and dips towards east/south-east. Further into the rift valley, the sand is underlain by lenses of silt and clay on top of sand mixed with finer matter. In the lower end of the investigated area the lenses of silt and clay appears as a more or less continuous layer between the two sand units. The topmost alluvial sand constitutes an unconfined aquifer under which the solid gneiss forms a hydraulic boundary and the fractured gneiss an unconfined aquifer. The sandstone is an unconfined aquifer in the west, becoming semi-confined down dip. The lenses of silt and clay forms an aquitard and the underlying sand mixed with finer matter a semi-confined aquifer. The surface runoff decreases downstream and it is therefore concluded that surface water infiltrates as recharge to the aquifers and moves as groundwater in an east/south-eastward direction.

  10. Fault Zone Hydrogeology of Crystalline and Sedimentary Aquifers in Arid Regions: The Case Sinai Peninsula, Egypt.

    NASA Astrophysics Data System (ADS)

    Ahmed, M.; Mohamed, L.; Sultan, M.; Farag, A. Z. A.

    2015-12-01

    Structural control on the groundwater flow in arid regions is still poorly understood. Understanding the distribution of structural discontinuities (i.e. faults, joints and shear zones), their cross cutting relationships, and their relation with the regional hydraulic gradient are critical for deciphering the complexity of water resources distribution in the highly fractured crystalline and sedimentary aquifers in Sinai. In order to achieve that, we conducted an integrated approach using remote sensing, geophysical and hydrogeological datasets: (1) identification of the spatial and temporal rainfall events using Tropical Rainfall Measuring Mission (TRMM) data; (2) delineation of major faults and shear zones using Landsat 8 and ASTER image ratioing, geological datasets and field investigation; (3) generation of a normalized difference ratio image using Envisat radar images before and after the rain events to identify preferential water-channeling discontinuities in the crystalline terrain; (4) validation of the water-channeling discontinuities using Very Low Frequency (VLF) method; (5) generation of regional groundwater flow and isotopic (18O and 2H ) distribution maps for the sedimentary aquifer and an approximation flow map for the crystalline aquifer; (6) developing a conceptual model for the groundwater flow in the fractured crystalline and sedimentary aquifers; (7) testing the model accuracy using Vertical Electrical Sounding (VES) method in seven locations. Our findings include: (1) in the crystalline aquifer, discontinuities that are sub-parallel to groundwater flow direction act as preferred pathways for groundwater flow, whereas those that intersect groundwater flow directions at high angles act as barriers causing considerable groundwater accumulations at the upstream side; (2) in the sedimentary aquifer, high angle E-W discontinuities (i.e. Themed shear zone and Sinai Hinge Belt) cause a considerable groundwater elevation, redirection of the groundwater

  11. Hydrogeologic conditions and water management modeling for a Sierra Nevada fen wetland

    NASA Astrophysics Data System (ADS)

    Ronayne, M. J.; Cooper, D.; Wolf, E. C.

    2012-12-01

    Small fens occur throughout the Sierra Nevada, providing carbon storage and critical habitat for plant and animal species. The accumulated peat within fens, which has distinct physical and hydraulic properties, plays an important role in the hydrologic function of these wetland systems. In this study, we investigated the hydrogeology of a 0.5-ha fen in Yosemite National Park using hydraulic head data, stable isotope analysis, and numerical modeling. Peat thickness within the fen ranges from less than 10 cm to 1.4 m. Saturated conditions are produced by convergent groundwater flow originating from two distinct source areas. Water levels throughout the fen and surrounding meadow vary seasonally and interannually in response to natural variability in precipitation. The water table position is also influenced by pumping from a deep water supply well, which extracts groundwater from a weathered bedrock zone that is hydraulically connected to the surficial sediments. A spatially distributed 3D numerical groundwater model was developed to assess the relative importance of precipitation and groundwater pumping in controlling the water table position. The model results indicate that groundwater pumping has a significant impact on shallow water levels during a year with below-average precipitation. In a representative dry year, existing groundwater pumping accounts for approximately two-thirds of the water table decline (> 1 m) that is observed during June through September. During a wet year characterized by high winter/spring precipitation, there is sufficient water in storage to maintain saturated conditions throughout the summer. Predictive modeling was performed to evaluate alternative groundwater-use scenarios. These results will be used to develop water management strategies that support wetland stability.

  12. Constraining age distributions of groundwater from public supply wells in diverse hydrogeological settings in Scania, Sweden

    NASA Astrophysics Data System (ADS)

    Åkesson, Maria; Suckow, Axel; Visser, Ate; Sültenfuβ, Jürgen; Laier, Troels; Purtschert, Roland; Sparrenbom, Charlotte J.

    2015-09-01

    Twenty-five public supply wells throughout the hydrogeologically diverse region of Scania, southern Sweden are subjected to environmental tracer analysis (3H-3He, 4He, CFCs, SF6 and for one well only also 85Kr and 39Ar) to study well and aquifer vulnerability and evaluate possibilities of groundwater age distribution assessment. We find CFC and SF6 concentrations well above solubility equilibrium with modern atmosphere, indicating local contamination, as well as indications of CFC degradation. The tracer-specific complications considerably constrain possibilities for sound quantitative regional groundwater age distribution assessments and demonstrate the importance of initial qualitative assessment of tracer-specific reliability, as well a need for additional, complementary tracers (e.g. 85Kr, 39Ar and potentially also 14C). Lumped parameter modelling yields credible age distribution assessments for representative wells in four type aquifers. Pollution vulnerability of the aquifer types was based on the selected LPM models and qualitative age characterisation. Most vulnerable are unconfined dual porosity and fractured bedrock aquifers, due to a large component of very young groundwater. Unconfined sedimentary aquifers are vulnerable due to young groundwater and a small pre-modern component. Less vulnerable are semi-confined sedimentary or dual-porosity aquifers, due to older age of the modern component and a larger pre-modern component. Confined aquifers appear least vulnerable, due an entirely pre-modern groundwater age distribution (recharged before 1963). Tracer complications aside, environmental tracer analyses and lumped parameter modelling aid in vulnerability assessment and protection of regional groundwater resources.

  13. Episodic origin of a large outwash complex during multiple glaciations -- Geologic and hydrogeologic implications

    SciTech Connect

    Brown, S.E.; Fleming, A.H. )

    1994-04-01

    The White River valley in Marion County is underlain by a massive outwash complex that constitutes the most productive aquifer in the greater Indianapolis area, and an understanding of its geologic evolution is essential to the proper development and protection of the resource. Subsurface studies indicate that this part of the valley functioned as a major meltwater conduit for glacial episodes that took place at times ranging from pre-Illinoian to late Wisconsin. Consequently, surficial outwash associated with the latest Wisconsin ice sheet appears to be of limited volumetric importance in many parts of the valley. Instead, the bulk of the complex consists of several distinct depositional sequences that exhibit a variety of cross-cutting and inset relations, and which are at places separated by prominent paleosurfaces. Each sequence typically consists of outwash fans and(or) meltwater channels that are broadly symmetric about the modern valley, or that parallel buried bedrock valleys that underlie some segments of the modern valley. The striking similarities between sequences of such vastly different ages suggest that they result from a basic depositional pattern that repeated over the course of successive glaciations. It seems likely that bedrock topography, particularly the Knobstone Escarpment that lies just west of the modern valley, was the ultimate control on the dynamics of relatively thin ice sheets and thus repeatedly influenced the distributions of meltwater and sedimentary facies in the valley. Recognition of similar depositional patterns through time provides the necessary facies models for many hydrogeologic applications, such as development and protection of public wellfields, investigations of environmental sites, and interpretation of water-quality samples.

  14. Correlation of Miocene sequences and hydrogeologic units, New Jersey Coastal Plain

    USGS Publications Warehouse

    Sugarman, P.J.; Miller, K.G.

    1997-01-01

    We have developed a Miocene sequence stratigraphic framework using data from recently drilled boreholes in the New Jersey Coastal Plain. Sequences are shallowing upward, unconformity-bounded units; fine-grained shelf and prodelta sediments grade upward to delta front and shallow-marine sands, corresponding to confining bed-aquifer couplets. By dating Miocene sequences using Sr-isotope stratigraphy, and mapping with borehole data and geophysical logs, we can predict the continuity and effectiveness of the confining beds and aquifers. The following are illustrated on a 90-km basinward dip section: (1) the composite confining bed is comprised of the KwO and lower Kw1a (ca. 23.8-20.5 Ma) sequences downdip at Atlantic City, and the Kw1b, Kw1a and older sequences updip (ca. 69.3-20.6 Ma), and is continuous throughout most of the coastal plain; (2) the major confined aquifer, the Atlantic City 800-foot sand, is comprised of the upper Kw1a and Kw1b sequences (ca. 20.5-20.2 Ma) and is an areally continuous sand that is interconnected with the Kirkwood-Cohansey aquifer system updip of Mays Landing; (3) the confining bed above the Atlantic City 800-foot sand is comprised of the Kw2a, Kw2b, and Kw3 sequences (18.1-13.3 Ma) and is an extensive confining bed that pinches out updip. These sequences and aquifer-confining bed couplets are linked to global sea-level changes evinced by the ??18O record. We conclude that sequence stratigraphy is a powerful tool when applied to regional hydrogeologic problems, although basinal tectonic differences and localized variations in sediment supply can affect aquifer thickness and permeability.

  15. A global review on ambient Limestone-Precipitating Springs (LPS): Hydrogeological setting, ecology, and conservation.

    PubMed

    Cantonati, Marco; Segadelli, Stefano; Ogata, Kei; Tran, Ha; Sanders, Diethard; Gerecke, Reinhard; Rott, Eugen; Filippini, Maria; Gargini, Alessandro; Celico, Fulvio

    2016-10-15

    Springs are biodiversity hotspots and unique habitats that are threatened, especially by water overdraft. Here we review knowledge on ambient-temperature (non-geothermal) freshwater springs that achieve sufficient oversaturation for CaCO3 -by physical CO2 degassing and activity of photoautotrophs- to deposit limestone, locally resulting in scenic carbonate structures: Limestone-Precipitating Springs (LPS). The most characteristic organisms in these springs are those that contribute to carbonate precipitation, e.g.: the mosses Palustriella and Eucladium, the crenophilous desmid Oocardium stratum, and cyanobacteria (e.g., Rivularia). These organisms appear to be sensitive to phosphorus pollution. Invertebrate diversity is modest, and highest in pools with an aquatic-terrestrial interface. Internationally, comprehensive legislation for spring protection is still relatively scarce. Where available, it covers all spring types. The situation in Europe is peculiar: the only widespread spring type included in the EU Habitat Directive is LPS, mainly because of landscape aesthetics. To support LPS inventorying and management to meet conservation-legislation requirements we developed a general conceptual model to predict where LPS are more likely to occur. The model is based on the pre-requisites for LPS: an aquifer lithology that enables build-up of high bicarbonate and Ca(2+) to sustain CaCO3 oversaturation after spring emergence, combined with intense groundwater percolation especially along structural discontinuities (e.g., fault zones, joints, schistosity), and a proper hydrogeological structure of the discharging area. We validated this model by means of the LPS information system for the Emilia-Romagna Region (northern Italy). The main threats to LPS are water diversion, nutrient enrichment, and lack of awareness by non-specialized persons and administrators. We discuss an emblematic case study to provide management suggestions. The present review is devoted to LPS but

  16. Groundwater intensive use and mining in south-eastern peninsular Spain: Hydrogeological, economic and social aspects.

    PubMed

    Custodio, Emilio; Andreu-Rodes, José Miguel; Aragón, Ramón; Estrela, Teodoro; Ferrer, Javier; García-Aróstegui, José Luis; Manzano, Marisol; Rodríguez-Hernández, Luis; Sahuquillo, Andrés; Del Villar, Alberto

    2016-07-15

    Intensive groundwater development is a common circumstance in semiarid and arid areas. Often abstraction exceeds recharge, thus continuously depleting reserves. There is groundwater mining when the recovery of aquifer reserves needs more than 50years. The MASE project has been carried out to compile what is known about Spain and specifically about the south-eastern Iberian Peninsula and the Canary Islands. The objective was the synthetic analysis of available data on the hydrological, economic, managerial, social, and ethical aspects of groundwater mining. Since the mid-20th century, intensive use of groundwater in south-eastern Spain allowed extending and securing the areas with traditional surface water irrigation of cash crops and their extension to former dry lands, taking advantage of good soils and climate. This fostered a huge economic and social development. Intensive agriculture is a main activity, although tourism plays currently an increasing economic role in the coasts. Many aquifers are relatively high yielding small carbonate units where the total groundwater level drawdown may currently exceed 300m. Groundwater storage depletion is estimated about 15km(3). This volume is close to the total contribution of the Tagus-Segura water transfer, but without large investments paid for with public funds. Seawater desalination complements urban supply and part of cash crop cultivation. Reclaimed urban waste water is used for irrigation. Groundwater mining produces benefits but associated to sometimes serious economic, administrative, legal and environmental problems. The use of an exhaustible vital resource raises ethical concerns. It cannot continue under the current legal conditions. A progressive change of water use paradigm is the way out, but this is not in the mind of most water managers and politicians. The positive and negative results observed in south-eastern Spain may help to analyse other areas under similar hydrogeological conditions in a less

  17. Hydrogeologic characterization of a proposed landfill expansion in Pickens County near Easley, South Carolina

    USGS Publications Warehouse

    Stringfield, W.J.

    1994-01-01

    This report presents the results of a hydrogeologic study in the Piedmont physiographic province of South Carolina to obtain geologic, hydrologic, and water-quality data from the site of a proposed landfill expansion in Pickens County near Easley, South Carolina. The geology of the study area is typical of the Piedmont region. The unconsolidated regolith on the site is soil and saprolite, which is a product of the weathered parent rock. The soil ranges in thickness from about 5 to 20 feet. The saprolite ranges in thickness from about 5 to 134 feet. The most abundant parent rock type in the area is a biotite gneiss. Ground- and surface-water data were collected at the site. Slug tests on the saprolite indicate a mean hydraulic conductivity of 3 x 0.000003 feet per second. Transmissivity ranges from 12 to 27 cubic feet per day per feet (squared per day). The ground-water velocity for the site ranges from 3 to 6 feet per year. The closest major stream to the site is Golden Creek. Based on low-flow data for Golden Creek, the estimated minimum 7 consecutive day flow that has a recurrence interval of 10 years (7Q10) at station 02186102 is 2.4 cubic feet per second. Water samples were collected from five monitoring wells at the proposed landfill expansion site and from one stream adjacent to the expansion site. Measured pH units ranged from 5.5 to 8.1, and alkalinity concentrations ranged from 5.1 to 73 milligrams per liter as CaCO3. Other water- quality data obtained included temperature and specific conductance, and 5-day BOD (biochemical oxygen demand), bicarbonate, ammonia-nitrogen, nitrite-nitrogen, nitrite plus nitrate, organic carbon, calcium, magnesium, sodium, potassium, chloride, sulfate, fluoride, and selected trace metal concentrations.

  18. Blocking Moving Window algorithm: Conditioning multiple-point simulations to hydrogeological data

    NASA Astrophysics Data System (ADS)

    Alcolea, Andres; Renard, Philippe

    2010-08-01

    Connectivity constraints and measurements of state variables contain valuable information on aquifer architecture. Multiple-point (MP) geostatistics allow one to simulate aquifer architectures, presenting a predefined degree of global connectivity. In this context, connectivity data are often disregarded. The conditioning to state variables is usually carried out by minimizing a suitable objective function (i.e., solving an inverse problem). However, the discontinuous nature of lithofacies distributions and of the corresponding objective function discourages the use of traditional sensitivity-based inversion techniques. This work presents the Blocking Moving Window algorithm (BMW), aimed at overcoming these limitations by conditioning MP simulations to hydrogeological data such as connectivity and heads. The BMW evolves iteratively until convergence: (1) MP simulation of lithofacies from geological/geophysical data and connectivity constraints, where only a random portion of the domain is simulated at every iteration (i.e., the blocking moving window, whose size is user-defined); (2) population of hydraulic properties at the intrafacies; (3) simulation of state variables; and (4) acceptance or rejection of the MP simulation depending on the quality of the fit of measured state variables. The outcome is a stack of MP simulations that (1) resemble a prior geological model depicted by a training image, (2) honor lithological data and connectivity constraints, (3) correlate with geophysical data, and (4) fit available measurements of state variables well. We analyze the performance of the algorithm on a 2-D synthetic example. Results show that (1) the size of the blocking moving window controls the behavior of the BMW, (2) conditioning to state variable data enhances dramatically the initial simulation (which accounts for geological/geophysical data only), and (3) connectivity constraints speed up the convergence but do not enhance the stack if the number of iterations

  19. Improving hydrogeological models of deltaic sedimentary media using GIS based 3D geological tools

    NASA Astrophysics Data System (ADS)

    Velasco, V.; Gogu, R.; Vázquez-Suñé, E.; Monfort, D.; Garriga, A.; Carrera, J.

    2009-04-01

    Due to the natural heterogeneity the hydrological modeling in the deltaic sedimentary media is complex. Reliable 3D hydrogeological models could be created by integrating properly detailed and accurate data. This data has to be properly managed and interpreted. The first task has been the creation of a geospatial database to store and to allow the management of a great amount of different data types coming from different sources (geophysical, geological, hydraulic, and others). The data structure allows storing an accurate and very detailed core geological description that can be straightforwardly generalized and further upscaled. The second step was to create tools within a GIS environment allowing querying and visualizing the data. One consists in illustrating the core with the detailed geological description of each selected borehole. Another creates geologic profiles by using an on screen defined buffer zone selection for the needed boreholes. The lithological columns of the boreholes together with the defined stratigraphic subunits appear on screen as a geological profile. Complementary information like the DTM profile, the distance between the boreholes, the depth of each strata complete the geological picture. In this working environment the user is able to analyze the possible existing stratigraphical units and to define them on screen in a deterministic way or by using geostatistics. Additionally information like the type of the contact surface, the position between the geological units or subunits as well as other parameters could be attached as attributes. The possible faults or fractures can be identified within the same environment. To date, a dictionary of terms describing the possible geological contact surfaces types is on the way to be defined. In parallel, a tool of converting the geological units/subunits analyzed data is developed in order to project the obtained information within a 3D environment. The export procedure provides a spatial

  20. Hydrogeological and isotopic study of surface water and groundwater in the Eastern Haouz Plain. Western Morocco

    NASA Astrophysics Data System (ADS)

    El Mandour, Abdennabi; Rochdane, Samia; Reddy, Venkat; Himi, Mahjoub; Casas, Albert

    2014-05-01

    The Eastern Haouz area, characterized by a semi-arid climate, is part of the Haouz plain. The basin is built over a broad synclinal between the High Atlas and the Jebilets mountains. The compilation of geological, geophysical and hydrogeological data shows that this area is straddling two major basins of western Morocco. Map of the river system and the piezometric map show the same division line of surface water and groundwater. This division line oriented NNW-SSE is evidenced by the rise of the basement constituted by Paleozoic schists that outcrop near Tamelalt. Thus we can distinguish two main directions of groundwater flow feeding two watersheds (Tensift and Oum Rabiaa rivers) and two large reservoirs in the region of Marrakech. As a contribution to solve the water supply problem in the area, a hydrochemical study has been conducted, involving 40 groundwater samples for major ions and 20 stable isotope analyses. Hydrochemical results show the geological control on water quality. Samples from Paleozoic schists and Triassic sediments are relatively highly mineralisation and unsuitable for drinking as well as for irrigation. Conversely, groundwater from the alluvial plains is relatively less mineralised than other older geological formations; however, many of the samples are also non-potable. Apart of salinity problem, about 25% of the samples have higher nitrate content than the drinking water permissible limit. Stable isotope analysis show that groundwater recharge to the phreatic aquifer is controlled by local conditions. The small difference in the isotopic content of river water and a group of groundwater samples is interpreted as the evaporation effect during the recharge. On the other hand, the group of samples with relatively depleted stable isotopic content shows faster recharge conditions and less water-rock interaction. Finally, another group of samples is relatively enriched in stable isotope content and confirm an increase during the recharge

  1. Hydrogeologic Controls on Water Dynamics in a Discontinuous Permafrost, Lake-Rich Landscape

    NASA Astrophysics Data System (ADS)

    Walvoord, M. A.; Briggs, M. A.; Day-Lewis, F. D.; Jepsen, S. M.; Lane, J. W., Jr.; McKenzie, J. M.; Minsley, B. J.; Striegl, R. G.; Voss, C. I.; Wellman, T. P.

    2014-12-01

    Understanding permafrost distribution, rate of change, and influence on groundwater movement are critical for assessing climate change impacts in northern ecosystems. Lake-rich lowlands in interior Alaska provide important habitat for migratory waterfowl, ungulates, and other wildlife. Despite low annual precipitation, the Yukon Flats area in the north central Yukon River Basin of Alaska (USA) supports over 20,000 lakes, due in part to the presence of permafrost. The fate of this lake-rich lowland and, by proxy, similar circumboreal lowland systems under projected climate warming is the focus of a series of recent studies highlighted here. Lake water chemistry analyses of over 200 lakes in the Yukon Flats reveal a large degree of spatial heterogeneity suggestive of a hydrologically disconnected system, a conclusion also supported by abrupt spatial changes in lake elevation. Airborne geophysical characterization shows a laterally continuous shallow gravel layer (~25-m thick) that would offer good hydraulic connectivity throughout the lowlands. However, the gravel layer is generally frozen (as permafrost) except beneath surface water bodies; thus inhibiting lateral pathways of groundwater flow under current conditions. Ground-based geophysical characterization provides a high resolution of permafrost distribution and relevant hydrogeologic features at several lake study sites. Relatively recent thaw in the gravel layer appears to be associated with lakes that have experienced change in size (area) over the past several decades, whereas lakes with taliks (unfrozen conduits) that fully penetrate the permafrost layer are more likely to be stable. Multi-scale permafrost characterization provides the basis for numerical models that simulate permafrost dynamics, lake-talik evolution, supra-, intra-, and sub-permafrost groundwater flow, lake-groundwater exchange, active layer dynamics, and permafrost aggradation response to lake recession. Collective field and simulation

  2. Faulting and groundwater in a desert environment: constraining hydrogeology using time-domain electromagnetic data

    USGS Publications Warehouse

    Bedrosian, Paul A.; Burgess, Matthew K.; Nishikawa, Tracy

    2013-01-01

    Within the south-western Mojave Desert, the Joshua Basin Water District is considering applying imported water into infiltration ponds in the Joshua Tree groundwater sub-basin in an attempt to artificially recharge the underlying aquifer. Scarce subsurface hydrogeological data are available near the proposed recharge site; therefore, time-domain electromagnetic (TDEM) data were collected and analysed to characterize the subsurface. TDEM soundings were acquired to estimate the depth to water on either side of the Pinto Mountain Fault, a major east-west trending strike-slip fault that transects the proposed recharge site. While TDEM is a standard technique for groundwater investigations, special care must be taken when acquiring and interpreting TDEM data in a twodimensional (2D) faulted environment. A subset of the TDEM data consistent with a layered-earth interpretation was identified through a combination of three-dimensional (3D) forward modelling and diffusion time-distance estimates. Inverse modelling indicates an offset in water table elevation of nearly 40 m across the fault. These findings imply that the fault acts as a low-permeability barrier to groundwater flow in the vicinity of the proposed recharge site. Existing production wells on the south side of the fault, together with a thick unsaturated zone and permeable near-surface deposits, suggest the southern half of the study area is suitable for artificial recharge. These results illustrate the effectiveness of targeted TDEM in support of hydrological studies in a heavily faulted desert environment where data are scarce and the cost of obtaining these data by conventional drilling techniques is prohibitive.

  3. Characterization of Physical and Hydro-Geological Properties of Kanamaru Research Site in Japan

    NASA Astrophysics Data System (ADS)

    Takeda, M.; Zhang, M.; Takeno, N.; Watanabe, Y.

    2004-12-01

    Establishing the comprehensive knowledge of applicability of the methods for investigating hydraulic properties of low permeability geologic strata is an urgent issue for supporting regulation of geological disposal of nuclear waste in the near future. As a beginning of this work, a systematic examination of various kinds of techniques for hydro-geological surveys has been started in Kanamaru Research Site in Japan. This paper briefly introduces the research plan and preliminary results obtained from the first year of investigation. The survey techniques include borehole excavation, borehole imaging, gamma-ray, caliper, acoustic, electrical resistivity and density loggings, permeability tests and flow direction measurement using a single borehole, permeability tests and flow direction measurement using multi boreholes, etc. Preliminary findings can be summarized as follows: (1) The stratigraphy at the survey area consists of topsoil, debris sediments, sandstone, mudstone, conglomeratic sandstone, mudstone, arkose sandstone, and granite. High uranium concentrations are detected at lower portion of the conglomeratic sandstone by gamma-ray logging. (2) The survey area is located at a slope inclined from the north to the south, and the dominant groundwater flow is considered to be in the direction form the north to the south. And the downward flow was also recognized by the flow direction measurements and water quality logging. (3) Hydraulic conductivities derived from permeability tests using a single borehole were in the range of 5E-10 to 1E-7 m/s. The hydraulic conductivities of the same lithology derived from different boreholes varied, and the discrepancies were up to an order. This result indicates that the formations in the survey area have hydraulic heterogeneity in both the vertical and horizontal directions. (4) On the whole, stratum with fast velocity of elastic wave showed large resistivity and low permeability. The degree of correlation between the

  4. Differential Hydrogeological Effects of Draining Tunnels Through the Northern Apennines, Italy

    NASA Astrophysics Data System (ADS)

    Vincenzi, Valentina; Gargini, Alessandro; Goldscheider, Nico; Piccinini, Leonardo

    2014-05-01

    Water inflows are a major challenge in tunnelling and particularly difficult to predict in geological settings consisting of heterogeneous sedimentary rock formations with complex tectonic structure. For a high-speed railway line between Bologna and Florence (Italy), a series of seven railway tunnels was drilled through turbiditic formations, ranging from pelitic rocks with thin arenitic layers over sequences including thick-bedded sandstone to calcareous rocks showing chemical dissolution phenomena (karstification). The tunnels were built as draining tunnels and caused significant impacts, such as drying of springs and base-flow losses at mountain streams. A comprehensive hydrological monitoring programme and four multi-tracer test were done, focusing on four sections of the tunnel system. The tracer tests delivered unprecedented data on groundwater flow and transport in turbiditic aquifers and made it possible to better characterize the differential impacts of tunnel drainage along a geological gradient. The impact radius is 200 m in the thin-bedded sequences but reaches 2.3-4.0 km in calcareous and thick-bedded arenitic turbidites. Linear flow velocities, as determined from the peaks of the tracer breakthrough curves, range from 3.6 m/day in the thin-bedded turbidites to 39 m/day in the calcareous rocks (average values from the four test sites). At several places, discrete fault zones were identified as main hydraulic pathways between impacted streams and draining tunnels. This case shows that ignoring the hydrogeological conditions in construction projects can cause terrible damage, and the study presents an approach to better predict hydraulic impacts of draining tunnels in complex sedimentary rock settings.

  5. Hydrogeologic Assessment of the East Bear Creek Unit, San LuisNational Wildlife Refuge

    SciTech Connect

    Quinn, Nigel W.T.

    2007-07-15

    San Luis National Wildlife Refuge Complex to meetReclamation s obligations for Level 4 water supply under the CentralValley Project Improvement Act. Hydrogeological assessment of the EastBear Creek Unit of the San Luis National Wildlife Refuge was conductedusing a combination of field investigations and a survey of availableliterature from past US Geological Survey Reports and reports by localgeological consultants. Conservative safe yield estimates made using theavailable data show that the East Bear Creek Unit may have sufficientgroundwater resources in the shallow groundwater aquifer to meet aboutbetween 25 percent and 52 percent of its current Level II and between 17percent and 35 percent of its level IV water supply needs. The rate ofsurface and lateral recharge to the Unit and the design of the well fieldand the layout and capacity of pumped wells will decide both thepercentage of annual needs that the shallow aquifer can supply andwhether this yield is sustainable without affecting long-term aquiferquality. In order to further investigate the merits of pumping the nearsurface aquifer, which appears to have reasonable water quality for usewithin the East Bear Creek Unit -- monitoring of the potential sources ofaquifer recharge and the installation of a pilot shallow well would bewarranted. Simple monitoring stations could be installed both upstreamand downstream of both the San Joaquin River and Bear Creek and beinstrumented to measureriver stage, flow and electrical conductivity.Ideally this would be done in conjunction with a shallow pilot well,pumped to supply a portion of the Unit's needs for the wetland inundationperiod.

  6. Progress Toward Understanding of Coupled Microbiology, Biogeochemistry, and Hydrogeology Controls on Subsurface Mobility of Uranium

    NASA Astrophysics Data System (ADS)

    Long, P. E.; Williams, K. H.; Davis, J. A.; Banfield, J. F.; Bargar, J.; Lovley, D. R.; Hatfield, K.; Wilkins, M. J.; Yabusaki, S.; Murray, C. J.; Jaffe, P. R.; Science Team, R.

    2011-12-01

    Uranium as an anthropogenic environmental contaminant stems from nuclear weapons production and the nuclear fuel cycle for nuclear power generation over the last 65 years. Progress in research, monitoring, and clean up at such sites has resulted in both long-term monitoring and field scale manipulation experimental data that are enabling in-depth understanding of coupling among microbiology, biogeochemistry, and hydrogeology subsurface processes controlling mobility of U. One such site, the U.S. Department of Energy's IFRC at Rifle, CO, has hosted several acetate electron donor amendment and non-biostimulated desorption tracer tests culminating in an experiment in 2010 in which bicarbonate promoted uranium desorption and acetate amendment were combined and compared to an acetate amendment-only experiment in the same experimental plot. Enzymatic U reduction rates were not impacted by the increased abundance of Ca-uranyl-carbonate aqueous complexes in the bicarbonate part of the experiment. However, the importance of changes in bicarbonate on U desorption is clear. Bicarbonate increases during acetate-only field experiments due to microbial activity promote U desorption and this must be accounted for in estimating field-scale reduction rates for U. The Rifle site also has more than a decade of monitoring data that show the plume is attenuating much slower than predicted. Naturally reduced zones at the site indicate that microbially-mediated natural reducing conditions have partially reduced U(VI) to U(IV) and this contributes to plume persistence. However, we are just beginning to explore the full range of biogeochemical processes that will enable us to more accurately predict plume attenuation and that will be needed to either enhance or decrease mobility of U as remedial strategies.

  7. Plan of study to define hydrogeologic characteristics of the Madera Limestone in the east mountain area of central New Mexico

    USGS Publications Warehouse

    Rankin, D.R.

    1999-01-01

    The east mountain area of central New Mexico includes the eastern one-third of Bernalillo County and portions of Sandoval, Santa Fe, and Torrance Counties. The area covers about 320 square miles. The Madera Limestone, the principal aquifer in the east mountain area, is the sole source of water for domestic, municipal, industrial, and agricultural uses for many residents. Some water is imported from wells near Edgewood by the Entranosa Water Cooperative, which serves a population of approximately 3,300. The remaining population is served by small water systems that derive supplies locally or by individually owned domestic wells. The population of the east mountain area has increased dramatically over the past 20 years. In 1970, the population of the east mountain area was about 4,000. Demographic projections suggest that approximately 1,000 people per year are moving into the area, and with a growth rate of 3.0 percent the population will be 16,700 in 2000. Consequently, ground-water withdrawals have increased substantially over the past 20 years, and will continue to increase. Little is known about the flow characteristics and hydrogeologic properties of the Madera Limestone. This report describes existing information about the geologic and hydrologic framework and flow characteristics of the Madera Limestone, and presents a plan of study for data-collection activities and interpretive studies that could be conducted to better define the hydrogeologic characteristics of the Madera Limestone. Data-collection activities and interpretive studies related to the hydrogeologic components of the Madera Limestone are prioritized. Activities that are necessary to improve the quantification of a component are prioritized as essential. Activities that could add additional understanding of a component, but would not be necessary to improve the quantification of a component, are prioritized as useful.

  8. Incorporating the social dimension into hydrogeochemical investigations for rural development: the Bir Al-Nas approach for socio-hydrogeology

    NASA Astrophysics Data System (ADS)

    Re, Viviana

    2015-11-01

    A replicable multidisciplinary approach is presented for science-based groundwater management practices: Bir Al-Nas (Bottom-up IntegRated Approach for sustainabLe grouNdwater mAnagement in rural areaS). This approach provides a practical example of the concept of "socio-hydrogeology", a way of incorporating the social dimension into hydrogeological investigations, as reinforced by the translation of the Arabic bir al-nas: "the people's well". To achieve this, hydrogeologists act as "social hydrologists" during their monitoring activities, which often bring them into contact with local communities and end users (and polluters) of water. Not only can they retrieve reliable information about traditional know-how and local issues, but they can also change the public perception of science/scientists to create the basis for mutual collaboration and understanding in view of implementing improved integrated groundwater management. The final outcomes are expected to be an increased awareness of communities at the local level and a clear understanding of their water issues and needs from the very early stages of the investigation. Although the importance of using such methods in groundwater analysis and management is widely recognized, hydrogeological investigations are currently dominated by sectorial approaches that are easier to implement but less sustainable. The pressure of population growth, the shift towards more water-dependent economies, climate change and its impact on water availability will require scientists to use a more integrated approach, such as Bir Al-Nas, when dealing with increasing water pollution and water-scarcity issues.

  9. Modelling of mine flooding and consequences in the mine hydrogeological environment: flooding of the Koenigstein mine, Germany

    NASA Astrophysics Data System (ADS)

    Jakubick, A.; Jenk, U.; Kahnt, R.

    2002-06-01

    The approach to modelling of flooding of the underground mines and hydrogeological consequences in the downstream aquifers of the mine followed in the WISMUT Decommissioning and Reclamation Programme is illustrated for the case of the uranium underground leach mine in Koenigstein, near Dresden, Germany. The modelling of the present and future quantity and quality of the water in the mine workings (source of the potential groundwater contamination) and of the contaminant transport in the hydrogeological environment of the mine is central to finding the optimal courses of action for a safe (i.e. controlled) flooding of the mine and for decision-making regarding water-treatment strategy. The results gained in two large scale in-situ flooding experiment lasting over several years and the models developed, calibrated and validated on this basis for the mine flooding is presented. The modelling of the migration of reactive multi-component contaminants in the hydrogeological environment of the mine proved to be useful for the identification of the significance of the geochemical processes. Because of the problems of up-scaling the commonly inadequate database and limited accuracy of the data available, and because of the inherent uncertainty of approximations used in the reactive transport model, the assessment of the environmental impact caused by long-term migration of contaminants downstream of the mine had to be done using a simplified conventional, non-reactive, single component transport model that provided conservative results. For simulation of the mine flooding, it is recommended to use a concurrent monitoring and modelling approach and step-wise forward calculations that do not exceed the length of each preceeding observation period.

  10. Determination of hydrogeological conditions in large unconfined aquifer: A case study in central Drava plain (NE Slovenia)

    NASA Astrophysics Data System (ADS)

    Keršmanc, Teja; Brenčič, Mihael

    2016-04-01

    In several countries, many unregulated landfills exits which releasing harmful contaminations to the underlying aquifer. The Kidričevo industrial complex is located in southeastern part of Drava plain in NW Slovenia. In the past during the production of alumina and aluminum approximately 11.2 million tons of wastes were deposit directly on the ground on two landfills covering an area of 61 hectares. Hydrogeological studies were intended to better characterized conditions bellow the landfill. Geological and hydrogeological conditions of Quaternary unconfined aquifer were analyzed with lithological characterization of well logs and cutting debris and XRF diffraction of silty sediments on 9 boreholes. Hydrogeological conditions: hydraulic permeability aquifer was determined with hydraulic tests and laboratory grain size analyses where empirical USBR and Hazen methods were applied. Dynamics of groundwater was determined by groundwater contour maps and groundwater level fluctuations. The impact of landfill was among chemical analyses of groundwater characterised by electrical conductivity measurements and XRF spectrometry of sand sediments. The heterogeneous Quaternary aquifer composed mainly of gravel and sand, is between 38 m and 47.5 m thick. Average hydraulic permeability of aquifer is within the decade 10-3 m/s. Average hydraulic permeability estimated on grain size curves is 6.29*10-3 m/s, and for the pumping tests is 4.0*10-3 m/s. General direction of groundwater flow is from west to east. During high water status the groundwater flow slightly changes flow direction to the southwest and when pumping station in Kidričevo (NW of landfill) is active groundwater flows to northeast. Landfills have significant impact on groundwater quality.

  11. Calendar year 1994 groundwater quality report for the Chestnut Ridge Hydrogeologic Regime, Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1995-09-01

    This groundwater quality report (GWQR) contains an evaluation of the groundwater quality data obtained during the 1994 calendar year (CY) at several hazardous and non-hazardous waste management facilities associated with the US Department of Energy (DOE) Y-12 Plant located on the DOE Oak Ridge Reservation (ORR) southeast of Oak Ridge, Tennessee (Figure 1). These sites lie within the boundaries of the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime), which is one of three hydrogeologic regimes defined for the purposes of groundwater quality monitoring at the Y-12 Plant (Figure 2). The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Organization manages the groundwater monitoring activities in each regime under the auspices of the Y-12 Plant Groundwater Protection Program (GWPP). The purpose of the GWPP is to characterize the hydrogeology and to monitor groundwater quality at the Y-12 Plant and surrounding area to protect local groundwater resources in accordance with federal, state, and local regulations, DOE Orders, and Lockheed Martin Energy Systems, Inc. (Energy Systems) corporate policy. The annual GWQR for the Chestnut Ridge Regime is completed in two parts. Part 1 consists primarily of data appendices and serves as a reference for the groundwater quality data obtained each CY under the lead of the Y-12 Plant GWPP. Because it contains information needed to comply with reporting requirements of Resource Conservation and Recovery Act (RCRA) interim status assessment monitoring, the Part 1 GWQR is submitted to the Tennessee Department of Environment and Conservation (TDEC) by the RCRA reporting deadline (March 1 of the following CY); Energy Systems submitted the 1994 Part 1 GWQR for the Chestnut Ridge Regime to the TDEC in February 1995 (HSW Environmental Consultants, Inc. 1995a).

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

    USGS Publications Warehouse

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

    2014-01-01

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

  13. Hydrogeologic, soil, and water-quality data for j-field, Aberdeen Proving Ground, Maryland, 1989-94

    USGS Publications Warehouse

    Phelan, D.J.

    1996-01-01

    Disposal of chemical-warfare agents, munitions, and industrial chemicals in J-Field, Aberdeen Proving Ground, Maryland, has resulted in ground-water, surface-water, and soil contamination. This report presents data collected by the U.S. Geological Survey from Novembr 1989 through September 1994 as part of a remedial investigation of J-Field in response to the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). Hydrogeologic data, soil-gas and soil-quality data, and water-qualtiy data are included.

  14. Hydrogeological conditions of heavy high-viscous oil distribution in northeast Ural-Povolzhye (Udmurtia, Perm, and Kirov Region)

    SciTech Connect

    Kouznetsova, T.A.

    1995-12-31

    The major question while investigating the origin of subsurface oilfield waters is the development of regional and local hydrogeological oil exploration indices. For determination of the influence of subsurface water on oil pools it is necessary to study paleohydrogeological interrelations and regularities, and the interaction of sub-surface waters and oils. While considering these problems, paleohydrogeological cycles, which include crustal elevation and sea level regression are identified. Nine or ten paleohydrogeological cycles are marked in the Udmurtia, Permian, and Kirov territories, depending on regional paleotectonical history. Mesozoic-Cainozoic tectonic movements are the important cause of generation of heavy high-viscous oil pools.

  15. Selected hydrogeologic data for the southwest Glendive Preliminary Logical Mining Unit and adjacent areas, Dawson County, Montana

    USGS Publications Warehouse

    Roberts, R.S.

    1987-01-01

    Hydrogeologic data were collected from a coal area in Dawson County, Montana, to provide a basis for identifying and characterizing the groundwater resources. Inventory records for 72 domestic, stock, irrigation, unused, and observation wells are tabulated in the report; the data were collected principally from 1977 through 1981. The location of each well is shown on a map. Natural-gamma geophysical logs, and water level measurements are also included for selection wells. Twenty-six analyses of groundwater identify the chemical-constituent concentrations and physical properties of water from sampled wells. (USGS)

  16. Hydrogeology and water quality of the Nanticoke Creek stratified-drift aquifer, near Endicott, New York

    USGS Publications Warehouse

    Kreitinger, Elizabeth A.; Kappel, William M.

    2014-01-01

    The Village of Endicott, New York, is seeking an alternate source of public drinking water with the potential to supplement their current supply, which requires treatment due to legacy contamination. The southerly-draining Nanticoke Creek valley, located north of the village, was identified as a potential water source and the local stratified-drift (valley fill) aquifer was investigated to determine its hydrogeologic and water-quality characteristics. Nanticoke Creek and its aquifer extend from the hamlet of Glen Aubrey, N.Y., to the village of Endicott, a distance of about 15 miles, where it joins the Susquehanna River and its aquifer. The glacial sediments that comprise the stratified-drift aquifer vary in thickness and are generally underlain by glacial till over Devonian-aged shale and siltstone. Groundwater is more plentiful in the northern part of the aquifer where sand and gravel deposits are generally more permeable than in the southern part of the aquifer where less-permeable unconsolidated deposits are found. Generally there is enough groundwater to supply most homeowner wells and in some cases, supply small public-water systems such as schools, mobile-home parks, and small commercial/industrial facilities. The aquifer is recharged by precipitation, runoff, and tributary streams. Most tributary streams flowing across alluvial deposits lose water to the aquifer as they flow off of their bedrock-lined channels and into the more permeable alluvial deposits at the edges of the valley. The quality of both surface water and groundwater is generally good. Some water wells do have water-quality issues related to natural constituents (manganese and iron) and several homeowners noted either the smell and (or) taste of hydrogen sulfide in their drinking water. Dissolved methane concentrations from five drinking-water wells were well below the potentially explosive value of 28 milligrams per liter. Samples from surface and groundwater met nearly all State and Federal

  17. Geodetic component of the monitoring of tectonic and hydrogeological activities in Kopacki Rit Nature Park

    NASA Astrophysics Data System (ADS)

    Dapo, Almin; Pribicevic, Bosko

    2013-04-01

    Based on the European and global experience, the amplitude change in the structural arrangement caused by recent tectonic movements, can be most accurately determined by repeated precise GPS measurements on specially stabilized geodetic and geodynamic points. Because of these reasons, the GPS method to determine the movements on specially stabilized points in the Nature park Kopacki rit is also applied in this project. Kopacki rit Nature Park is the biggest preserved natural flooded area on the Danube. It is spread over 23 000 hectares between the rivers Danube and Drava and is one of the biggest fluvial wetland valleys in Europe. In 1993 it was listed as one of internationally valuable wetlands according to the Ramsar Convention. By now in Kopacki rit there have been sights of about 295 bird species, more than 400 species of invertebrates and 44 types of fish. Many of them are globally endangered species like, white tailed eagle, black stork and prairie hawk. It's not rare to come across some deer herds, wild boars or others. Today's geological and geomorphological relations in the Nature park Kopacki rit are largely the result of climate, sedimentary, tectonic and anthropogenic activity in the last 10,000 years. Unfortunately the phenomenon of the Kopacki rit Nature park is in danger to be over in the near future due to those and of course man made activities on the Danube river. It is trough scientific investigations of tectonic and hydrogeological activities that scientist from University of Zagreb are trying to contribute to wider knowledge and possible solutions to this problem. In the year 2009 the first GPS campaign was conducted, and the first set of coordinates of stabilized points was determined which can be considered zero-series measurements. In 2010 a second GPS campaign was conducted and the first set of movements on the Geodynamic Network of Kopacki Rit Nature Park was determined. Processing GPS measurements from 2009 and 2010 was carried out in a

  18. Hydrogeology of the North Coast Limestone aquifer system of Puerto Rico

    USGS Publications Warehouse

    Rodríguez-Martínez, Jesús

    1995-01-01

    The North Coast Limestone aquifer system of Puerto Rico is composed of three regional hydrogeologic units: an upper aquifer that contains an underlying saltwater zone near the coast, a middle confining unit, and a lower aquifer. The upper aquifer is unconfined, except in coastal areas where it is locally confined by fine-grained surficial deposits. The upper aquifer is mostly absent in the Rio Piedras area of northeastern Puerto Rico. The confining unit is composed of calcareous claystone, marl, chalky and silicified limestone, and locally clayey fine-grained sandstone. Test hole data indicate that the confining unit is locally leaky in the San Juan metropolitan area. An artesian zone of limited areal extent exists within the middle confining unit, in the central part of the study area. The lower aquifer mostly contains ground water under confined conditions except in the outcrop areas, where it is unconfined. The lower aquifer is thickest and most transmissive in the north-central part of the study area. Water in the lower aquifer is fresh throughout much of the area, but is brackish in some areas near San Juan and Guaynabo. West of the Rio Grande de Arecibo, the extent of the lower aquifer is uncertain. Data are insufficient to determine whether or not the existing multiple water-bearing units in this area are an extension of the more productive lower aquifer in the Manati to Arecibo area. Zones of moderate permeability exist within small lenses of volcanic conglomerate and sandstone of the San Sebastian Formation, but in general this formation is not a productive aquifer. Transmissivity values for the upper aquifer range from 200 to more than 280,000 feet squared per day. The transmissivity values for the upper aquifer generally are highest in the area between the Rio de la Plata and Rio Grande de Arecibo, where transmissivity values have been reported to exceed 100,000 feet squared per day in six locations. Transmissivity estimates for the lower aquifer are

  19. Application of GPR and seismic methods in landslides investigation and determination of hydrogeological conditions

    NASA Astrophysics Data System (ADS)

    Czaja, Klaudia; Matuła, Rafał

    2013-04-01

    verify GPR interpretation seismic measurements was performed. The basic assumption of the applicability of seismic methods is the existance of a distinct boundary between two lithological horizons defined by a change in material density and elastic modulus, which results in an increase or a decrase in wave velocity. Seismic refraction and MASW (multichannel analysis of surface waves) were the main methods. Geophones with frequencies 4 Hz and 10 Hz were used. Topographical variations were included during interpretation. It is possible to correlate GPR and seismic results especially during localization of water saturation zones. All applied methods gave also satisfactory results in recognition of the hydrogeological conditions.

  20. Groundwater geochemistry of the Yucatan Peninsula, Mexico: Constraints on stratigraphy and hydrogeology

    NASA Astrophysics Data System (ADS)

    Perry, Eugene; Paytan, Adina; Pedersen, Bianca; Velazquez-Oliman, Guadalupe

    2009-03-01

    SummaryWe report 87Sr/ 86Sr and ion concentrations of sulfate, chloride, and strontium in the groundwater of the northern and central Yucatan Peninsula, Mexico. Correlation between these data indicates that ejecta from the 65.95 m.y. old Chicxulub impact crater have an important effect on hydrogeology, geomorphology, and soil development of the region. Ejecta are present at relatively shallow subsurface depths in north-central Yucatan and at the surface along the Rio Hondo escarpment in southeast Quintana Roo, where they are referred to as the Albion Formation. Anhydrite/gypsum (and by inference celestite) are common in impact ejecta clasts and in beds and cements of overlying Paleocene and Lower Eocene rocks cored around the margin of the crater. The sulfate-rich minerals that are found in rocks immediately overlying the impact ejecta blanket, may either be partially mobilized from the ejecta layer itself or may have been deposited after the K/T impact event in an extensive pre-Oligocene shallow sea. These deposits form a distinctive sedimentary package that can be easily traced by the Eocene-Cretaceous 87Sr/ 86Sr signal. A distinct Sr isotopic signature and high SO 4/Cl ratios are observed in groundwater of northwestern and north-central Yucatan that interacts with these rocks. Moreover, the distribution of the gypsum-rich stratigraphic unit provides a solution-enhanced subsurface drainage pathway for a broad region characterized by dissolution features (poljes) extending from Chetumal, Quintana Roo to Campeche, Campeche. The presence of gypsum quarries in the area is also consistent with a sulfate-rich stratigraphic "package" that includes ejecta. The distinctive chemistry of groundwater that has been in contact with evaporite/ejecta can be used to trace flow directions and confirms a groundwater divide in the northern Peninsula. Information about groundwater flow directions and about deep subsurface zones of high permeability is useful for groundwater and

  1. Hydrogeologic reconnaissance of the Mekong Delta in South Vietnam and Cambodia

    USGS Publications Warehouse

    Anderson, Henry R.

    1978-01-01

    The present report describes the results of a hydrogeologic reconnaissance in the Mekong Delta region by the writer, a hydrogeologist of the U.S. Geological Survey, while on assignment as an adviser to the Vietnamese Directorate of Water Supply from October 1968 to April 1970 under the auspices of the U.s. Agency for International Development. The delta of the Mekong River, comprising an area of about 70,000 square kilometres in South Vietnam and Cambodia, is an almost featureless plain rising gradually from sea level to about 5 metres above sea level at its apex 300 kilometres inland. Most of the shallow ground water in the Holocene Alluvium of the delta in Vietnam is brackish or saline down to depths of 50 to 100 metres. Moreover, in the Dong Thap Mu?oi (Plain of Reeds) the shallow ground water is alum-bearing. Locally, however, perched bodies of fresh ground water occur in ancient beach and dune ridges and are tapped by shallow dug wells or pits for village and domestic water supply. The Old Alluvium beneath the lower delta contains freshwater in some areas, notably in the Ca Mau Peninsula and adjacent areas, in the viciniy of Bau Xau near Saigon, and in the Tinh Long An area. Elsewhere in the lower delta both the Holocene and Old Alluvium may contain brackish or saline water from the land surface to depths of as much as 568 metres, as for example in Tinh Vinh Binh. Ground water in the outcrop area of Old Alluvium northwest of Saigon is generally fresh and potable, but high iron and low pH are locally troublesome. Although considerable exploratory drilling for ground water down to depths of as much as 568 metres has already been completed, large areas of the delta remain yet to be explored before full development of the ground-water potential can be realized. With careful development and controlled management to avoid saltwater contamination, however, it is estimated that freshwater aquifers could provide approximately 80 percent of existing needs for village

  2. Hydrogeologic and Hydrochemical Studies in a Semi-arid Watershed in Northern Mexico

    NASA Astrophysics Data System (ADS)

    Kretzschmar, T.; Vazquez, R.; Hinojosa, A.

    2006-12-01

    Within the Baja California panhandle exist quite a significant number of valleys which hydrogeology conditions are of great importance for the communities of the region. The Guadalupe Valley for example, located 30 km Northeast of Ensenada, hosts an important wine industry which presents a mayor factor for agriculture and tourism in Baja California. The irrigation is carried out basically by groundwater extracted from quaternary sediments filling this post-Miocene depression. Besides the intensive usage of the water by the wine industry in the Guadalupe Valley, the local waterworks installed in 1985 a gallery of 10 wells extracting around 320 l/s or 30 % of the total water extraction in the valley to supply the city of Ensenada with drinking water. A total of more than 500 wells with a combined annual consumption of about 28 Mio m3 are at the moment active in the valley. In the arid portions of northern Mexico Mountain front recharge presents an important recharge source for the alluvial aquifers. Other important sources directly related to precipitation are direct infiltration, recharge by surface water runoff in the arroyos as well as by active fault systems. The principal recharge sources for the Guadalupe Valley aquifer are the Sierra Juárez and the Guadalupe River. To be able to address the state of equilibrium of aquifer, recharge estimates for the watershed were calculated determining the runoff/infiltration relationships obtained by curve number determinations combined with the interpretation of satellite images. These results were integrated into an evaluation and hydrologic modeling of the hydrologic data pointing towards differences of up to over 50 percent in the recharge estimation in comparison to earlier studies carried out in the area. Furthermore hydrochemical and isotopic studies were carried out to show the effects of the excessive ground water extraction on the water quality of the aquifer. The hydrochemical data indicate that intense use of

  3. Hydrogeological system of erosional convergent margins and its influence on tectonics and interplate seismogenesis

    NASA Astrophysics Data System (ADS)

    Ranero, C. R.; Grevemeyer, I.; Sahling, H.; Barckhausen, U.; Hensen, C.; Wallmann, K.; Weinrebe, W.; Vannucchi, P.; von Huene, R.; McIntosh, K.

    2008-03-01

    Fluid distribution in convergent margins is by most accounts closely related to tectonics. This association has been widely studied at accretionary prisms, but at half of the Earth's convergent margins, tectonic erosion grinds down overriding plates, and here fluid distribution and its relation to tectonics remain speculative. Here we present a new conceptual model for the hydrological system of erosional convergent margins. The model is based largely on new data and recently published observations from along the Middle America Trench offshore Nicaragua and Costa Rica, and it is consistent with observations from other erosional margins. The observations indicate that erosional margins possess previously unrecognized distinct hydrogeological systems: Most fluid contained in the sediment pores and liberated by early dehydration reactions drains from the plate boundary through a fractured upper plate to seep at the seafloor across the slope, rather than migrating along the décollement toward the deformation front as described for accretionary prisms. The observations indicate that the relative fluid abundance across the plate-boundary fault zone and fluid migration influence long-term tectonics and the transition from aseismic to seismogenic behavior. The segment of the plate boundary where fluid appears to be more abundant corresponds to the locus of long-term tectonic erosion, where tectonic thinning of the overriding plate causes subsidence and the formation of the continental slope. This correspondence between observations indicates that tectonic erosion is possibly linked to the migration of overpressured fluids into the overriding plate. The presence of overpressured fluids at the plate boundary is compatible with the highest flow rates estimated at slope seeps. The change from aseismic to seismogenic behavior along the plate boundary of the erosional margin begins where the amount of fluid at the fault declines with depth, indicating a control on interplate

  4. Large-Scale Transport Model Uncertainty and Sensitivity Analysis: Distributed Sources in Complex, Hydrogeologic Systems

    NASA Astrophysics Data System (ADS)

    Wolfsberg, A.; Kang, Q.; Li, C.; Ruskauff, G.; Bhark, E.; Freeman, E.; Prothro, L.; Drellack, S.

    2007-12-01

    The Underground Test Area (UGTA) Project of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office is in the process of assessing and developing regulatory decision options based on modeling predictions of contaminant transport from underground testing of nuclear weapons at the Nevada Test Site (NTS). The UGTA Project is attempting to develop an effective modeling strategy that addresses and quantifies multiple components of uncertainty including natural variability, parameter uncertainty, conceptual/model uncertainty, and decision uncertainty in translating model results into regulatory requirements. The modeling task presents multiple unique challenges to the hydrological sciences as a result of the complex fractured and faulted hydrostratigraphy, the distributed locations of sources, the suite of reactive and non-reactive radionuclides, and uncertainty in conceptual models. Characterization of the hydrogeologic system is difficult and expensive because of deep groundwater in the arid desert setting and the large spatial setting of the NTS. Therefore, conceptual model uncertainty is partially addressed through the development of multiple alternative conceptual models of the hydrostratigraphic framework and multiple alternative models of recharge and discharge. Uncertainty in boundary conditions is assessed through development of alternative groundwater fluxes through multiple simulations using the regional groundwater flow model. Calibration of alternative models to heads and measured or inferred fluxes has not proven to provide clear measures of model quality. Therefore, model screening by comparison to independently-derived natural geochemical mixing targets through cluster analysis has also been invoked to evaluate differences between alternative conceptual models. Advancing multiple alternative flow models, sensitivity of transport predictions to parameter uncertainty is assessed through Monte Carlo simulations. The

  5. Large-Scale Transport Model Uncertainty and Sensitivity Analysis: Distributed Sources in Complex Hydrogeologic Systems

    SciTech Connect

    Sig Drellack, Lance Prothro

    2007-12-01

    The Underground Test Area (UGTA) Project of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office is in the process of assessing and developing regulatory decision options based on modeling predictions of contaminant transport from underground testing of nuclear weapons at the Nevada Test Site (NTS). The UGTA Project is attempting to develop an effective modeling strategy that addresses and quantifies multiple components of uncertainty including natural variability, parameter uncertainty, conceptual/model uncertainty, and decision uncertainty in translating model results into regulatory requirements. The modeling task presents multiple unique challenges to the hydrological sciences as a result of the complex fractured and faulted hydrostratigraphy, the distributed locations of sources, the suite of reactive and non-reactive radionuclides, and uncertainty in conceptual models. Characterization of the hydrogeologic system is difficult and expensive because of deep groundwater in the arid desert setting and the large spatial setting of the NTS. Therefore, conceptual model uncertainty is partially addressed through the development of multiple alternative conceptual models of the hydrostratigraphic framework and multiple alternative models of recharge and discharge. Uncertainty in boundary conditions is assessed through development of alternative groundwater fluxes through multiple simulations using the regional groundwater flow model. Calibration of alternative models to heads and measured or inferred fluxes has not proven to provide clear measures of model quality. Therefore, model screening by comparison to independently-derived natural geochemical mixing targets through cluster analysis has also been invoked to evaluate differences between alternative conceptual models. Advancing multiple alternative flow models, sensitivity of transport predictions to parameter uncertainty is assessed through Monte Carlo simulations. The

  6. Evaluating Traditional Hydrogeologic Characterization Approaches in a Highly Heterogeneous Glaciofluvial Aquifer

    NASA Astrophysics Data System (ADS)

    Alexander, M.; Berg, S. J.; Illman, W.

    2009-05-01

    Hydraulic conductivity (K) and specific storage (Ss) estimates are two of the most essential parameters when designing transient groundwater flow models which are commonly used in contaminant transport and water resource investigations. The purpose of this study was to evaluate the effectiveness of traditional hydrogeologic characterization approaches in a highly heterogeneous glaciofluvial aquifer at the North Campus Research Site (NCRS) situated on the University of Waterloo campus. The site is instrumented with four Continuous Multichannel Tubing (CMT) wells containing a total of 28 monitoring points and a multi-screen well used for pumping at different elevations. Continuous soil cores to a depth of approximately 18 m were collected during the installation of the CMTs and the multi-screen well. The cores were subsequently characterized using the Unified Soil Classification System and grain size analysis. Samples were obtained from the core at approximately 10 cm increments and a falling head permeameter was used to make 471 K estimates. The estimates from the falling head permeameter showed K to vary from 10-4 - 10-10 m/s illustrating the highly heterogeneous nature of the aquifer at the NCRS. A geostatistical analysis performed on the core K dataset yielded a strongly heterogeneous K field for the site. K and Ss estimates were also obtained via slug tests in the CMT ports through type curve analysis. Cross-hole pumping tests were conducted using the center multi-screened well and the 4 CMTs installed in a 5-spot pattern. Pumping was conducted in 7 zones using a straddle packer system and the corresponding drawdown responses were recorded in 28 zones in the CMTs and 3 zones in the center well using pressure transducers. The various K and Ss estimates were then evaluated by simulating the transient drawdown data using a 3D forward numerical model constructed using Hydrogeosphere (Therrien et al., 2005). Simulation was conducted using 3 separate K and Ss fields

  7. A multidisciplinary geophysical, geotechnical and hydrogeological investigation of quick-clay landslides in Sweden

    NASA Astrophysics Data System (ADS)

    Malehmir, A.; Krawczyk, C.; Polom, U.; Lundberg, E.; Adamczyk, A.; Malinowski, M.; Bastani, M.; Gurk, M.; Juhlin, C.; Persson, L.; Ismail, N.

    2012-04-01

    In Spring 2011, the Society of Exploration Geophysicists (SEG) through its Geoscientists Without Borders (GWB) program sponsored our project to study clay-related landslides in the Nordic countries. This project will study quick clay or rapid earth flow landslides in Sweden. Undisturbed quick clay resembles a water-saturated gel. When a mass of quick clay undergoes sufficient stress, it instantly turns into a flowing ooze, a process known as liquefaction. A small block of quick clay can liquefy from a stress change due to as little as a modest blow from a human hand, while a larger deposit is mainly vulnerable to greater stress changes, such as increased saturation by excess rainwater. Despite their abundance, our geophysical understanding of clay behavior in terms of both changes in the geometrical shape (clay formations) and changes in the physical properties are limited and require a better understanding. Quick clay landslides are not particularly constrained to steep slopes and have been known to slide even in low-to-moderate angle slopes. Geophysical investigations began in September 2011 over a known landslide scar near the Göta river in southwest Sweden, an area known to contain quick clays in parts of it. The investigations involved 2D and 3D P- and S-wave source and receiver surveys, geoelectrics, controlled-source and radio-magnetotellurics, ground gravity and magnetic surveys. These data in combination with existing geotechnical information and hydrogeological investigations should allow better insight into the mechanism(s) governing clay-related landslides in the Nordic countries and to provide high-resolution images of subsurface structures down to the bedrock. We will present preliminary results from the seismic investigations, including the 2D and 3D reflection and refraction surveys. The reflection seismic data show excellent quality and image the bedrock topography and internal layering above it down to about 100 m. Tomography results suggest the

  8. Hazard connected to railway tunnel construction in karstic area: applied geomorphological and hydrogeological surveys

    NASA Astrophysics Data System (ADS)

    Casagrande, G.; Cucchi, F.; Zini, L.

    2005-02-01

    different cavity typologies for each area. To make an example, out of 27000m of studied gallery 3930 are the metres expected to be at very high "karst risk". Out of these, as a whole 310 are risky because of the probable presence of gallery cavities, 2170 because of the probable presence of pits and sinkholes diffusely present under the dolines, and along 1450m karst is particularly intense. Moreover, 2200 should be the metres in which the rocky mass will be particularly divided because of tectonic causes. From a hydrogeological point of view a monitoring of water level has started to quantify water excursion, due to closeness of the railway tunnel to the mean water level. First results related to galleries intersection are here presented.

  9. Implementation of a Shallow Groundwater Temperature Manipulation: Linking Hydrogeology, Biogeochemistry, and Aquatic Ecology

    NASA Astrophysics Data System (ADS)

    Wilson, K. P.; Williams, D. D.

    2004-05-01

    Integration of the fields of hydrogeology, biogeochemistry, and meiofaunal and microbial ecology is being used for a shallow groundwater temperature manipulation which simulates global climate change predictions. This study is being conducted on a first order spring-stream, Valley Spring, (southern Ontario, Canada) the headwater of which has been longitudinally divided to a sediment depth of -100 cm. To examine groundwater flow paths and hydraulic conductivity, and to collect physicochemical parameters and nutrient samples, a series of nested piezometers have been installed along three transects across the stream channel. Each nest evaluates water characteristics at depths of -20, -40, -60, -80, and -100 cm. Meiofaunal and microbial samples are collected, using a standpipe corer at the same depths as the piezometer openings. Sampling started in June 2002 and heating of one side of the groundwater began in March 2004. Hydraulic conductivity is heterogeneous with depth ranging from 0.0004 cm/s at -20 cm to 0.00002 cm/s at -100cm, but relatively uniform laterally, ranging from 0.0004 cm/s at 1 m to 0.0003 cm/s at 3 m from the stream channel. Pre-manipulation water temperatures decrease with depth in the summer, ranging from 14.5° C at the surface to 12.5° C at -100 cm. In contrast, temperature increases from 13.1 at the surface to 14.5° C at -100 cm in the fall. Temperature during the winter and spring are within 1.0° C from the surface to -100 cm, but range from 9.0-9.5° C in the winter and 8.0-7.0° C in the spring, respectively. Pre-manipulation nitrate concentrations are higher in winter (0.45 mg/l) then in summer (0.28 mg/l) and decrease with depth. Ammonia shows an inverse relationship, with lower concentrations in winter than summer (0.19 and 0.32 mg/l, respectively) and increase with depth. Dissolved organic carbon (DOC) also shows an increase with depth, ranging from 1.6 mg/l at the surface to 6.23 mg/l at -100 cm. Pre-manipulation meiofaunal abundance

  10. Sensitivity analysis of hydrogeological parameters affecting groundwater storage change caused by sea level rise

    NASA Astrophysics Data System (ADS)

    Shin, J.; Kim, K.-H.; Lee, K.-K.

    2012-04-01

    Sea level rise, which is one of the representative phenomena of climate changes caused by global warming, can affect groundwater system. The rising trend of the sea level caused by the global warming is reported to be about 3 mm/year for the most recent 10 year average (IPCC, 2007). The rate of sea level rise around the Korean peninsula is reported to be 2.30±2.22 mm/yr during the 1960-1999 period (Cho, 2002) and 2.16±1.77 mm/yr (Kim et al., 2009) during the 1968-2007 period. Both of these rates are faster than the 1.8±0.5 mm/yr global average for the similar 1961-2003 period (IPCC, 2007). In this study, we analyzed changes in the groundwater environment affected by the sea level rise by using an analytical methodology. We tried to find the most effective parameters of groundwater amount change in order to estimate the change in fresh water amount in coastal groundwater. A hypothetical island model of a cylindrical shape in considered. The groundwater storage change is bi-directional as the sea level rises according to the natural and hydrogeological conditions. Analysis of the computation results shows that topographic slope and hydraulic conductivity are the most sensitive factors. The contributions of the groundwater recharge rate and the thickness of aquifer below sea level are relatively less effective. In the island with steep seashore slopes larger than 1~2 degrees or so, the storage amount of fresh water in a coastal area increases as sea level rises. On the other hand, when sea level drops, the storage amount decreases. This is because the groundwater level also rises with the rising sea level in steep seashores. For relatively flat seashores, where the slope is smaller than around 1-2 degrees, the storage amount of coastal fresh water decreases when the sea level rises because the area flooded by the rising sea water is increased. The volume of aquifer fresh water in this circumstance is greatly reduced in proportion to the flooded area with the sea

  11. A methodological approach to assess the severity of historical damaging hydrogeological events

    NASA Astrophysics Data System (ADS)

    Petrucci, Olga; Aceto, Luigi; Aurora Pasqua, Angela; Caloiero, Tommaso

    2016-04-01

    We present a methodological approach to assess the severity of Damaging Hydrogeological Events (DHEs), defined as rainy periods affecting wide regions for several days, and during which landslides and floods cause economic damage and fatalities. A DHE is the result of a triggering rainfall event affecting a region and causing damaging phenomena, as river floods and mass movements, on its territory. The methodological approach, thus, is founded on the historical series of both triggering rainfall and resulting damage. For the DHE that occurred in Calabria (Southern Italy) during the last 100 years, we assessed some severity indicators of both the damage and the daily rainfall recorded. Using these indicators, we built a chart where the events can be plotted and classified, according to their magnitude, as major catastrophic, catastrophic, extraordinary and ordinary events. The results show that, in the study region, winter events, among the others, affected the wider regional sectors, while the most numerous cases occurred in autumn season. Results on the temporal evolution of the DHEs show that the frequency of major catastrophic and catastrophic events has decreased since 1971, and that, in recent decades, Calabria has suffered from damaging effects even though daily rain did not reached extreme values. In fact, the duration of triggering rain, the maximum daily rain of the events and the frequency of the high-return-period-rain showed a decreasing trend throughout the study period. As to what concerns the damaging phenomena, landslides were identified as the most frequent in every season and in each type of events, and the eastern side of the region was identified as the most frequently and heavily damaged. In autumn cases, landslides caused the majority of damage, besides to relevant percentages of damage caused by flash floods and floods. Finally, according to literature, a decreasing trend in the number of victims per event was also evaluated. The proposed

  12. Arsenic in midwestern glacial deposits? Occurrence and relation to selected hydrogeologic and geochemical factors

    USGS Publications Warehouse

    Thomas, Mary Ann

    2003-01-01

    Ground-water-quality data collected as part of 12 U.S. Geological Survey National Water-Quality Assessment studies during 1996-2001 were analyzed to (1) document arsenic occurrence in four types of gla-cial deposits that occur in large areas of the Midwest, (2) identify hydrogeologic or geochemical factors asso-ciated with elevated arsenic concentrations, and (3) search for clues as to arsenic source(s) or mechanism(s) of mobilization that could be useful for designing future studies. Arsenic and other water-quality constituents were sampled in 342 monitor and domestic wells in parts of Illinois Indiana Ohio Michigan and Wisconsin. Arsenic was detected (at a concentration >1 ?g/L) in one-third of the samples. The maximum concentration was 84 ?g/L, and the median was less than 1 ?g/L. Eight percent of samples had arsenic concentrations that exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level (MCL) of 10?g/L. Samples were from four aquifer types?confined valley fill, unconfined valley fill, outwash plain, and till with sand lenses. Highest arsenic concentrations were found in reducing waters from valley-fill depos-its. In confined valley fill, all waters were reducing and old (recharged before 1953), and almost half of sam-ples had arsenic concentrations greater than the MCL. In unconfined valley fill, redox conditions and ages were varied, and elevated arsenic concentrations were sporadic. In both types of valley fill, elevated arsenic concentrations are linked to the underlying bedrock on the basis of spatial relations and geochemical correla-tions. In shallow (150 ft), all deep wells were from a distinctive aquifer type (confined valley fill). It is not known whether wells at similar depths in other aquifer types would produce waters with simi-larly high arsenic concentrations. Correlations of arsenic with fluoride, strontium, and barium suggest that arsenic might be related to epi-genetic (Mississippi Valley-type) sulfide deposits in

  13. Hydrogeology, ground-water movement, and subsurface storage in the Floridan aquifer system in southern Florida

    USGS Publications Warehouse

    Meyer, Frederick W.

    1989-01-01

    The Floridan aquifer system of southern Florida is composed chiefly of carbonate rocks that range in age from early Miocene to Paleocene. The top of the aquifer system in southern Florida generally is at depths ranging from 500 to 1,000 feet, and the average thickness is about 3,000 feet. It is divided into three general hydrogeologic units: (1) the Upper Floridan aquifer, (2) the middle confining unit, and (3) the Lower Floridan aquifer. The Upper Floridan aquifer contains brackish ground water, and the Lower Floridan aquifer contains salty ground water that compares chemically to modern seawater. Zones of high permeability are present in the Upper and Lower Floridan aquifers. A thick, cavernous dolostone in the Lower Floridan aquifer, called the Boulder Zone, is one of the most permeable carbonate units in the world (transmissivity of about 2.5 x 107 feet squared per day). Ground-water movement in the Upper Floridan aquifer is generally southward from the area of highest head in central Florida, eastward to the Straits of Florida, and westward to the Gulf of Mexico. Distributions of natural isotopes of carbon and uranium generally confirm hydraulic gradients in the Lower Floridan aquifer. Groundwater movement in the Lower Floridan aquifer is inland from the Straits of Florida. The concentration gradients of the carbon and uranium isotopes indicate that the source of cold saltwater in the Lower Floridan aquifer is seawater that has entered through the karat features on the submarine Miami Terrace near Fort Lauderdale. The relative ages of the saltwater suggest that the rate of inland movement is related in part to rising sea level during the Holocene transgression. Isotope, temperature, and salinity anomalies in waters from the Upper Floridan aquifer of southern Florida suggest upwelling of saltwater from the Lower Floridan aquifer. The results of the study support the hypothesis of circulating relatively modern seawater and cast doubt on the theory that the

  14. Coupling of hydrogeological models with hydrogeophysical data to characterize seawater intrusion and shallow geothermal systems

    NASA Astrophysics Data System (ADS)

    Beaujean, J.; Kemna, A.; Engesgaard, P. K.; Hermans, T.; Vandenbohede, A.; Nguyen, F.

    2013-12-01

    case are tested. They consist in a thermal injection and storage of water in a shallow sandy aquifer. The use of a physically-based constraint accounting for the difference in conductivity between the formation and the tap injected water and based on the hydrogeological model calibrated first on temperatures is necessary to improve the parameter estimation. Results suggest that time-lapse ERT data may be limited but useful information for estimating groundwater flow and transport parameters for both the convection and conduction phases.

  15. Hydrogeology and leachate plume delineation at a closed municipal landfill, Norman, Oklahoma

    USGS Publications Warehouse

    Becker, Carol J.

    2002-01-01

    The City of Norman operated a solid-waste municipal landfill at two sites on the Canadian River alluvium in Cleveland County, Oklahoma from 1970 to 1985. The sites, referred to as the west and east cells of the landfill, were originally excavations in the unconsolidated alluvial deposits and were not lined. Analysis of ground-water samples indicate that leachate from the west cell is discharging into an adjacent abandoned river channel, referred to as the slough, and is migrating downgradient in ground water toward the Canadian River. The report describes the hydrogeologic features at the landfill, including the topography of the bedrock, water-level changes in the alluvial aquifer, and delineates the leachate plume using specific conductance data. The leading edge of the leachate plume along the 35-80 transect extended over 250 meters downgradient of the west cell. The leading edge of the leachate plume along the 40-SOUTH transect had moved about 60 meters from the west cell in a south-southwesterly direction and had not moved past the slough as of 1997. Specific conductance measurements exceeding 7,000 microsiemens per centimeter at site 40 indicate the most concentrated part of the plume remained in the upper half of the alluvial aquifer adjacent to the west cell. The direction of ground-water flow in the alluvial aquifer surrounding the landfill was generally north-northeast to south-southwest toward the river. However, between the west cell and the slough along the 40-SOUTH transect, head measurements indicate a directional change to the east and southeast toward a channel referred to as the sewage outfall. Near the 35-80 transect, at 0.5 meter below the water table and at the base of the aquifer, the direction of ground-water flow was south-southeast with a gradient of about 30 centimeters per 100 meters. Generally, ground-water levels in the alluvial aquifer were higher during the winter months and lower during summer months, due to a normal decrease in

  16. Solute transport modelling in a coupled water and heat flow system applied to cold regions hydrogeology

    NASA Astrophysics Data System (ADS)

    Frampton, Andrew; Destouni, Georgia

    2016-04-01

    In cold regions, flow in the unsaturated zone is highly dynamic with seasonal variability and changes in temperature, moisture, and heat and water fluxes, all of which affect ground freeze-thaw processes and influence transport of inert and reactive waterborne substances. In arctic permafrost environments, near-surface groundwater flow is further restricted to a relatively shallow and seasonally variable active layer, confined by perennially frozen ground below. The active layer is typically partially saturated with ice, liquid water and air, and is strongly dependent on seasonal temperature fluctuations, thermal forcing and infiltration patterns. Here there is a need for improved understanding of the mechanisms controlling subsurface solute transport in the partially saturated active layer zone. Studying solute transport in cold regions is relevant to improve the understanding of how natural and anthropogenic pollution may change as activities in arctic and sub-arctic regions increase. It is also particularly relevant for understanding how dissolved carbon is transported in coupled surface and subsurface hydrological systems under climate change, in order to better understand the permafrost-hydrological-carbon climate feedback. In this contribution subsurface solute transport under surface warming and degrading permafrost conditions is studied using a physically based model of coupled cryotic and hydrogeological flow processes combined with a particle tracking method. Changes in subsurface water flows and solute transport travel times are analysed for different modelled geological configurations during a 100-year warming period. Results show that for all simulated cases, the minimum and mean travel times increase non-linearly with warming irrespective of geological configuration and heterogeneity structure. The travel time changes are shown to depend on combined warming effects of increase in pathway length due to deepening of the active layer, reduced transport

  17. Hydrogeological impact of fault zones on a fractured carbonate aquifer, Semmering (Austria)

    NASA Astrophysics Data System (ADS)

    Mayaud, Cyril; Winkler, Gerfried; Reichl, Peter

    2015-04-01

    Fault zones are the result of tectonic processes and are geometrical features frequently encountered in carbonate aquifer systems. They can hamper the fluid migration (hydrogeological barriers), propagate the movement of fluid (draining conduits) or be a combination of both processes. Numerical modelling of fractured carbonate aquifer systems is strongly bound on the knowledge of a profound conceptual model including geological and tectonic settings such as fault zones. In further consequence, numerical models can be used to evaluate the conceptual model and its introduced approximations. The study was conducted in a fractured carbonate aquifer built up by permomesozoic dolo/limestones of the Semmering-Wechsel complex in the Eastern Alps (Austria). The aquifer has an assumed thickness of about 200 m and dips to the north. It is covered by a thin quartzite layer and a very low permeable layer of quartz-phyllite having a thickness of up to several hundred meters. The carbonate layer crops out only in the southern part of the investigation area, where it receives autogenic recharge. The geological complexity affects some uncertainties related to the extent of the model area, which was determined to be about 15 km². Three vertical fault zones cross the area approximately in a N-S direction. The test site includes an infrastructural pilot tunnel gallery of 4.3 km length with two pumping stations, respectively active since August 1997 and June 1998. The total pumping rate is about 90 l/s and the drawdown data were analysed analytically, providing a hydraulic conductivity of about 5E-05 m/s for the carbonate layer. About 120 m drawdown between the initial situation and situation with pumping is reported by piezometers. This led to the drying up of one spring located at the southern border of the carbonates. A continuum approach using MODFLOW-2005 was applied to reproduce numerically the observed aquifer behaviour and investigate the impact of the three fault zones. First

  18. Hydrogeologic Assessment of the 4-S Land and Cattle CompanyRanch

    SciTech Connect

    Quinn, Nigel W.T.

    2006-04-10

    Hydrogeological assessment of the 4-S Land and Cattle Company (4-S Ranch) was conducted using a combination of field investigations and a survey of available literature from nearby agricultural water districts and other entities. The 4-S Ranch has been able to meet most of its own water needs providing irrigated pasture for beef cattle by an active program of shallow groundwater pumping in these miconfined aquifer above the Corcoran Clay. Comparison of groundwater pumping on the 4-S Ranch property with groundwater pumping in the adjacent Merquin and Stevinson Water Districts shows great similarity in the well screened depths and the quality of the groundwater produced by the well fields. The pump yield for the eight active production wells on the 4-S property are comparable to the production and drainage wells in the adjacent water districts. Like these Districts the 4-S Ranch lies close to the Valley trough in a historic discharge area. The 4-S Ranch is unique in that it is bounded and bisected by several major water conveyance facilities including Bear Creek. Although the large number of potential recharge structures would suggest significant groundwater conjunctive use potential the major well field development has occurred along the length of the Eastside Canal. The Eastside Canal is known to be leaky above the ''A'' Clay the Canal passes through sandy areas and experiences significant groundwater seepage. This seepage can be intercepted by adjacent groundwater wells. Pumping adjacent to, and along the alignment of the Canal, may induce higher rates of seepage from the Eastside Canal. Groundwater quality below and adjacent to the Eastside Canal is very good, reflecting the origin of this diverted