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1

Hydrogeology  

NSDL National Science Digital Library

This project contains a variety of resources for faculty members who teach undergraduate hydrogeology. We have provided links to a growing collection of activities and assignments, internet and computer resources, useful articles, presentations from the summer 2005 workshop on teaching hydrogeology, working groups and a discussion forum, and lots of creative ideas for teaching hydrogeology.

2

Hydrogeology  

SciTech Connect

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.

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

1988-01-01

3

Hydrogeologic Mapping  

NSDL National Science Digital Library

In this exercise, students learn how to make a preliminary evaluation of the hydrogeology of a site. Students map the location and elevation of important hydrogeologic features, then produce a hydrogeologic map of the site, including a water profile and estimated flow paths for groundwater. This type of map is crucial for evaluating potential sources of groundwater, as well as potential sources of groundwater contamination.

Brikowski, Tom

4

Environmental Hydrogeology  

NSDL National Science Digital Library

This is the homepage for a 200-level environmental hydrogeology course at the College of Wooster. The site includes a course syllabus, questions to help students prepare for each day of the course, practice exam questions, links and supplemental notes and materials.

Wiles, Greg; Department Of Geology, The C.

5

Contaminant hydrogeology  

SciTech Connect

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.

Fetter, C.W.

1993-01-01

6

Hydrogeological Environments  

NSDL National Science Digital Library

This assignment is designed to expose students in my undergraduate 3 credit non lab elective geohydrology course to a variety of hydrogeological environments and groundwater issues/problems that exist in the United States. Much of the course (field trip and local groundwater contamination case study) highlights and emphasizes understanding of the shallow unconsolidated aquifers in Michigan. Students use as their main source of information the data and illustration rich professional USGS Groundwater Atlases. Using this resource, in this activity students learn about the structure of aquifers in volcanic rock, karst and permafrost regions. They teach their fellow students about groundwater problems that result due due to overpumping, subsidence, sinkholes, saltwater intrusion and coal mining. Key words: hydrogeologic environments, water supply and water quality problems, aquifers

Riemersma, Peter

7

Undergraduate Education in Hydrogeology.  

ERIC Educational Resources Information Center

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)

Tinker, John Richard, Jr.

1989-01-01

8

Coral Reef Hydrogeology.  

National Technical Information Service (NTIS)

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 Pacifi...

R. W. Buddemeier J. A. Oberdorfer

1985-01-01

9

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...

10

Hydrogeology of wetlands  

USGS Publications Warehouse

A collection of 10 papers presented at the Hydrogeology of Wetlands Symposium, 28th International Geological Congress in Washington, DC, in July 1989. The purpose of the symposium was to assemble papers describing hydrogeologic studies of wetlands representative of different geographic regions, wetland types, and study approaches. The papers presented at the Symposium ranged geographically from wetlands in the Arctic to the Subtropics. Different wetland types included coastal, riverine, depressional glacial terrane, and dunal depressions. Different study approaches included regional syntheses, analyses of groundwater flow systems, wetland-river interaction, and geomorphology-vegetation interaction. -from Editors

Winter, T. C.; Llamas, M. R.

1993-01-01

11

Hydrogeology Field Course  

NSDL National Science Digital Library

This applied hydrogeology field course taught at Western Michigan University is designed to educate and train students in environmental surface geophysics, well drilling and installation, aquifer testing, groundwater sampling and testing, and remediation. The course also offers OSHA 40 hour hazardous waste operations training. This website provides a course outline, photo galleries, a list of skills that will be acquired by students, and logistical information.

Geosciences, Department O.; University, Western M.

12

ESCI 339: Field Hydrogeology  

NSDL National Science Digital Library

This is the course home page for a field hydrogeology course taught by Dr. Laura Sanders at Northeastern Illinois University. The site includes the course syllabus, goals for the course as a whole and for each lecture, and a list of field trips. Field methods include stream discharge measurement, storm water management, measuring groundwater elevations, well installation and use of a geoprobe. Field trips include a wetland, a site with a leaking underground storage tank and a landfill.

Sanders, Laura; Department Of Geology, Northeastern I.

13

Hydrogeology and Hydrologic Landscape Regions of Nevada.  

National Technical Information Service (NTIS)

The purpose of this report is to describe the hydrogeology and hydrologic landscape regions of Nevada. The description of the hydrogeology includes the lithology, horizontal hydraulic conductivity, soil permeability, and recent faulting of hydrogeologic u...

D. K. Maurer T. J. Lopes R. L. Medina J. LaRue Smith

2004-01-01

14

Education and Employment in Hydrogeology.  

ERIC Educational Resources Information Center

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…

Pederson, Darryll T.

1987-01-01

15

Hydrogeology Research Project  

NSDL National Science Digital Library

This activity is for students to work in teams (2012) or individually (2013) to develop a project (such as a physical or numerical model), survey based research, case study, technical briefs on a remediation technology, etc. of the students' choice, based on their understanding of and interest in the subjects covered in the class. This is used in the GL 199 Hydrogeology course, which is offered through the Department of Geology and Environmental Sciences at Norwich University. This is an experimental course that has not made it to the course catalogue as yet. It is currently offered to students majoring in Geology, with an acknowledgement that a course in hydrogeology is a desirable component of a Geology curriculum. Environmental Science students are encouraged to take it to deepen their understanding of subsurface processes. This course is considered a science elective for Civil and Environmental Engineering majors, and greatly complements the Hydrology, and Soils and Materials classes that are a part of the regular CE&E curriculum. Students from freshmen through seniors across these three majors are accepted into the course. With a cross section of majors and academic years in the class, it was determined that a project that has students thinking about a topic of their choice and developing fundamental research and collaboration skills is critical to meeting common workplace demands.

Kulkarni, Tara

16

Bulletin: Engineering Geology and Hydrogeology.  

National Technical Information Service (NTIS)

Contents: Detailed seismic regionalization of the locality of bar; A method of studying the hydrodynamic regime of Karst aquifers by analysis of the discharge curve and level fluctuations during recession; Hydrogeological possibilities for more efficient ...

1970-01-01

17

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...

18

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...

19

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...

20

Coral reef hydrogeology  

SciTech Connect

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.

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

1985-05-21

21

ESCI 337: Principles of Hydrogeology  

NSDL National Science Digital Library

This is the course home page for Dr. Laura Sanders' hydrogeology course at Northeastern Illinois University. This web site includes the course syllabus, goals for the course as a whole and for each lecture, homework assignments, hints for solving quantitative problems, and tips for working in groups.

Sanders, Laura; Department Of Geology, Northeastern I.

22

Hydrogeology of Wetlands in Massachusetts.  

National Technical Information Service (NTIS)

Results of a study of the relationship of freshwater wetlands to hydrogeology throughout Massachusetts are presented. The distribution and character of wetlands which occupy about 327,000 acres or 6.5% of the state's land area are related to eight physiog...

R. W. Heeley

1973-01-01

23

Using Scant Data in Hydrogeology  

NSDL National Science Digital Library

I presented the short case studies at the Teaching Hydrogeology workshop to illustrate the five fundamental points I emphasize in my basic hydrogeology class. These five points are what consultants tell me my students should know cold; what the difference is between the water table and potentiometric head, that a contaminant plume from an individual source should be narrow, that water table maps should be related to the topography, that major dissolved species are important to know about, and that organic matter conditions a lot of contaminant transport. How to apply this knowledge where there is scant data is the rub, and I draw from my consulting files to illustrate how I, at least, do it.

Siegel, Don

24

The hydrogeology of Kilauea volcano  

Microsoft Academic Search

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

S. E. Ingebritsen; M. A. Scholl

1993-01-01

25

Hydrogeologic characterization of Illinois wetlands  

SciTech Connect

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.

Miner, J.J.; Miller, M.V.; Rorick, N.L.; Fucciolo, C.S. (Illinois State Geological Survey, Champaign, IL (United States))

1994-04-01

26

Hydrogeology of Oil and Gas Deposits.  

National Technical Information Service (NTIS)

The book is written as a textbook for the course 'Hydrogeology and water of oilfield' presented to geologists of oil and gas specialization. Lectures, delivered by the author since 1953 in Moscow Institute of Petroleum Chemistry and Gas Industry 'Godkin',...

A. A. Kartsev

1974-01-01

27

Contaminant hydrogeology — Dollars and sense  

NASA Astrophysics Data System (ADS)

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".

Schwartz, Franklin W.

1988-07-01

28

Teaching hydrogeology: a review of current practice  

NASA Astrophysics Data System (ADS)

Hydrogeology is now taught in a broad spectrum of departments and institutions to students with diverse backgrounds. Successful instruction in hydrogeology thus requires a variety of pedagogical approaches depending on desired learning outcomes and the background of students. We review the pedagogical literature in hydrogeology to highlight recent advances and analyze a 2005 survey among 68 hydrogeology instructors. The literature and survey results suggest there are only ~ 15 topics that are considered crucial by most hydrogeologists and > 100 other topics that are considered crucial by some hydrogeologists. The crucial topics focus on properties of aquifers and fundamentals of groundwater flow, and should likely be part of all undergraduate hydrogeology courses. Other topics can supplement and support these crucial topics, depending on desired learning outcomes. Classroom settings continue to provide a venue for emphasizing fundamental knowledge. However, recent pedagogical advances are biased towards field and laboratory instruction with a goal of bolstering experiential learning. Field methods build on the fundamentals taught in the classroom and emphasize the collection of data, data uncertainty, and the development of vocational skills. Laboratory and computer-based exercises similarly build on theory, and offer an opportunity for data analysis and integration. The literature suggests curricula at all levels should ideally balance field, laboratory, and classroom pedagogy into an iterative and integrative whole. An integrated, iterative and balanced approach leads to greater student motivation and advancement of theoretical and vocational knowledge.

Gleeson, T.; Allen, D. M.; Ferguson, G.

2012-07-01

29

Engineering Geology and Hydrogeology. Vestnik. Series B, No. 9, 1969.  

National Technical Information Service (NTIS)

Contents: Analysis of earlier detailed seismic zoning of bar and environs after the earthquake of 3 November 1968; Rock investigations on the Ciflik dam site; Quantitative treatment in hydrogeology; Geophysical methods in composite hydrogeological survey;...

1974-01-01

30

SRP baseline hydrogeologic investigation, Phase 2  

SciTech Connect

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.

Bledsoe, H.W.

1987-11-01

31

SRP Baseline Hydrogeologic Investigation, Phase 3  

SciTech Connect

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.

Bledsoe, H.W.

1988-08-01

32

SRP baseline hydrogeologic investigation: Aquifer characterization  

SciTech Connect

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.

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

1992-03-31

33

HydroCube: an entity-relationship hydrogeological data model  

NASA Astrophysics Data System (ADS)

Managing, handling and accessing hydrogeological information depends heavily on the applied hydrogeological data models, which differ between institutions and countries. The effective dissemination of hydrogeological information requires the convergence of such models to make hydrogeological information accessible to multiple users such as universities, water suppliers, and administration and research organisations. Furthermore, because hydrogeological studies are complex, they require a wide variety of high-quality hydrogeological data with appropriate metadata in clearly designed and coherent structures. A need exists, therefore, to develop and implement hydrogeological data models that cover, as much as possible, the full hydrogeological domain. A new data model, called HydroCube, was developed for the Walloon Region in Belgium in 2005. The HydroCube model presents an innovative holistic project-based approach which covers a full set of hydrogeological concepts and features, allowing for effective hydrogeological project management. The model stores data relating to the project locality, hydrogeological equipment, and related observations and measurements. In particular, it focuses on specialized hydrogeological field experiments such as pumping and tracer tests. This logical data model uses entity-relationship diagrams and it has been implemented in the Microsoft Access environment. It has been enriched with a fully functional user interface.

Wojda, Piotr; Brouyère, Serge; Derouane, Johan; Dassargues, Alain

2010-12-01

34

2101-M Pond hydrogeologic characterization report  

Microsoft Academic Search

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

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

1990-01-01

35

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...

36

Hydrogeology and Flooding on the Web  

NSDL National Science Digital Library

Hydrogeology and Flooding on the Web reviews internet sites which contain information on water resources and flood events. Resource categories are flooding, weather-related sites, and hydrology. Some site addresses and image galleries are hyper-linked, while others must be manually cut and pasted into the resource user's browser location.

Gore, Pamela

1997-02-19

37

Home page for Applied Hydrogeology textbook  

NSDL National Science Digital Library

This is a supplement to the Fourth Edition of Applied Hydrogeology, by C.W. Fetter. The site contains corrections to the text, a review of basic math useful for hydrogeologists, a brief history of the science of groundwater, and the text of the California water rights ruling for Mono Lake. Answers to the text's odd-numbered questions are also provided.

Fetter, C. W.

38

Hydrogeology of the Mogollon Highlands, Central Arizona.  

National Technical Information Service (NTIS)

This report presents the findings of an investigation into the hydrogeology of the Mogollon Highlands conducted by the U.S. Geological Survey (USGS) in cooperation with the Arizona Department of Water Resources (ADWR) under the auspices of the State of Ar...

J. T. C. Parker W. C. Steinkampf M. E. Flynn

2004-01-01

39

Hydrogeology, waste disposal, science and politics: Proceedings  

SciTech Connect

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.

Link, P.K. [ed.

1994-07-01

40

The physical hydrogeology of ore deposits  

USGS Publications Warehouse

Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

Ingebritsen, Steven E.; Appold, M. S.

2012-01-01

41

Hydrogeology at the University of Calgary  

NSDL National Science Digital Library

This University of Calgary website provides summaries of the educational opportunities and of the diverse research interests of the hydrogeology group. Individuals can find synopses of the group's applied isotope geochemistry, electrical resistivity imaging, groundwater modeling, surface-ground water interaction, and hydrology research. The website offers information on the research interests, educational background, and publications of the many faculty, post doctorate, and graduate students. Geologists can find out about graduate assistantships and other research opportunities.

42

GEO-SCI 587: Introduction to Hydrogeology  

NSDL National Science Digital Library

This is the home page of a hydrogeology course taught by Dr. David Boutt at the University of Massachusetts. The website includes the course syllabus, lecture notes, homework assignments and lab activities (including three field labs). The course addresses the hydrologic cycle, Darcy's Law, aquifer parameters, steady and transient flow equations, well hydraulics, elementary multi-phase flow, groundwater recharge, watershed hydrology, geological controls on groundwater flow, well construction, and groundwater chemistry and pollution.

Boutt, David; Amherst, University O.

43

Seismic refraction exercise for a hydrogeology course  

NSDL National Science Digital Library

After reviewing a power point presentation on the use of seismic refraction methods in hydrogeology, students are given seismic refraction data collected on the campus of the State University of New York, College at Oneonta, and asked to determine the depth to the water table in addition to drawing a stratigraphic column. The project can be conducted during class or as a take home assignment. Has minimal/no quantitative component Uses geophysics to solve problems in other fields

Castendyk, Devin

44

Marine hydrogeology: recent accomplishments and future opportunities  

Microsoft Academic Search

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

A. T. Fisher

2005-01-01

45

Hydrogeology and Hydrologic Landscape Regions of Nevada  

USGS Publications Warehouse

In 1999, the U.S. Environmental Protection Agency initiated a rule to protect ground water in areas other than source-water protection areas. These other sensitive ground water areas (OSGWAs) are aquifers that are not currently but could eventually be used as a source of drinking water. The OSGWA program specifically addresses existing wells that are used for underground injection of motor vehicle waste. If the injection well is in a ground-water protection area or an OSGWA, well owners must either close the well or apply for a permit. The Nevada Division of Environmental Protection will evaluate site-specific information and determine if the aquifer associated with a permit application is susceptible to contamination. A basic part of evaluating OSGWAs is characterizing the hydrogeology of aquifer systems including the lithology, hydrologic properties, soil permeability, and faulting, which partly control the susceptibility of ground water to contamination. Detailed studies that evaluate ground-water susceptibility are not practical in a largely unpopulated State like Nevada. However, existing and new information could be extrapolated to other areas of the State if there is an objective framework to transfer the information. The concept of hydrologic landscape regions, which identify areas with similar hydrologic characteristics, provides this framework. This report describes the hydrogeology and hydrologic landscape regions of Nevada. Consolidated rocks that form mountain ranges and unconsolidated sediments that fill the basins between the ranges are grouped into hydrogeologic units having similar lithology and assumed to have similar hydrologic properties. Consolidated rocks and unconsolidated sediments are the two major hydrogeologic units and comprise 51 and 49 percent of the State, respectively. Consolidated rocks are subdivided into 8 hydrogeologic units. In approximate order of decreasing horizontal hydraulic conductivity, consolidated-rock hydrogeologic units consist of: (1) carbonate rocks, Quaternary to Tertiary age; (2) basaltic, (3) rhyolitic, and (4) andesitic volcanic flows; (5) volcanic breccias, tuffs, and volcanic rocks older than Tertiary age; (6) intrusive and metamorphic rocks; (7) consolidated and semi-consolidated tuffaceous rocks and sediments; and (8) clastic rocks consisting of sandstone and siltstone. Unconsolidated sediments are subdivided into four hydrogeologic units on the basis of flow regime, topographic slope, and mapped stream channels. The four units are (1) alluvial slopes, (2) valley floors, (3) fluvial deposits, and (4) playas. Soil permeability was grouped into five descriptive categories ranging from very high to very low, which generally correspond to mapped geomorphic features such as playas and alluvial slopes. In general, soil permeability is low to moderate in northern, northeastern, and eastern Nevada and high to very high in western, southwestern, and southern Nevada. Within a particular basin, soil permeability decreases downslope from the bedrock contact. The type of parent rock, climate, and streamflow velocities are factors that likely cause these spatial patterns. Faults in unconsolidated sediments usually are barriers to ground-water flow. In consolidated rocks, permeability and ground-water flow is reduced in directions normal to the fault zone and increased in directions parallel to the fault zone. With time, mineral precipitation may seal fractures in consolidated rocks, reducing the permeability. However, continued movement along the fault may form new fractures, resulting in a fault alternating from a zone of preferred flow to a flow barrier during geologic time. The effect of faults on ground-water flow at a particular location is difficult to determine without a site- specific investigation. Hydrologic landscape regions were delineated by overlaying a grid of 100-foot (30-meter) cells over the State, estimating the value of five variables for each cell, an

Maurer, Douglas K.; Lopes, Thomas J.; Medina, Rose L.; Smith, J. LaRue

2004-01-01

46

University of Tennessee: Hydrogeology Research Program  

NSDL National Science Digital Library

The hydrogeology research program at the University of Tennessee developed this website to promote its investigation related primarily to groundwater flow and contaminant transport. After reading an overview of the program and its facilities, visitors can discover the endeavors and successes of the numerous researchers. Users can find information and publications discussing the three featured research projects: Chattanooga Creek, Pathogen Transport, and Saprolite Pore Structure; as well as materials on other recent projects. Students can discover the program's three excellent field teaching sites and research opportunities.

47

Surface and subsurface mapping in hydrogeology  

SciTech Connect

This book concentrates on the often neglected but useful aspects of hydrogeological mapping. It covers geophysical survey methods and the importance of water chemistry as a tool in tracing the route of subsurface water, and goes on to lay a basic foundation in subjects needed for practice in field: stratigraphy, structural geology, mineralogy, petrography, and geochemistry. Also covers basic disciplines and techniques indispensable for geological mapping, e.g., cartography and surveying, geophysics, drilling, soil science, hydrology, and botanics. Written from a uniquely practical standpoint.

Erdelyi, M.; Galfi, J.

1987-01-01

48

A hydrogeologic model of submarine groundwater discharge: Florida intercomparison experiment  

Microsoft Academic Search

A hydrogeologic model of submarine groundwater discharge (SGD) to the near-shore environment at a site on the northeast Gulf of Mexico has been developed to provide a basis for comparison with measurements of SGD made using seepage meters, and with estimates derived from chemical tracers. The hydrogeologic model incorporates the seaward movement of fresh water and the recirculation of sea

Leslie Smith; Willy Zawadzki

2003-01-01

49

Hydrogeology of thermal waters in Viterbo area, central Italy  

Microsoft Academic Search

A conceptual hydrogeological model of the Viterbo thermal area (central Italy) has been developed. Though numerous studies have been conducted on its geological, geochemical and geothermal features, there is no generalized picture defining the origin and yield of the hydrothermal system. These latter aspects have therefore become the objectives of this research, which is based on new hydrogeological and geochemical

V. Piscopo; M. Barbieri; V. Monetti; G. Pagano; S. Pistoni; E. Ruggi; D. Stanzione

2006-01-01

50

Hydrogeological model of the Baltic Artesian Basin  

NASA Astrophysics Data System (ADS)

The Baltic Artesian Basin (BAB) is a complex multi-layered hydrogeological system in the south-eastern Baltic covering about 480,000 km2. The aim of this study is to develop a closed hydrogeological mathematical model for the BAB. Heterogeneous geological data from different sources were used to build the geometry of the model, i.e. geological maps and stratigraphic information from around 20,000 boreholes. The finite element method was used for the calculation of the steady-state three-dimensional (3D) flow of unconfined groundwater. The 24-layer model was divided into about 1,000,000 finite elements. A simple recharge model was applied to describe the rate of infiltration, and the discharge was set at the water-supply wells. Variable hydraulic conductivities were used for the upper (Quaternary) deposits, while constant hydraulic conductivity values were assumed for the deeper layers. The model was calibrated on the statistically weighted borehole water-level measurements, applying L-BFGS-B (automatic parameter optimization method) for the hydraulic conductivities of each layer. The principal flows inside the BAB and the integral flow parameters were analyzed. The modeling results suggest that deeper aquifers are characterized by strong southeast-northwest groundwater flow, which is altered by the local topography in the upper, active water-exchange aquifers.

Virbulis, Janis; Bethers, Uldis; Saks, Tomas; Sennikovs, Juris; Timuhins, Andrejs

2013-06-01

51

Case studies in organic contaminant hydrogeology  

NASA Astrophysics Data System (ADS)

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.

Baker, John A.

1989-07-01

52

Hydrogeology in North America: past and future  

NASA Astrophysics Data System (ADS)

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'hydrogéologie est à la transition entre la volonté de découvrir de nouvelles ressources et l' exploitation la plus bénéfique au possible, et un management judicieux des ressources finies, interconnectées, qui sont vitales pour l' approvisionnement des hommes et autres formes de vie. Le futur de l' hydrogéologie sera dicté par la balance subtile dans laquelle intervient les cycles de l'hydrologie, de l'érosion, de la nutrition, et la décision d'une société technologique qui s'adapterait aux contraintes de la balance, ou qui continuerait d'exploiter les systèmes hydrologiques pour un bénéfice maximum. Par ailleurs il y a une nette tendance à inclure les aspects écologiques, les aspects environnementaux, et les changements humains qui pourraient être influencés par les modifications hydrogéologiques observées depuis une dizaine d'années. Este articulo es una retrospectiva sobre la evolución de la hidrogeología en Norte América en los pasados dos siglos, y una breve especulación de su futuro. La historia de la hidrogeología está marcada por desarrollos en muchos campos diferentes tal como hidrología de aguas subterráneas, mecánica de suelos, ciencia del suelo, geología económica, ingeniería del petróleo, geología estructural, geoquímica, geofísica, geología marina, y más recientemente, ecología. El campo se ha enriquecido por las contribuciones de investigadores distinguidos en todos esos campos. Actualmente, la hidrogeología se encuentra en transición de un estado de descubrir nuevos recursos y explotarlos eficientemente para un beneficio máximo, a un estado de gestión juiciosa de recursos finitos, interconectados, que son vitales para el sustento de humanos y otras cosas vivientes. El futuro de la hidrogeología posiblemente esté determinado por el balance sutil con el cual funcionan los ciclos nutricionales, erosionales e hidrológicos, y la decisión de una sociedad tecnológica para ya sea adaptarse a las restricciones impuestas por el balance o para continuar con la explotación de los sistemas hidrogeológicos para un benefici

Narasimhan, T. N.

2005-03-01

53

Hydrogeology Laboratory Semester Project: Hydrogeologic Assessment for CenTex Water Supply, Inc.  

NSDL National Science Digital Library

This activity is a single, semester-long project that involves a hydrogeologic assessment of a property in Central Texas. The project is presented in the lab portion of a hydrogeology class, and it is broken into several separate steps. Each step is treated as a separate assignment, however, the data and results associated with each assignment are applied towards the overall goal of the project. Students are required to maintain a file and a master Excel workbook containing all information, data, and results from each of the steps. All this information is then used to develop an analytical model that simulated drawdowns in the aquifer. This model is used to answer the primary question associated with the project. The results are then documented in a technical report.

Uliana, Matthew

54

An OGC Hydrology and Hydrogeology Interoperability Experiment  

NASA Astrophysics Data System (ADS)

The Hydrology Domain Working group of OGC is working in collaboration with the WMO to develop WaterML 2.0. WaterML 2.0 is a data transfer standard that is used in conjunction with other OGC standards, such as SOS, to transmit surface water and groundwater information. We discuss our preliminary progress on a proposed OGC Interoperability Experiment (IE), in which groundwater data collected by sensors are shared across the Canadian and US borders. The IE tests various standards and technologies for sensors, evaluates the use of GroundwaterML with WaterML 2.0, and includes agencies from Canada, Australia, and the USA. This IE represents an important step forward in the development of international standards and systems for hydrologic and hydrogeologic information.

Booth, N. L.; Brodaric, B.; Taylor, P.; Zaslavsky, I.

2009-12-01

55

Chemical hydrogeology in natural and contaminated environments  

USGS Publications Warehouse

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 determining the distribution and concentrations cf. constituents are provided by several studies, including infiltration of sewage effluent and migration of creosote in coastal plain aquifers. These studies show that heterogeneity and the dominance of organically controlled reactions greatly increase the complexity of investigations.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 application 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. 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 is illustrated by studies of infiltration of sewage effluent and migration of creosote in coastal plain aquifers.

Back, W.; Baedecker, M. J.

1989-01-01

56

Insights into Mejerda basin hydrogeology, Tunisia  

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

57

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...

58

Hydrogeology of Picacho Basin, South-Central Arizona.  

National Technical Information Service (NTIS)

The hydrogeology of Picacho Basin was studied to define the stratigraphy, basin structure, physical and hydraulic properties of the basin sediments, and predevelopment and postdevelopment conditions of ground-water flow as of 1985. The study area includes...

D. R. Pool R. L. Carruth W. D. Meehan

2001-01-01

59

Deep hydrogeologic flow system underlying the Oak Ridge Reservation.  

National Technical Information Service (NTIS)

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 ...

R. Nativ A. E. Hunley

1993-01-01

60

The application of ecohydrological groundwater indicators to hydrogeological conceptual models.  

PubMed

This article reviews the application of ecohydrological indicators to hydrogeological conceptual models for earth-scientists with little or no botanical training. Ecohydrological indicators are plants whose presence or morphology can provide data about the hydrogeological setting. By examining the literature from the fields of ecohydrology, hydrogeology, geobotany, and ecology, this article summarizes what is known about groundwater indicator plants, their potential for providing information about the aquifer, and how this data can be a cost-effective addition to hydrogeological conceptual models. We conclude that the distribution and morphology of ecohydrological groundwater indicator plants can be useful to hydrogeologists in certain circumstances. They are easiest to evaluate in arid and semiarid climates. Ecohydrological groundwater indicators can provide information about the absolute depth to the water table, patterns of groundwater fluctuation, and the mineralization of the aquifer. It is shown that an understanding of the meteorological conditions of a region is often necessary to accurately interpret groundwater indicator plants and that useful data is usually obtained by observing patterns of vegetation behavior rather than interpreting individual plants. The most serious limitations to applying this source of information to hydrogeological conceptual models are the limited data in the literature and the regional nature of many indicator plants. The physical and physiological indications of the plants exist, but little effort has been made to interpret them. This article concludes by outlining several potential lines of research that could further the usefulness of ecohydrological groundwater indicators to the hydrogeological community. PMID:22150517

Lewis, Jeff

2012-01-01

61

Peatland hydrogeological function at the regional scale  

NASA Astrophysics Data System (ADS)

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 cranberry crops which have been developing extremely rapidly in the study area. Nine peatlands from different parts of the study area were sampled to determine the nature of the underlying sediments. Results show that eight out of the nine studied peatlands are located on relatively permeable sand deposits and can therefore sustain hydrogeological exchanges with the surrounding aquifer. Darcy fluxes calculated from piezometric data for the nine peatlands show that five of them receive water from the superficial aquifer while four contribute water to it. Using Quaternary deposits data and a 3D hydrostratigraphic model, the proportion of peatlands receiving groundwater or contributing water to the aquifer was found to be similar at the regional scale. For the nine studied peatlands, aquifer-peatland fluxes represent between 6 and 11% of the total water input to the organic deposits. Results also show that exchanged aquifer-peatland fluxes increase with the size of the peatland, either towards the peatland or from the organic deposits to the aquifer. This study suggests that peatlands have a buffer function to keep relatively stable levels in a superficial unconsolidated aquifer. Maintaining a peatland coverage on the landscape could contribute to sustain groundwater resources.

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

2012-12-01

62

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

Microsoft Academic Search

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

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

1995-01-01

63

Hydrogeology of formation waters, northwestern Alberta basin  

SciTech Connect

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.

Bachu, S.; Underschultz, J.R. (Alberta Geological Survey, Edmonton (Canada))

1993-10-01

64

Flowing with the changing needs of hydrogeology instruction  

NASA Astrophysics Data System (ADS)

Hydrogeology is now taught in a broad spectrum of departments and institutions to students with diverse backgrounds. Successful instruction in hydrogeology thus requires a variety of pedagogical approaches depending on desired learning outcomes and the diverse background of students. We review the pedagogical literature in hydrogeology to highlight recent advances and analyze a 2005 survey of 68 hydrogeology instructors. The literature and survey results suggest there are ~15 topics that are considered crucial by most hydrogeologists and >100 other topics that are considered crucial by some hydrogeologists. The crucial topics focus on properties of aquifers and fundamentals of groundwater flow, and should likely be part of all undergraduate hydrogeology courses. Other topics can supplement and support these crucial topics, depending on desired learning outcomes. Classroom settings continue to provide a venue for emphasizing fundamental knowledge. However, recent pedagogical advances are biased towards field and laboratory instruction with a goal of bolstering experiential learning. Field methods build on the fundamentals taught in the classroom and emphasize the collection of data, data uncertainty, and the development of vocational skills. Laboratory and computer-based exercises similarly build on theory, and offer an opportunity for data analysis and integration. The literature suggests curricula at all levels should ideally balance field, laboratory, and classroom pedagogy into an iterative and integrative whole. An integrated approach leads to greater student motivation and advancement of theoretical and vocational knowledge.

Gleeson, T.; Allen, D. M.; Ferguson, G.

2012-01-01

65

Airborne EM for geothermal and hydrogeological mapping  

NASA Astrophysics Data System (ADS)

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. SkyTEM data have been acquired in a series of flight lines and were then processed and inverted. In the "Termini" area the flight line spacing had 150 m separation. In the "Western Sicily" area two different line spacing were used: the 1 km spacing was used for the regional mapping, whereas for infill areas, around the main hydrothermal springs, the flight lines had 100 m spacing. The total number of flight line was 4580 km, and the explored surface was in excess of 2000 km2. After acquisition, data were processed to eliminate coupling with infrastructures, and noise. Inversions was then carried out using the quasi 3-D Spatially Constrained Inversion. The obtained resistivity volume has then been the base for a detailed lithological and geothermal interpretation. Lithological and geological maps were used to constrain surface condition and to understand the resistivity ranges of the different lithological units. On the base of resistivity values, lithological units were combined to establish the main litho-resistive units, then modeled at depth, down to achievable investigation depth. This detailed interpretative modeling was also the occasion of recognizing resistivity anomalies within carbonate units, which may possibly represent hydrogeological or hydrothermal bodies. The litho-resitive 3D model is now under investigation to verify how it can represent a viable way to image thermal conductivity variations at depth.

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

2012-12-01

66

Python-Based Applications for Hydrogeological Modeling  

NASA Astrophysics Data System (ADS)

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 python wrapper invokes the underlying FORTRAN layer to compute transient groundwater elevations and processes this information to create time-series and 2D plots.

Khambhammettu, P.

2013-12-01

67

Hydrogeologic atlas of aquifers in Indiana  

USGS Publications Warehouse

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.

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

68

Hydrogeology of Ljubljana polje perched aquifers  

NASA Astrophysics Data System (ADS)

Ljubljana polje aquifer lies in central part of Slovenia and is one of the biggest and most important aquifers in Slovenia. Aquifer was formed in quaternary basin which was filled with sediments from local rivers. River Sava is the biggest and the most important among them. Thickness of the aquifer varies from 20 m to 100 m. In general it is an unconfined aquifer, but locally, between gravel and sand sediments which have good hydraulic conductivity, layers with low hydraulic conductivity, such as silt and clay, appear. Those layers or lenses can form perched aquifers. Perched aquifers are important for prevention of pollution of the main aquifer and also for the water recharge in the time periods with high precipitation. The perched aquifers were located by boreholes, while their spatial distribution has not been studied yet. Within the project INCOME all the existing lithological borehole logs were collected and analysed with Jewel Suite 2011 software. A geostatistical method sequential indicator simulation was used to create spatial distribution of five hydrofacies at the Ljubljana polje aquifer. The layers/lenses that are bigger than 0.07 km2 and have hydraulic conductivity lower than K = 10-7 m/s were defined as lenses that can potentially form perched aquifers. In the modelling area, two areas with higher concentration of lenses with low hydraulic conductivity were defined. At those areas, according to the borehole data, perched aquifers appear few meters below surface to the depth around 30 m. At the other parts of the model area lenses with low hydraulic conductivity are less abundant. With spatial information (lateral and vertical extension) of perched aquifers in Ljubljana polje improvement of existing hydrogeological models can be made which can help to improve the qualitative and quantitative status of the Ljubljana polje main aquifer.

Šram, D.; Bren?i?, M.

2012-04-01

69

Interdisciplinary hydrogeologic site characterization at the Nevada Test Site  

SciTech Connect

The Nevada Test Site was established in 1950 as a continental area for testing nuclear devices. Hydrogeologic investigations began in earnest with the US Geological Survey mapping much of the area from 1960 to 1965. Since 1963, all nuclear detonations have been underground. Most tests are conducted in vertical shafts, but a small percentage are conducted in tunnels. The majority of detonation points are above the water table, primarily in volcanic rocks, but sometimes in alluvium. Hydrogeologic investigations began in earnest with the US Geological Survey`s mapping of much of the NTS region from 1960 to 1965. Following the BANEBERRY test in December 1970, which produced an accidental release of radioactivity to the atmosphere, the US Department of Energy (then the Atomic Energy Commission) established the Containment Evaluation Panel (CEP). Results of interdisciplinary hydrogeologic investigations for each test location are included in a Containment Prospectus which is thoroughly reviewed by the CEP.

Hawkins, W.L. [Los Alamos National Lab., NM (United States); Wagoner, J.L. [Lawrence Livermore National Lab., CA (United States); Drellack, S.L. [Raytheon Services Nevada, Mercury, NV (United States)

1992-06-01

70

Interdisciplinary hydrogeologic site characterization at the Nevada Test Site  

SciTech Connect

The Nevada Test Site was established in 1950 as a continental area for testing nuclear devices. Hydrogeologic investigations began in earnest with the US Geological Survey mapping much of the area from 1960 to 1965. Since 1963, all nuclear detonations have been underground. Most tests are conducted in vertical shafts, but a small percentage are conducted in tunnels. The majority of detonation points are above the water table, primarily in volcanic rocks, but sometimes in alluvium. Hydrogeologic investigations began in earnest with the US Geological Survey's mapping of much of the NTS region from 1960 to 1965. Following the BANEBERRY test in December 1970, which produced an accidental release of radioactivity to the atmosphere, the US Department of Energy (then the Atomic Energy Commission) established the Containment Evaluation Panel (CEP). Results of interdisciplinary hydrogeologic investigations for each test location are included in a Containment Prospectus which is thoroughly reviewed by the CEP.

Hawkins, W.L. (Los Alamos National Lab., NM (United States)); Wagoner, J.L. (Lawrence Livermore National Lab., CA (United States)); Drellack, S.L. (Raytheon Services Nevada, Mercury, NV (United States))

1992-01-01

71

Groundwater availability as constrained by hydrogeology and environmental flows.  

PubMed

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. PMID:23582026

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

2014-01-01

72

A Task-oriented Approach for Hydrogeological Site Characterization  

Microsoft Academic Search

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

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

2010-01-01

73

Hydraulic Pulse Interference Tests for Site Hydrogeologic Characterization  

Microsoft Academic Search

Hydraulic pulse interference tests involve a cyclic injection of fluid into the source well, and by high precision measurement of the pressure pulse in a neighboring well, detailed hydraulic characterization between wells can be made. The pulse interference test is highly sensitive to hydrogeological properties between the pulse source and receiver wells. The transient nature of the test, involving the

Grant Hocking; GeoSierra LLC

74

The macroinvertebrate fauna and hydrogeology of springs in central Sweden  

Microsoft Academic Search

The macroinvertebrate fauna of 23 springs in central Sweden was sampled. A total of 79 taxa was recorded, including three crenobiont, nine crenophilic, 33 lotic, 11 lentic and 21 ubiquitous taxa. Only eight were non-insect taxa. Geological and hydrogeological maps were used to categorize each spring, resulting in eight glaciofluvial, 11 moraine and four limestone springs. Faunal composition and environmental

Per-Ola Hoffsten; Björn Malmqvist

2000-01-01

75

Hydrogeology Of Fractured Rocks - A Question Of Uncertainty About Geometry  

Microsoft Academic Search

An approach to understanding the hydrogeology of fractured rocks is proposed. It starts by assuming that the geometry of the fracture based flow system is unknown. Fracture network concepts are reviewed briefly. The approach uses a discrete fracture network computer code to evaluate the impact of different geometric concepts and to aid in the design of \\

J. H. Black

1994-01-01

76

Hydrogeologic Framework of Onslow County, North Carolina, 2008  

USGS Publications Warehouse

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.

Fine, Jason M.

2008-01-01

77

Hydrogeologic model of the Ahuachapan geothermal field, El Salvador  

SciTech Connect

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.

Laky, C.; Lippmann, M.J.; Bodvarsson, G.S. (Lawrence Berkeley Lab., CA (USA)); Retana, M.; Cuellar, G. (Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) (El Salvador))

1989-01-01

78

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

USGS Publications Warehouse

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 relation of flow properties to porosity that are described can be used to produce detailed and accurate representations of the core-scale hydrologic processes ongoing at Yucca Mountain.

Flint, L. E.

1998-01-01

79

Hydrogeology of an alkaline fly ash landfill in Eastern Iowa  

Microsoft Academic Search

The hydrogeology and chemical quality of the shallow ground-water regime at a coal fly ash landfill was investigated near Montpelier, Iowa. An embankment dam retains the two-hectare deposit of silt-sized alkaline coal fly ash in an upland ravine. The fly ash landfill was operated between 1964-1973 and was subsequently capped with a thin loess layer and seeded to pasture. The

Linda Le Seur Spencer; Lon D. Drake

1987-01-01

80

Hydrogeological monitoring in the newly restored Cheonggyecheon stream, Seoul, Korea.  

NASA Astrophysics Data System (ADS)

The understanding of hydrogeological characteristics related to the Cheonggyecheon (Cheonggye-stream) restoration is important from the viewpoint of water cycle in the city and stream flow after restoration. The hydrogeological characteristics in the Cheonggyecheon is very complicated by the pumping, underground structure, pumping associated with subway tunnel and road pavement. A impervious layer beneath the stream and barrier walls along the stream was installed for the leakage prevention of the stream water. We monitored the hydraulic head, hydrogeochemical properties and changes of hydrogeological properties for the sustainability in the restored Cheonggyecheon. The range of hydraulic head fluctuation was about 2 m ~ 3 m due to a rainfall event before the restoration. But the fluctuation range of hydraulic head was not so high after the restoration to be about 0.5 m to 1 m. The hydrogeochemical properties indicated that the groundwater quality is likely to be recovered gradually because the incoming of contaminants from the surface water to groundwater have been decreased. For example, the concentration of nitrate contaminant inside the barrier wall in groundwater was 0.28 ppm after the barrier wall installation but the nitrate concentration outside the barrier wall was 46.11 ppm.

Jae-Ha, Y.; Yoon-Young, K.; Doo-Hyung, C.; Kang-Kun, L.

2006-12-01

81

Developing a Modular Hydrogeology Ontology Extending the SWEET Ontologies  

NASA Astrophysics Data System (ADS)

Reengineering upper-level ontologies to make them useful for specific domains can be achieved using modular software development techniques. The challenge of manipulating complex and general, upper-level ontologies can be overcome by using ontology development tools for the purpose of analysis and design of new concepts and extension of existing concepts. As a use case representing this approach we present the reengineering of NASA's Semantic Web for Earth and Environmental Terminology (SWEET) ontologies to include part of the hydrogeology concepts. We have maintained the modular design of the SWEET ontologies for maximum extensibility and reusability. The modular reengineering of the SWEET ontologies to include hydrogeology domain involved the following steps: (1): Identify the terms and concepts relevant to the hydrogeology domain through scenarios, competency questions, and interviews with domain experts. (2): Establish the inter-relationships between concepts (e.g., vadose zone = unsaturated zone). (3): Identify the dependent concepts, such as physical properties or units, and determine their relationships to external concepts. (4): Download the OWL files from SWEET, and save them on local systems for editing. (5): Use ontology editing tools like SWOOP and Protege to analyze the structure of the existing OWL files. (6): Add new domain concepts as new classes in the OWL files, or as subclasses of already existing classes in the SWEET ontologies. The step involved changing the relationships (properties) and/or adding new relationships where they were required in the domain. Sometimes the entire structure of the existing concepts needed to be changed to represent the domain concept more meaningfully. (7): Test the consistency of concepts using appropriate tools (e.g., Protege, which uses the Racer reasoner to check consistency of concepts). (8) Add individuals to the new concepts to test the modified ontologies. We present an example of a simple RDQL query to test and demonstrate the new hydrogeology ontology. Our work shows that SWEET ontologies can successfully be extended and reused by other Earth science domains without losing their modular structure.

Tripathi, A.; Babaie, H. A.

2005-12-01

82

Hydrogeological modeling of prb for remediation of a contaminated site  

NASA Astrophysics Data System (ADS)

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 for both shallow and deep aquifers. The flow fields and paths of the shallow/deep aquifer were predicted with time under various PRB designs. Therefore such modeling exercises have provided sound information for the remediation of the contaminated land and groundwater.

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

2003-04-01

83

Hydrogeology characterization of roto-translational slides in flysch rock masses  

Microsoft Academic Search

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

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

2009-01-01

84

Hydrogeologic Characterization of the Minnelusa and Madison Aquifers near Spearfish, South Dakota.  

National Technical Information Service (NTIS)

The purpose of this report is to present the results of a 3-year study to characterize the hydrogeology and describe the hydraulic properties of the Minnelusa and Madison aquifers in the Spearfish area. In addition, the hydrogeology of the aquifers is syn...

E. A. Greene A. M. Shapiro J. M. Carter

1999-01-01

85

First USA/USSR joint conference on environmental hydrology and hydrogeology  

SciTech Connect

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.

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

1991-01-01

86

Summary of Hydrogeologic Conditions by County for the State of Michigan.  

National Technical Information Service (NTIS)

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 re...

B. A. Apple H. W. Reeves

2007-01-01

87

Hydrogeology and groundwater ecology: Does each inform the other?  

NASA Astrophysics Data System (ADS)

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.

Humphreys, W. F.

2009-02-01

88

Flawed processing of airborne EM data affecting hydrogeological interpretation.  

PubMed

Airborne electromagnetics (AEMs) is increasingly being used across the globe as a tool for groundwater and environmental management. Focus is on ensuring the quality of the source data, their processing and modeling, and the integration of results with ancillary information to generate accurate and relevant products. Accurate processing and editing of raw AEM data, the topic of this article, is one of the crucial steps in obtaining quantitative information for groundwater modeling and management. In this article, we examine the consequences that different levels of processing of helicopter transient electromagnetic method data have on the resulting electrical models and subsequently on hydrogeological models. We focus on different approaches used in the industry for processing of the raw data and show how the electrical resistivity-depth models, which is the end "geophysical" product (after data inversion) of an AEM survey, change with different levels of processing of the raw data. We then extend the study to show the impact on some of the hydrogeological parameters or models, which can be derived from the geophysical results. The consequences of improper handling of raw data to groundwater and environmental management can be significant and expensive. PMID:22775586

Viezzoli, Andrea; Jørgensen, Flemming; Sørensen, Camilla

2013-03-01

89

Proceedings of the joint Russian-American hydrogeology seminar  

SciTech Connect

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.

Tsang, C.F. [ed.] [Lawrence Berkeley National Lab., CA (United States); Mironenko, V. [ed.] [Russian Academy of Sciences, St. Petersburg (Russian Federation). Inst. of Environmental Geology; Pozdniakov, S. [ed.] [Moscow State Univ. (Russian Federation)

1997-12-31

90

The use of multicomponent statistical analysis in hydrogeological environmental research.  

PubMed

The present article examines the possibilities of investigating NO(3)(-) spread in aquifers by applying multicomponent statistical methods (factor, cluster and discriminant analysis) on hydrogeological, hydrochemical, and environmental parameters. A 4-R-Mode factor model determined from the analysis showed its useful role in investigating hydrogeological parameters affecting NO(3)(-) concentration, such as its dilution by upcoming groundwater of the recharge areas. The relationship between NO(3)(-) concentration and agricultural activities can be determined sufficiently by the first factor which relies on NO(3)(-) and SO(4)(2-) of the same origin-that of agricultural fertilizers. The other three factors of R-Mode analysis are not connected directly to the NO(3)(-) problem. They do however, by extracting the role of the unsaturated zone, show an interesting relationship between organic matter content, thickness and saturated hydraulic conductivity. The application of Hirerarchical Cluster Analysis, based on all possible combinations of classification method, showed two main groups of samples. The first group comprises samples from the edges and the second from the central part of the study area. By the application of Discriminant Analysis it was shown that NO(3)(-) and SO(4)(2-) ions are the most significant variables in the discriminant function. Therefore, the first group is considered to comprise all samples from areas not influenced by fertilizers lying on the edges of contaminating activities such as crop cultivation, while the second comprises all the other samples. PMID:15026241

Lambrakis, Nicolaos; Antonakos, Andreas; Panagopoulos, George

2004-04-01

91

Multiscale Hydrogeologic Modeling with Emphasis on Hybrid Multiscale Methods (Invited)  

NASA Astrophysics Data System (ADS)

One of the most significant challenges facing hydrogeologic modelers is the disparity between those spatial and temporal scales at which porous media 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. This presentation will focus on a class of multiscale methods in which two or more models with different physics described at fundamentally different scales are directly coupled within a single simulation (hybrid multiscale methods). Very recently these methods have begun to be applied to groundwater flow and transport simulations, and we will present and discuss these applications in the broader context of other better-known multiscale modeling approaches.

Scheibe, T. D.; Murphy, E. M.; Chen, X.; Rice, A. K.; Carroll, K. C.; Palmer, B.; Tartakovsky, A. M.; Battiato, I.; Wood, B. D.

2013-12-01

92

Forensic Analysis of MTBE Contamination Using Basic Hydrogeologic Concepts.  

PubMed

Contamination of groundwater with petroleum hydrocarbons and additives, such as methyl tert-butyl ether (MTBE), is often linked to the leaking product distribution system of gas stations. In very few cases is it know if and when a leak occurred and how much product was released to the environment. In the absence of direct evidence, a careful analysis of the available data, such as contaminant breakthrough at receptor wells or discrepancies in the product inventory data, may provide evidence about the nature of the release, its timing and magnitude. Using a MTBE contamination site in the formerly glaciated New England region as an example, two possible release scenarios (slow, long-term release vs. spill) were examined. Of the two scenarios, the slow release could be ruled out as the sole source even though there was no direct evidence for a spill. The analysis of hydraulic test results together with chemical data further permitted to estimate when such an undocumented spill might have occurred. Analyses of the data also allowed these results to be compared to that of a prior transport and fate modeling study. Good agreement and consistency for contaminant travel times was confirmed. This forensic analysis demonstrates that applying basic hydrogeologic principles can aide in the reconstruction of contamination events while providing more readily understandable and defendable evidence relative to complex models. Conceptually, the approach described herein is transferable to other sites with similar hydrogeologies. PMID:24840309

Boving, Thomas

2014-07-01

93

Hydrogeologic framework of the middle San Pedro watershed, southeastern Arizona  

USGS Publications Warehouse

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 the upper basin fill may be more permeable than the lower basin fill, but it is generally unsaturated in the study area. The lower basin fill stratigraphic unit was delineated into three HGUs on the basis of lithologic descriptions in driller?s logs and one-dimensional (1D) electrical models of airborne transient electromagnetic (TEM) surveys. The interbedded lower basin fill (ILBF) HGU represents an upper sequence having resistivity values between 5 and 40 ohm-m identified as interbedded sand, gravel, and clay in driller?s logs. Below this upper sequence, fine-grained lower basin fill (FLBF) HGU represents a thick silt and clay sequence having resistivity values between 5 and 20 ohm-m. Within the coarse-grained lower basin fill (CLBF) HGU, which underlies the silt and clay of the FLBF, the resistivity values on logs and 1D models increase to several hundred ohm-m and are highly variable within sand and gravel layers. These sequences match distinct resistivity and lithologic layers identified by geophysical logs in the adjacent Sierra Vista subwatershed, suggesting that these sequences are laterally continuous within both the Benson and Sierra Vista subwatersheds in the Upper San Pedro Basin. A subsurface density model based on gravity data was constructed to identify the top of bedrock and structures that may affect regional groundwater flow. The subsurface density model contains six layers having uniform density values, which are assigned on the basis of geophysical logs. The density values for the layers range between 1.65 g/cm3 for unsaturated sediments near the land surface and 2.67 g/cm3 for bedrock. Major features include three subbasins within the study area, the Huachuca City subbasin, the Tombstone subbasin, and the Benson subbasin, which have no expression in surface topography or lithology. Bedrock altitudes from the subsurface density model defined top altitudes of the bedrock HGU. The HFM includes the following HGUs in ascending stratigr

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

2010-01-01

94

Application of End-Member Mixing Analysis to karst hydrogeology  

NASA Astrophysics Data System (ADS)

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 pre-event water stored in the karst and of epikarst water to the runoff. The application of EMMA to hydrogeology looks promising, especially in complex aquifers where the origin of groundwater is not straightforward. Principal Component Analysis of Lez spring water bounded by three end-members Water level and deep end-member contribution at Lez spring

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

2013-12-01

95

Water and Mud: Linking hydrogeology and landscape change  

NSDL National Science Digital Library

This exercise demonstrates the role of groundwater in Earth's surface processes and natural hazards through a simple sensitivity analysis using Excel and a case study of a landslide in glacial sediments. In the first part of the exercise, students use a spreadsheet to model the infinite slope equation to determine which variables are sensitive to change. In this part of the exercise students discover the relationship and importance between hydrogeology and Earth's surface processes. In the second part of the exercise students use a case study, of a landslide that occurred in glacial sediments, to calculate the lag time between precipitation events and slope failure. This exercise highlights the relationship between groundwater and natural hazards. Finally, students combine their knowledge of both exercises and use the infinite slope equation to predict the percent of ground saturation for the landslide case study.

Nichols, Kyle

96

Hydrogeology and Water Quality of the Leetown Area, West Virginia  

USGS Publications Warehouse

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 characterize the quality of water and the hydraulic properties of the aquifer. Surface geophysical surveys provided a 3-dimensional view of bedrock resistivity in order to assess geologic and lithologic controls on ground-water flow. Borehole geophysical surveys were conducted in monitoring wells to assess the storage and movement of water in subsurface fractures. Numerous single-well, multi-well, and straddle packer aquifer tests and step-drawdown tests were conducted to define the hydraulic properties of the aquifer and to assess the role of bedrock fractures and solution conduits in the flow of ground water. Water samples collected from wells and springs were analyzed to assess the current quality of ground water and provide a baseline for future assessment. Microbiological sampling of wells for indicator bacteria and human and animal DNA provided an analysis of agricultural and suburban development impacts on ground-water quality. Light detection and ranging (LiDAR) data were analyzed to develop digital elevation models (DEMs) for assessing sinkhole distribution, to provide elevation data for development of a ground-water flow model, and to assess the distribution of major fractures and faults in the Leetown area. The flow of ground water in the study area is controlled by lithology and geologic structure. Bedrock, especially low permeability units such as the shale Martinsburg Formation and the Conococheague Limestone, act as barriers to water flowing down gradient and across bedding. This retardation of cross-strike flow is especially pronounced in the Leetown area, where bedding typically dips at steep angles. Highly permeable fault and fracture zones that disrupt the rocks in cross-strike directions provide avenues through which ground water can flow laterally across or through strata of low primary permeability. Significant strike parallel thrust faults and cross-strike faults typically coincide with larger solution conduits and act as drains for the more

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

2008-01-01

97

Hydrogeologic Unit Flow Characterization Using Transition Probability Geostatistics  

SciTech Connect

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.

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

2003-11-21

98

Hydrogeology and quality of ground water in Orange County, Florida  

USGS Publications Warehouse

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 on reported measurements or estimates: precipitation was 53 inches per year (in/yr), runoff was 11 in/yr, spring discharge was 2 in/yr, and net lateral subsurface outflow and exported water was 1 in/yr. Evapotranspiration was 39 in/yr, which was calculated as the residual of the water-budget analysis, assuming changes in storage were negligible. Water-quality samples were collected from April 1999 through May 2001 from a total of 26 wells tapping the surficial aquifer system, 1 well tapping the intermediate confining unit, 24 wells tapping the Upper Floridan aquifer, 2 springs issuing from the Upper Floridan aquifer, and 8 wells tapping the Lower Floridan aquifer. These data were supplemented with existing water-quality data collected by the U.S. Geological Survey and St. Johns River Water Management District. Concentrations of total dissolved solids, sulfate, and chloride in samples from the surficial aquifer system generally were low. Concentrations of nitrate were higher in samples from the surficial aquifer system than in samples from the Upper Floridan or Lower Floridan aquifers, probably as a result of agricultural and residential land use. Water type throughout most of the Upper Floridan and Lower Floridan aquifers was calcium or calcium-magnesium bicarbonate, probably as a result of dissolution of the carbonate rocks. Water type in both the surficial and Floridan aquifer systems in eastern Orange County is sodium chloride. Concentrations of total dissolved solids, sulfate, and chloride in the aquifers increase toward eastern Orange County. Data from 16 of 24 wells in eastern Orange County with long-term water-quality records indicated distinct increases in concentrations of chloride over time. The increases probably are related to withdrawal of ground water at the Cocoa well field, causing an upwelling of deeper, more saline water. The most commonly detected trace elements were aluminum, barium, boron, iron, manganese, and strontium. In addition, arse

Adamski, James C.; German, Edward R.

2004-01-01

99

Hydrogeological analysis of slug tests in glacier boreholes  

NASA Astrophysics Data System (ADS)

Slug testing allows estimation of subglacial hydraulic properties by evaluating the response of a coupled borehole subglacial flow system to an artificial displacement of its steady-state hydraulic head. However, existing models developed specifically for application to slug-test data collected in glacier boreholes are challenging to apply in practice. Here, we demonstrate that conventional linear methods, which are relatively readily applicable and widely used in groundwater studies, can also be used to estimate subglacial hydraulic properties. Overdamped, underdamped and critically damped slug-test data were recorded in fluctuating boreholes drilled to the bed of Haut Glacier d'Arolla, Valais, Switzerland. We find that non-linear effects in the data are negligible, supporting the application of conventional hydrogeological methods. Results suggest that the hydraulic conductivity of the unconsolidated sediments within the area influenced by a major subglacial drainage channel is enhanced (several 10-2 ms-1; typical of gravelly sand) compared to areas outside the zone of influence (˜0.1 × 10-2 ms-1; typical of silty sand). A distance to a flow boundary within the subglacial aquifer, inferred on the basis of slug-test analysis, was found to coincide with the actual location of the subglacial channel. Sensitivity analyses reveal that uncertainties in borehole and filter radii, as well as the storage coefficient of the subglacial aquifer, are more likely to affect the accuracy of the hydraulic and distance estimates than uncertainties regarding the repeatability of the slug-test responses and curve-fitting procedures involved in the conventional hydrogeological methods.

Kulessa, Bernd; Hubbard, Bryn; Williamson, Mike; Brown, Giles H.

100

Hydrogeologie et transport dans le champ lointain. (Hydrogeology and migration in the remote field).  

National Technical Information Service (NTIS)

This paper gives the main data on Oklo - Okelobondo site: hydrogeology, stratigraphy, geologic fractures, hydrochemical data. Then the results of computerized simulations of convective - dispersive transport with the help of METIS code (Modelling of flows...

P. L. Blanc P. Escalier des Orres I. Gurban E. Ledoux L. Raimbault

1991-01-01

101

Hydrogeology of the West Branch Delaware River Basin, Delaware County, New York.  

National Technical Information Service (NTIS)

In 2009, the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, began a study of the hydrogeology of the West Branch Delaware River (Cannonsville Reservoir) watershed. There has been recent interest by...

R. J. Reynolds

2013-01-01

102

Hydrogeological Evaluation of Qatar Peninsula Using LANDSAT Imagery and Geophysical Data.  

National Technical Information Service (NTIS)

The application of image processing techniques to landsat satellite images proved to be of major significance in the evaluation of the hydrogeological situation in Qatar peninsula. The images are correlatable with the geophysical resistivity maps of the p...

M. A. Yehia I. E. Harhash

1982-01-01

103

Hydrogeology and Tritium Transport in Chicken Creek Canyon, Lawrence Berkeley National Laboratory, Berkeley, California.  

National Technical Information Service (NTIS)

This study of the hydrogeology of Chicken Creek Canyon was conducted by the Environmental Restoration Program (ERP) at Lawrence Berkeley National Laboratory (LBNL). This canyon extends downhill from Building 31 at LBNL to Centennial Road below. The leadin...

I. Javandel P. D. Jordan

2007-01-01

104

Hydrogeology of the rock mass encountered at the 240 level of Canada's Underground Research Laboratory.  

National Technical Information Service (NTIS)

The rock mass surrounding the 240 level of Canada's Underground Research Laboratory (URL) has been hydrogeologically characterized through observations made in the tunnel and room excavations and from a network of radiating low-dipping boreholes. The 240 ...

E. T. Kozak C. C. Davison

1992-01-01

105

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

PubMed

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

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

2012-11-01

106

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

USGS Publications Warehouse

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.

Welch, Wendy B.; Savoca, Mark E.

2011-01-01

107

Hydrogeological framework of the Deccan basalt groundwater systems, west-central India  

Microsoft Academic Search

Deccan basalts of west-central India are hydrogeologically inhomogeneous rocks. A proper understanding of the physical framework\\u000a of the basalts within which groundwater resides and moves is a key to the hydrogeology of these rocks. Two types of basalt,\\u000a the vesicular amygdaloidal basalt and the compact basalt, occur as alternate layers in the volcanic pile. Although the rocks\\u000a are generally inhomogeneous,

Himanshu Kulkarni; S. B. Deolankar; A. Lalwani; B. Joseph; S. Pawar

2000-01-01

108

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

SciTech Connect

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.

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

1997-12-31

109

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

USGS Publications Warehouse

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.

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

1997-01-01

110

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

SciTech Connect

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.

Foley, M.G.

1994-05-01

111

Hydrogeologic Modeling at the Sylvania Corning FUSRAP Site - 13419  

SciTech Connect

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 better understand the contaminant transport and fate mechanisms through the underlying aquifers. This regional model, developed for the N.Y. State Department of Environmental Conservation (NYSDEC) by Camp Dresser and McKee (CDM), uses the finite element model DYNFLOW developed by CDM, Cambridge, Massachusetts. The coarseness of the regional model, however, could not adequately capture the hydrogeologic heterogeneity of the aquifer. Specifically, the regional model did not adequately capture the interbedded nature of the Magothy aquifer and, as such, simulated particles tended to track down-gradient from the Site in relatively straight lines while the movement of groundwater in such a heterogeneous aquifer is expected to proceed along a more tortuous path. This paper presents a qualitative comparison of site-specific groundwater flow modeling results with results obtained from the regional model. In order to assess the potential contaminant migration pathways, a particle tracking method was employed. Available site-specific and regional hydraulic conductivity data measured in-situ with respect to depth and location were incorporated into the T-PROG module in GMS model to define statistical variation to better represent the actual stratigraphy and layer heterogeneity. The groundwater flow characteristics in the Magothy aquifer were simulated with the stochastic hydraulic conductivity variation as opposed to constant values as employed in the regional model. Contaminant sources and their exact locations have been fully delineated at the Site during the Remedial Investigation (RI) phase of the project. Contaminant migration pathways originating from these source locations at the Site are qualitatively traced within the sole source aquifer utilizing particles introduced at source locations. Contaminant transport mechanism modeled in the current study is based on pure advection (i.e., plug flow) and mechanical dispersion while molecular diffusion effects are neglected due to relatively high groundwater velocities encountered in the aquifer. In addition, fate of contam

Ewy, Ann [U.S. Army Corps of Engineers, Kansas City District (United States)] [U.S. Army Corps of Engineers, Kansas City District (United States); Heim, Kenneth J. [U.S. Army Corps of Engineers, New England District (United States)] [U.S. Army Corps of Engineers, New England District (United States); McGonigal, Sean T.; Talimcioglu, Nazmi M. [The Louis Berger Group, Inc. (United States)] [The Louis Berger Group, Inc. (United States)

2013-07-01

112

Hydrogeology of the Potsdam Sandstone in northern New York  

USGS Publications Warehouse

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 across the eastern part of the study area; the largest of these is Altona Flat Rock. Most recharge to the sandstone aquifer occurs in areas of thin, discontinuous till and exposed bedrock; little recharge occurs in areas where this unit is overlain by thick till and clay. Discharge from the sandstone aquifer provides stream and river baseflow and is the source of many springs. A series of springs that are used for municipal bottled water and fish-hatchery supply discharge from 1,000 to 5,000 L/min adjacent to several tributaries east of the Chateauguay River. The major recharge areas for the Chateauguay springs are probably upgradient to the southeast, where the till cover is thin or absent.

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

2010-01-01

113

A New Hydrogeological Research Site in the Willamette River Floodplain  

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

114

Hydrogeological-Geophysical Methods for Subsurface Site Characterization - Final Report  

SciTech Connect

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.

Rubin, Yoram

2001-01-01

115

The deep hydrogeologic flow system underlying the Oak Ridge Reservation  

SciTech Connect

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.

Nativ, R. [Hebrew Univ., Jerusalem (IL); Hunley, A.E. [Oak Ridge National Lab., TN (United States)

1993-07-01

116

A Bayesian Markov geostatistical model for estimation of hydrogeological properties  

SciTech Connect

A geostatistical methodology based on Markov-chain analysis and Bayesian statistics was developed for probability estimations of hydrogeological and geological properties in the siting process of a nuclear waste repository. The probability estimates have practical use in decision-making on issues such as siting, investigation programs, and construction design. The methodology is nonparametric which makes it possible to handle information that does not exhibit standard statistical distributions, as is often the case for classified information. Data do not need to meet the requirements on additivity and normality as with the geostatistical methods based on regionalized variable theory, e.g., kriging. The methodology also has a formal way for incorporating professional judgments through the use of Bayesian statistics, which allows for updating of prior estimates to posterior probabilities each time new information becomes available. A Bayesian Markov Geostatistical Model (BayMar) software was developed for implementation of the methodology in two and three dimensions. This paper gives (1) a theoretical description of the Bayesian Markov Geostatistical Model; (2) a short description of the BayMar software; and (3) an example of application of the model for estimating the suitability for repository establishment with respect to the three parameters of lithology, hydraulic conductivity, and rock quality designation index (RQD) at 400--500 meters below ground surface in an area around the Aespoe Hard Rock Laboratory in southeastern Sweden.

Rosen, L.; Gustafson, G. [Chalmers Univ. of Technology, Gothenburg (Sweden). Dept. of Geology

1996-09-01

117

The Research of Hydrogeological Precursors of Earthquakes in Armenia  

NASA Astrophysics Data System (ADS)

The observations of hydro-geological regime of underground waters in observed boreholes began in Armenia in 1986. Now observations are being carried out by National Seismic Service. For a long time observations were done by studying several parameters (debit, temperature, chemical and gas composition) in several deposits of carbon mineral waters of Armenia. The interpretation of materials shows that a number of strong and medium-strength earthquakes are accompanied by anomalous changes of underground water level. 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 epicentral distance. The majority of precursors are registered up to the 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 that this or that borehole reaches; by the increase of this angle the deformation of the zone of the fault during the preparation of earthquakes is stronger, than in case of small angles.

Hakhverdyan, L.; Pashayan, R.

2013-12-01

118

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

SciTech Connect

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.

Cohen, A.J.B.

1993-10-01

119

Analysis of Hydrogeologic Conceptual Model and Parameter Uncertainty  

SciTech Connect

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.

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

2003-06-24

120

Quantitative methods to direct exploration based on hydrogeologic information  

USGS Publications Warehouse

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.

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

2006-01-01

121

Hydrogeologic reconnaissance of the San Miguel River basin, southwestern Colorado  

USGS Publications Warehouse

The San Miguel River Basin encompasses 4,130 square kilometers of which about two-thirds is in the southeastern part of the Paradox Basin. The Paradox Basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Evaporite beds of mostly salt are both overlain and underlain by confining beds. Aquifers are present above and below the confining-bed sequence. The principal element of ground-water outflow from the upper aquifer is flow to the San Miguel River and its tributaries; this averages about 90 million cubic meters per year. A water budget for the lower aquifer has only two equal, unestimated elements, subsurface outflow and recharge from precipitation. The aquifers are generally isolated from the evaporite beds by the bounding confining beds; as a result, most ground water has little if any contact with the evaporites. No brines have been sampled and no brine discharges have been identified in the basin. Salt water has been reported for petroleum-exploration wells, but no active salt solution has been identified. (USGS)

Ackerman, D. J.; Rush, F. E.

1984-01-01

122

Hydrogeological study of an anti-tank range.  

PubMed

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

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

2008-01-01

123

Hydrogeologic controls on water quality at a university dairy farm  

NASA Astrophysics Data System (ADS)

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 by black shale or limestone. Several active sinkholes are present in the portion of the fields underlain by limestone. The fields are bounded on two sides by the Little River, a popular recreational river, and on the third side by Ellejoy Creek, which is on the state’s 303(d) list for impairment by nutrients, sediment and fecal microorganisms, which are derived from upstream agricultural and rural residential development. These fields will be fertilized with treated dairy wastes and are the main area of concern for offsite migration of contaminants through groundwater, drainage ditches and (eventually) a tile drain system. A secondary area of concern is the dairy waste treatment pond which is located, along with the dairy barns, on the upland portion of the site, which is underlain by 1-2 m of clay-rich residual soils developed on fractured shale bedrock. Long term water quality monitoring of runnoff, streams, drainage ditches and groundwater is planned, with the intent of measuring environmental impact of dairy operations and testing the effectiveness of different management practises.

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

2010-12-01

124

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

USGS Publications Warehouse

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 Tuolumne River east of Modesto, a feature that may have important implications for ground-water flow and transport in the region. Although extensive work has been done by earlier investigators to define the structure of the Modesto area aquifer system, this report has resulted in some modification to the lateral extent of the Corcoran Clay and the regional dip of the Mehrten Formation. Well logs in the database indicating the presence of the Corcoran Clay were used to revise the eastern extent of the Corcoran Clay, which lies approximately parallel to the axis of valley. The Mehrten Formation is distinguished in the well-log database by its characteristic black sands consisting of predominantly andesitic fragments. Black sands in wells listed in the database indicate that the formation may lie as shallow as 120 meters (400 feet) below land surface under Modesto, approximately 90 meters (300 feet) shallower than previously thought. The alluvial aquifer system in the Modesto area comprises an unconfined to semiconfined aquifer above and east of the Corcoran Clay confining unit and a confined aquifer beneath the Corcoran Clay. The unconfined aquifer is composed of alluvial sediments of the Modesto, Riverbank, and upper Turlock Lake formations. The unconfined aquifer east of the Corcoran Clay becomes semiconfined with depth due to the numerous discontinuous clay lenses and extensive paleosols throughout the aquifer thickness. The confined aquifer is composed primarily of alluvial sediments of the Turlock Lake and upper Mehrten Formations, extending from beneath the Corcoran Clay to the base of fresh water. Ground water in the unconfined to semiconfined aquifer flows to the west and southwest. The primary source of present-day recharge is percolating excess irrigation water. The primary ground-water discharge is extensive ground-water pumping in the unconfined to semiconfined aquifer, imposing a significant component of vertical flo

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

2004-01-01

125

Hydrogeologic Framework of the Salt Basin, New Mexico and Texas  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

126

Hydrogeologic Controls on Lake Level at Mountain Lake, Virginia  

NASA Astrophysics Data System (ADS)

Mountain Lake in Giles County, Virginia has a documented history of severe natural lake-level changes involving groundwater seepage that extend over the past 4200 years. Featured in the 1986 movie Dirty Dancing, the natural lake dried up completely in September 2008 and levels have not yet recovered. A hydrogeologic investigation was undertaken in an effort to determine the factors influencing lake level changes. A daily water balance, dipole-dipole electrical resistivity surveying, well logging and chemical sampling have shed light on: 1) the influence of a fault not previously discussed in literature regarding the lake, 2) the seasonal response to precipitation of a forested first-order drainage system in fractured rock, and 3) the possibility of flow pathways related to karst features. Geologic controls on lake level were investigated using several techniques. Geophysical surveys using dipole-dipole resistivity located possible subsurface flowpaths both to and from the lake. Well logs, lineament analysis, and joint sampling were used to assess structural controls on lake hydrology. Major ions were sampled at wells, springs, streams, and the lake to evaluate possible mixing of different sources of water in the lake. Groundwater levels were monitored for correlation to lake levels, rainfall events, and possible seismic effects. The hydrology of the lake was quantified with a water balance on a daily time step. Results from the water balance indicate steady net drainage and significant recharge when vegetation is dormant, particularly during rain-on-snow melt events. The resistivity survey reveals discrete areas that represent flow pathways from the lake, as well as flowpaths to springs upgradient of the lake located in the vicinity of the fault. The survey also suggests that some flowpaths may originate outside of the topographic watershed of the lake. Chemical evidence indicates karst may underlie the lakebed. Historical data suggest that artificial intervention to mitigate seepage would be required for lake level recovery in the near future.

Roningen, J. M.; Burbey, T. J.

2011-12-01

127

Preliminary evaluation of the hydrogeologic system in Owens Valley, California  

USGS Publications Warehouse

A preliminary, two-layer, steady-state, groundwater flow model was used to evaluate present data and hydrologic concepts of Owens Valley, California. Simulations of the groundwater system indicate that areas where water levels are most affected by changes in recharge and discharge are near toes of alluvial fans and along the edge of permeable volcanic deposits. Sensitivity analysis for each model parameter shows that steady state simulations are most sensitive to uncertainties in evapotranspiration rates. Tungsten Hills, Poverty Hills, and Alabama Hills were found to act as virtually impermeable barriers to groundwater flow. Accurate simulation of the groundwater system between Bishop and Lone Pine appears to be possible without simulating the groundwater system in Round Valley, near Owens Lake, or in aquifer materials more than 1,000 ft below land surface. Although vast amounts of geologic and hydrologic data have been collected for Owens Valley, many parts of the hydrogeologic system have not been defined with sufficient detail to answer present water management questions. Location and extent of geologic materials that impede the vertical movement of water are poorly documented. The likely range of aquifer characteristics, except vertical hydraulic conductivity, is well known, but spatial distribution of these characteristics is not well documented. A set of consistent water budgets is needed, including one for surface water, groundwater, and the entire valley. The largest component of previous water budgets (evapotranspiration) is largely unverified. More definitive estimates of local gains and losses for Owens River are needed. Although groundwater pumpage from each well is measured, the quantity of withdrawal from different zones of permeable material has not been defined. (USGS)

Danskin, W. R.

1988-01-01

128

Hydrogeology of Regional Valley Fill Aquifers with Mountain System Recharge  

NASA Astrophysics Data System (ADS)

Groundwater in the North Okanagan was investigated using an integrated physical, geochemical and numerical approach. The North Okanagan Groundwater Characterization and Assessment (NOGWCA) project began with an investigation of the geology and hydrostratigraphy of the North Okanagan region. The Deep Creek and Fortune Creek watersheds were found to contain multiple valley-fill aquifers which are recharged via mountain system recharge (MSR) and direct recharge to unconfined aquifers in the valley bottom. Detailed hydrometric data indicates groundwater recharge within the alluvial fan of Fortune Creek, and discharge to surface water in the lower reaches of Deep Creek. Valley side recharge from the adjacent mountains generates artesian conditions in the valley center. Physical hydrogeological measurements and groundwater and surface water geochemistry were used to determine the overall groundwater flow regime, inter-aquifer exchange and surface-water groundwater interactions. Conservative elements and deuterium/oxygen isotopes were used in a mixing cell model (MCM) approach to assess groundwater flow between aquifers. Efforts to accurately quantify and understand MSR are hampered by sparse data on the geochemical character of bedrock aquifers. Watershed scale recharge estimates and water balances were derived from a regional integrated climate dataset coupled to FEFLOW simulations. The first stage modeled steady state conditions within the main valley center aquifer. Integrated surface water and groundwater modeling is to be carried out in the future. The groundwater flow modeling will contribute to subsequent water management decisions at the watershed scale. Climate change and economic change scenarios will be considered in the integrated surface water and groundwater modeling.

Ping, J.; Nichol, C.; Wei, A.

2009-05-01

129

Hydrogeology of Palm Valley, central Australia; a Pleistocene flora refuge?  

NASA Astrophysics Data System (ADS)

The Palm Valley Oasis (Finke Gorge National Park) in arid central Australia is characterised by large stands of red cabbage palm trees ( Livistona mariae). How these unique plants, over 1000 km away from nearest relatives in the tropical parts of northern Australia persist, has long fascinated visitors. The hydrogeology of this area helps explain this phenomenon. Stable isotope (? 2H, ? 8O) analyses shows groundwater to have a uniform composition that plots on or near a local meteoric water line. Carbon-14 results are observed to vary throughout this aquifer from effectively dead (<4%) to 87% modern carbon. Ratios of chlorine-36 to chloride range from 130 to 290×10 -1536Cl/Cl. In this region atmospheric 36Cl/Cl ratio is around 300×10 -15. Thus an age range of around 300 ka is indicated if, as is apparent radioactive decay is the only significant cause of 36Cl/Cl variation within the aquifer. The classic homogenous aquifer with varying surface topography flow model is the simplest conceptual model that need be invoked to explain these data. Complexities, associated with local topography flow cells superimposed on the regional gradient, may mean groundwater with markedly different flow path lengths has been sampled. This potential flow path complexity, which is also evidenced by slight variation in groundwater cation ratios, can account for the distribution of isotope age data throughout the aquifer. Given the likely very slow travel times indicated by this aquifer's hydraulic properties, age differences of the magnitude indicated from chlorine-36 data are feasible. The likely slow travel times (>100 ka) along some flow paths indicate groundwater discharge would endure through arid phases associated with Quaternary climate oscillations. Such a flow system can explain the persistence of this population of Palms and also highlight the possibility that Palm Valley has acted as a flora refuge since at least the mid Pleistocene.

Wischusen, John D. H.; Fifield, L. Keith; Cresswell, Richard G.

2004-06-01

130

A new hydrogeologic model to predict anthropogenic uplift of Venice  

NASA Astrophysics Data System (ADS)

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 ?z 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, ?z may be reduced to as much as 0.1 × 10-5 throughout the city.

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

2011-12-01

131

Hydrogeology and potential water-resource targets in Mauritania, Africa  

NASA Astrophysics Data System (ADS)

A hydrogeologic study is conducted in support of mineral-resource assessment activities in Mauritania, Africa. Airborne magnetic depth estimates reveal two primary ground-water basins: the porous Continental Terminal coastal system (fill deposits); and the interior, fractured interior Taoudeni Basin system (carbonate, clastic, metasedimentary, and metavolcanic rocks). In the Continental Terminal basin, there is uniform vertical recharge and localized discharge that is coincident with ground-water pumping at Nouakchott. This pumping center induces eastward flow of ground water from the Atlantic Ocean resulting in a salinity gradient that diminishes quality over 100 km. Ground water also flows southward into the basin from Western Sahara. By contrast, an interbasin exchange occurs as fresh ground-water flows westward from the Taoudeni basin. In the Taoudeni basin, zones of local recharge occur in three areas: northwest at the edge of the Réguibat Shield, at the city of Tidjikdja, and to the south overlying Tillites. Ground water also flows across country boundaries: northward into Western Sahara and westward into Mali. At the southern country boundary, the Sengal River serves as both a source and sink of fresh ground water to these two basins. Using a geographical information system, 13 hydrostratigraphic units are identified based on lateral extent and distinct hydrologic properties for future groundwater model development. Combining this information with drilling productivity, water quality, and geophysical interpretations (fracturing and absence of subsurface dikes) identified 3 potential water-resource development targets: sedimentary rocks of Cambrian-Ordovician age, sedimentary rocks of Neoproterozoic age, and carbonate rocks of middle Mesoproterozoic age.

Horton, J. D.; Friedel, M. J.; Finn, C.

2012-12-01

132

Research of Hydro-Geological Precursors of Earthquakes in Armenia  

NASA Astrophysics Data System (ADS)

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

Pashayan, R.

2007-12-01

133

Hydrogeologic Framework of the Yakima River Basin Aquifer System, Washington  

USGS Publications Warehouse

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 the CRBG and basin-fill units and that the source of surface and groundwater is derived from atmospheric precipitation. The concentrations of dissolved methane were larger than could be attributable to atmospheric sources in more than 80 percent of wells with measured methane concentrations. The concentrations of the stable isotope of carbon-13 of methane were indicative of a thermogenic source of methane. Most of the occurrences of methane were at locations several miles distant from mapped structural fault features, suggesting the upward vertical movement of thermogenic methane from the underlying bedrock may be more widespread than previously assumed or there may be a more general occurrence of unmapped (buried) fault structures. Carbon and tritium isotope data and the concentrations of dissolved constituents indicate a complex groundwater flow system with multiple contributing zones to groundwater wells and relative groundwater residence time on the order of a few tens to many thousands of years. Potential mean annual recharge for water years 1950-2003 was estimated to be about 15.6 in. or 7,149 ft3/s (5.2 million acre-ft) and includes affects of human activities such as irrigation of croplands. If there had been no human activities (predevelopment conditions) during that time period, estimated recharge would have been about 11.9 in. or 5,450 ft3/s (3.9 million acre-ft). Estimated mean annual recharge ranges from virtually zero in the dry parts of the lower basin to more than 100 in. in the humid uplands, where annual precipitation is more than 120 in. Groundwater in the different hydrogeologic units occurs under perched, unconfined, semiconfined, and confined conditions. Groundwater moves from topographic highs in the uplands to topographic low areas along the streams. The flow system in the basin-fill units is compartmentalized due to topography and geologic structure. The flow system also is compartmentalized for the CRBG units but not to as large

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

2009-01-01

134

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)

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 groundwater numerical simulation. Modelling validation has been performed through the matching between the experimental and calculated discharge values, between the piezometric field and topography (the calculated piezometric field always resulting above the spring altitude and below the hydrographical network without base flow) and between the piezometric field and altitude of aquiclude that limits the aquifer. If one of these three conditions is not verified the model is not realistic and the hypotheses must be rejected. In two cases the modelling results suggested a revision of the assumptions and only through a depth structural analysis has been possible to estimate the real role of Vettore Mont normal fault and recognize a secondary fault that divide an aquifer. In conclusion this study represents an example of necessary combination between structural and hydrogeological analyses and underlines the importance of information exchange and/or cooperation to allow the 3-D reconstruction of hydrogeological setting.

Tarragoni, C.

2012-04-01

135

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

SciTech Connect

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.

Weaver, B. [American Geophysical Union, Washington, DC (United States)

1994-12-31

136

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

SciTech Connect

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.

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

1992-03-31

137

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

SciTech Connect

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.

Brahana, J.V. (Geological Survey, Fayetteville, AR (United States))

1993-03-01

138

Evaluation of Hydrochemical and Hydrogeological Characteristics of Riverbank Filtration Aquifer  

NASA Astrophysics Data System (ADS)

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. The research results showed the minimum three times of repetitive change of sedimentation environment. Thick clay layers in the aquifer are preventing the inflow of river water to the production wells. In addition, the aquifer underneath the clay layer is under reducing condition, which might cause the high concentration of reduced iron and manganese. Manganese in the sediments was in the form of easily reducible and exchangeable phase but iron were present dominantly in the form of reducible and carbonate phase from the modified sequential analysis. This indicates the different reactivity of manganese and iron for redox state. From the above results, manganese was extracted under weakly reduced condition but iron was extracted strong reducing condition.

Ko, K.; Suk, H.

2009-12-01

139

A Task-oriented Approach for Hydrogeological Site Characterization  

NASA Astrophysics Data System (ADS)

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 completed. Accept/reject regions for hypothesis testing can be determined based on goals determined by regulations or by agreement between the stakeholders. Hypothesis-driven design could help in minimizing the chances of making wrong decision (false positives or false negatives) with regard to the site-specific goals.

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

2010-12-01

140

Using Optic Pressure Measurements in Hydrogeology - New Experimental Possibilities  

NASA Astrophysics Data System (ADS)

Typically, hydrogeological investigations require temporally resolved measurements of pressure, e.g. as hydraulic head, drawdown or water level. For this purpose, state-of-the-art pressure transducer systems are used which have a design size of at least 14 mm in diameter, which therefore limits their application to well systems of 1-inch (25.4 mm) and more. In this work, we present an optic pressure transducer system that has a design size of 5 mm in diameter and due to its inertial free response it is able to provide data with a temporal resolution of more than 100 Hz. Also, these transducers have performed with pressure change resolution of 1mm or less. They are inserted in small-diameter tubing (e.g., 0.25-inch or 6.35-mm ID) to depths below the water level that are not much greater than maximum drawdown expected in a given set of tests. With such shallow submergence in tubing connected to open wells or Direct Push tubes, or to isolated zones within wells (i.e., transducers do not need to be located in actual zones of interest), two operational benefits are gained: (1) the dynamic range setting can be small (e.g., 2 psi or 5 psi) so the sensitivity can be kept high and (2) placement and removal of transducers is fast and easy. Both - design size as well as temporal and pressure resolution - open up several new possibilities in terms of experiments and measurements which cannot be achieved by current state-of-the-art transducers. In this context, we present the principle of optic pressure measurements and show two application examples which are related to hydraulic tomography: The first example shows the application of the optic pressure transducer system with a well-packer-system for highly resolved hydraulic measurements in tomographic arrays. This example shows especially the advantage of optic pressure measurement in terms of temporal resolutions but also the high spatial resolution that can even be achieved in larger well bores. The second example focuses on the small design size that allows innovative applications in combination with minimal-invasive, easy-to-deploy installations based on Direct Push Technology. In this example, it is shown that even with small diameter installations a large vertical but also lateral spatial resolution of pressure measurements can be achieved. Besides these two examples, the experimental possibilities that are given by optic pressure measurements are manifold and are waiting to be explored.

Leven, C.; Barrash, W.; Cardiff, M. A.

2012-12-01

141

Application of the self-potential method in hydrogeology  

NASA Astrophysics Data System (ADS)

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 electrical resistivity measurements. The inferred hydrologic information was then used to comment on the stability of the dam with respect to seepage erosion. SP data revealed that seepage is concentrated in the area adjacent to suspected fine sediment output, suggesting that seepage erosion likely occurred at some time during the life of the dam.

Moore, Jeffrey Ralston

142

Hydrogeology of a Transboundary Sandstone Aquifer, Quebec - New York  

NASA Astrophysics Data System (ADS)

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. During aquifer tests, significant drawdown was observed in observation wells at distances of more than a kilometer from pumped wells, whereas nearby nested piezometers screened in different bedding planes showed markedly less drawdown. Groundwater users that exploit the same permeable fracture zones are thus highly interdependent and vulnerable to their respective pumping rates. On the other hand, the more densely fractured upper unit apparently has more dispersed groundwater flow. Numerical modeling of the regional groundwater flow substantiates these differences. In order to match measured hydraulic heads, the calibrated vertical anisotropy of the lower unit was in average 100 times higher than that of the upper unit. Simulated capture areas of production wells display elongated forms commonly crossing the Quebec-New York border. Simulated scenarios are the first step towards the joint management of the groundwater resources.

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

2005-12-01

143

Hydrogeochemistry of volcanic hydrogeology based on cluster analysis of Mount Ciremai, West Java, Indonesia  

Microsoft Academic Search

Hydrogeochemical analysis has been conducted on 119 spring locations to portray volcanic hydrogeological system of Mount Ciremai, West Java, Indonesia. Cluster analysis on 14 parameters has extracted three clusters. Cluster 1 (112 springs) is distinguished by normal temperatures, low TDS, EC, and high bicarbonate concentrations. Cluster 2 (five springs) has moderately high temperature, TDS, EC, and high concentration of chloride.

Dasapta Erwin Irawan; Deny Juanda Puradimaja; Sudarto Notosiswoyo; Prihadi Soemintadiredja

2009-01-01

144

Integrated hydrogeological and geophysical study of depression-focused groundwater recharge in the Canadian prairies  

Microsoft Academic Search

In the northern prairie region of North America, numerous seasonal wetlands and ephemeral ponds form as snowmelt water is trapped in small topographical depressions. A detailed hydrogeological investigation is combined with electrical resistivity imaging (ERI) to evaluate the roles of the wetlands and ponds on depression-focused groundwater recharge at the St. Denis National Wildlife Area in Saskatchewan, Canada. The analysis

Susann Berthold; Laurence R. Bentley; Masaki Hayashi

2004-01-01

145

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...

146

Linking Physical and Numerical Modelling in Hydrogeology using Sand Tank Experiments and COMSOL Multiphysics  

Microsoft Academic Search

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, boundary conditions, and coupling processes, and numerical modelling exercises are also

Kamini Singha; Steven P. Loheide II

2011-01-01

147

Hydrogeologic Framework of Antelope Valley and Bedell Flat, Washoe County, West-Central Nevada.  

National Technical Information Service (NTIS)

The purpose of this report is to describe the hydrogeologic framework of the Antelope Valley and Bedell Flat Hydrographic Areas. This framework is defined by: (1) the rocks and deposits that transmit ground water or impede its movement, and (2) the combin...

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

2001-01-01

148

Advances in research on earthquake fluids hydrogeology in China: a review  

NASA Astrophysics Data System (ADS)

Monitoring of subsurface fluid (underground fluid) is an important part of efforts for earthquake prediction in China. The nationwide network, which monitors groundwater level, water temperature, and radon and mercury in groundwater, has been constructed in the last decades. Large amounts of abnormal fluid changes before and after major earthquakes have been recorded, providing precious data for research in earthquake sciences. Many studies have been done in earthquake fluid hydrogeology in order to probe the nature of the earthquake. Much progress in earthquake fluid hydrogeology has been made in the last decades. The paper provides a review of the advances in research on earthquake fluid hydrogeology over the last 40 years in China. It deals with the following five aspects: (1) an introduction to the development history of monitoring networks construction; (2) cases of different subsurface fluid changes recorded before some major earthquakes which occurred in the last decades; (3) characteristics of subsurface fluid changes following major earthquakes; (4) mechanism of subsurface fluid changes before and following earthquakes; (5) application of earthquake fluids in the hydrogeology field.

Shi, Zheming; Wang, Guangcai; Liu, Chenglong

2013-12-01

149

Prime candidate sites for astrobiological exploration through the hydrogeological history of Mars  

Microsoft Academic Search

The hydrogeological evolution of Mars has been proposed to be dominated by the development of the Tharsis Magmatic Complex through superplume activity, with related magmatic-pulse-driven flood inundations that directly influence the shaping of the northern plains, the evolution of the atmosphere and climate, and subsurface and surface water processes. On the other hand, several possible biological models and terrestrial analogues

Alberto G. Fairén; James M. Dohm; Esther R. Uceda; Alexis P. Rodríguez; Victor R. Baker; David Fernández-Remolar; Dirk Schulze-Makuch; Ricardo Amils

2005-01-01

150

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...

151

Analysis of natural groundwater level variations for hydrogeologic conceptualization, Hanford Site, Washington  

Microsoft Academic Search

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

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

1989-01-01

152

Hydrogeological factors affecting the multiple plumes of chlorinated contaminants in an industrial complex, Wonju, Korea  

Microsoft Academic Search

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

J. Yang; D. Kaown; H. Lee; K. Lee

2010-01-01

153

Hydrogeologic investigation at a waste disposal site in northern New Jersey  

Microsoft Academic Search

A hydrogeologic investigation was performed near a waste disposal site in northern New Jersey to determine the adverse effects of past waste disposal activities on local groundwater. Major elements of the investigation included drilling, well installations, aquifer testing, and groundwater sampling. Two groundwater flow systems within glacial drift deposits and two within bedrock were identified and characterized during the study.

Orient

1990-01-01

154

Radar facies of unconsolidated sediments in The Netherlands: A radar stratigraphy interpretation method for hydrogeology  

Microsoft Academic Search

Since 1990, The Netherlands Institute of Applied Geoscience TNO has been carrying out ground penetrating radar (GPR) measurements to assess the potential for imaging and characterising different hydrogeological targets in more than 30 pilot areas in The Netherlands. The experience gained by processing this large amount of radar data has enabled reflection patterns characteristic of different depositional sedimentary environments to

R. A. van Overmeeren

1998-01-01

155

Theoretical model of the hydrogeology of a pull-apart basin  

SciTech Connect

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.

White, P.M.

1991-03-01

156

To be or not to be multi-Gaussian? A reflection on stochastic hydrogeology  

Microsoft Academic Search

The multivariate Gaussian random function model is commonly used in stochastic hydrogeology to model spatial variability of log-conductivity. The multi-Gaussian model is attractive because it is fully characterized by an expected value and a covariance function or matrix, hence its mathematical simplicity and easy inference. Field data may support a Gaussian univariate distribution for log hydraulic conductivity, but, in general,

J. Jaime Gómez-Hernández; Xian-Huan Wen

1998-01-01

157

An integrated geophysical investigation of the hydrogeology of an anisotropic unconfined aquifer  

Microsoft Academic Search

The predictive capability of groundwater flow models is frequently restricted by insufficient characterisation of a typically heterogeneous and anisotropic subsurface. Trace levels of volatile organic compounds have been detected at municipal water supply wells in Gray, Maine. Groundwater flow modelling based on available hydrogeologic data defines a dominant W–E transport vector that is inconsistent with the apparent N40E transport of

S. K Sandberg; L. D Slater; R Versteeg

2002-01-01

158

Using multiple geochemical tracers to characterize the hydrogeology of the submarine spring off Crescent Beach, Florida  

Microsoft Academic Search

A spectacular submarine spring is located about 4 km east of Crescent Beach, FL, in the Atlantic Ocean. The single vent feature of Crescent Beach Spring provides a unique opportunity to examine onshore–offshore hydrogeologic processes, as well as point source submarine ground water discharge. The Floridan aquifer system in northeastern Florida consists of Tertiary interspersed limestone and dolomite strata. Impermeable

P. W Swarzenski; C. D Reich; R. M Spechler; J. L Kindinger; W. S Moore

2001-01-01

159

Hydrogeological insights in antiquity as indicated by Canaanite and Israelite water systems  

Microsoft Academic Search

Hazor, one of the largest fortified city during the Israelite (Iron-Age) period, encompasses a gigantic underground water system within its perimeter, supplying water to thousands of its inhabitants. It is considered as the ultimate example that Iron-Age engineers had mastered the concept of regional groundwater table. However, evaluating the hydrogeological conditions and the degree of success in finding water in

Ram Weinberger; Amihai Sneh; Eyal Shalev

2008-01-01

160

Hydrogeological and numerical analysis of CO 2 disposal in deep aquifers in the Alberta sedimentary basin  

Microsoft Academic Search

For landlocked large sources of CO2, the best approaches for reducing CO2 emissions into the atmosphere are its utilization and deep disposal into deep sedimentary aquifers or depleted oil and gas reservoirs. A number of coal-based power plants (total capacity of more than 4000 MW) are located near Lake Wabamun in central Alberta, Canada. A hydrogeological study of the sedimentary

David H.-S. Law; Stefan Bachu

1996-01-01

161

Hydrogeological Characteristics of a Karst Mountainous Catchment in the Northwest of Vietnam  

Microsoft Academic Search

This paper presents a preliminary assessment of the hydrogeological characteristics of a karst mountainous catchment, the Suoi Muoi River catchment, in the northwest of Vietnam. The catchment is loca ted at 600 -700 m a.s.l. and covers an area of 284 km. Exposed limestone occupies 32% of the total catchment area. Various types of assessments have been carried out, including

V. T. TAM; T. M. N. VU; O. BATELAAN

162

An innovative hydrogeologic setting for disposal of low-level radioactive wastes  

Microsoft Academic Search

A natural unique hydrogeological setting favorable for safe and economical disposal of low-level radioactive wastes occurs in the flat hinterland of southeastern North Carolina. The uniqueness results partly from the absence of vertical and horizontal groundwater gradients, representing a nonflow, or null, zone. The null setting is localized to key horizons 30 to 75 feet below land surface and to

Harry E. Legrand

1989-01-01

163

Quantitative Hydrogeological Framework Interpretations from Modeling Helicopter Electromagnetic Survey Data, Nebraska Panhandle  

NASA Astrophysics Data System (ADS)

The need for allocation and management of water resources within the state of Nebraska has created a demand for innovative approaches to data collection for development of hydrogeologic frameworks to be used for 2D and 3D groundwater models. In 2008, the USGS in cooperation with the North Platte Natural Resources District, the South Platte Natural Resources District, and the University of Nebraska Conservation and Survey Division began using frequency domain helicopter electromagnetic (HEM) surveys to map selected sections of the Nebraska Panhandle. The surveys took place in selected sections of the North Platte River valley, Lodgepole Creek, and portions of the adjacent tablelands. The objective of the surveys is to map the aquifers of the area to improve understanding of the groundwater-surface water relationships and develop better hydrogeologic frameworks used in making more accurate 3D groundwater models of the area. For the HEM method to have an impact in a groundwater model at the basin scale, hydrostratigraphic units need to have detectable physical property (electrical resistivity) contrasts. When these contrasts exist within the study area and they are detectable from an airborne platform, large areas can be surveyed to rapidly generate 2D and 3D maps and models of 3D hydrogeologic features. To make the geophysical data useful to multidimensional groundwater models, numerical inversion is necessary to produce a depth-dependent physical property data set reflecting hydrogeologic features. These maps and depth images of electrical resistivity in themselves are not useful for the hydrogeologist. They need to be turned into maps and depth images of the hydrostratigraphic units and hydrogeologic features. Through a process of numerical imaging, inversion, sensitivity analysis, geological ground truthing (boreholes), geological interpretation, hydrogeologic features are characterized. Resistivity depth sections produced from this process are used to pick contacts between hydrostratigraphic units. This provides a 3D image of the hydrostratigraphic units interpreted from the electrical resistivity derived from the HEM tied to statistical confidences on the picked contacts. The interpreted 2D and 3D data provides the groundwater modeler with a high-resolution hydrogeologic framework and a solid understanding of the uncertainty in the information it provides. This interpretation facilitates more informed modeling decisions, more accurate groundwater models, and development of more effective water-resources management strategies.

Abraham, J. D.; Ball, L. B.; Bedrosian, P. A.; Cannia, J. C.; Deszcz-Pan, M.; Minsley, B. J.; Peterson, S. M.; Smith, B. D.

2009-12-01

164

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)

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 and expert judgement are used to extrapolate the DFN model over the regional domain. For regional-scale flow simulations, 3D stochastic realisations of the DFN model are converted, using flux-based upscaling techniques, to an equivalent continuum porous medium (ECPM) model that includes density driven flow and rock matrix diffusion. Testing of the model parameterisation is achieved by simulating hydraulic interference tests and transport of natural chemical tracers. The tracers include major elemental ions, stable isotopes and tritium measured in groundwater samples from boreholes. The hydrochemistry of these coastal sites has been strongly affected by palaeo-hydrogeolgical processes resulting from glacial melting, land-rise and marine transgressions following the last ice age. Therefore, 3D transient coupled groundwater flow and solute transport simulations are used to model these processes with the purpose of calibrating and testing the hydrogeological models against the present-day hydrochemistry data. The site-descriptive model is subsequently used for engineering design, safety assessment and environmental impact assessment studies. In the safety assessment application, an explicit repository scale DFN model is nested within the regional scale ECPM model and used to assess flow rates in deposition holes and flow paths, including flow-related transport properties along the groundwater paths, from the deposition holes to the biosphere Keywords: Discrete fracture networks, Hydrogeology, Hydrochemistry, 3D Groundwater flow, modelling

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

2006-12-01

165

Reconnaissance of the Hydrogeology of Ta'u, American Samoa  

USGS Publications Warehouse

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 landfill itself (history, construction, contents, water chemistry), surface-water flow directions, spatial distribution of ground-water levels, and the quality of water in nearby wells. Monitoring water levels and chemistry in one or more monitoring wells between the landfill and existing or proposed wells can provide a means to detect movement of contaminants before they reach production wells. Steps that can be implemented in the short term include analyzing water in the landfill and monitoring of water chemistry and water levels in all existing and new production wells. Placing future wells farther inland may mitigate saltwater intrusion problems, but the steep topography of Ta'u limits the feasibility of this approach. Alternative solutions include distributing ground-water withdrawal among several shallow-penetrating, low-yield wells.

Izuka, Scot K.

2005-01-01

166

An Assessment of Current Concepts for Hydrogeological Site Characterization, and Alternatives  

NASA Astrophysics Data System (ADS)

Characterization of the geological and hydrogeological conditions of contaminated sites is a critical element of risk management. Characterization includes data acquisition and interpretation that intends to provide the analytical tools needed for decision making related to transport of contaminants and for remediation. Despite many years of experience, site characterization is still not as well understood and regulated as it should be. The chasm between some of the newer concepts developed by researchers on the one hand, and the technology used in the field by service providers on the other, has never been wider than it is today. Consequently, questions that should be addressed using well-documented rational tools may continue to be addressed based on intuition and experience. Instead of coming up with defensible action plans and implementing them rapidly, such action plans are often a source of contention and end up in the courts. This paper evaluates concepts often used in the practice of hydrogeological site characterization, and tries to distinguish between myth and reality. It explores concepts such as: 1. Accurate descriptions of geological and hydrogeological conditions are attainable; 2. Sound planning and action plans in response to accidents require a large amount of data; 3. Investing in site characterization is a sound investment; 4. Experience gained in decontamination and decommissioning in the field is a sound basis for planning future efforts; 5. If you do not find the contaminants, they do not exist; 6. Numerical models for flow and transport processes in the subsurface are beneficial; 7. Current regulations in the area of hydrogeology are helpful. These concepts, while often invoked in applications, are often wrong and misleading or applied incorrectly, and reflect the many ambiguities prevailing in this area. This paper explores the issues raised above in detail. It also presents the elements of a consistent approach for site characterization, and demonstrates it through a case study that involves uncertainty in the hydrogeology as well as in human physiology.

Rubin, Y.; Barros, F.

2007-05-01

167

Digital Surfaces and Thicknesses of Selected Hydrogeologic Units within the Mississippi Embayment Regional Aquifer Study (MERAS)  

USGS Publications Warehouse

Digital surfaces of selected Tertiary and younger age hydrogeologic units within the Mississippi embayment aquifer system were created using more than 2,600 geophysical logs for an area that covers approximately 70,000 square miles and encompasses parts of eight states. The digital surfaces were developed to define and display the hydrogeologic framework for the Mississippi Embayment Regional Aquifer Study (MERAS). The digital surfaces also provide a foundation of the selected hydrogeologic units for development of a steady-state and transient regional ground-water flow model of the Mississippi embayment aquifer system from the top of the Midway confining unit upwards to land surface. The ground-water flow model is under development as part of the U.S. Geological Survey Ground-Water Resources Program. Using a Geographic Information System, nine digital surfaces of the tops of selected hydrogeologic units were created using the Australian National University Digital Elevation Model method as an interpolation scheme. Thickness maps also were constructed using the Geographic Information System by calculating the difference between the altitude of the interpreted base of an overlying unit and the altitude of the interpreted top of an underlying unit. In general, the highest hydrogeologic unit altitudes are located along the eastern edge of the study area in the outcrop, and the lowest altitudes, in general, are located along the southern edge of the study area along the axis of the embayment. The Mississippi River Valley alluvial aquifer and the lower Claiborne aquifer are the thinnest aquifers of importance in the study area; the thickest aquifer of importance is the middle Claiborne aquifer.

Hart, Rheannon M.; Clark, Brian R.; Bolyard, Susan E.

2008-01-01

168

Hydrogeological properties of bank storage area in Changwon city, Korea  

NASA Astrophysics Data System (ADS)

Bank filtrated water has been used in developed countries such as United States, France, Germany, Austria, Nederland and so on. In Korea, most of the drinking water is provided from the surface water. However, drinking water acquisition is becoming difficult due to the degradation of surface water quality. In special, the quality of drinking water source is much lower in downstream area than in upstream area. Thus, the use of bank filtrated water is getting attracted by central and local governments in Korea. The bank filtrated water was surveyed in the areas of Yeongsan river, Nakdong river, Geum river and Han river. Up to present, however, the downstream areas of Nakdong river are most suitable places to apply the bank filtration system. This study investigates hydrogeological characteristics of bank-storage area located in Daesan- Myeon, Changwon city, adjacent the downstream of Nakdong river. Changwon city is the capital city of Gyeongsangnam-Do province. Changwon city uses water derived from Nakdong river as municipal water. However, the quantity and quality of the river water are gradually decreased. Thus, Changwon city developed two sites of bank filtration system in Daesan-myeon and Buk-myeon. Pumping rate is 2,000m3/day at present and will be increased to 60,000m3/day in Daesan-myeon site at the end of the first stage of the project. For the study, we conducted pumping tests four times on seven pumping wells (PW1, PW2, PW3, PW4, PW5, PW6, and PW7) and twelve drill holes (BH-2, OW2-OW12) in the area of 370 m x 100 m. Pumping wells PW1 and PW2 were drilled in 1999 by Samjung Engineering Co. and pumping wells PW3, PW4, PW5, PW6 and PW7 were drilled in 2000 by Donga Construction Co. and Daeduk Gongyeong Co. The pumping wells are located at 45-110 meters from Nakdong riverside. The geology of the study area is composed of volcanic rocks (Palryeongsan tuff and Jusasan andesitic rock) and alluvium. Palryeongsan tuff consists of mostly green tuff with partly tuffaceous sandstone, shale, mudstone and sandstone. Thick alluvium is overlain on Palryeongsan tuff (Samjung Engineering Co., 1999; Donga Construction Co. and Daeduk Gongyeong Co., 2000; Kim and Lee, 1964). The alluvium is composed of sand, sandy gravel and weathered zone from the surface (Table 1, Fig. 3). The aquifer is sandy gravel layer (Samjung Engineering Co., 1999). The gravel layer is thicker near the wells of PW1, PW2, PW3, and PW4 (13.5-17.5m), whereas is thinner near the wells of PW5, PW6, and PW7 (6.3-10.5m). The pumping data obtained were analyzed to determine hydraulic parameters (transmissivity and storativity) using various models of pumping test analysis. The appropriate models for the study area were found from several models. The selected model for observation well is Theis model using corrected drawdown and the selected model for pumped well is Papadopulos-Cooper model using corrected drawdown. As a result, alluvial aquifer in the study area behaviors as confined aquifer rather than phreatic aquifer. Thus, infiltration amount from the river to the aquifer in the study area is lower than that from river to phreatic aquifer for the same water level change. And also storativity of the aquifer is represented by elastic storativity rather than specific yield. Transmissivity obtained by the models ranges from 4.54x10-4 to 1.79x10-1 m2/s with arithmetic mean 2.92x10-2 m2/s. Storativity ranges from 2.59x10-4-5.54x10-1 with arithmetic mean 6.36x10-2. Frequency distribution of hydraulic parameters was determined from statistical analyses. The distribution of transmissivity values does not follow normal distribution showing skewness 2.36 and kurtosis 5.085. Aquifer heterogeneity was found by hydraulic parameters and subsurface geology data in the study area. Furthermore, hydraulic parameters obtained at a well that serves as both pumping well and observation well were compared, and the correlation equation was determined to evaluate hydraulic parameters considering aquifer loss. Transmissivity values obtained by the two cases do not show distinct correlati

Hamm, S.-Y.; Kim, H.-S.; Cheong, J.-Y.; Ryu, S. M.; Kim, M. J.

2003-04-01

169

Hydrogeologic characteristics of domains of sparsely fractured rock in the granitic Lac Du Bonnet Batholith, southeastern Manitoba, Canada.  

National Technical Information Service (NTIS)

The hydrogeologic characteristics of the granitic Lac du Bonnet batholith in southeastern Manitoba have been studied since 1978, as part of AECL's program to assess the concept of disposing of Canada's nuclear fuel waste deep within plutonic rocks of the ...

D. R. Stevenson E. T. Kozak C. C. Davison M. Gascoyne R. A. Broadfoot

1996-01-01

170

Hydrogeology and Simulation of Ground-Water Flow in the Cretaceous-Paleozoic Aquifer System in Northeastern Mississippi.  

National Technical Information Service (NTIS)

This report describes the hydrogeology and simulations of ground-water flow in the Coffee Sand, Eutaw-McShan, Gordo, Coker, massive sand, and Lower Cretaceous aquifers, and two aquifers recently delineated in Paleozoic rocks in northeastern Mississippi. T...

E. W. Strom

1998-01-01

171

Characterization of hydrogeologic properties for a multi-layered alluvial aquifer using hydraulic and tracer tests and electrical resistivity survey  

Microsoft Academic Search

A multi-layered aquifer, typical of riverbank alluvial deposits in Korea, was studied to determine the hydrologic properties.\\u000a The geologic logging showed that the subsurface of the study site was comprised of four distinctive hydrogeologic units: silt,\\u000a sand, highly weathered and fresh bedrock layers. The electrical resistivity survey supplied information on lateral extension\\u000a of hydrogeologic strata only partially identified by a

Jeong-Woo Kim; Heechul Choi; Jin-Yong Lee

2005-01-01

172

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

USGS Publications Warehouse

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.

Lampe, David C.

2009-01-01

173

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

USGS Publications Warehouse

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 layers are defined by their predominant sediment textures as aquifers and leaky confining layers. The confining layer at the base of the Kirkwood-Cohansey aquifer system, depending on location, is defined as one of two distinct clays of the Kirkwood Formation. The framework models are described using hydrogeologic sections, maps of structure tops of layers, and thickness maps showing variations of sediment textures of the various model layers. The three framework models are similar in structure but unique to their respective study areas. The hydraulic conductivity of the Kirkwood-Cohansey aquifer system in the vicinity of the three study areas was determined from analysis of 16 slug tests and 136 well-performance tests. The mean values for hydraulic conductivity in the three study areas ranged from about 84 feet per day to 130 feet per day. With the exception of the basal confining layers, the variable and discontinuous nature of clay layers within the Kirkwood-Cohansey aquifer system was confirmed by the geophysical and lithologic records. Leaky confining layers and discontinuous clays are generally more common in the upper part of the aquifer system. Although the Kirkwood-Cohansey aquifer system generally has been considered a water-table aquifer in most areas, localized clays in the aquifer layers and the effectiveness of the leaky confining layers may act to impede the flow of ground water in varying amounts depending on the degree of confinement and the location, duration, and magnitude of the hydraulic stresses applied. Considerable variability exists in the different sediment textures. The extent to which this hydrogeologic variability can be characterized is constrained by the extent of the available data. Thus, the hydraulic properties of the modeled layers were estimated on the basis of available horizontal hydraulic conductivity data and the range of sediment textures estimated from geophysical and lithologic data.

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

2008-01-01

174

Relating lithofacies to hydrofacies: outcrop-based hydrogeological characterisation of Quaternary gravel deposits  

NASA Astrophysics Data System (ADS)

A considerable part of today's drinking water supplies in Europe and North America rely on clean groundwater from gravelly valley aquifers of Quaternary age. The sedimentary architecture, the distribution of lithofacies and of architectural elements in such heterogeneous deposits are of fundamental importance for the analysis of groundwater flow and contaminant transport. As the aquifers are not directly accessible for observation, representative outcrop analogues were used to study the sedimentology on a local scale. Conventional sedimentological classification schemes were adapted for the purpose of hydrogeological evaluations. Measurements of hydraulic properties were then used to define a set of 5 hydrofacies from 23 possible sediment lithofacies. A digital-photographic mapping procedure was developed to allow fast data acquisition in the field. The sedimentologically interpreted outcrops were stored in a GIS style database and thus allow the output for further sedimentological or hydrogeological analysis.

Klingbeil, Ralf; Kleineidam, Sybille; Asprion, Ulrich; Aigner, Thomas; Teutsch, Georg

1999-12-01

175

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

SciTech Connect

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.

Feckley, D.L. (Baylor Univ., Waco, TX (United States). Geology Dept.)

1993-02-01

176

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

USGS Publications Warehouse

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.

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

1993-01-01

177

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

USGS Publications Warehouse

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.

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

1997-01-01

178

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

USGS Publications Warehouse

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.

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

1978-01-01

179

Hydrogeological characterisation of a glacially affected barrier island - the North Frisian Island of Föhr  

NASA Astrophysics Data System (ADS)

We present the application of geophysical investigations to characterise and improve the geological/hydrogeological model through the estimation of petrophysical parameters for groundwater modelling. Seismic reflection and airborne electromagnetic surveys in combination with borehole information enhance the 3-D geological model and allow a petrophysical interpretation of the subsurface. The North Sea Island of Föhr has a very complex underground structure what was already known from boreholes. The local waterworks use a freshwater body embedded in saline groundwater. Several glaciations disordered the Youngest Tertiary and Quaternary sediments by glaciotectonic thrust-faulting as well as incision and refill of glacial valleys. Both underground structures have a strong impact on the distribution of freshwater bearing aquifers. An initial hydrogeological model of Föhr was built from borehole data alone and was restricted to the southern part of the island where in the sandy areas of the Geest a large freshwater body was formed. We improved the geological/hydrogeological model by adding data from different geophysical methods, e.g. airborne electromagnetics (EM) for mapping the resistivity of the entire island, seismic reflections for detailed cross sections in the groundwater catchment area, and geophysical borehole logging for calibration of these measurements. An integrated evaluation of the results from the different geophysical methods yields reliable data. To determinate petrophysical parameter about 18 borehole logs, more than 75 m deep, and nearby airborne EM inversion models were analyzed concerning resistivity. We establish an empirical relation between measured resistivity and hydraulic conductivity for the specific area - the North Sea island of Föhr. Five boreholes concerning seismic interval velocities discriminate sand and till. The interpretation of these data was the basis for building the geological/hydrogeological 3-D model. We fitted the relevant model layers to all geophysical and geological data and created a consistent 3-D model. This model is the fundament for groundwater simulations considering forecasted changes in precipitation and sea level rise due to climate change.

Burschil, T.; Scheer, W.; Kirsch, R.; Wiederhold, H.

2012-04-01

180

Teaching and learning hydrogeology using a physically-based modelling framework  

NASA Astrophysics Data System (ADS)

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.

Frampton, Andrew; Dessirier, Benoit; Pannetier, Romain

2014-05-01

181

Hydrogeological model of a high-energy geothermal field (Bouillante area, Guadeloupe, French West Indies)  

Microsoft Academic Search

The Bouillante geothermal field provides about 8% of the annual electricity needs of the French West Indies island of Guadeloupe.\\u000a It has been the subject of several studies covering various disciplines. A hydrogeological conceptual model of the field is\\u000a proposed. The reservoir consists of two perpendicular sets of fractures and faults, related to major regional tectonic structures,\\u000a which have been

P. Lachassagne; J. C. Marechal; B. Sanjuan

2009-01-01

182

Hydrogeology and Leachate Movement Near Two Chemical-waste Sites in Oswego County, New York  

Microsoft Academic Search

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

Henry R. Anderson; Todd S. Miller

1986-01-01

183

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

Microsoft Academic Search

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

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

2008-01-01

184

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

SciTech Connect

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.

Reynolds, R.; Nowacki, P.

1991-04-01

185

Hydrogeologic characteristics of the valley-fill aquifer in the Arkansas River valley, Pueblo County, Colorado  

USGS Publications Warehouse

The hydrogeology of the valley-fill aquifer of the Arkansas River valley in Pueblo County, Colorado is presented in a series of three maps. The map shows: (1) the altitude and configuration of the bedrock surface beneath the valley-fill material; (2) the altitude and configuration of the water table in the spring of 1966; and (3) the saturation thickness of the valley-fill aquifer in the spring of 1966. (USGS)

Nelson, Gregory A.; Hurr, R. T.; Moore, John E.

1989-01-01

186

Hydrogeologic characteristics of the valley-fill aquifer in the Arkansas River valley, Prowers County, Colorado  

USGS Publications Warehouse

The hydrogeology of the valley-fill aquifer of the Arkansas River valley in Prowers County, Colorado is presented in a series of three maps. The map shows: (1) the altitude and configuration of the bedrock surface beneath the valley-fill material; (2) the altitude and configuration of the water table in the spring of 1966; and (3) the saturation thickness of the valley-fill aquifer in the spring of 1966. (USGS)

Nelson, Gregory A.; Hurr, R. T.; Moore, John E.

1989-01-01

187

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

PubMed

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

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

2012-06-15

188

Hydrogeology of the Kabul Basin (Afghanistan), part I: aquifers and hydrology  

Microsoft Academic Search

Shallow groundwater represents the main source for water supply in Kabul, Afghanistan. Detailed information on the hydrogeology\\u000a of the Kabul Basin is therefore needed to improve the current supply situation and to develop a sustainable framework for\\u000a future groundwater use. The basin is situated at the intersection of three major fault systems of partially translational\\u000a and extensional character. It comprises

Georg Houben; Nadege Niard; Torge Tünnermeier; Thomas Himmelsbach

2009-01-01

189

Constraining fault-zone hydrogeology through integrated hydrological and geoelectrical analysis  

Microsoft Academic Search

The hydrogeologic influence of the Elkhorn fault in South Park, Colorado, USA, is examined through hydrologic data supplemented\\u000a by electrical resistivity tomography and self-potential measurements. Water-level data indicate that groundwater flow is impeded\\u000a by the fault on the spatial scale of tens of meters, but the lack of outcrop prevents interpretation of why the fault creates\\u000a this hydrologic heterogeneity. By

Lyndsay B. Ball; Shemin Ge; Jonathan Saul Caine; André Revil; Abderrahim Jardani

2010-01-01

190

HYDROGEOLOGICAL MODELLING, A PREREQUISITE IN LONG-TERM SAFETY ASSESSMENT FOR UNDERGROUND WASTE DISPOSAL  

Microsoft Academic Search

The disposal of heat generating and long-lived radioactive waste in deep geological formations is a technically and scientifically challenging problem. Due to the fact that long-term impact on the environment and man can not be ruled out from the outset the characterisation of the hydrogeological conditions of such repositories or waste disposal sites forms the basis for any long-term safety

Wernt Brewitz; Eckhard Fein; Christine Fahrenholz

191

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

SciTech Connect

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.)

Not Available

1992-11-01

192

Transport and Fate of Nitrate and Pesticides: Hydrogeology and Riparian Zone Processes  

Microsoft Academic Search

controllingfactor.Hydrologicandchemicaldataindicatedthatground United States and concluded that NO 3 removal effec- water discharges to the creek and chemical exchange takes place tiveness may be limited by several hydrogeologic fac- withintheupper0.7mofthestreambed.Groundwaterhaditsgreatest tors. These factors include (i) total denitrification in influence on surface-water chemistry during low-flow periods, causing the upgradient aquifer; (ii) long residence times along a decrease in concentrations of Cl ,N

Larry J. Puckett; W. Brian Hughes

193

Regional and local hydrogeology of calcareous fens in the Minnesota River basin, USA  

Microsoft Academic Search

Six calcareous fens in the Minnesota River Basin, USA are in regional hydrogeologic settings with large discharges of calcareous\\u000a ground water. These settings juxtapose topographically high areas of ground-water recharge with fens in lower areas of discharge,\\u000a thus creating steep upward hydraulic gradients at the fens. Coarse glacial deposits with high permeability connect recharge\\u000a areas to discharge areas and transmit

James E. Almendinger; Jeanette H. Leete

1998-01-01

194

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

SciTech Connect

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.)

Not Available

1994-01-01

195

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

Microsoft Academic Search

The application of satellite differential synthetic aperture radar (SAR) interferometry, principally coherent (InSAR) and\\u000a to a lesser extent, persistent-scatterer (PSI) techniques to hydrogeologic studies has improved capabilities to map, monitor,\\u000a analyze, and simulate groundwater flow, aquifer-system compaction and land subsidence. A number of investigations over the\\u000a previous decade show how the spatially detailed images of ground displacements measured with InSAR

Devin L. Galloway; Jörn Hoffmann

2007-01-01

196

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

Microsoft Academic Search

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 capa- bilities to map, monitor, analyze, and simulate groundwa- ter 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

Devin L. Galloway; Jörn Hoffmann

2006-01-01

197

Geoelectrical investigation for characterizing the hydrogeological conditions in semi-arid region in Khanasser valley, Syria  

Microsoft Academic Search

In the Khanasser valley, considered as a semi-arid region in Syria, the shallow ground-water presents electrical conductivities ranging from 0.1 to 20mS\\/cm. In order to study the hydrogeological conditions of such region, a good knowledge is required of the geometry of the aquifer at depth. Ninety-six vertical electrical soundings (VES) using the Schlumberger array were carried out in the study

J. Asfahani

2007-01-01

198

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

SciTech Connect

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.

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

2009-04-20

199

Conceptual hydrogeological model of volcanic Easter Island (Chile) after chemical and isotopic surveys  

NASA Astrophysics Data System (ADS)

Most human activities and hydrogeological information on small young volcanic islands are near the coastal area. There are almost no hydrological data from inland areas, where permanent springs and/or boreholes may be rare or nonexistent. A major concern is the excessive salinity of near-the-coast wells. Obtaining a conceptual hydrogeological model is crucial for groundwater resources development and management. Surveys of water seepages and rain for chemical and environmental isotope contents may provide information on the whole island groundwater flow conditions, in spite of remaining geological and hydrogeological uncertainties. New data from Easter Island (Isla de Pascua), in the Pacific Ocean, are considered. Whether Easter Island has a central low permeability volcanic “core” sustaining an elevated water table remains unknown. Average recharge is estimated at 300-400 mm/year, with a low salinity of 15-50 mg/L Cl. There is an apron of highly permeable volcanics that extends to the coast. The salinity of near-the-coast wells, >1,000 mg/L Cl, is marine in origin. This is the result of a thick mixing zone of island groundwater and encroached seawater, locally enhanced by upconings below pumping wells. This conceptual model explains what is observed, in the absence of inland boreholes and springs.

Herrera, Christian; Custodio, Emilio

2008-11-01

200

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

NASA Astrophysics Data System (ADS)

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.

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.

2014-05-01

201

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

SciTech Connect

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.

Liikala, T.L.

1994-09-01

202

Geologic framework and hydrogeologic characteristics of the Edwards Aquifer outcrop, Medina County, Texas  

USGS Publications Warehouse

The hydrogeologic subdivisions of the Edwards aquifer outcrop in Medina County 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. The most porous and permeable rocks of the Devils River Formation in Medina County appear to be in the top layer. The upper member of the Glen Rose Limestone, the lower confining unit, has much less porosity and permeability than that observed in the Edwards aquifer. The Edwards aquifer has relatively large porosity and permeability resulting, in part, from the development or redistribution of secondary porosity. Lithology, stratigraphy, diagenesis, and karstification account for the effective porosity and permeability in the Edwards aquifer outcrop. Karst features that can greatly enhance effective porosity and permeability in the Edwards aquifer outcrop include sinkholes, dolines, and caves. The Edwards aquifer rocks in Medina County change from the eight-member Edwards Group to the essentially indivisible Devils River Formation. The facies change occurs along a line extending northwestward from just south of Medina Lake.

Small, Ted A.; Clark, Allan K.

2000-01-01

203

Improvements in near-surface geophysical applications for hydrogeological parameter estimation  

NASA Astrophysics Data System (ADS)

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.

Addison, Adrian Demond

204

A geophysical and hydrogeological study of aquifers contamination by a landfill  

NASA Astrophysics Data System (ADS)

Landfills are the classical solution for waste disposal. During the last years there has been a growing concern about the effect of landfills in public health, because leaching water can contaminate nearby aquifers. Hydrogeological studies are very important to investigate and remedy these contamination problems but an integrated use of both geophysical and hydrological methods can be even more effective. In this paper, the groundwater contamination by a landfill, located on very porous and permeable formations, is assessed by both geophysical and hydrogeological techniques. Bearing in mind the geological and hydrogeological characteristics of the area, electrical methods were chosen to carry out the geophysical survey. At first, electromagnetic methods were used and a ground conductivity survey was carried out to determine the contamination plume. Then several resistivity soundings were proposed and two resistivity pseudo-sections obtained so that a more detailed study of the contamination was accomplished. From the geophysical data interpretation, strategically located boreholes were drilled, water samples obtained and chemical analysis carried out. Finally, the overall results are integrated and discussed as well as the merits and disadvantages of the techniques that have been employed.

Senos Matias, M.; Marques da Silva, M.; Ferreira, P.; Ramalho, E.

1994-08-01

205

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

PubMed

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

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

2013-12-15

206

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

SciTech Connect

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.

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

1989-01-01

207

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

SciTech Connect

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-19 is clipped, reducing the vertical extent to the interpreted top of the water table. The HFM-19 grid consists of a rectangular array of nodes with a spacing of 125 meters discussed in Sections 4.1, 5, and 6.3, and this selection simplifies the available data near the repository and extrapolates from very widely spaced data in other areas of the model domain. The HFM-19 is assembled by using geometric gridding techniques and software (described in Sections 3 and 6.3) to fill the domain area with 3-D elements corresponding to the 19 hydrogeologic units of interest. The HFM-19 is limited by simplifications that accommodate computer mapping, framework modeling, and modeling limitations and contains an inherent level of uncertainty that is a function of data distribution and geologic complexity. Uncertainty and limitations are discussed in Section 6.4 and model validation is discussed in Section 7. The HFM-19 provides the hydrogeologically defined internal geometry for SZ flow and transport process models, which was used to assign unit numbers to nodes in a mesh for use in site-scale SZ flow and transport models. The ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]) directly uses the output of this report to provide the spatial boundaries for each of the hydrogeologic units.

T. Miller

2004-11-15

208

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

The Edwards-Trinity aquifer is a vital groundwater resource for agricultural, industrial, and municipal uses in the Trans-Pecos region of west Texas. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system in the 4,700 square-mile study area was developed by the U.S. Geological Survey (USGS) in cooperation with the Middle Pecos Groundwater Conservation District, Pecos County, City of Fort Stockton, Brewster County, and Pecos County Water Control and Improvement District No. 1. The model was developed to gain a better understanding of the groundwater system and to establish a scientific foundation for resource-management decisions. Data and information were collected or obtained from various sources to develop the model. Lithologic information obtained from well reports and geophysical data were used to describe the hydrostratigraphy and structural features of the groundwater system, and aquifer-test data were used to estimate aquifer hydraulic properties. Groundwater-quality data were used to evaluate groundwater-flow paths, water and rock interaction, aquifer interaction, and the mixing of water from different sources. Groundwater-level data also were used to evaluate aquifer interaction as well as to develop a potentiometric-surface map, delineate regional groundwater divides, and describe regional groundwater-flow paths. 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.

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

209

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

USGS Publications Warehouse

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, pesticide concentrations in ground water rarely exceed U.S. Environmental Protection Agency Drinking Water Standards or Health Advisory Levels. Analyses of samples from 1,159 private water supplies reveal only 3 sites for which samples with concentrations of pesticides exceeded drinking-water standards. In most cases, samples with elevated concentrations could be traced to point sources at pesticide loading or mixing areas. These analyses included data from some of the most vulnerable areas of the state, indicating that it is highly unlikely that pesticide concentrations in water from wells in other areas of the state would exceed the drinking-water standards unless a point source of contamination were present. Analysis of existing data showed that water from wells in areas of the state underlain by carbonate (limestone and dolomite) bedrock, which commonly have a high percentage of corn production, was much more likely to have pesticides detected. Application of pesticides to the land surface generally has not caused concentrations of the five state priority pesticides in ground water to exceed health standards; however, this study has not evaluated the potential human health effects of mixtures of pesticides or pesticide degradation products in drinking water. This study also has not determined whether concentrations in ground water are stable, increasing, or decreasing.

Lindsey, Bruce D.; Bickford, Tammy M.

1999-01-01

210

Hydrogeologic setting and conceptual hydrologic model of the Spring Creek basin, Centre County, Pennsylvania  

USGS Publications Warehouse

The Spring Creek Basin, Centre County, Pa., is experiencing some of the most rapid growth and development within the Commonwealth. This trend has resulted in land-use changes and increased water use, which will affect the quantity and quality of stormwater runoff, surface water, ground water, and aquatic resources within the basin. The U.S. Geological Survey (USGS), in cooperation with the ClearWater Conservancy (CWC), Spring Creek Watershed Community (SCWC), and Spring Creek Watershed Commission (SCWCm), has developed a Watershed Plan (Plan) to assist decision makers in water-resources planning. One element of the Plan is to provide a summary of the basin characteristics and a conceptual model that incorporates the hydrogeologic characteristics of the basin. The report presents hydrogeologic data for the basin and presents a conceptual model that can be used as the basis for simulating surface-water and ground-water flow within the basin. Basin characteristics; sources of data referenced in this text; physical characteristics such as climate, physiography, topography, and land use; hydrogeologic characteristics; and water-quality characteristics are discussed. A conceptual model is a simplified description of the physical components and interaction of the surface- and ground-water systems. The purpose for constructing a conceptual model is to simplify the problem and to organize the available data so that the system can be analyzed accurately. Simplification is necessary, because a complete accounting of a system, such as Spring Creek, is not possible. The data and the conceptual model could be used in development of a fully coupled numerical model that dynamically links surface water, ground water, and land-use changes. The model could be used by decision makers to manage water resources within the basin and as a prototype that is transferable to other watersheds.

Fulton, John W.; Koerkle, Edward H.; McAuley, Steven D.; Hoffman, Scott A.; Zarr, Linda F.

2005-01-01

211

A discussion of issues related to hydrogeology of deep geologic systems  

NASA Astrophysics Data System (ADS)

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.

Tsang, C. F.; Niemi, A.

2012-04-01

212

The use of ecohydrological groundwater indicator plants in hydrogeological conceptual models  

NASA Astrophysics Data System (ADS)

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 some botanical training, but is still possible.

Lewis, J.

2011-12-01

213

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

SciTech Connect

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-dimensions, the ability to image many reactions of environmental interest in artificial and natural porous media, and the ability to image selected processes over a range of scales in artificial and natural porous media.

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

2010-03-08

214

Hydrogeology and aquifer simulation of the basement rocks of the Kaduna-Zaria area, northern Nigeria  

NASA Astrophysics Data System (ADS)

The study area is situated in the central northern part of Nigeria, which experiences a typical semiarid climate. The aquifer consists of weathered and fractured basement rocks, mainly covered by lateritic soil. For rural water supply purposes, more than 40 wells were drilled in an area of about 2500 km 2. Field checked interpretation of pumping tests, geophysical data and soil investigations lead to a fairly precise description of the hydrogeologic situation in the study area. By application of a simplified steady-state groundwater flow model conducted on microcomputer-based systems, recharge conditions were simulated.

Adanu, E. A.; Schneider, M.

215

Service Learning and Local Hydrogeology in the Classroom: An example from Anchorage, Alaska  

NSDL National Science Digital Library

This project is designed to introduce students to a local hydrogeologic problem or issue of interest to the community. The project requires the students to learn about their local groundwater environment and apply principles and concepts that they learn in the classroom to an issue that is of concern to the public. This project provides a good introduction to "real world" problems that the students are likely to encounter as professionals. Students are required to synthesize information from a variety of sources and develop their own assessment of the problem and also to make recommendations based on their professional opinions.

Munk, Leeann

216

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

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

217

Hydrogeologic assessment of Denver sands along north boundary of Rocky Mountain Arsenal  

SciTech Connect

The purpose of this study is to describe the characteristics of the Denver formation sands in the vicinity of the prosed containment barrier extensions along the north boundary of RMA. Specific objectives include obtaining sufficient hydrogeologic data to ascertain: (A) The presence and extent of water-bearing Denver sands, (B) The maximum depth of contamination in these sands, (c) The concentration of contamination present, and (D) The physical and Hydrologic characteristics of the sands (i.e. grain size, color, piezometric levels, interconnecting of aquifers, transmissivity and permeability).

May, J.H.; Thompson, D.W.; Law, P.K.; Wahl, R.E.

1980-01-01

218

Hydrogeology of an ancient arid closed basin: implications for tabular sandstone-hosted uranium deposits  

USGS Publications Warehouse

Hydrogeologic modeling shows that tabular-type uranium deposits in the Grants uranium region of the San Juan basin, New Mexico, formed in zones of ascending and discharging regional ground-water flow. The association of either lacustrine mudstone or actively subsiding structures and uranium deposits can best be explained by the occurrence of lakes at topographic depressions where ground water having different sources and compositions is likely to converge, mix, and discharge. Ascending and discharging flow also explains the association of uranium deposits with underlying evaporites and suggests a brine interface. The simulations contradict previous suggestions that ground water moved downward in the mudflat. -Author

Sanford, R. F.

1990-01-01

219

Hydrogeologic and water-quality data for the main site, Naval Surface Warfare Center, Dahlgren Laboratory, Dahlgren, Virginia  

USGS Publications Warehouse

Hydrogeologic and water-quality data were collected at the Naval Surface Warfare Center, Dahlgren Laboratory at Dahlgren, Virginia, as part of a hydrogeologic assessment of the shallow aquifer system begun in 1992. The U.S. Geological Survey conducted this study to provide the Navy with hydrogeologic data to meet the requirements of a Spill Contingency Plan. This report describes the ground-water observation-well network, hydro- geologic, and water-quality data collected between August 1992 and September 1993. The report includes a description of the locations and con- struction of 35 observation wells on the Main Site. Hydrologic data include lithologic core samples, geophysical logs, and vertical hydraulic conductivity measurements of selected core intervals. Hydrologic data include synoptic and hourly measurements of ground-water levels, observation-well slug tests to determine horizontal hydraulic conductivity, and tide data. Water-quality data include analyses of major dissolved constituents in ground water and surface water.

Bell, Clifton F.; Bolles, Thomas P.; Harlow, George E.

1994-01-01

220

Hydrogeology and redox geochemistry of CH4 in a Late Wisconsinan Till and Loess Sequence in central Iowa  

Microsoft Academic Search

The hydrogeology and redox geochemistry of CH4 in two hydrogeological settings within a late Wisconsinan till and loess sequence in central Iowa were investigated using CH4, Eh, dissolved O2, NO3-N, NH4-N, dissolved Fe, SO4, H2S, dissolved organic carbon (DOC), particulate organic carbon (POC), ?13C-CH4, ?2H-CH4, ?13C of dissolved inorganic carbon (DIC), and 14C?CH4. Depleted ?13C-CH4 and ?2H-CH4 values, enriched ?13C-DIC

W. W. Simpkins; T. B. Parkin

1993-01-01

221

Storage of low-level radioactive wastes in the ground; hydrogeologic and hydrochemical factors  

USGS Publications Warehouse

The status of mathematical simulation techniques, as they apply to radioactive waste burial sites, is briefly reviewed, and hydrogeologic and hydrochemical data needs are listed in order of increasing difficulty and cost of acquisition. Predictive modeling, monitoring, and management of radionuclides dissolved and transported by ground water can best be done for sites in relatively simple hydrogeologic settings; namely, in unfaulted relatively flat-lying strata of intermediate permeability such as silt, siltstone and silty sandstone. In contrast, dense fractured or soluble media, and poorly permeable porous media (aquitards) are not suitable for use as burial sites, first because of media heterogeneity and difficulties of sampling, and consequently of predictive modeling, and second, because in humid zones burial trenches in aquitards may overflow. A buffer zone several thousands of feet to perhaps several miles around existing or proposed sites is a mandatory consequence of the site selection criteria. As a specific example, the Maxey Flats, Kentucky low-level waste disposal site is examined. (Woodard-USGS)

Papadopulos, Stavros Stefanu; Winograd, Isaac Judah

1974-01-01

222

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

NASA Astrophysics Data System (ADS)

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.

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

2009-07-01

223

Hydrogeological characterization and first CO2 injection experiment in the Heletz sands Reservoir, Heletz (Israel)  

NASA Astrophysics Data System (ADS)

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. Progress achieved in Heletz includes the completion of the instrumentation of the injection well and the installation of the CO2 injection kit and the accompanying facilities on site, the conduction of hydraulic and tracer tests for the characterization of the hydro-geological properties of the reservoir and the starting of the first single well CO2 injection experiment. This paper presents the results of the hydraulic tests and water sampling, which have allowed refining our understanding of the reservoir hydrogeological behavior. This includes: 1) information on the chemical composition of the formation water; 2) a more representative estimation of the hydraulic conductivity and of the anisotropy; and 3) a relatively high content of suspended solids, which require and adequate abstraction policy. Additionally, it provides preliminary information on the monitoring of the single CO2 injection experiment.

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

2014-05-01

224

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

USGS Publications Warehouse

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.

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

2000-01-01

225

A hydrogeological type section for the Duna-Tisza Interfluve, Hungary  

NASA Astrophysics Data System (ADS)

The Duna-Tisza Interfluve, Hungary has an agricultural economy but is plagued by severe problems of soil and wetland salinization despite 200 years of intensive research. The study’s objective was to determine the origin of salts and the mechanisms of salinity distribution. To this end, flow-patterns and chemistry of groundwater were evaluated in a 100 km × 65 km area, with emphasis on the Kolon- and Kelemenszék Lakes region. The lakes are located 13 km apart and have chemically contrasting water and soil types. Two groundwater flow-domains were identified: a gravity-drive meteoric fresh water and an over-pressured deeper domain of saline water. The waters are channeled by a highly permeable gravel aquifer to the surface and may merge near Kelemenszék Lake, causing it to be saline. Kolon Lake receives meteoric groundwater only, hence its fresh chemical character. The cross-formational ascent of the deep waters, combined with the gravitational systems’ geometry and the flow-channeling effect of the near-surface rocks, explains the contrasting chemistry between lakes, and the origin and pattern of soil salinization. The scheme is proposed as a generally valid hydrogeological profile for the interfluve, and has been named the Duna-Tisza Interfluve Hydrogeological Type Section.

Mádl-Sz?nyi, Judit; Tóth, József

2009-06-01

226

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

USGS Publications Warehouse

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.

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

2001-01-01

227

Hydrogeological research on intensively exploited deep aquifers in the `Loma de Úbeda' area (Jaén, southern Spain)  

NASA Astrophysics Data System (ADS)

The intensive use of groundwater for irrigation in the area of Úbeda (`Loma de Úbeda', Jaén, southern Spain) has transformed an area of traditionally rain-fed dry farmland into fields with some of the highest olive oil productivity in the world. Early hydrogeological research studies, initiated just after the beginning of the groundwater exploitation, revealed that the water was collected from three different overlapping aquifers occupying an area of over 1,100 km2, with the lower aquifers located at depths from 300 to over 700 m in an area of 440 km2. Multidisciplinary research, based on geological characterization, and piezometric, hydrochemical and isotopic data, has led to a conceptual model of functioning in this complex hydrogeological system. The proposed model allows for the identification of the recharge areas, and the discharge, which is at present mainly associated with the groundwater pumping. Areas of mixing of waters from the different aquifers and the main hydrogeochemical processes affecting groundwater quality are described.

González-Ramón, Antonio; Rodríguez-Arévalo, Javier; Martos-Rosillo, Sergio; Gollonet, Javier

2013-06-01

228

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

PubMed Central

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.

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

2013-01-01

229

Applications of Ground Penetrating Radar to Hydrogeological Investigations in Coastal Environments  

NASA Astrophysics Data System (ADS)

Ground penetrating radar is sensitive to the porosity and compositional variations common in coastal sands, and hence has become a staple tool for coastal stratigraphers. Under the right circumstances, GPR can also provide useful information on surficial aquifer hydrogeology in coastal zones. Here we present examples of the primary uses for GPR in coastal hydrogeology: (1) to identify depth to the water table; (2) to estimate the depth to the freshwater/saltwater interface; (3) to map hydrostratigraphic units; and (4) to track water flow and changes in water content in surficial aquifers. The water table generally produces a distinct GPR reflection where the capillary zone is thin relative to the radar wavelength. Uncertainties in the water table depth come primarily from uncertainties in the wave velocity and in the thickness of the capillary fringe. The freshwater/saltwater interface is typically too gradational to reflect energy; instead the radar pulse is attenuated. For some GPR instruments, a very shallow freshwater/saltwater interface can cause saturation in pre-amplifiers, resulting in a spurious high-frequency pulse in the record. On a coastal barrier island in the Outer Banks of North Carolina, GPR proved an excellent tool for mapping a muddy marsh layer that serves as a (semi) confining unit for a perched water table. In siliciclastic and carbonate units in Florida, repeated GPR surveying of individual sites has been used for qualitative tracking of unsaturated zone flow, water table migration, and changes in water content.

Kruse, S.; Grasmueck, M.; Bentley, L.; Guha, S.; Juster, T.

2005-12-01

230

Defining Hydrogeological Boundaries for Mountain Front Recharge (MFR) Predictions in Multi-Catchment Mountainous Systems  

NASA Astrophysics Data System (ADS)

Cross-catchment groundwater flow in mountainous watersheds results from the development of local, intermediate, and regional groundwater flow pathways in multi-catchment systems. As such, hydrogeological analysis (e.g. water balance calculations and numerical modelling) to assess contributions of groundwater to mountain front recharge (MFR) must consider the choice of boundaries based on hydrological divides. Numerical 3-dimensional hydrogeological modelling was completed using FeFlow (DHI-WASY), for conceptual regional-scale multi-catchment systems; extending from a watershed boundary to a mountain front. The modelled systems were designed to represent major ridge and valley configurations observed in mountainous watersheds including: nested, adjacent, disconnected, non-parallel, and parallel catchments. Both homogeneous and heterogeneous hydraulic conductivity scenarios were simulated; with the heterogeneous scenario including a shallow zone of higher hydraulic conductivity bedrock overlying less permeable bedrock. The influence of cross-catchment flow in the development of groundwater flow pathways contributing to MFR was examined. The results provide a basis for identifying topographic scenarios where contributions to MFR may originate outside hydrological divides. This understanding will contribute to improving MFR predictions using both the numerical modelling approach and the water balance approach.

Neilson-Welch, L. A.; Allen, D. M.

2010-12-01

231

Hydrogeochemistry of volcanic hydrogeology based on cluster analysis of Mount Ciremai, West Java, Indonesia  

NASA Astrophysics Data System (ADS)

SummaryHydrogeochemical analysis has been conducted on 119 spring locations to portray volcanic hydrogeological system of Mount Ciremai, West Java, Indonesia. Cluster analysis on 14 parameters has extracted three clusters. Cluster 1 (112 springs) is distinguished by normal temperatures, low TDS, EC, and high bicarbonate concentrations. Cluster 2 (five springs) has moderately high temperature, TDS, EC, and high concentration of chloride. Cluster 3 (two springs) exhibits high temperature, anomalous high TDS, EC, and chloride concentration. Three hydrogeological systems have been pictured based on the 3 clusters consecutively. The 1st system is developed in shallow unconfined aquifer, with domination of high bicarbonate (4.2 me/L) meteoric water. The 2nd system is predominated with mixing processes, between groundwater in unconfined aquifer and hot groundwater from deeper aquifers. The 3rd system is primarily dominated by groundwater flow from deep formation. The hot - deep seated groundwater flow also carries mud particles. It has anomalous high TDS (>1000 mg/L), EC (515 ?S/cm), and chloride (99 me/L) from interaction between groundwater with clay formations, interpreted as Kaliwangu Formation.

Irawan, Dasapta Erwin; Puradimaja, Deny Juanda; Notosiswoyo, Sudarto; Soemintadiredja, Prihadi

2009-09-01

232

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

USGS Publications Warehouse

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-permeability confining units that separate discontinuous bodies of aquifer material and act as local groundwater-flow barriers. Groundwater-level fluctuations observed during the monitoring period (2011–12) in wells completed in unconsolidated hydrogeologic units indicated seasonal variations ranging from 1 to about 20 feet. The largest fluctuation of 33 feet occurred in a well that was completed in the bedrock unit. Streamgage discharge measurements made during 2012 indicate that groundwater discharge to creeks in the area ranged from about 0.41 to 33.3 cubic feet per second. During 2012, which was an above-average year of precipitation, the groundwater system received an average of about 664,610 acre-feet of recharge from precipitation and 22,122 acre-feet of recharge from return flows. Most of this annual recharge (66 percent) discharged to streams, and only about 4 percent was withdrawn from wells. The remaining groundwater recharge (30 percent) left the groundwater system as discharge to Hood Canal and Puget Sound.

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

2014-01-01

233

Extraterrestrial hydrogeology  

Microsoft Academic Search

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

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

2005-01-01

234

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

USGS Publications Warehouse

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.

Galloway, J. M.

1999-01-01

235

Numerical Groundwater-Flow Model of the Minnelusa and Madison Hydrogeologic Units in the Rapid City Area, South Dakota.  

National Technical Information Service (NTIS)

The city of Rapid City and other water users in the Rapid City area obtain water supplies from the Minnelusa and Madison aquifers, which are contained in the Minnelusa and Madison hydrogeologic units. A numerical groundwater-flow model of the Minnelusa an...

2009-01-01

236

Hydrogeologic Behavior of an Alluvial Aquifer, Salta Province, Argentina: Simulations of Hydraulic Conductivity Field, Groundwater Flow, and Chloride Migration  

Microsoft Academic Search

This work was designed to analyze the hydrogeological behavior of an alluvial aquifer in the River Mojotoro basin site in the Province of Salta, Argentina. The study area presents coarse-grained sediments with high infiltration capacity. The hydraulic conductivity field is affected by the physical heterogeneity of the medium and a geostatistical method, kriging, was used to construct this field from

Jacqueline Köhn; Eduardo E. Kruse; Juan E. Santos

2002-01-01

237

Sediment deformation and hydrogeology of the Nankai Trough accretionary prism: Synthesis of shipboard results of ODP Leg 131  

Microsoft Academic Search

The main objective of Leg 131 was to provide data on the deformational processes and associated hydrogeology of the Nankai prism toe. Drilling succeeded, for the first time in the history of ocean drilling, in penetrating the complete sedimentary sequence to basaltic basement, reaching 1327 mbsf (metres below seafloor) with good core recovery (55%). Excellent correlation of the lithology and

A. Taira; I. Hill; J. Firth; U. Berner; W. Brückmann; T. Byrne; T. Chabernaud; A. Fisher; J.-P. Foucher; T. Gamo; J. Gieskes; R. Hyndman; D. Karig; M. Kastner; Y. Kato; S. Lallemant; R. Lu; A. Maltman; G. Moore; K. Moran; G. Olaffson; W. Owens; K. Pickering; F. Siena; E. Taylor; M. Underwood; C. Wilkinson; M. Yamano; J. Zhang

1992-01-01

238

Hydrogeology and Simulation of Ground-Water Flow at Superfund-Site Wells G and H, Woburn, Massachusetts.  

National Technical Information Service (NTIS)

The area around wells G and H, two former public-supply wells for the city of Woburn, Massachusetts and currently designated as a U.S. Environmental Protection Agency 'Superfund' site, was the focus of intensive hydrogeologic investigations from 1983 to 1...

J. C. Olimpio V. de Lima

1990-01-01

239

Geologic and Hydrogeologic Information for a Geodatabase for the Brazos River Alluvium Aquifer, Bosque County to Fort Bend County, Texas  

USGS Publications Warehouse

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.

Shah, Sachin D.; Houston, Natalie A.

2007-01-01

240

Hydrogeology and Water Quality in the Snake River Alluvial Aquifer at Jackson Hole Airport, Jackson, Wyoming, September 2008-June 2009.  

National Technical Information Service (NTIS)

The hydrogeology and water quality of the Snake River alluvial aquifer, at the Jackson Hole Airport in northwest Wyoming, was studied by the U.S. Geological Survey in cooperation with the Jackson Hole Airport Board and the Teton Conservation District duri...

P. R. Wright

2010-01-01

241

Hydrogeologic characterization of fractured carbonate aquifers employing ground-penetrating radar  

NASA Astrophysics Data System (ADS)

Ground-penetrating radar (GPR) surveying is proposed as a remote sensing method for high-resolution characterization of fractured carbonate aquifer hydrogeologic properties in three dimensions. Understanding a geologic formation's fluid flow properties is important to hydrogeologic and environmental studies and the petroleum industry. Fractured anisotropic carbonate aquifers are major sources of water supply. To predict flow in these aquifers, fracture network and rock matrix hydraulic properties must be characterized accurately in three dimensions. GPR is employed to investigate rock matrix and fracture hydraulic properties by direct imaging (reflection surveying), signal attribute analysis (velocity, amplitude and phase) and waveform analysis. Overlapping GPR surveys were collected over the fractured Byron Dolomite aquiferin Door County, Wisconsin. A high-resolution, single-offset 3-D volume and 2-D lines successfully imaged varying carbonate lithofacies, lithologic discontinuities, dissolution zones, bedforms and horizontal fractures (also referred to as bedding plane discontinuities). Prominent flow conduits were clearly identifiable in the GPR data volumes and delineated in three dimensions by distinct continuous reflections. Velocity analysis of common mid-point surveys identified cyclic velocity variations that correlate to cyclic alternating middle and inner shelf carbonate facies. Within each facies, velocity trends controlled by the volumetric water content of the rock matrix were resolved to 0.5 m vertically. Radar reflector amplitude variation up to one order of magnitude along known flow conduits suggested centimeter-scale conduit aperture variation, with considerable effects on flow properties. New data acquisition techniques exploiting the polarization properties of electromagnetic waves demonstrated that the location and orientation of areas of anisotropy (i.e. vertical fractures) can be determined by acquiring multi-azimuth data of varying polarization. Phase analysis of these data sets yielded consistent observations relating the polarization of the electric field to the orientation of the fracture plane. GPR data collected during a pumping test identified fracture drainage patterns and showed that GPR surveying can be used for real-time observation of aquifer response to hydraulic tests. This study demonstrates that in addition to the traditional GPR reflection surveying, radar signal attributes can be used to provide information about the hydrogeologic properties of the subsurface.

Tsoflias, Georgios Padelis

242

An Attempt of Hydrogeological Classification of Fault Zones in Karst Areas  

NASA Astrophysics Data System (ADS)

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. In summary, the volume of fault rocks seems to be a function of size and displacement of the faults. Fracture densities in damage zones shows gradual increase from fault zone margins towards fault cores and significant asymmetries. Highest fracture densities with nearly isotropic fracture networks are often located adjacent to the fault core boundary and seem to be depending again on fault size/displacement. More research has to be done, but the presented results provide a useful base for further applications in hydrogeological modelling.

Bauer, Helene; Decker, Kurt

2014-05-01

243

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

NASA Astrophysics Data System (ADS)

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 aquifer altitudes and confining unit thicknesses. Areas of outcrop of the aquifers and confining units were corrected using the USGS HydroSHEDS land surface topography dataset. Ongoing work includes the use of this constructed dataset in the hydrologic model to determine regional groundwater flow paths and travel times.

Seck, A.; Welty, C.

2012-12-01

244

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

NASA Astrophysics Data System (ADS)

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 tracers of infiltration (global system response) and artificial tracers (single response) in karst waters has revealed the usefulness and complementarily of both techniques for characterising the hydrogeological functioning of karst aquifers and, even more important, for validating contamination vulnerability mapping in these medium. 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 recent research.

Andreo, B.

2013-12-01

245

Integrating advanced 3D Mapping into Improved Hydrogeologic Frameworks, a Future path for Groundwater Modeling? Results from Western Nebraska  

NASA Astrophysics Data System (ADS)

The U.S. Geological Survey and its partners have collaborated to provide an innovative, advanced 3 dimensional hydrogeologic framework which was used in a groundwater model designed to test water management scenarios. Principal aquifers for the area mostly consist of Quaternary alluvium and Tertiary-age fluvial sediments which are heavily used for irrigation, municipal and environmental uses. This strategy used airborne electromagnetic (AEM) surveys, validated through sensitivity analysis of geophysical and geological ground truth to provide new geologic interpretation to characterize the hydrogeologic framework in the area. The base of aquifer created through this work leads to new interpretations of saturated thickness and groundwater connectivity to the surface water system. The current version of the groundwater model which uses the advanced hydrogeologic framework shows a distinct change in flow path orientation, timing and amount of base flow to the streams of the area. Ongoing efforts for development of the hydrogeologic framework development include subdivision of the aquifers into new hydrostratigraphic units based on analysis of geophysical and lithologic characteristics which will be incorporated into future groundwater models. The hydrostratigraphic units are further enhanced by Nuclear Magnetic Resonance (NMR) measurements to characterize aquifers. NMR measures the free water in the aquifer in situ allowing for a determination of hydraulic conductivity. NMR hydraulic conductivity values will be mapped to the hydrostratigraphic units, which in turn are incorporated into the latest versions of the groundwater model. The addition of innovative, advanced 3 dimensional hydrogeologic frameworks, which incorporates AEM and NMR, for groundwater modeling, has a definite advantage over traditional frameworks. These groundwater models represent the natural system at a level of reality not achievable by other methods, which lead to greater confidence in the management decisions for the resource.

Cannia, J. C.; Abraham, J. D.; Peterson, S. M.; Sibray, S. S.

2012-12-01

246

Numerical Groundwater-Flow Model of the Minnelusa and Madison Hydrogeologic Units in the Rapid City Area, South Dakota  

USGS Publications Warehouse

The city of Rapid City and other water users in the Rapid City area obtain water supplies from the Minnelusa and Madison aquifers, which are contained in the Minnelusa and Madison hydrogeologic units. A numerical groundwater-flow model of the Minnelusa and Madison hydrogeologic units in the Rapid City area was developed to synthesize estimates of water-budget components and hydraulic properties, and to provide a tool to analyze the effect of additional stress on water-level altitudes within the aquifers and on discharge to springs. This report, prepared in cooperation with the city of Rapid City, documents a numerical groundwater-flow model of the Minnelusa and Madison hydrogeologic units for the 1,000-square-mile study area that includes Rapid City and the surrounding area. Water-table conditions generally exist in outcrop areas of the Minnelusa and Madison hydrogeologic units, which form generally concentric rings that surround the Precambrian core of the uplifted Black Hills. Confined conditions exist east of the water-table areas in the study area. The Minnelusa hydrogeologic unit is 375 to 800 feet (ft) thick in the study area with the more permeable upper part containing predominantly sandstone and the less permeable lower part containing more shale and limestone than the upper part. Shale units in the lower part generally impede flow between the Minnelusa hydrogeologic unit and the underlying Madison hydrogeologic unit; however, fracturing and weathering may result in hydraulic connections in some areas. The Madison hydrogeologic unit is composed of limestone and dolomite that is about 250 to 610 ft thick in the study area, and the upper part contains substantial secondary permeability from solution openings and fractures. Recharge to the Minnelusa and Madison hydrogeologic units is from streamflow loss where streams cross the outcrop and from infiltration of precipitation on the outcrops (areal recharge). MODFLOW-2000, a finite-difference groundwater-flow model, was used to simulate flow in the Minnelusa and Madison hydrogeologic units with five layers. Layer 1 represented the fractured sandstone layers in the upper 250 ft of the Minnelusa hydrogeologic unit, and layer 2 represented the lower part of the Minnelusa hydrogeologic unit. Layer 3 represented the upper 150 ft of the Madison hydrogeologic unit, and layer 4 represented the less permeable lower part. Layer 5 represented an approximation of the underlying Deadwood aquifer to simulate upward flow to the Madison hydrogeologic unit. The finite-difference grid, oriented 23 degrees counterclockwise, included 221 rows and 169 columns with a square cell size of 492.1 ft in the detailed study area that surrounded Rapid City. The northern and southern boundaries for layers 1-4 were represented as no-flow boundaries, and the boundary on the east was represented with head-dependent flow cells. Streamflow recharge was represented with specified-flow cells, and areal recharge to layers 1-4 was represented with a specified-flux boundary. Calibration of the model was accomplished by two simulations: (1) steady-state simulation of average conditions for water years 1988-97 and (2) transient simulations of water years 1988-97 divided into twenty 6-month stress periods. Flow-system components represented in the model include recharge, discharge, and hydraulic properties. The steady-state streamflow recharge rate was 42.2 cubic feet per second (ft3/s), and transient streamflow recharge rates ranged from 14.1 to 102.2 ft3/s. The steady-state areal recharge rate was 20.9 ft3/s, and transient areal recharge rates ranged from 1.1 to 98.4 ft3/s. The upward flow rate from the Deadwood aquifer to the Madison hydrogeologic unit was 6.3 ft3/s. Discharge included springflow, water use, flow to overlying units, and regional outflow. The estimated steady-state springflow of 32.8 ft3/s from seven springs was similar to the simulated springflow of 31.6 ft3/s, which included 20.5 ft3

Putnam, Larry D.; Long, Andrew J.

2009-01-01

247

Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications  

USGS Publications Warehouse

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 region has been loosely divided into six domains based on structural style and overall geophysical character. For each domain, the subsurface tectonic and magmatic features that have been inferred or interpreted from previous geophysical work has been reviewed. Where possible, abrupt changes in geophysical fields as evidence for potential structural lithologic control on ground-water flow has been noted. Inferred lithology is used to suggest associated hydrogeologic units in the subsurface. The resulting framework provides a basis for investigators to develop hypotheses from regional ground-water pathways where no drill-hole information exists.

Grauch, V. J.; Sawyer, David A.; Fridrich, Chris J.; Hudson, Mark R.

1999-01-01

248

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

USGS Publications Warehouse

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.

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

2012-01-01

249

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

USGS Publications Warehouse

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.

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

2003-01-01

250

Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications  

SciTech Connect

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 from Pahute Mesa is likely to follow a flow path that extends southwestward to Oasis Valley discharge area.

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

2000-06-08

251

TDEM survey in urban environmental for hydrogeological study at USP campus in São Paulo city, Brazil  

NASA Astrophysics Data System (ADS)

In this work, some TDEM (Time Domain Electromagnetic) results at USP ( University of São Paulo) campus in São Paulo city, Brazil, are presented. The data were acquired focusing on two mains objectives: (i) to map geoelectrical stratigraphy of São Paulo sedimentary basin, emphasizing on hydrogeological studies about sedimentary and crystalline aquifers, and (ii) to analyze the viability of TDEM data acquisition use in urban environment. The study area is located in São Paulo basin border, characterized by Resende and São Paulo formations, which are constituted by sand-clays sediments over a granite-gneissic basement. Two equipments were used in order to acquire database: Protem47 (low power), and Protem57-MK2 (high power). Capacitive noise affect obtained data with Protem47 due to the presence of metal pipes buried at IAG/USP (Institute of Astronomy, Geophysics, and Atmospheric Science) test site at USP. On the other hand, capacitive noise did not affect acquired data with Protem57-MK2, and the data present high signal to noise ratio. Surveys helped in determining sedimentary and crystalline aquifers, characterized by a fracture zone with water inside basin basement (conductive zone). Results show good agreement with local geology obtained from lithological boreholes located in the study areas. Moreover, it shows that TDEM method can be used in urban environments with a countless potential in hydrogeological studies, offering great reliability. Studies showed that main TDEM-method limitation at USP was the lack of space for opening the transmitter loop. Results are very promising and open new perspectives for TDEM-method use in urban environments as this area remains unexplored.

Porsani, Jorge Luís; Bortolozo, Cassiano Antonio; Almeida, Emerson Rodrigo; Sobrinho, Esther Novais Santos; Santos, Thiago Gomes dos

2012-01-01

252

Hydrogeology and analysis of aquifer characteristics in west-central Pinellas County, Florida  

USGS Publications Warehouse

The U.S. Geological Survey, in cooperation with Pinellas County, Florida, conducted an investigation to describe the hydrogeology and analyze the aquifer characteristics in west-central Pinellas County. A production test well and four monitor wells were constructed in Pinellas County at Walsingham Park during 1996-97. Water-quality sampling, static and dynamic borehole geophysical surveys, and hydraulic tests were conducted at the wells to delineate the hydrogeology at Walsingham Park. A 9-day aquifer test was conducted to determine the hydraulic characteristics of the aquifer system and observe the changes in water quality due to pumping. A numerical model was constructed to simulate the aquifer test and calculate values for hydraulic conductivity and storage coefficient for permeable zones and confining units at Walsingham Park. Final calibrated values for hydraulic conductivity for the different permeable zones and confining units at the test site were 18 feet per day for Upper Zone A, 750 feet per day for Lower Zone A, 1 foot per day for Zone B, 1x10-4 feet per day for the intermediate confining unit, and 10 feet per day for the semiconfining unit separating Upper Zone A and Lower Zone A. Final calibrated values for storage coefficient were 3.1x10-4 for Upper Zone A, 8.6x10-5 for Lower Zone A, 2.6x10-5 for Zone B, 3.1x10-4 for the intermediate confining unit, and 4.3x10-5 for the semiconfining unit separating Upper Zone A and Lower Zone A. Estimates of transmissivity for Upper Zone A and Lower Zone A were about 2,500 and 37,500 feet squared per day, respectively.

Broska, J. C.; Barnette, H. L.

1999-01-01

253

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

SciTech Connect

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.

Martin, A.J. (Emory Univ., Atlanta, GA (United States). Geosciences Program); Simones, G.C. (South Carolina Water Resources Commission, Columbia, SC (United States))

1992-01-01

254

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

USGS Publications Warehouse

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.

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

2001-01-01

255

An innovative hydrogeologic setting for disposal of low-level radioactive wastes  

NASA Astrophysics Data System (ADS)

A natural unique hydrogeological setting favorable for safe and economical disposal of low-level radioactive wastes occurs in the flat hinterland of southeastern North Carolina. The uniqueness results partly from the absence of vertical and horizontal groundwater gradients, representing a nonflow, or null, zone. The null setting is localized to key horizons 30 to 75 feet below land surface and to areas where glauconitic sandy clays of the Peedee Formation lie under less than 25 feet of surficial sandy clays; the Peedee contains nearly stagnant brackish groundwater slightly below the proposed disposal zone. Issues to overcome include: (1) demonstrating better combined safety and economical features over conventional and prescribed settings, (2) dewatering the low-permeability disposal zone for the 20-year operational period, and (3) changing rules to allow disposal slightly below the zone in which the normal water table occurs. Favorable site characteristics of the key setting are: (1) no major aquifer to contaminate, (2) no surface streams or lakes to contaminate, (3) optimal ion exchange and sorptive capacity (clay and glauconite pellets), (4) no appreciable or distinctive vertical and horizontal gradients, (5) no elongated contaminated plume to develop, (6) no surface erosion, (7) a capable setting for injection of potential contaminated water into deep brackish water wells, if needed and allowed, (8) minimum problems of the “overfilled bathtub effect,” (9) no apparent long-term harmful environmental impact (normal water table would be restored after the 20-year period), (10) relatively inexpensive disposal (engineered barriers not needed and desired), (11) simple and relatively inexpensive monitoring, (12) large tracts of land likely available, and (13) sparse population. In spite of legal and political obstacles to shallow land burial, the null setting described is a capable hydrogeological host to contain low-level radioactive wastes. The setting may have safety and economic advantages over selected sites in eastern North America and over innovative technological experiences in Europe.

Legrand, Harry E.

1989-05-01

256

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)

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.

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

2012-12-01

257

Hydrogeologic Characterization of Basalts: The Northern Rim of the Columbia Plateau Physiographic Province and of the Creston Study Area, Eastern Washington.  

National Technical Information Service (NTIS)

The report provides a general but comprehensive characterization of hydrogeologic and hydrogeochemical baseline conditions for the Creston area located along the northern rim of the Columbia Plateau physiographic province. Historical as well as recent dat...

J. A. Paschis R. A. Koenig T. D. Steele

1988-01-01

258

Hydrogeology of the southeastern coastal plain aquifer system in parts of eastern Mississippi and western Alabama. Regional aquifer-system analysis. Southeastern coastal plain. Professional paper  

SciTech Connect

The report presents an analysis of the hydrogeology of the clastic Cretaceous Coastal Plain aquifers in parts of eastern Mississippi and western Alabama. This report provides descriptions of (1) the hydrogeologic framework and associated ground-water flow system and (2) a calibrated digital computer model capable of assessing the effects of ground-water withdrawals or other stresses on the ground-water flow system.

Mallory, M.J.

1993-12-31

259

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

NASA Astrophysics Data System (ADS)

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 resistivity profiles combined with rock core data, the geologic units can be primarily categorized into colluvium and weathered rock at depths of 4-23 m and 23-80 m, respectively. An approximately 20 m shear zone at depths of 45-65 m was found based on the detection outcome of low electrical resistance. Also, according to the borehole electrical logging, the layer of sandstone was identified in the interval of 48-59 m and 68.5-74 m and showed low water-bearing capacity. In addition, the electrical logging identified the layer of shale was in the interval of 59-68.5 m, which possessed a high water-bearing capacity. The velocity profile along the borehole was obtained from the flowmeter logging. A relatively high velocity zone (1.36~2.23 m/min) was measured in the interval of sandstone and relatively low velocity zone (0.12~0.78 m/min) was measured in the interval of shale, which is similar to those found in electrical logging. Moreover, 198 discontinuity planes were identified from the borehole image logging. The orientations of all discontinuities were calculated and compiled to draw a stereographic projection diagram. Judging from the discontinuity clusters on the stereographic projection diagram, a plane failure may possibly occur based on Hoek and Brown's criteria. This is a good demonstration that slope failure geometry and type can be determined by stereographic projection diagram analysis. The borehole images also clearly showed the structures of discontinuities at depth. They not only helped to characterize the results of the above investigation technologies but also provided useful indication in selecting specific geologic intervals for packer tests. The packer tests were conducted and the intervals were isolated based on the results of borehole and flowmeter logging. They indicated that the hydraulic conductivities of the shale and sandstone intervals are respectively 1.37Ã-10-8 m/sec and 2.68Ã-10-5-3.76Ã-10-5 m/sec, which are in good accordance with the hydraulic characteristics inferred by flowmeter logging. The aforementioned investigation results, incl

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

2009-04-01

260

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

USGS Publications Warehouse

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)

Levings, J. F.

1985-01-01

261

A summary and discussion of hydrologic data from the Calico Hills nonwelded hydrogeologic unit at Yucca Mountain, Nevada  

SciTech Connect

This report is a summary of available hydrologic data from in situ and laboratory testing of the Calico Hills nonwelded hydrogeologic unit, including hydraulic conductivity, porosity, saturation, pore-size distribution and parameters from curve-fits to pressure-saturation data. Sample statistics of hydraulic conductivity, porosity and saturation data for vitric, devitrified and zeolitic tuffs are presented and discussed. While a high degree of variability is observed in both laboratory and in situ hydraulic conductivity measurements, uncertainties arising from differences in size of laboratory test samples, sample handling, test procedures and insufficient number of samples point to the need for additional data of specific types to adequately characterize the unit. Hydrologic issues related to transport analysis in the Calico Hills nonwelded hydrogeologic unit at Yucca Mountain are discussed together with recommendations for future work. The compiled data are included as an appendix.

Loeven, C.

1993-01-01

262

Hydrogeology and extent of saltwater intrusion on Manhasset Neck, Nassau County, New York  

USGS Publications Warehouse

Manhasset Neck, a peninsula on the northern shore of Long Island, N.Y., is underlain by unconsolidated deposits that form a sequence of aquifers and confning units. Ground water at several public-supply wells has been affected by the intrusion of saltwater from the surrounding embayments (Manhasset Bay, Long Island Sound, Hempstead Harbor). Twenty-two boreholes were drilled during 1992-96 for the collection of hydrogeologic, geochemical, and geophysical data to delineate the subsurface geology and the extent of saltwater intrusion within the peninsula. A series of continuous high-resolution seismic- reflection surveys was completed in 1993 and 1994 to delineate the character and extent of the hydrogeologic deposits beneath the embayments surrounding Manhasset Neck. The new drill-core data indicate two hydrogeologic units--the North Shore aquifer and the North Shore confining unit--where the Lloyd aquifer, Raritan confining unit, and the Magothy aquifer have been completely removed by glacial erosion. Water levels at selected observation wells were measured quarterly throughout the study. These data, and continuous water-level records, indicate that (1) the upper glacial (water-table) and Magothy aquifers are hydraulically connected and that their water levels do not respond to tidal fluctuations, and (2) the Lloyd and North Shore aquifers also are hydraulically connected, but their water levels do respond to pumping and tidal fluctuations. Offshore seismic-reflection surveys in the surrounding embayments, and drill-core samples, indicate at least four glacially eroded buried valleys with subhorizontal, parallel reflectors indicative of draped bedding that is interpreted as infilling by silt and clay. The buried valleys (1) truncate the surrounding coarse-grained deposits, (2) are asymmetrical and steep sided, (3) trend northwest-southeast, (4) are 2 to 4 miles long and about 1 mile wide, and (5) extend to more than 400 feet below sea level. Water from 12 public-supply wells screened in the Magothy and upper glacial aquifers contained volatile organic compounds in concentrations above the New York State Department of Health Drinking Water maximum contaminant levels, as did water from one public- supply well screened in the Lloyd aquifer and from two observation wells screened in the upper glacial aquifer. Five distinct areas of saltwater intrusion have been delineated in Manhasset Neck; three extend into the Lloyd and North Shore aquifers, and two extend into the upper glacial and Magothy aquifers. Borehole-geophysical-logging data indicate that several of these saltwater wedges range from a few feet to more than 125 feet in thickness and have sharp freshwater-saltwater interfaces, and that chloride concentrations within these wedges in 1997 ranged from 102 to 9,750 milligrams per liter. Several public-supply wells have either been shut down or are currently being affected by these saltwater wedges. Data show active saltwater intrusion in at least two of the wedges.

Stumm, Frederick; Lange, A. D.; Candela, J. L.

2002-01-01

263

Hydrogeological and Geomechanical Aspects of Underground Coal Gasification and its Direct Coupling to Carbon Capture and Storage  

Microsoft Academic Search

Underground coal gasification (UCG) using boreholes drilled from the surface has been feasible for almost a century, but is\\u000a only now being implemented in market economies. Good analogues for the hydrogeological effects of UCG are provided by longwall\\u000a mining. Careful planning of UCG void locations and dimensions can result in minimal disturbance of overlying aquifers as close\\u000a as 40 m above

Paul L. Younger

2011-01-01

264

Hydrogeologic characteristics of the valley-fill aquifer in the Arkansas River valley, Crowley and Otero Counties, Colorado  

USGS Publications Warehouse

The hydrogeology of the valley-fill aquifer of the Arkansas River valley in Crowley and Otero Counties, Colorado is presented in a series of three maps. The map shows: (1) the altitude and configuration of the bedrock surface beneath the valley-fill material; (2) the altitude and configuration of the water table in the spring of 1966; and (3) the saturation thickness of the valley-fill aquifer in the spring of 1966. (USGS)

Nelson, Gregory A.; Hurr, R. T.; Moore, John E.

1989-01-01

265

Groundwater flow modelling of multi-aquifer systems for regional resources evaluation: the Gdansk hydrogeological system, Poland  

Microsoft Academic Search

In order to evaluate groundwater regional resources, a mathematical model of the Gdansk hydrogeological system (Poland) was\\u000a developed. The research area covers about 2,800 km2. Groundwater occurs in Cretaceous, Paleogene and Neogene formations. The recharge zone is situated in the glacial upland\\u000a of the Kashubian Lake District. The discharge zone spreads over the lowlands of Gdansk and beneath the Bay of

Beata Jaworska-Szulc

2009-01-01

266

Hydrogeological Modeling of Radionuclide Transport in Heterogeneous Low-Permeability Media: A Comparison Between Boom Clay and Ieper Clay  

Microsoft Academic Search

Deep low-permeability clay layers are considered as possible suitable environments for disposal of high-level radioactive\\u000a waste. In Belgium, the Boom Clay is the reference host formation and the Ieper Clay an alternative host formation for research\\u000a and safety and feasibility assessment of deep disposal of nuclear waste. In this study, two hydrogeological models are built\\u000a to calculate the radionuclide fluxes

M. Huysmans; A. Dassargues

267

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

USGS Publications Warehouse

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.

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

2011-01-01

268

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

USGS Publications Warehouse

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 wells are shallow (about 20 m) open holes that are cased only through the surficial sediments.

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

269

Hydrogeologic Controls on the Deep Terrestrial Biosphere - Chemolithotrophic Energy for Subsurface Life on Earth and Mars  

NASA Astrophysics Data System (ADS)

As exploration for gold, diamonds and base metals expand mine workings to depths of almost 3 km below the Earth's surface, the mines of the Canadian Shield provide a window into the deep biosphere as diverse, but to date less well-explored than the South African Gold Mines. To date investigations of the deep biosphere have, in most cases, focused on the marine subsurface, including deep sea sediments, hydrothermal vents, off-axis spreading centers and cold seeps. Yet the deep terrestrial subsurface hosted in the fracture waters of Archean Shield rocks provides an important analog and counterpoint to studies of the deep marine biosphere. Depending on the particular geologic and hydrogeologic setting, sites vary from those dominated by paleometeoric waters and microbial hydrocarbon production, to those in which H2 and hydrocarbon gases have been suggested to be a function of long-term accumulation of the products of water-rock interaction in the deepest, most saline fracture waters with residence times on the order of tens of millions of years. The hydrogeologically isolated fracture-controlled ground water system periodically generates steep redox gradients and chemical disequilibrium due to fracture opening, and episodic release of mM levels of H2 that support a redox driven microbial community of H2-utilizing sulfate reducers and methanogens. Exploration of these systems may provide information about the limits of the deep terrestrial biosphere, controls on the distribution of deep subsurface life, and the diversity of geochemical reactions that produce substrates on which microbiological communities at great depths survive. The geologically stable Precambrian cratons of Earth are arguably the closest analogs available to single-plate planets such as Mars. Studies of these Earth analogs imply that the habitability of the Martian crust might similarly not be restricted to sites of localized hydrothermal activity. While the presence of the Martian cryosphere and potential clathrates will affect the porosity and permeability, and net flux of gases from the Martian crust, the underlying principles of fracture-controlled energy sequestration and episodic release remain. Furthermore understanding the origin and distribution of biogenic and geologic sources of CH4 at these analog Earth sites will inform models and strategies for deciphering the origin of CH4 recently reported in the Martian atmosphere.

Sherwood Lollar, B.; Moran, J.; Tille, S.; Voglesonger, K.; Lacrampe-Couloume, G.; Onstott, T.; Pratt, L.; Slater, G.

2009-05-01

270

Scientific Cruise Report from KR02-10: Hydrogeological and Geothermotic study around the Naikai Trough.  

NASA Astrophysics Data System (ADS)

Recent studies on seismogenic zone or active faults, it has been clearly indicate that the necessity lies to understand fluid circulation in and out of the seismogenic zones. Parameters related to hypotheses include fault materials, stress state around the faults, fluid pressure distributions, temperature distributions, permeability, chemical composition of fluid, etc., on top of the other elastic properties of rocks. As a first step towards the seismogenic mechanism at the Nankai Trough, we have set questions to solve: (1) if fluid drains out through thrust faults, (2) if biological communities are directly related to fluid discharge, and (3) if pressure transient in the oceanic sediments on top of the crust can be explain by horizontal flow so that fluid movement may take place along decollement zone. For ultimately understanding seismogenic mechanisms at the plate boundary along the Nankai Trough, a research cruise was scheduled in Jul. 31 until Aug. 13, using a JAMSTEC R/V Kairei and submersible Kaiko, for marking a footprint in the history of seismogenic studies at the Nankai Troungh towards the future riser drilling. For the above questions, (1) and (2), intensive heat flow measurements were planned at two transects, Muroto and Kumano, for understanding fluid discharge at the sea floor. The results from the heat flow measurements indicated that the peak of heat flow would be located at the thrust-sea floor intersection but not at the location of the seep at the Muroto transect. Question (3) is strongly related to hypotheses presented for ODP leg-196 in which they installed two longterm hydrogeological observatories (Advanced-CORKs). During this leg KR02-10, we accessed the observatories and succeeded to start running the installed instruments. It was confirmed that the build-up of pressure in the sediments started and data from the instruments will be retrieved in further cruises. Further studies are currently on-going using SSS, SBP of the ROV system, geological/geochemical studies on pushcore samples, biological dating of calyptogena shells, hydrogeological analysis of the heat flow data, etc., would give us certain boundary conditions at the shallowmost sediments on fluid circulation in and around the Nankai accretionary prism.

Mikada, H.; Kinoshita, M.; Becker, K.; Davis, E. E.; Meldrum, R. D.; Flemings, P.; Gulick, S. P.; Matsubayashi, O.; Morita, S.; Goto, S.; Misawa, N.; Fujino, K.; Toizumi, M.

2002-12-01

271

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

NASA Astrophysics Data System (ADS)

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 can provide a helpful guideline for effective usage and design of open-loop GHPS under various hydrogeological conditions.

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

2008-12-01

272

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

NASA Astrophysics Data System (ADS)

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, mass spectroscopy elemental chemistry, and petrography. Preliminary results from all analyses are remarkably consistent with one another and suggest a heterogeneously distributed, fracture-dominated groundwater flow system. Resistivity models show a well-defined, highly resistive near-surface layer, likely representing the unsaturated zone. Selective leaching of pyrite combined with fracturing in the Ohio Creek formation may be responsible for localized areas of lower resistivity where surface waters intersect these features and result in increased saturation. Steeply dipping resistive features are spatially coincident with the observed major faults and veins, and are also evident in the self-potential data. Resistivity data, outcrop observations, petrography, and mercury injection permeability and porosity data are consistent with the Wasatch formation having significantly lower porosity and permeability than the Ohio Creek formation and associated fault rocks. This suggests that the physical juxtaposition of the two contrasting units may be a critical factor in controlling the distribution of surface water infiltration and groundwater-related acid rock drainage.

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

2009-12-01

273

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

USGS Publications Warehouse

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 Pond Brook. Beneath the upper confining unit, ground water flows southwestward, down the valley. Between First Street and Farley Avenue, the upper confining unit pinches out near the valley walls, resulting in a major input of water to, and causing a local potentiometric high in, the underlying aquifer layers. Ground-water-flow directions southwest of the southern arsenal boundary are predominantly to the Rockaway River.

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

1996-01-01

274

Seismicity Induced by Groundwater Recharge at Mt. Hood, Oregon, and its Implications for Hydrogeologic Properties.  

NASA Astrophysics Data System (ADS)

Earthquakes induced by human-caused changes in fluid pressure have been documented for many years. Examples include seismicity induced by filling reservoirs and by fluid injection or extraction. Less well-documented are seismic events that potentially are triggered by natural variations in groundwater recharge rates (e.g., Wolf et al., BSSA, 1997; Jimenez and Garcia-Fernandez, JVGR, 2000; Audin et al., GRL, 2002). Large groundwater recharge rates can occur in Volcanic Arcs such as the Oregon Cascades where annual precipitation is > 2 m of which > 50 % infiltrates the ground mostly during snowmelt in spring. As a result, infiltration rates of > 1 m per year concentrated during a few months can occur. Near-surface porosities are about 5-10 %. Thus, groundwater levels may fluctuate annually by about 10-20 m resulting in seasonal pore fluid pressure variations of about 1-2 x 105 Pa. Such large-amplitude, narrow-duration fluid pressure signals may allow investigation of seismicity induced by pore fluid pressure diffusion without the influence of engineered systems such as reservoirs. This kind of in-situ study of natural systems over large representative elementary volumes may allow determination of hydrologic parameters at spatial and temporal scales that are relevant for regional hydrogeology. Furthermore, natural hydrologic triggering of earthquakes that persist for decades provides insight into the state of stress in the crust and suggest long-term near-critical failure conditions. Here, we approximate the temporal variations in groundwater recharge with discharge in runoff-dominated streams at high elevations that show a peak in discharge during snow melt. Seismicity is evaluated as time series of daily number of earthquakes and seismic moments. Both stream discharge and seismicity are compared at equivalent frequency bands by applying segmented least-squares polynomial fits to the data. We find statistically significant correlation between groundwater recharge and seismicity at Mt. Hood, Oregon. We can use the time lag of about 120 days between the two records to estimate the regional hydraulic diffusivity (1 m2/s) and other hydrogeologic parameters (permeability ? 10-13 m2, vertical matrix compressibility ? 10-10 m2/N). These values are comparable with our results from coupled heat and groundwater flow studies that are based on bore hole temperature data at Mt. Hood.

Saar, M. O.; Manga, M.

2002-12-01

275

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

NASA Astrophysics Data System (ADS)

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 used in information and awareness campaigns for people on self-protective behavior to be used during damaging hydrogeological events.

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

2014-05-01

276

Hydrogeological application of electrical resistivity tomography: Implementing a fixed-electrode strategy  

NASA Astrophysics Data System (ADS)

The requirements of environmental assessments and of understanding and monitoring in-situ mass and heat processes in porous media have led to the development of geophysical methods for remote mapping and monitoring of contaminant plumes and fluid migration. With the possible exception of seismic approaches, electrical methods known as Electrical Resistivity Tomography (ERT) have become the most widely studied and used for these purposes. Wherever a sufficient contrast in ground resistivity is generated by human or natural processes, monitoring the resistivity structure over time may give insight into these processes. ERT has monitoring applications in processes such as Enhanced Oil Recovery (EOR), Slurry Fracture Injection (SFI), and monitoring transport processes in hydrogeology. A permanent electrode arrangement for long term monitoring removes the effects of Earth's heterogeneity and anisotropy when a process is analyzed as a function of time. As a starting point on the work described in this thesis, ERT data were collected from a Cambridge, Ontario, sand pit before, immediately after and one week following a 11000 liters slurry injection. These measurements verified that ERT could detect changes caused by the injection and later movement of this conductive mixture in the ground. The commercial equipment used for these measurements was not well suited to the tasks, mainly because it was extremely slow. Further, there was a lack of robust and user-friendly three-dimensional modeling software to use as a means of predicting response and---eventually---as the engine of an inversion routine. Finally, it was difficult to analyze the injection situation in terms of how best to place a limited number of surface and borehole electrodes to most effectively monitor the injection fluids. The remainder of the thesis addresses these problems. The first objective was to design and construct a more suitable ERT measurement system. The second objective was to adapt SALTFLOW as a platform for both the resistivity and hydrogeological modeling of the saline groundwater flow resulting from waste injection. The third objective was to develop methods of sensitivity analysis that will allow a more efficient examination of the electrode arrays that could be effectively used in a given situation. The fourth objective was to demonstrate the ERT method and the improvements undertaken by the author on the data collected at the Cambridge injection site. The thesis has not, in fact, met all these objectives, but has made substantial progress towards them. The complete design of the measurement system and the construction of its potential measurement components were achieved. A lack of capacity in the science shops, however, resulted in the power (current) supply not being constructed in time for field evaluation of the injection or its aftermath. (Abstract shortened by UMI.)

Pezeshkpour, Parsa

277

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

NASA Astrophysics Data System (ADS)

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.

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

278

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

SciTech Connect

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.

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

2002-05-21

279

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

SciTech Connect

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.

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

1997-12-31

280

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

USGS Publications Warehouse

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.

Barr, G. L.

1993-01-01

281

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

NASA Astrophysics Data System (ADS)

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 wells (step test and constant rate test) - Results of the long-term pumping test. Based on the results of these tests a Conceptual hydrogeological model of the area and the dewatering concept will be presented. The conceptual model is the basis for the numerical model of groundwater flow developed and calibrated in two successive phases (see abstract: L. San Nicolò, U. Burger, R. Zurlo).

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

2014-05-01

282

Hydrogeological Mapping and Hydrological Process Modelling for understanding the interaction of surface runoff and infiltration in a karstic catchment  

NASA Astrophysics Data System (ADS)

This paper presents a study at the interface hydrogeology - hydrology, concerning mapping of surface runoff generation areas in a karstic catchment. The governing processes range from surface runoff with subsequent infiltration to direct infiltration and further deep percolation into different karst conduits. The aim is to identify areas with a potential of surface erosion and thus, identify the hazard of solute/contaminant input into the karst system during aestival thundershowers, which can affect water quality at springs draining the karst massif. According to hydrogeological methods the emphasis of the study are field investigations based on hydrogeological mapping and field measurements in order to gain extensive knowledge about processes and their spatial distribution in the catchment to establish a site specific Dominant Process Concept (DPC). Based on the hydrogeological map, which describes the lithological units relating to their hydrogeological classification, mapping focuses on the following attributes of the overlaying loose material/debris and soils: (i) infiltration capability, (ii) soil depth (as a measure for storage capacity), and (iii) potential surface flow length. Detailed mapping is performed in the reference area, where a variety of data are acquired, such as soil grain size distribution, soil moisture through TDR measurements at characteristic points, etc. The reference area borders both end-members of the dominant surface runoff processes as described above. Geomorphologic analyses based on a 1m resolution Laserscan assist in allocating sinks and flow accumulation paths in the catchment. By a regionalisation model, developed and calibrated based on the results in the reference areas, the process disposition is transposed onto the whole study area. In a further step, a hydrological model will be set up, where model structure and parameters are identified based on above described working steps and following the DPC. The model will be validated to surface runoff data in parts of the reference area and in a second phase, to data of the main spring of the karst massif. Therefore a conceptual karst module will be implemented and tested. Water quality data (like SAC 254 and microbial indicators) are used amendatory to obtain a better understanding of the karst system and its drainage characteristics and to estimate particle travel.

Stadler, Hermann; Reszler, Christian; Komma, Jürgen; Poltnig, Walter; Strobl, Elmar; Blöschl, Günter

2013-04-01

283

Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada  

USGS Publications Warehouse

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.

Nastev, M.; Morin, R.; Godin, R.; Rouleau, A.

2008-01-01

284

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

USGS Publications Warehouse

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.

Mack, T. J.

1995-01-01

285

Numerical analysis of the hydrogeologic controls in a layered coastal aquifer system, Oahu, Hawaii, USA  

USGS Publications Warehouse

The coastal aquifer system of southern Oahu, Hawaii, USA, consists of highly permeable volcanic aquifers overlain by weathered volcanic rocks and interbedded marine and terrestrial sediments of both high and low permeability. The weathered volcanic rocks and sediments are collectively known as caprock, because they impede the free discharge of groundwater from the underlying volcanic aquifers. A cross-sectional groundwater flow and transport model was used to evaluate the hydrogeologic controls on the regional flow system in southwestern Oahu. Controls considered were: (a) overall caprock hydraulic conductivity; and (b) stratigraphic variations of hydraulic conductivity in the caprock. Within the caprock, variations in hydraulic conductivity, caused by stratigraphy or discontinuities of the stratigraphic units, are a major control on the direction of groundwater flow and the distribution of water levels and salinity. Results of cross-sectional modeling confirm the general groundwater flow pattern that would be expected in a layered coastal system. Ground-water flow is: (a) predominantly upward in the low-permeability sedimentary units; and (b) predominantly horizontal in the high-permeability sedimentary units.

Oki, D. S.; Souza, W. R.; Bolke, E. L.; Bauer, G. R.

1998-01-01

286

Hydrogeological definition and applicability of abandoned coal mines as water reservoirs.  

PubMed

Hydrogeologically, the Central Coal Basin (Asturias, Spain) is characterized by predominantly low-permeability materials that make up a multilayer aquifer with very low porosity and permeability values, where the sandstones act as limited aquifers, and wackes, mudstones, shales and coal seams act as confining levels. Preferential groundwater flow paths are open fractures and zones of decompression associated with them, so the hydraulic behaviour of the system is more associated with fracturing than lithology. Thus, abandoned and flooded mines in the area acquire an important role in the management of water resources, setting up an artificial "pseudo-karst" aquifer. This paper evaluates the potential application of the abandoned mines as underground reservoirs, both for water supply and energetic use, mainly through heat pumps and small hydropower plants. In particular, the groundwater reservoir shaped by the connected shafts Barredo and Figaredo has been chosen, and a detailed and multifaceted study has been undertaken in the area. The exposed applications fit with an integrated management of water resources and contribute to improve economic and social conditions of a traditional mining area in gradual decline due to the cessation of such activity. PMID:22833009

Ordóñez, A; Jardón, S; Álvarez, R; Andrés, C; Pendás, F

2012-08-01

287

An integrated model for simulating nitrogen trading in an agricultural catchment with complex hydrogeology.  

PubMed

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

Cox, T J; Rutherford, J C; Kerr, S C; Smeaton, D C; Palliser, C C

2013-09-30

288

Description and hydrogeologic evaluation of nine hazardous-waste sites in Kansas, 1984-86  

USGS Publications Warehouse

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)

Hart, R. J.; Spruill, T. B.

1988-01-01

289

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

USGS Publications Warehouse

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)

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

1986-01-01

290

The hydrogeology of the Condamine River Alluvial Aquifer, Australia: a critical assessment  

NASA Astrophysics Data System (ADS)

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.

Dafny, Elad; Silburn, D. Mark

2013-12-01

291

The inversion of geoelectrical data for hydrogeological applications in crystalline basement areas of Nigeria  

NASA Astrophysics Data System (ADS)

A methodology is presented for the inversion of two-dimensional (2-D) geoelectrical data for solving hydrogeological problems in crystalline basement areas. The initial step entails compiling an earth model using all available geological, borehole and geophysical information. This model then served as the input to a 2-D inversion algorithm based on the Simultaneous Iterative Reconstruction Technique (SIRT). The algorithm tries to find a model that is as close as possible to the starting model. To demonstrate the usefulness of this procedure, two field examples from Nigeria, conducted as part of a borehole siting programme, are described. In the first example, borehole information regarding the thickness of the weathered zone overlying a gneissic bedrock was used to constrain the 1-D inversion of sounding data and the model thus compiled was used as the starting model for 2-D inversion. In the second example, only sounding information was used to determine the starting model. If the starting model has incorporated all the available information as constraints, it is generally possible to compute a model that not only fits the measured data but is also a good approximation of the subsurface geology, more so when several 2-D models can fit the same set of field measurements on account of the limitations posed by equivalence.

Olayinka, A. I.; Weller, A.

1997-06-01

292

Hydrogeology of the unsaturated zone, North Ramp area of the Exploratory Studies Facility, Yucca Mountain, Nevada  

SciTech Connect

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.

Rousseau, J.P.; Kwicklis, E.M.; Gillies, D.C. [eds.

1999-03-01

293

The hydrogeology of the Condamine River Alluvial Aquifer, Australia: a critical assessment  

NASA Astrophysics Data System (ADS)

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.

Dafny, Elad; Silburn, D. Mark

2014-05-01

294

Hydrogeology of the Kabul Basin (Afghanistan), part I: aquifers and hydrology  

NASA Astrophysics Data System (ADS)

Shallow groundwater represents the main source for water supply in Kabul, Afghanistan. Detailed information on the hydrogeology of the Kabul Basin is therefore needed to improve the current supply situation and to develop a sustainable framework for future groundwater use. The basin is situated at the intersection of three major fault systems of partially translational and extensional character. It comprises three interconnected aquifers, 20-70 m thick, consisting of coarse sandy to gravely detritus originating from the surrounding mountains. The aquifers were deposited by three rivers flowing through the basin. The coarse aquifer material implies a high permeability. Deeper parts are affected by cementation of pore spaces, resulting in formation of semi-diagenetic conglomerates, causing decreased well yields. Usually the aquifers are covered by low-permeability loess which acts as an important protection layer. The main groundwater recharge occurs after the snowmelt from direct infiltration from the rivers. The steadily rising population is estimated to consume 30-40 million m3 groundwater per year which is contrasted by an estimated recharge of 20-45 million m3/a in wet years. The 2000-2005 drought has prevented significant recharge resulting in intense overexploitation indicated by falling groundwater levels.

Houben, Georg; Niard, Nadege; Tünnermeier, Torge; Himmelsbach, Thomas

2009-05-01

295

Hydrogeological relationships of sandy deposits: modeling of two-dimensional unsaturated water and pesticide transport.  

PubMed

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

Iversen, Bo V; van der Keur, Peter; Vosgerau, Henrik

2008-01-01

296

The Influence of Subsurface Karst Terrain on Hydrology and Hydrogeology in Southwestern Victoria, Australia  

NASA Astrophysics Data System (ADS)

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.

Perveen, F.; Webb, J.; Dresel, E.; Hekmeijer, P.; Zydor, H.

2012-12-01

297

Hydrogeological factors affecting the multiple plumes of chlorinated contaminants in an industrial complex, Wonju, Korea  

NASA Astrophysics Data System (ADS)

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.

Yang, J.; Kaown, D.; Lee, H.; Lee, K.

2010-12-01

298

Borehole Fluid Logging Methods for Hydrogeologic Characterization: What Have We Learned in Twenty-Five Years?  

NASA Astrophysics Data System (ADS)

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.

Pedler, W. H.

2012-12-01

299

Hydrogeology of the Little Spokane River Basin, Spokane, Stevens, and Pend Oreille Counties, Washington  

USGS Publications Warehouse

A study of the hydrogeologic framework of the Little Spokane River Basin was conducted to identify and describe the principal hydrogeologic units in the study area, their hydraulic characteristics, and general directions of groundwater movement. The Little Spokane River Basin includes an area of 679 square miles in northeastern Washington State covering parts of Spokane, Stevens, and Pend Oreille Counties. The groundwater system consists of unconsolidated sedimentary deposits and isolated, remnant basalt layers overlying crystalline bedrock. In 1976, a water resources program for the Little Spokane River was adopted into rule by the State of Washington, setting instream flows for the river and closing its tributaries to further uses. Spokane County representatives are concerned about the effects that additional groundwater development within the basin might have on the Little Spokane River and on existing groundwater resources. Information provided by this study will be used in future investigations to evaluate the effects of potential increases in groundwater withdrawals on groundwater and surface-water resources in the basin. The hydrogeologic framework consists of eight hydrogeologic units: the Upper aquifer, Upper confining unit, Lower aquifers, Lower confining unit, Wanapum basalt unit, Latah unit, Grande Ronde basalt unit, and Bedrock. The Upper aquifer is composed mostly of sand and gravel and varies in thickness from 4 to 360 ft, with an average thickness of 70 ft. The aquifer is generally finer grained in areas farther from main outwash channels. The estimated horizontal hydraulic conductivity ranges from 4.4 to 410,000 feet per day (ft/d), with a median hydraulic conductivity of 900 ft/d. The Upper confining unit is a low-permeability unit consisting mostly of silt and clay, and varies in thickness from 5 to 400 ft, with an average thickness of 100 ft. The estimated horizontal hydraulic conductivity ranges from 0.5 to 5,600 ft/d, with a median hydraulic conductivity of 8.2 ft/d. The Lower aquifers unit consists of localized confined aquifers or lenses consisting mostly of sand that occur at depth in various places in the basin; thickness of the unit ranges from 8 to 150 ft, with an average thickness of 50 ft. The Lower confining unit is a low-permeability unit consisting mostly of silt and clay; thickness of the unit ranges from 35 to 310 ft, with an average thickness of 130 ft. The Wanapum basalt unit includes the Wanapum Basalt of the Columbia River Basalt Group, thin sedimentary interbeds, and, in some places, overlying loess. The unit occurs as isolated remnants on the basalt bluffs in the study area and ranges in thickness from 7 to 140 ft, with an average thickness of 60 ft. The Latah unit is a mostly low-permeability unit consisting of silt, clay, and sand that underlies and is interbedded with the basalt units. The Latah unit ranges in thickness from 10 to 700 ft, with an average thickness of 250 ft. The estimated horizontal hydraulic conductivity ranges from 0.19 to 15 ft/d, with a median hydraulic conductivity of 0.56 ft/d. The Grande Ronde unit includes the Grande Ronde Basalt of the Columbia River Basalt Group and sedimentary interbeds. Unit thickness ranges from 30 to 260 ft, with an average thickness of 140 ft. The estimated horizontal hydraulic conductivity ranges from 0.03 to 13 ft/d, with a median hydraulic conductivity of 2.9 ft/d. The Bedrock unit is the only available source of groundwater where overlying sediments are absent or insufficiently saturated. The estimated horizontal hydraulic conductivity ranges from 0.01 to 5,000 ft/d, with a median hydraulic conductivity of 1.4 ft/d. The altitude of the buried bedrock surface ranges from about 2,200 ft to about 1,200 ft. Groundwater movement in the Little Spokane River Basin mimics the surface-water drainage pattern of the basin, moving from the topographically high tributary-basin areas toward the topographically lower valley floors. Water-level altitudes range from more than 2,700 ft to about 1,500 ft near the basin’s outlet.

Kahle, Sue C.; Olsen, Theresa D.; Fasser, Elisabeth T.

2013-01-01

300

Numerical Modeling of the Soil Cover System Performance from Hydrogeological Analysis  

NASA Astrophysics Data System (ADS)

Decline of mining industry is drastic in production and consumption in Korea, and the number of operating mines has been reduced by more than 90 percent in last two decades. Environmental concern and the collapse of commercial viability has necessitated the government to close down uneconomical mines, and reclamation of mine waste dumps and the proper treatment of the mine drainage constitute the most important factors for regional rehabilitation programs. A dry soil cover system for mine waste is steadily increasing in Korea, to minimize the influx of water and oxygen into the waste dump. Traditional cover design procedures based on empirical or semi-quantitative analyses can be improved by implementing environmental and hydrological parameters including total precipitation, evapotranspiration, surface runoff, and infiltration associated with different cover configurations. The main objective of this study is to develop a standardized design procedure for dry cover systems to minimize environmental impacts in mine lands, securing both efficiency and long-term structural stability. A numerical analysis technique was adopted for selecting governing parameters which dictate hydrogeologic characteristics of the unsaturated zone in soil cover system. Variables included the soil water characteristic curve, hydraulic conductivity function, and water balance of the study area. A commercial finite element analysis software was applied for performance analysis of three soil cover systems including a simple growth medium, sand layer, and sand-clay-sand complex layer.

Min, D.; Cheong, Y.; Yim, G.; Baek, H.

2008-05-01

301

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

USGS Publications Warehouse

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.

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

1996-01-01

302

Hydrogeologic Characterization of the Brazos River Alluvium Aquifer, Bosque County to Fort Bend County, Texas  

USGS Publications Warehouse

Introduction The Brazos River alluvium aquifer underlies the Brazos River in Texas from Bosque County to Fort Bend County. The aquifer, one of 21 minor aquifers in the State, supplies water for irrigation, domestic, stock, and commercial use. The Brazos River alluvium aquifer likely will become more important in the future as demand for water increases statewide. A thorough understanding of the hydrogeology of the alluvium aquifer will be the foundation for future studies in the area. During October 2006-April 2007, the U.S. Geological Survey, in cooperation with the Texas Water Development Board, conducted a study to delineate the altitude of the top, altitude of the base, and thickness of the Brazos River alluvium aquifer, and to compile and summarize available hydraulic property (specific capacity, transmissivity, and hydraulic conductivity) data. A digital elevation model was used as the altitude of the top of the aquifer. The altitude of the base of the aquifer was generated using data from wells. The study area encompasses the Brazos River alluvium aquifer in parts of Bosque, Hill, McLennan, Falls, Robertson, Milam, Brazos, Burleson, Grimes, Washington, Waller, Austin, and Fort Bend Counties and a 1.5-mile-wide lateral buffer adjacent to the aquifer. The results of this study will be used by the Texas Water Development Board for input into a ground-water availability model.

Shah, Sachin D.; Houston, Natalie A.; Braun, Christopher L.

2007-01-01

303

Evaluation of intrinsic groundwater vulnerability to pollution: COP method for pilot area of Carrara hydrogeological system (Northern Tuscany, Italy)  

NASA Astrophysics Data System (ADS)

During the characterization of the Apuan Alps groundwater body ( "Corpo Idrico Sotterraneo Significativo", briefly CISS) (Regione Toscana, 2007) the intrinsic vulnerability has been evaluated for Carrara hydrogeological system (Northern Tuscany, Italy) by means of COP method, developed within COST 620 European Action (Zwalhlen, 2003). This system is both characterized by large data availability and it is considered an highly risky zone since groundwater protection problems (turbidity of the tapped spring waters and hydrocarbons contamination) and anthropic activity (marble quarries). The study area, 20 Km2large, has high relief energy, with elevations ranging from 5 to 1700 m amsl in almost 5 km. Runoff is scarce except during heavy rainfall; due to the presence of carbonate rocks infiltration is high: groundwater discharge at 155-255 m amsl. The area is located in the north-western part of Apuan Alps Metamorphic Complex, characterized by carbonate and non-carbonate rocks belonging to the non-metamorphic Tuscan Units (Carnic-Oligocene), Mesozoic Succession, Middle-Triassic Succession, and metamorphic Paleozoic rocks. The main geological structure of the area is the Carrara Syncline, constituted prevalently by dolostones, marbles and cherty limestones. These carbonate formations define several moderately to highly productive hydrogeological units, characterized by fissured and karst flow. Hydrogeological system may be subdivided in two different subsets, because of both geo-structural set up and area conformation. However, these are hydrogeologically connected since anisotropy and fractures of karst groundwater. The southern boundary of Carrara hydrogeological system shows important dammed springs, defined by low productive units of Massa Unit (Cambriano?-Carnic). COP methodology for evaluating intrinsic vulnerability of karst groundwater is based on three main factors for the definition of vulnerability itself: COPIndex = C (flow Concentration) *O (Overlying layers) *P (Precipitation). In this way it is possible to estimate the natural grade of groundwater protection (O factor), determined by both soils properties and vadose zone lithology, and then evaluate how this protection could be modified by infiltration processes (diffused or concentrated, C factor) and climatic conditions (P factor). Factor elaborations have been calculated by study area discretization by means of raster grid with square cells, 100 m large, yielding the values distribution of sub-factor for each factor, and then the spatial distribution of intrinsic vulnerability, as result of geoprocessing and map analysis raster techniques in software ESRI ArcInfo® 9.1. Results shows in the study area: 1) Medium and high values of vulnerability classes; 2) Areas with high vulnerability located in zones with low O protection index and moderate protection reduction; 3) C factor contributes to the high vulnerability where superficial cover supports more the infiltration than the run-off (slope between 8 and 31%); 4) Low vulnerability grade areas are either inside unproductive hydrogeological units, or with thick superficial covers. Comparing these results with previous study, the distribution obtained by COP methodology shows larger variations between very high and high vulnerability area distribution. Most of the first areas are located in the central part of hydrogeological system, near to the main spring, and also in northern areas, where there is a swallow hole. This result yields a more precautionary scenario for particularly sensitive are characterized by high anthropogenic activity (marble quarry). Moreover, the vulnerability of such area is confirmed by both natural tracers (Lycopodium clavatum; Baldi, 2004) and environmental isotopes (2H, 3H, 18O; Doveri, 2005). This methodology allowed adding further information about intrinsic vulnerability of a hydrological contest very sensitive to anthropogenic pressures, and it is important for water resource as well. Such vulnerability map highlights higher vulnerability areas than those showed in previ

Baldi, B.; Guastaldi, E.; Rossetto, R.

2009-04-01

304

Probability distributions of hydraulic conductivity for the hydrogeologic units of the Death Valley regional ground-water flow system, Nevada and California  

SciTech Connect

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.

Belcher, W.R.; Sweetkind, D.S.; Elliott, P.E.

2002-11-19

305

Hydrogeology and water-quality characteristics of the Lower Floridan aquifer in east-central Florida  

USGS Publications Warehouse

The hydrogeology and water-quality characteristics of the Lower Floridan aquifer and the relation of the Lower Floridan aquifer to the framework of the Floridan aquifer system were evaluated during a 6-year (1995-2001) study. The study area, a 7,500 square-mile area of east-central Florida, is underlain by three principal hydrogeologic units: the surficial aquifer system, the intermediate confining unit, and the Floridan aquifer system. The Floridan aquifer system, a carbonate-rock aquifer system composed of the Upper Floridan aquifer, a middle semiconfining unit, a middle confining unit, and the Lower Floridan aquifer, is the major source of water supply to east-central Florida. The Upper Floridan aquifer provides much of the water required to meet the current (2002) demand; however, the Lower Floridan aquifer is being used increasingly as a source of freshwater, particularly for municipal needs. For this reason, a better understanding of the aquifer is needed. The Lower Floridan aquifer is present throughout east-central Florida. The aquifer is composed of alternating beds of limestone and dolomite, and is characterized by abundant fractured dolomite zones and solution cavities. The altitude of the top of the Lower Floridan aquifer ranges from less than 600 feet below sea level in the northern part of the study area to more than 1,600 feet below sea level in the southwestern part. Thickness of the unit ranges from about 910 to 1,180 feet. The top of the Lower Floridan aquifer generally is marked by an increase in formation resistivity and by an increase in the occurrence of fractures and solution cavities within the carbonates. Also, a noticeable increase in borehole flow often marks the top of the unit. The bottom of the Lower Floridan aquifer is based on the first occurrence of evaporites. Ground-water in the Lower Floridan aquifer generally moves in a southwest-to-northeast direction across the study area. In September 1998, the altitude of the potentiometric surface of the Lower Floridan aquifer ranged from about 16 to 113 feet above sea level, and altitudes in May 1999 were about 2 to 7 feet lower than those measured in September 1998. The potentiometric surface of the Floridan aquifer system is constantly fluctuating, mainly in response to seasonal variations in rainfall and ground-water withdrawals. Seasonal fluctuations in the Lower Floridan aquifer typically range from about 2 to 10 feet. Water samples from 50 Lower Floridan aquifer wells were collected during this study. Most samples were analyzed in the field for temperature, pH, and specific conductance, and in the laboratory for major cations and anions. Specific conductance ranged from 147 to 6,710 microsiemens per centimeter. Chloride concentrations ranged from 3.0 to 2,188 milligrams per liter; sulfate concentrations ranged from 0.2 to 750 milli-grams per liter; and hardness ranged from 69 to 940 milligrams per liter. Water was least mineralized in the recharge areas of the Lower Floridan aquifer in the western part of the study area. The most mineralized water in the Lower Floridan aquifer occurred along parts of the Wekiva and St. Johns Rivers and in much of the eastern and southern parts of the study area. The altitude of the base of freshwater in the Floridan aquifer system (where chloride concentrations are equal to 250 milligrams per liter) is variable throughout the study area. The estimated position of the 250 milligram per liter isochlor surface is less than 200 feet below sea level in much of the eastern part of the study area, including the areas along the St. Johns River in Lake, Seminole, and Volusia Counties and near the Wekiva River in western Seminole County. The altitude of the 250 milligram per liter isochlor exceeds 3,000 feet below sea level in the extreme southwestern part of the study area.

O'Reilly, Andrew M.; Spechler, Rick M.; McGurk, Brian E.

2002-01-01

306

Conceptual hydrogeologic framework of the shallow aquifer system at Virginia Beach, Virginia  

USGS Publications Warehouse

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. Concentrations of manganese and chloride were higher than the Secondary Drinking Water Regulations in samples from some wells.In the humid climate of Virginia Beach, the periodic recharge of freshwater through the sand units of the shallow aquifer system occurs often enough to create a dynamic equilibrium whereby freshwater flows continually down and away from the center of the ridges to mix with and sweep brackish water and saltwater back toward the tidal rivers, bays, salt marshes, and the Atlantic Ocean.The aquifers and confining units of the shallow aquifer system at Virginia Beach are heterogeneous, discontinuous, and without exact marker beds, which makes correlations in the study area difficult. Investigations using well cuttings, spot cores, or split-spoon samples with geophysical logs are not as definitive as continuous cores for determining or correlating hydrogeologic units. Future investigations of the shallow aquifer system would benefit by collecting continuous cores.

Smith, Barry S.; Harlow, George E., Jr.

2002-01-01

307

Hydrogeology of the West Branch Delaware River basin, Delaware County, New York  

USGS Publications Warehouse

In 2009, the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, began a study of the hydrogeology of the West Branch Delaware River (Cannonsville Reservoir) watershed. There has been recent interest by energy companies in developing the natural gas reserves that are trapped within the Marcellus Shale, which is part of the Hamilton Group of Devonian age that underlies all the West Branch Delaware River Basin. Knowing the extent and thickness of stratified-drift (sand and gravel) aquifers within this basin can help State and Federal regulatory agencies evaluate any effects on these aquifers that gas-well drilling might produce. This report describes the hydrogeology of the 455-square-mile basin in the southwestern Catskill Mountain region of southeastern New York and includes a detailed surficial geologic map of the basin. Analysis of surficial geologic data indicates that the most widespread surficial geologic unit within the basin is till, which is present as deposits of ablation till in major stream valleys and as thick deposits of lodgment till that fill upland basins. Till and colluvium (remobilized till) cover about 89 percent of the West Branch Delaware River Basin, whereas stratified drift (outwash and ice-contact deposits) and alluvium account for 8.9 percent. The Cannonsville Reservoir occupies about 1.9 percent of the basin area. Large areas of outwash and ice-contact deposits occupy the West Branch Delaware River valley along its entire length. These deposits form a stratified-drift aquifer that ranges in thickness from 40 to 50 feet (ft) in the upper West Branch Delaware River valley, from 70 to 140 ft in the middle West Branch Delaware River valley, and from 60 to 70 ft in the lower West Branch Delaware River valley. The gas-bearing Marcellus Shale underlies the entire West Branch Delaware River Basin and ranges in thickness from 600 to 650 ft along the northern divide of the basin to 750 ft thick along the southern divide. The depth to the top of the Marcellus Shale ranges from 3,240 ft along the northern basin divide to 4,150 ft along the southern basin divide. Yields of wells completed in the aquifer are as high as 500 gallons per minute (gal/min). Springs from fractured sandstone bedrock are an important source of domestic and small municipal water supplies in the West Branch Delaware River Basin and elsewhere in Delaware County. The average yield of 178 springs in Delaware County is 8.5 gal/min with a median yield of 3 gal/min. An analysis of two low-flow statistics indicates that groundwater contributions from fractured bedrock compose a significant part of the base flow of the West Branch Delaware River and its tributaries.

Reynolds, Richard J.

2013-01-01

308

Correlation of Miocene sequences and hydrogeologic units, New Jersey Coastal Plain  

USGS Publications Warehouse

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.

Sugarman, P. J.; Miller, K. G.

1997-01-01

309

Data requirements for simulation of hydrogeologic effects of liquid waste injection, Harrison and Jackson Counties, Mississippi  

USGS Publications Warehouse

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.

Rebich, Richard A.

1994-01-01

310

A hydrogeological study of the Nhandugue River, Mozambique - A major groundwater recharge zone  

NASA Astrophysics Data System (ADS)

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.

Arvidsson, K.; Stenberg, L.; Chirindja, F.; Dahlin, T.; Owen, R.; Steinbruch, F.

311

Transport and fate of nitrate and pesticides: Hydrogeology and riparian zone processes  

USGS Publications Warehouse

There is continuing concern over potential impacts of widespread application of nutrients and pesticides on ground- and surface-water quality. Transport and fate of nitrate and pesticides were investigated in a shallow aquifer and adjacent stream, Cow Castle Creek, in Orangeburg County, South Carolina. Pesticide and pesticide degradate concentrations were detected in ground water with greatest frequency and largest concentrations directly beneath and downgradient from the corn (Zea mays L.) field where they were applied. In almost all samples in which they were detected, concentrations of pesticide degradates greatly exceeded those of parent compounds, and were still present in ground waters that were recharged during the previous 18 yr. The absence of both parent and degradate compounds in samples collected from deeper in the aquifer suggests that this persistence is limited or that the ground water had recharged before use of the pesticide. Concentrations of NO3- in ground water decreased with increasing depth and age, but denitrification was not a dominant controlling factor. Hydrologic and chemical data indicated that ground water discharges to the creek and chemical exchange takes place within the upper 0.7 m of the streambed. Ground water had its greatest influence on surface-water chemistry during low-flow periods, causing a decrease in concentrations of Cl-, NO3-, pesticides, and pesticide degradates. Conversely, shallow subsurface drainage dominates stream chemistry during high-flow periods, increasing stream concentrations of Cl-, NO3-, pesticides, and pesticide degradates. These results point out the importance of understanding the hydrogeologic setting when investigating transport and fate of contaminants in ground water and surface water. ?? ASA, CSSA, SSSA.

Puckett, L. J.; Hughes, W. B.

2005-01-01

312

Developing a modular hydrogeology ontology by extending the SWEET upper-level ontologies  

NASA Astrophysics Data System (ADS)

Upper-level ontologies comprise general concepts and properties which need to be extended to include more diverse and specific domain vocabularies. We present the extension of NASA's Semantic Web for Earth and Environmental Terminology (SWEET) ontologies to include part of the hydrogeology domain. We describe a methodology that can be followed by other allied domain experts who intend to adopt the SWEET ontologies in their own discipline. We have maintained the modular design of the SWEET ontologies for maximum extensibility and reusability of our ontology in other fields, to ensure inter-disciplinary knowledge reuse, management, and discovery. The extension of the SWEET ontologies involved identification of the general SWEET concepts (classes) to serve as the super-class of the domain concepts. This was followed by establishing the special inter-relationships between domain concepts (e.g., equivalence for vadose zone and unsaturated zone), and identifying the dependent concepts such as physical properties and units, and their relationship to external concepts. Ontology editing tools such as SWOOP and Protégé were used to analyze and visualize the structure of the existing OWL files. Domain concepts were introduced either as standalone new classes or as subclasses of existing SWEET ontologies. This involved changing the relationships (properties) and/or adding new relationships based on domain theories. In places, in the Owl files, the entire structure of the existing concepts needed to be changed to represent the domain concept more meaningfully. Throughout this process, the orthogonal structure of SWEET ontologies was maintained and the consistency of the concepts was tested using the Racer reasoner. Individuals were added to the new concepts to test the modified ontologies. Our work shows that SWEET ontologies can successfully be extended and reused in any field without losing their modular or reference structure, or disrupting their URI links.

Tripathi, Ajay; Babaie, Hassan A.

2008-09-01

313

Hydrogeologic controls on nitrate transport in a small agricultural catchment, Iowa  

USGS Publications Warehouse

Effects of subsurface deposits 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 Iowa catchment. Subsurface deposits in the catchment consisted of upland areas of loess overlying weathered pre-Illinoian till, drained by two ephemeral drainageways that consisted of Holocene-age silty and organic rich alluvium. Water tables in upland areas fluctuated more than 4 m per year compared to less than 0.3 m in the drainageway. Water quality patterns showed a distinct spatial pattern, with groundwater in the drainageways having lower nitrate concentrations (10 mg L-1) as wells as lower pH, dissolved oxygen and redox, and higher ammonium and dissolved organic carbon levels. Several lines of evidence suggested that conditions are conducive for denitrification of groundwater flowing from uplands through the drainageways. Field-measured nitrate decay rates in the drainageways (???0.02 day-1) were consistent with other laboratory studies and regional patterns. Results from MODFLOW and MT3DMS simulations indicated that soils in the ephemeral drainageways could process all upland groundwater nitrate flowing through them. However, model-simulated tile drainage increased both water flux and nitrate loss from the upland catchment. Study results suggest that ephemeral drainageways can provide a natural nitrate treatment system in our upland glaciated catchments, offering management opportunities to reduce nitrate delivery to streams. Copyright 2007 by the American Geophysical Union.

Schilling, K. E.; Tomer, M. D.; Zhang, Y. -K.; Weisbrod, T.; Jacobson, P.; Cambardella, C. A.

2007-01-01

314

Hydrogeologic conditions and water management modeling for a Sierra Nevada fen wetland  

NASA Astrophysics Data System (ADS)

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.

Ronayne, M. J.; Cooper, D.; Wolf, E. C.

2012-12-01

315

Collaborative research: Hydrogeological-geophysical methods for subsurface site characterization. 1997 annual progress report  

SciTech Connect

'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.'

Rubin, Y.; Morrison, F.; Rector, J.

1997-10-31

316

Transport and fate of nitrate and pesticides: hydrogeology and riparian zone processes.  

PubMed

There is continuing concern over potential impacts of widespread application of nutrients and pesticides on ground- and surface-water quality. Transport and fate of nitrate and pesticides were investigated in a shallow aquifer and adjacent stream, Cow Castle Creek, in Orangeburg County, South Carolina. Pesticide and pesticide degradate concentrations were detected in ground water with greatest frequency and largest concentrations directly beneath and downgradient from the corn (Zea mays L.) field where they were applied. In almost all samples in which they were detected, concentrations of pesticide degradates greatly exceeded those of parent compounds, and were still present in ground waters that were recharged during the previous 18 yr. The absence of both parent and degradate compounds in samples collected from deeper in the aquifer suggests that this persistence is limited or that the ground water had recharged before use of the pesticide. Concentrations of NO(-)(3) in ground water decreased with increasing depth and age, but denitrification was not a dominant controlling factor. Hydrologic and chemical data indicated that ground water discharges to the creek and chemical exchange takes place within the upper 0.7 m of the streambed. Ground water had its greatest influence on surface-water chemistry during low-flow periods, causing a decrease in concentrations of Cl(-), NO(-)(3), pesticides, and pesticide degradates. Conversely, shallow subsurface drainage dominates stream chemistry during high-flow periods, increasing stream concentrations of Cl(-), NO(-)(3), pesticides, and pesticide degradates. These results point out the importance of understanding the hydrogeologic setting when investigating transport and fate of contaminants in ground water and surface water. PMID:16275729

Puckett, Larry J; Hughes, W Brian

2005-01-01

317

Providing a Connection between a Bayesian Inverse Modeling Tool and a Coupled Hydrogeological Processes Modeling Software  

NASA Astrophysics Data System (ADS)

The Method of Anchored Distributions (MAD) is a Bayesian technique for characterizing the uncertainty in geostatistical model parameters. Open-source software has been developed in a modular framework such that this technique can be applied to any forward model software via a driver. This presentation is about the driver that has been developed for OpenGeoSys (OGS), open-source software that can simulate many hydrogeological processes, including couple processes. MAD allows the use of multiple data types for conditioning the spatially random fields and assessing model parameter likelihood. For example, if simulating flow and mass transport, the inversion target variable could be hydraulic conductivity and the inversion data types could be head, concentration, or both. The driver detects from the OGS files which processes and variables are being used in a given project and allows MAD to prompt the user to choose those that are to be modeled or to be treated deterministically. In this way, any combination of processes allowed by OGS can have MAD applied. As for the software, there are two versions, each with its own OGS driver. A Windows desktop version is available as a graphical user interface and is ideal for the learning and teaching environment. High-throughput computing can even be achieved with this version via HTCondor if large projects want to be pursued in a computer lab. In addition to this desktop application, a Linux version is available equipped with MPI such that it can be run in parallel on a computer cluster. All releases can be downloaded from the MAD Codeplex site given below.

Frystacky, H.; Osorio-Murillo, C. A.; Over, M. W.; Kalbacher, T.; Gunnell, D.; Kolditz, O.; Ames, D.; Rubin, Y.

2013-12-01

318

Denitrification and patterns of electron donors and acceptors in 8 riparian zones with contrasting hydrogeology  

NASA Astrophysics Data System (ADS)

A better understanding of nitrate removal mechanisms is important for managing the water quality function of stream riparian zones. We examined the linkages between hydrologic flow paths, patterns of electron donors and acceptors and the importance of denitrification as a nitrate removal mechanism in 8 riparian zones on glacial till and outwash landscapes in southern Ontario, Canada. Nitrate-N concentrations in shallow groundwater from adjacent cropland declined from levels that were often 10-30 mg L-1 near the field-riparian edge to <1 mg L-1 in the riparian zones throughout the year. Chloride data suggest that dilution cannot account for most of this nitrate decline. Despite contrasting hydrogeologic settings, these riparian zones displayed a well-organized pattern of electron donors and acceptors that resulted from the transport of oxic nitrate-rich groundwater to portions of the riparian zones where low DO concentrations and an increase in DOC concentrations were encountered. The natural abundances of d15N and in situ acetylene injection to piezometers indicate that denitrification is the primary mechanism of nitrate removal in all of the riparian zones. Our data indicate that effective nitrate removal by denitrification occurs in riparian zones with hydric soils as well as in non-hydric riparian zones and that a shallow water table is not always necessary for efficient nitrate removal by denitrification. The location of "hot spots" of denitrification within riparian areas can be explained by the influence of key landscape variables such as slope, sediment texture and depth of confining layers on hydrologic pathways that link supplies of electron donors and acceptors.

Vidon, P.; Hill, A.

2004-12-01

319

Hydrogeological and isotopic study of surface water and groundwater in the Eastern Haouz Plain. Western Morocco  

NASA Astrophysics Data System (ADS)

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 processes and higher soil-water interaction. This may be partially due to return flow from agricultural irrigation.

El Mandour, Abdennabi; Rochdane, Samia; Reddy, Venkat; Himi, Mahjoub; Casas, Albert

2014-05-01

320

Hydrogeologic characterization of a proposed landfill expansion in Pickens County near Easley, South Carolina  

USGS Publications Warehouse

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.

Stringfield, W. J.

1994-01-01

321

Hydrogeology and ground-water-quality conditions at the Emporia- Lyon County Landfill, eastern Kansas, 1988  

USGS Publications Warehouse

Hydrogeology and water-quality conditions at the Emporia-Lyon County Landfill, eastern Kansas, were investigated from April 1988 through April 1989. Potentiometric-surface maps indicated groundwater movement from the northeast and northwest towards the landfill and then south through the landfill to the Cottonwood River. The maps indicate that during periods of low groundwater levels, groundwater flows northward in the north-west part of the landfill, which may have been induced by water withdrawal from wells north of the landfill or by water ponded in waste lagoons south and west of the landfill. Chemical analysis of water samples from monitoring wells upgradient and downgradient of the landfill indicate calcium bicarbonate to be the dominant water type. No inorganic or organic chemical concentrations exceeded Kansas or Federal primary drinking-water standards. Kansas secondary drinking-water standards were equaled or exceeded, however, in water from some or all wells for total hardness, dissolved solids, iron, and manganese. Water from one upgradient well contained larger concentrations of dissolved oxygen and nitrate, and smaller concentrations of bicarbonate, alkalinity, ammonia, arsenic, iron, and manganese as compared to all other monitoring wells. Results of this investigation indicate that groundwater quality downgradient of well MW-2 has increased concentrations of some inorganic and organic compounds. Due to the industrial nature of the area and the changing directions of groundwater flow, it is not clear what the source of these compounds might be. Long-term monitoring, additional wells, and access to nearby waste lagoons and waste-lagoon monitoring wells would help define the sources of increased inorganic and organic compounds. (USGS)

Myers, N. C.; Bigsby, P. R.

1990-01-01

322

Hydrogeologic factors affecting cavern morphology within rocks of Mississippian age in northwestern Arkansas  

SciTech Connect

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.

Fanning, B.J. (Univ. of Arkansas, Fayetteville, AR (United States). Dept. of Geology); Brahana, J.V. (Univ. of Arkansas , Fayetteville, AR (United States). Geological Survey)

1993-02-01

323

Groundwater protection and unconventional gas extraction: the critical need for field-based hydrogeological research.  

PubMed

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

Jackson, R E; Gorody, A W; Mayer, B; Roy, J W; Ryan, M C; Van Stempvoort, D R

2013-01-01

324

Faulting and groundwater in a desert environment: constraining hydrogeology using time-domain electromagnetic data  

USGS Publications Warehouse

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.

Bedrosian, Paul A.; Burgess, Matthew K.; Nishikawa, Tracy

2013-01-01

325

Hydrogeology and water quality of the North Canadian River alluvium, Concho Reserve, Canadian County, Oklahoma  

USGS Publications Warehouse

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.

Becker, C. J.

1998-01-01

326

Hydrogeology and ground-water flow at the Muddy Brook riparian zone, north-central Connecticut  

USGS Publications Warehouse

The hydrogeology and ground-water flow of Muddy Brook were investigated as part of a study to determine the effects of restoring agricultural riparian land to forest on water quality. Test-hole drilling, well installation, and slug-test analyses indicate that the part of Muddy Brook studied is underlain by thin stratified-drift deposits. These deposits are mostly less than 10 feet thick and have estimated horizontal hydraulic conductivities of 4 to 30 feet per day. Till deposits from 1 to 14 feet thick underlie the stratified-drift deposits and have estimated horizontal hydraulic conductivities of 0.1 and 4.3 feet per day. The water table in stratified drift is less than 10 feet below land surface during most of the year, and the horizontal hydraulic gradient varies seasonally and areally from 0.015 to 0.07 feet per foot. The horizontal hydraulic gradient in the till deposits is as great as 0.1 feet per foot. Vertical hydraulic gradients of as large as 0.4 feet per foot are present between the till and stratified drift and are predominantly upward from the till into the stratified drift but can reverse direction in response to recharge. Ground-water discharge to Muddy Brook comes mostly from the saturated stratified-drift deposits, and during April through September 1992, flowed at a rate of 0.015 to 0.027 cubic feet per second. Average ground-water velocity is about 1 feet per day in the stratified drift and about 0.2 foot per day through the till deposits. Discharge of ground water from the till can contribute as much as 0.006 cubic feet per second of water to the stratified drift.

Mullaney, J. R.

1995-01-01

327

Progress Toward Understanding of Coupled Microbiology, Biogeochemistry, and Hydrogeology Controls on Subsurface Mobility of Uranium  

NASA Astrophysics Data System (ADS)

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.

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

328

Hydrochemistry and hydrogeologic conditions within the Hanford Site upper basalt confined aquifer system  

SciTech Connect

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.

Spane, F.A. Jr.; Webber, W.D.

1995-09-01

329

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

USGS Publications Warehouse

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)

Grannemann, N. G.

1984-01-01

330

Differential Hydrogeological Effects of Draining Tunnels Through the Northern Apennines, Italy  

NASA Astrophysics Data System (ADS)

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.

Vincenzi, Valentina; Gargini, Alessandro; Goldscheider, Nico; Piccinini, Leonardo

2014-05-01

331

Hydrogeology and Ground-Water Flow in the Opequon Creek Watershed area, Virginia and West Virginia  

USGS Publications Warehouse

Due to increasing population and economic development in the northern Shenandoah Valley of Virginia and West Virginia, water availability has become a primary concern for water-resource managers in the region. To address these issues, the U.S. Geological Survey (USGS), in cooperation with the West Virginia Department of Health and Human Services and the West Virginia Department of Environmental Protection, developed a numerical steady-state simulation of ground-water flow for the 1,013-square-kilometer Opequon Creek watershed area. The model was based on data aggregated for several recently completed and ongoing USGS hydrogeologic investigations conducted in Jefferson, Berkeley, and Morgan Counties in West Virginia and Clarke, Frederick, and Warren Counties in Virginia. A previous detailed hydrogeologic assessment of the watershed area of Hopewell Run (tributary to the Opequon Creek), which includes the USGS Leetown Science Center in Jefferson County, West Virginia, provided key understanding of ground-water flow processes in the aquifer. The ground-water flow model developed for the Opequon Creek watershed area is a steady-state, three-layer representation of ground-water flow in the region. The primary objective of the simulation was to develop water budgets for average and drought hydrologic conditions. The simulation results can provide water managers with preliminary estimates on which water-resource decisions may be based. Results of the ground-water flow simulation of the Opequon Creek watershed area indicate that hydrogeologic concepts developed for the Hopewell Run watershed area can be extrapolated to the larger watershed model. Sensitivity analyses conducted as part of the current modeling effort and geographic information system analyses of spring location and yield reveal that thrust and cross-strike faults and low-permeability bedding, which provide structural and lithologic controls, respectively, on ground-water flow, must be incorporated into the model to develop a realistic simulation of ground-water flow in the larger Opequon Creek watershed area. In the model, recharge for average hydrologic conditions was 689 m3/d/km2 (cubic meters per day per square kilometer) over the entire Opequon Creek watershed area. Mean and median measured base flows at the streamflow-gaging station on the Opequon Creek near Martinsburg, West Virginia, were 604,384 and 349,907 m3/d (cubic meters per day), respectively. The simulated base flow of 432,834 m3/d fell between the mean and median measured stream base flows for the station. Simulated base-flow yields for subwatersheds during average conditions ranged from 0 to 2,643 m3/d/km2, and the median for the entire Opequon Creek watershed area was 557 m3/d/km2. A drought was simulated by reducing model recharge by 40 percent, a rate that approximates the recharge during the prolonged 16-month drought that affected the region from November 1998 to February 2000. Mean and median measured streamflows for the Opequon Creek watershed area at the Martinsburg, West Virginia, streamflow-gaging station during the 1999 drought were 341,098 and 216,551 m3/d, respectively. The simulated drought base flow at the station of 252,356 m3/d is within the range of flows measured during the 1999 drought. Recharge was 413 m3/d/km2 over the entire watershed during the simulated drought, and was 388 m3/d/km2 at the gaging station. Simulated base-flow yields for drought conditions ranged from 0 to 1,865 m3/d/km2 and averaged 327 m3/d/km2 over the entire Opequon Creek watershed. Water budgets developed from the simulation results indicate a substantial component of direct ground-water discharge to the Potomac River. This phenomenon had long been suspected but had not been quantified. During average conditions, approximately 564,176 m3/d of base flow discharges to the Potomac River. An additional 124,379 m3/d of ground water is also estimated to discharge directly to the Potomac River and rep

Kozar, Mark D.; Weary, David J.

2009-01-01

332

A multidisciplinary approach to define the hydrogeological model of the carbonate aquifer system in the Versilia River basin (Tuscany, Italy)  

NASA Astrophysics Data System (ADS)

A hydrogeological study was carried out on important fractured/karst aquifer systems located in the Versilia River basin (Tuscany, Italy), in order to optimize the groundwater resources management. The main aim was the individuation of the feeding areas of the most important springs by means of a multidisciplinary approach using geological, hydrogeological and geochemical-isotopic tools. Some hydrogeological sections were elaborated in order to define the geometry of the main hydrostructures and to individuate possible groundwater divides. The elaboration of geochemical data allowed at identifying 3 main chemical facies: Ca-HCO3, Ca-SO4 and Na-Cl. The first two highlight the interaction of water with limestone/dolostone and carbonate-evaporite rocks for a time sufficient to acquire these chemical compositions and to achieve saturation/supersaturation in calcite and dolomite. The Na-Cl groundwater shows low salinity and a composition similar to rainwater, indicating a circulation in rocks containing minerals not very reactive and/or short interaction time with carbonate rocks. These two main types of water-rock interaction are confirmed by the isotopic ratio ?13C: for the Ca-HCO3 and Ca-SO4 types, ?13C value requires a significant contribution of carbon derived from dissolution of calcite, while for Na-Cl water, ?13C values are consistent with the addition of biogenic CO2 in rainwater. Stable water isotopes (?18O and ?2H) confirm that groundwaters have a meteoric origin and that the wide range of values essentially depends on the different average altitude of feeding zone. Comparing the geological and hydrogeological features with the results of the geochemical processing, it is reasonable to assume that: the Na-Cl springs are representative of the superficial circuits, with small feeding zones and very low residence times in aquifer; whereas the Ca-HCO3 and Ca-SO4 springs are representative of relatively deep circuits developed in extensive aquifers with high permeability. The first type of springs was used to obtain the relationship between the ?18O ratio and the altitude of rainwater infiltration. Taking into account that they drain a small basin and considering the regulator effect of the aquifers, the isotopic composition of these springs are very similar to the annual average isotopic values of the local meteoric water. This relationship was used to evaluate the average altitude of the feeding area of the second type of springs. All these elements, and some tracer test results available in literature, allowed us to delimit the hydrogeological basins likely drained by the most important springs under study. In addition, for each hydrogeological system, a simplified water balance using meteorological data and the effective infiltration coefficients reported in the literature was performed, verifying that the delimited catchment areas are entirely consistent with the flow rate data of the springs.

Menichini, M.; Doveri, M.; Giannecchini, R.; Raco, B.; Rosi, M.

2012-12-01

333

Plan of study to define hydrogeologic characteristics of the Madera Limestone in the east mountain area of central New Mexico  

USGS Publications Warehouse

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.

Rankin, D. R.

1999-01-01

334

An integrated geological, hydrogeological and geophysical approach to the characterisation of the aquifer in a contaminated site  

NASA Astrophysics Data System (ADS)

This work sets out a physical - stratigraphical reconstruction of the superficial aquifer in the Brindisi area; this site is recognized to be at significant environmental risk (Law no. 426/98) by the Italian government. Geological, hydrogeological and geophysical methodologies were applied. The geological characterisation consisted of surface and subsoil surveys. The existing stratigraphical, geotechnical and hydrogeological data were collected, processed and homogenised, and the information inserted in a database managed with a specific software (arcview). Hydrogeological surveys were conducted in a number of boreholes uniformly distributed over the studied area. Geophysical prospecting was conducted in the most industrialized part of the area, adjacent to a combined industrial road/conveyor belt - the "Asse Attrezzato" - in order to better describe the site and evaluate the impact of this structure on the environment. This research enabled us to characterise the superficial aquifer of the Brindisi area. The groundwater is of the phreatic type. In the upper part of the deposit, the presence of low permeability sediments (recent continental deposits) means that the groundwater is confined. Subapennine Clays (Lower Pleistocene), present across the whole of the area, form the impermeable base of the aquifer. The deposits that make up the superficial aquifer vary greatly in their permeability. The greatest permeability is associated with the calcarenite deposits (Terraced Deposits, Middle-Upper Pleistocene). The higher the proportion of slime in the granulometric assortment, the lower the permeability of the deposit. The lower section of the aquifer, characterized by the presence of slimy-sandy sediments (Brindisi sands, Lower-Middle Pleistocene), has a lower permeability. The results of the geophysical investigations enabled us to reconstruct in detail the lateral and vertical lithological variations of the geological formations. Furthermore, by supplementing the data from boreholes (direct surveys), the geophysical surveys proved to be useful in that they reduce the need for perforations of the ground, which are potential conduits of pollution.

di Paola, M. A.; Margiotta, S.; Mazzone, F.; Negri, S.

2005-01-01

335

Selected hydrogeologic data for the southwest Glendive Preliminary Logical Mining Unit and adjacent areas, Dawson County, Montana  

USGS Publications Warehouse

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)

Roberts, R. S.

1987-01-01

336

Data integration and standardization in cross-border hydrogeological studies: a novel approach to hydrostratigraphic model development  

Microsoft Academic Search

Data integration—or the merging of multiple source data sets—is central to hydrogeological studies. In cross-border situations,\\u000a data heterogeneities are the source of most integration problems. Semantic integration of the subsurface geological terms\\u000a is undertaken for the Abbotsford–Sumas aquifer, a cross-border (trans-national) aquifer, which is equally shared by British\\u000a Columbia (Canada) and Washington State (US). Subsurface information is largely derived from

Diana M. Allen; Nadine Schuurman; Aparna Deshpande; Jacek Scibek

2008-01-01

337

Tectonic Evolution and Hydrogeological Characteristics of the Khanaser Valley, Northern Syria, Derived from the Interpretation of Vertical Electrical Soundings  

NASA Astrophysics Data System (ADS)

The Khanaser Valley was geoelectrically thoroughly surveyed through a grid which consisted of twelve VES profiles. The tectonically-oriented Pichgin and Habibullaev method was enhanced to be applicable in areas of rugged relief and topography. The enhanced profiles were tectonically interpreted and subsurface structures within the Khanaser Valley were delineated. Accordingly, a tectonic evolutional scenario of the valley was established and its hydrogeological characteristics were derived. An approach for groundwater exploration in areas of prominent relief and topography in dry areas such as the Khanaser Valley was established and its validity was estimated.

Asfahani, J.; Radwan, Y.

2007-12-01

338

Hydrogeology and Simulated Ground-Water Flow in the Salt Pond Region of Southern Rhode Island  

USGS Publications Warehouse

The Salt Pond region of southern Rhode Island extends from Westerly to Narragansett Bay and forms the natural boundary between the Atlantic Ocean and the shallow, highly permeable freshwater aquifer of the South Coastal Basin. Large inputs of fresh ground water coupled with the low flushing rates to the open ocean make the salt ponds particularly susceptible to eutrophication and bacterial contamination. Ground-water discharge to the salt ponds is an important though poorly quantified source of contaminants, such as dissolved nutrients. A ground-water-flow model was developed and used to delineate the watersheds to the salt ponds, including the areas that contribute ground water directly to the ponds and the areas that contribute ground water to streams that flow into ponds. The model also was used to calculate ground-water fluxes to these coastal areas for long-term average conditions. As part of the modeling analysis, adjustments were made to model input parameters to assess potential uncertainties in model-calculated watershed delineations and in ground-water discharge to the salt ponds. The results of the simulations indicate that flow to the salt ponds is affected primarily by the ease with which water is transmitted through a glacial moraine deposit near the regional ground-water divide, and by the specified recharge rate used in the model simulations. The distribution of the total freshwater flow between direct ground-water discharge and ground-water-derived surface-water (streamflow) discharge to the salt ponds is affected primarily by simulated stream characteristics, including the streambed-aquifer connection and the stream stage. The simulated position of the ground-water divide and, therefore, the model-calculated watershed delineations for the salt ponds, were affected only by changes in the transmissivity of the glacial moraine. Selected changes in other simulated hydraulic parameters had substantial effects on total freshwater discharge and the distribution of direct ground-water discharge and ground-water-derived surface-water (streamflow) discharge to the salt ponds, but still provided a reasonable match to the hydrologic data available for model calibration. To reduce the uncertainty in predictions of watershed areas and ground-water discharge to the salt ponds, additional hydrogeologic data would be required to constrain the model input parameters that have the greatest effect on the simulation results.

Masterson, John P.; Sorenson, Jason R.; Stone, Janet R.; Moran, S. Bradley; Hougham, Andrea

2007-01-01

339

Groundwater geochemistry of the Yucatan Peninsula, Mexico: Constraints on stratigraphy and hydrogeology  

NASA Astrophysics Data System (ADS)

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 liquid waste management in the area. Where it discharges at the coast, the unique chemistry of the groundwater that has interacted with the evaporite/ejecta strata may also have significant geomorphologic implications. While groundwater-seawater mixing at the coast has been shown to dissolve and erode limestone, PHREEQC modeling shows that mixing of water nearly saturated in CaSO 4 with seawater has a less vigorous dissolution effect due to its high Ca content.

Perry, Eugene; Paytan, Adina; Pedersen, Bianca; Velazquez-Oliman, Guadalupe

2009-03-01

340

Flowmeter and Ground Penetrating Radar: comparison between hydrogeological and geophysical methods  

NASA Astrophysics Data System (ADS)

A comparison between saturated hydraulic conductivity calculated with Electromagnetic Borehole Flowmeter (EBF) and water content obtained by Ground Penetrating Radar (GPR) Zero Offset Profile (ZOP) is presented. EBF technique permits to obtain permeability profiles along one borehole in the saturated zone by using the Moltz (1993) method. The analysis of ZOP data provides information about the water content (Topp, 1980) in the section between two adjacent boreholes. Water content profiles in the saturated zone can be related to the porosity of the medium which, together with the permeability from EBF measurements, is fundamental for any hydrogeological characterization. These two methods have been applied to three different test-sites located in the Northern Italy. A first site regards a complex aquifer, characterized by a chaotic sequence of gypsum-marls. The other two sites are characterized by an alternation of sandy and silty-sandy layers. For each site, we adopted the EBF along screened boreholes with 0.25 m spacing, under ambient and stressed conditions. The cross-hole georadar survey was performed within the saturated zone by using 100 Hz borehole antennas with 0.25 m spacing. The results from the analysis of EBF and ZOP profiles show a general positive correlation between permeability and water content and porosity. This is reasonable for granular soils where the permeability is controlled by the pore space available for water flow, i.e., the effective porosity. For this soils, where EBF permeability and ZOP water-content profiles are in good agreement, the volume between the boreholes can be supposed to be homogeneous. On the other hand, a poor correlation suggests the presence of heterogeneity between the boreholes, which can be observed because the two techniques involve different volumes of soil: the EBF permeability refers to a portion of volume just around the borehole while the ZOP investigates the entire volume between the two boreholes. The poor correlation could be enhanced when enlarging the borehole separation, because the difference in the involved volume between the two techniques increases. Finally, the degree of correlation between the EBF permeability profile and the ZOP water content profile can indicate how much the volume investigated by EBF is effectively representative of the entire volume between the boreholes. Molz, F.J. and S.C. Young, 1993. Development and Application of Borehole Flowmeters for Environmental Assessment, The Log Analyst, 13-23. Topp G.C., J.L. Davis and A.P. Annan, 1980. Electromagnetic determination of soil water content: measurements in coaxial transmission lines, Water Resources Research, 16, 574-582.

Villa, A.; Basirico', S.; Arato, A.; Crosta, G. B.; Frattini, P.; Godio, A.

2012-04-01

341

Optimization of hydrogeological parameters of riverbank filtrated aquifers of the Szendendre Island using natural tracers  

NASA Astrophysics Data System (ADS)

Hungary's capital, Budapest, and a number of surrounding settlements are supplied with drinking water largely from the bank filtered aquifer at Szentendre Island of the Danube River lying to the north of the city. Precise knowledge of regional hydrogeological processes in riverbank filtrated aquifers are indispensable for aquifer protection and adequate quality water supply. To reach this goal, the origin and velocity/transit time of filtrating water was studied: stable isotopic, e.g. O-18 tracing measurement. Basis of these studies was the fact that d18O of Danube water (-10.9 % as a mean) differs from the locally infiltrated precipitation (shallow groundwater, -9,5 %) as a consequence of the „altitude effect". Szentendre Island itself sits mainly on Tertiary marine clayey sediments. These are topped by gravels and sands of Pleistocene age. Surface formations consist of semi-consolidated shifting sands and a few floodplain horizons. Widespread gravel formations on the island provide the basis for one of the largest volumes of abstraction of riparian-water in Europe. Supplied water comes largely from the river, and is supplemented by locally infiltrated precipitation. While filtrating from the watercourse through porous sediments to the wells, water is cleared from physical as well as biological contaminations. Water samples were taken on a daily basis from the Vác arm of the Danube, as well as from the water producing Kisoroszi-2 horizontal collector well, lying at the bank of Danube on the Szentendre Island. Collectors of this well are aligned to two horizons at the depth of ca. 12 m in the Pleistocene gravels. Electric conductivity, temperature and pH were measured daily, and were supplemented by d18O measurements for characterizing the region between the Danube and the well. To study larger scale systems, at first three, then six monitoring wells were sampled for the parameters stated above. These wells are aligned along a line connecting the two river arms around the island, thus provide information about the inner parts of the island. Highest conductivity and d18O values for monitoring wells were expected in the central part of the island. However, one of the marginal wells proved to show the highest measured values, suggesting extraordinary behavior of the local flow regime. Anomalous behavior of conductivity and oxygen isotopic values (both higher in the Danube than in the collector well) were detected, indicating conditions different from that to be predicted by a simple conceptual model. In accordance with seasonal variations during the test period, river temperature fell almost 8 °C, while well temperature increased linearly about 1.4 °C. These values suggest more complicated flow/storage conditions.

Kármán, K.; Fórizs, I.; Deák, J.; Szabó, Cs.

2009-04-01

342

Application of GPR and seismic methods in landslides investigation and determination of hydrogeological conditions  

NASA Astrophysics Data System (ADS)

Ground Penetrating Radar (GPR) belongs to non-invasive geophysical methods which use an artificially induced electromagnetic field as the way for inspection. GPR is applied not only to recognition of shallow geological structure but also to archeological studies. The basic assumption of the applicability of GPR is the existance of a distinct boundary between two lithological horizons defined by a change in permittivity values, which results in a change in electromagnetic wave velocity. For that reason this method is used to locate empty spaces and saturated zones. The purpose of this measurements was to determine the details of the sliding body, including the thickness and lateral extension of the landslide material, the depth of the sliding surface and water content of the subsurface. What is more correlation between GPR and seismic methods was searched. Studied area was located in the Southern part of Poland. Geological structure is characteristic for Carpathian flysch - overlaying claystones, shales and sandstones. Measurements were carried out using GPR equipment from the Swedish company Mala Geoscience. Due to the required depth range and resolution unshielded antennas with frequencies from 25 MHz to 200 MHz were used. Profiles were traced parallel to the landslide axis. Following forms of GPR survey were applied: CO (common offset), CMP (common mid point), WARR (wide-angle reflection-refraction). Modeling attempt electromagnetic field distribution in the medium was undertaken to select the most appropriate measurement parameters and to improve the interpretation. Programme GPRMax2D v. 2.0 was used to create models. The GPR numerical analysis uses the finite - difference time - domain method (FDTD). The FDTD approach to the numerical solution of Maxwell's equations consist of discretization both the space and the time continua. Due to geological structure (presence of low resistivity clays and shales) attenuation of electromagnetic wave was high. In order to 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.

Czaja, Klaudia; Matu?a, Rafa?

2013-04-01

343

Hydrogeology and results of injection tests at waste-injection test sites in Pinellas County, Florida  

USGS Publications Warehouse

Potential benefits or hazards to freshwater resources could result from subsurface injection of treated wastewater. Recognizing this, the U.S. Geological Survey, in cooperation with Pinellas County and the city of St. Petersburg, undertook an evaluation of the hydrogeology and injection of wastewater at proposed test sites on the Pinellas peninsula. The injection sites are underlain by sedimentary rocks ranging in age from Cretaceous to Pleistocene. Lower Eocene carbonate rocks were penetrated to a maximum depth of 3,504 feet and were found to have relatively low water yields. The most permeable part of the investigated section was in rocks of middle Eocene age within the Floridan aquifer. At the injection sites, the Floridan aquifer was subdivided into four permeable zones and three semiconfining beds. The test injection zone is within the Avon Park Limestone, the most productive of the identified permeable zones, with a transmissivity of about 1,000,000 feet squared per day. Two semiconfining beds are above the injection zone in the Suwannee Limestone and Ocala Limestone and have vertical hydraulic conductivities estimated to range from about 0.1 to 1 foot per day where these beds do not contain clay. Limited fresh ground-water supplies exist in the Floridan aquifer within the Pinellas peninsula. At all test sites, chloride concentration in the injection zone ranged from 19,000 to 20,000 milligrams per liter. Injection tests ranging in duration from 3 to 91.1 days were run at three different sites. Pressure buildup occurred in permeable zones above and below the injection zone during these tests. Calculated pressure buildup in observation wells close to and at some distance from the test wells was typically less than 1 pound per square inch. Injection and formation water will probably move slowly through the semiconfining bed overlying the injection zone, and long-term injection tests will be needed to determine the effectiveness of these beds to retard flow. The injected water was well mixed with the native formation water, which, in part, is a direct consequence of the fractures in the injection zone.

Hickey, John J.

1982-01-01

344

A multidisciplinary geophysical, geotechnical and hydrogeological investigation of quick-clay landslides in Sweden  

NASA Astrophysics Data System (ADS)

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 presence of low-velocity zones associated with some of the reflections, making the integration of the two methods interesting. A shear-wave survey also shows excellent data quality and very high resolution. It helps to image fine structures above the bedrock, as well as the bedrock topography. The level of the detail already revealed by the seismic data demonstrates that the project will be able to image fine structures associated with quick-clay landslides that are important and valuable for any site assessment.

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

345

Hydrogeologic Assessment of the 4-S Land and Cattle CompanyRanch  

SciTech Connect

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 water from the Merced River. Most of the pumpage occurs in a depth interval between 30 ft and 130 ft. Safe yield estimates made using the available data show that the 4-S Ranch has sufficient resources to meet its own needs. Further exploitation of the groundwater will be limited if the leakage from the Eastside Bypass, Mariposa Bypass and Bear Creek are insufficient to replace the pumped water on an average annual basis. Should any future lining of the Eastside Canal occur, it would have a significant impact on the groundwater resource potential of the 4-S Ranch and impair the overall quality of the available water supply.

Quinn, Nigel W.T.

2006-04-10

346

Large-Scale Transport Model Uncertainty and Sensitivity Analysis: Distributed Sources in Complex, Hydrogeologic Systems  

NASA Astrophysics Data System (ADS)

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 simulations are challenged by the distributed sources in each of the Corrective Action Units, by complex mass transfer processes, and by the size and complexity of the field- scale flow models. An efficient methodology utilizing particle tracking results and convolution integrals provides insitu concentrations appropriate for Monte Carlo analysis. Uncertainty in source releases and transport parameters including effective porosity, fracture apertures and spacing, matrix diffusion coefficients, sorption coefficients, and colloid load and mobility are considered. With the distributions of input uncertainties and output plume volumes, global analysis methods including stepwise regression, contingency table analysis, and classification tree analysis are used to develop sensitivity rankings of parameter uncertainties for each model considered, thus assisting a variety of decisions. The National Security Technologies, LLC component of this work is DOE/NV/25946--xxx and was done under contract number DE-AC52-O6NA25946 with the U.S. Department of Energy

Wolfsberg, A.; Kang, Q.; Li, C.; Ruskauff, G.; Bhark, E.; Freeman, E.; Prothro, L.; Drellack, S.

2007-12-01

347

Hydrogeology and leachate plume delineation at a closed municipal landfill, Norman, Oklahoma  

USGS Publications Warehouse

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 precipitation and increased evapotranspiration in the summer. Hydrographs show temporal water-level changes in ground water and the slough, indicating a hydrologic connection between the alluvial aquifer and the slough.

Becker, Carol J.

2002-01-01

348

Hydrogeology and effects of landfills on ground-water quality, southern Franklin County, Ohio  

USGS Publications Warehouse

Hydrogeology and water quality were evaluated near five land-fills along a 5-mile segment of the Scioto River valley south of Columbus, Ohio. Heterogenous surficial deposits o sand, gravel, and till up to 160 feet thick are hydraulically connected to the underlying Devonian limestone, the landfills and Scioto River, which has been leveed with 12 to 35 feet of refuse. Ground-water withdrawals caused a maximum 21-foot decline in ground-water levels from 1979 to 1982. The study reach of Scioto River within the influence of ground-water pumping is a losing stream, except for s small segment adjacent to one landfill. Analysis of variance indicated significant difference in ground-water quality between wells upgradient of landfills, down-gradient of landfills, and wells penetrating refuse. Elevated specific conductance and concentrations of total dissolved solids, ammonia, carbon dioxide, and dissolved organic carbon in water from wells downgradient from and penetrating landfills indicate leachate production and migration is occurring. Analysis of bed-material samples from Scioto River and Scioto Big Run revealed concentrations of polynuclear aromatic hydrocarbons ranging from 220 to 9,440 micograms per kilogram of sediment (?g/kg) and concentrations of toxic metals ranging from 1 to 720 ?g/kg. Samples from an upstream control station on Scioto River contained no organic compounds and lower concentrations of metals (ranging from 1 to 260 ?g/kg). Because of multiple land uses within the study area, organic compounds recovered from the streamed sediments cannot be attributed to any single source. The generation of hydrogen sulfide and methane gases, presence of a zone of increased hardness, elevated concentrations of common ionic species, and dominance of ammonia over other nitrogen species indicate that leachate is being produced and its migrating from four landfills and the river levee. Based on hydraulic relationships between ground water and surface water, it is highly probable that ground water contaminated by leachate from the levee and from one of the landfills is discharging to Scioto River. Leachate-enriched groundwater from other landfills also may begin to discharge to the river if water-withdrawal patterns in the study area change.

De Roche, J. T.

1985-01-01

349

Hydrogeology of the eastern part of the Salt River Valley area, Maricopa and Pinal Counties, Arizona  

USGS Publications Warehouse

The Salt River Valley is a major agricultural and metropolitan area in semiarid south-central Arizona. Groundwater in the permeable sedimentary deposits underlying the area is a major water supply for agricultural, municipal, and industrial users. Groundwater levels have declined as much as 400 ft in recent years. Management of the remaining groundwater resources and their protection from contamination will require knowledge of the hydrogeologic framework and the water-bearing characteristics of the sedimentary units in the groundwater system. The rocks in the eastern part of the Salt River Valley are divided into six units--crystalline rocks, extrusive rocks, red units, lower unit, middle unit, and upper unit. The crystalline and extrusive rocks underlie the basin and form virtually impermeable hydrologic boundaries. The red, lower, middle and upper sedimentary units contain most of the groundwater. The red unit contains usable quantities of ground water, principally near Scottsdale, where it yields as much as 1 ,000 gallons/min (gpm) of water to wells. The lower unit, which makes up the largest volume of sedimentary deposits, consists mostly of mudstone, clay, silt, and evaporite deposits that may be as much as 10,000 ft thick in the central part of the basin. Wells tapping the mudstone, clay, silt yield 50 (gpm) or less but the conglomerate and the sand and gravel may yield as much as 3,500 gpm. The middle unit is the principal water-bearing unit in the basin and consists mostly of silt, siltstone, and silty sand and gravel. The unit is as much as 1,000 ft thick in the central part of the basin and as much as 700 ft is saturated. The unit will yield as much as 1,000 gpm where the saturated thickness is at least 500 ft. Locally, north of Mesa, the unit yields as much as 4,000 gpm. The upper unit is gravel, sand, and silt and is saturated only in a small area in the southwestern part of the basin. Where saturated, the unit may yield as much as 4,500 gpm. The upper unit transmits recharge derived from sheet flow, from flood flow in ephemeral streams, and from irrigation to the water table. (Author 's abstract)

Laney, R. L.; Hahn, Mary Ellen

1986-01-01

350

Hydrogeology and Water Quality of the Clinton Street-Ballpark Aquifer near Johnson City, New York  

USGS Publications Warehouse

The Clinton Street-Ballpark aquifer, in the Susquehanna River valley in southern Broome County, N.Y., supplies drinking water to the Village of Johnson City near Binghamton. The hydrogeology and water quality of the aquifer were studied in 1994-95 to identify the source area of 1,1,1-trichloroethane, which was detected at the Johnson City Camden Street wellfield in 1991. The aquifer is generally 100 to 150 ft thick and consists primarily of ice-contact deposits of silty sand and gravel that are overlain by outwash deposits of sand and gravel. These two types of deposits are separated by lacustrine silt and clay of variable thickness into an upper and a lower layer of the aquifer. The coarse deposits form a single aquifer in areas where the lacustrine deposits are absent. Synoptic water-level surveys indicated that ground water moves from upgradient areas flanking the aquifer boundaries toward two major pumping centers?the Anitec wellfield in Binghamton and the Camden Street wellfield in Johnson City. Areas contributing recharge to municipal and industrial wells in the aquifer were delineated by a previously developed groundwater- flow model. The residence time of ground water within the area contributing recharge to Johnson City well no. 2 in the Camden Street wellfield was estimated to be less than 6 years. 1,1,1-Trichloroethane, trichloroethene, and their metabolites were detected in ground water at several locations in and near Johnson City. Relatively high concentrations of 1,1,1-trichloroethane were found in ground water about 3,000 ft north of the Camden Street wellfield. The suspected source is an area bordered on the south by Field Street, on the north by Harry L. Drive, on the east by New York State Route 201, and on the west by Marie Street. A trichloroethene metabolite, cis-1,2-dichloroethene, appears to be migrating westward from U.S. Air Force Plant 59 toward the Camden Street well-field, 1,000 ft southwest of the plant, although this compound has not been detected in water pumped by municipal wells, possibly because it has become diluted by ground water from other locations within the contributing area to the wells.

Coon, William F.; Yager, Richard M.; Surface, Jan M.; Randall, Allan D.; Eckhardt, David A.

1998-01-01

351

Evaluating Traditional Hydrogeologic Characterization Approaches in a Highly Heterogeneous Glaciofluvial Aquifer  

NASA Astrophysics Data System (ADS)

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: 1) a homogeneous case with K and Ss estimates obtained by averaging equivalent K and Ss values from the cross-hole pumping tests, 2) a layered heterogeneous case with K and Ss estimates from the slug tests and 3) a heterogeneous case with the kriged K from the permeameter tests and equivalent Ss from the slug tests. Results showed that, while drawdown predictions, in general, improved as more complexity was introduced into the model, the ability to make accurate drawdown predictions at all of the CMT ports was inconsistent. These results suggest that new techniques may be required to accurately capture subsurface heterogeneity for improved predictions of drawdown responses. Accurate predictions of drawdown responses should lead to improved modeling of contaminant transport and remediation designs.

Alexander, M.; Berg, S. J.; Illman, W.

2009-05-01

352

Hydrogeology of the Cross Bar Ranch well-field area and projected impact of pumping, Pasco County, Florida  

USGS Publications Warehouse

The hydrogeology and development of a groundwater flow model are described for a 121-square-mile area in Pasco County, Florida. The hydrogeologic framework consists of the surficial aquifer--a thin blanket of sand--and the underlying carbonates of the upper Floridian aquifer. The aquifers are separated by a leaky sand and clay confining unit. The Cross Bar Ranch well field occupies 13 square miles and contains 17 production wells averaging about 700 feet deep and tapping the upper Florida aquifer. Procedures to calibrate, test sensitivity to input parameters, and validate the model 's accuracy are described. Pumping at 30 million gallons per day should result in 5 feet of decline in the water table of the surficial aquifer over an 8-square-mile area and in the potentiometric surface of the Upper Florida aquifer over a 15-square-mile area. Under the 45-million-per-day maximum permitted rate, drawdown should be 5 feet or more in the water table and potentiometric surface over areas of 16 and 28 square miles, respectively. At the center of pumping, water levels could decline 15 to 25 feet. The surficial aquifer could possibly be completely dewatered in a small area of the well field when pumping is at the maximum rate. (USGS)

Hutchinson, C. B.

1985-01-01

353

Hydrogeological and geophysical study for deeper groundwater resource in quartzitic hard rock ridge region from 2D resistivity data  

NASA Astrophysics Data System (ADS)

Electrical resistivity method is a versatile and economical technique for groundwater prospecting in different geological settings due to wide spectrum of resistivity compared to other geophysical parameters. Exploration and exploitation of groundwater, a vital and precious resource, is a challenging task in hard rock, which exhibits inherent heterogeneity. In the present study, two-dimensional Electrical Resistivity Tomography (2D-ERT) technique using two different arrays, viz., pole-dipole and pole-pole, were deployed to look into high signal strength data in a tectonically disturbed hard rock ridge region for groundwater. Four selected sites were investigated. 2D subsurface resistivity tomography data were collected using Syscal Pro Switch-10 channel system and covered a 2 km long profile in a tough terrain. The hydrogeological interpretation based on resistivity models reveal the water horizons trap within the clayey sand and weathered/fractured quartzite formations. Aquifer resistivity lies between ˜3-35 and 100-200 ?m. The results of the resistivity models decipher potential aquifer lying between 40 and 88 m depth, nevertheless, it corroborates with the static water level measurements in the area of study. The advantage of using pole-pole in conjunction with the pole-dipole array is well appreciated and proved worth which gives clear insight of the aquifer extent, variability and their dimension from shallow to deeper strata from the hydrogeological perspective in the present geological context.

Kumar, Dewashish; Rao, V. Ananda; Sarma, V. S.

2014-05-01

354

The gravitational accommodation of the Chicxulub crater and its influence on the development of hydrogeological parameters in Yucatan  

NASA Astrophysics Data System (ADS)

The northern Yucatan Peninsula is characterized by a young and dynamic karstic system that yields very high secondary porosity and permeability. However, we have little, if none, knowledge about the hydraulic conductivity and the amount of groundwater being discharged in to ocean. Here we present and estimation of the hydraulic conductivity and quantity of groundwater being discharged by the northern Yucatan Peninsula coastal aquifer into the Gulf of Mexico, using the Sea Surface Temperature (SST) Images offshore the Yucatan coast, where we have detected a thermal anomaly that appears few hours after heavy rainfall in northern Yucatan. We associated these thermal anomalies of the SST to the groundwater being discharged into the ocean. To test our hypothesis we conducted a review of extreme rainfall events in the last 10 years; in parallel we used data from pressure and flow direction gauges installed in a known submarine groundwater discharge (SGD) to estimate the hydraulic conductivity and the quantity of groundwater being discharged. The satellite imagery and the rainfall data, allowed us to estimate the time lag between the rainfall and the SGD beginning, along with the hydraulic data from the gauges we have estimated the hydrogeological parameters of the coastal aquifer. This data is very important to contribute to the understanding the hydrogeological setting of the Yucatan coastal aquifer and its implications of the impact of human activities on the water quality.

Rebolledo-Vieyra, M.; Iglesias-Prieto, R.; Marino-Tapia, I.

2013-05-01

355

Hydrogeologic characterization of wells HTH-1, UE18r, UE6e, and HTH-3, Nevada Test Site  

SciTech Connect

Monitoring for the migration of contaminants in groundwater or for the proper design of nuclear test emplacement holes at the Nevada Test Site (NTS) requires proper placement and completion of monitoring wells. This is only possible if the hydrogeologic system is understood in a regional and local context, necessitating data from existing wells and boreholes. Though the NTS Groundwater Characterization Project will be drilling wells, their great expense limits the number of new wells. However, there are many existing boreholes and wells on the NTS which have not been completely evaluated hydrologically. Some of these are incorporated in the Long Term Hydrologic Monitoring Program (LTHMP) of the US Environmental Protection Agency (EPA), others are related to the testing programs. In all cases, additional site investigation in necessary to properly interpret the hydrogeologic data from these wells. Monitoring wells on the NTS are poorly characterized with regard to aquifers penetrated, vertical hydraulic gradients, and vertical variations in water quality. One of the goals of the well validation program was to gain a thorough understanding of the parameters needed to interpret the source and fate potential hazardous and radioactive substances that may be detected in these wells in the future. One of the most critical parameters for monitoring is the knowledge of what aquifer or geologic unit is being sampled when a water sample is collected. Pumped water samples are weighted most heavily to the water quality of the most productive (highest transmissivity) aquifer penetrated by the well.

Lyles, B.F.; McKay, W.A.; Chapman, J.B.; Tyler, S.W.

1991-06-01

356

Preliminary hydrogeologic evaluation of the Cincinnati Arch region for underground high-level radioactive waste disposal, Indiana, Kentucky , and Ohio  

USGS Publications Warehouse

Preliminary interpretation of available hydrogeologic data suggests that some areas underlying eastern Indiana, north-central Kentucky, and western Ohio might be worthy of further study regarding the disposal of high-level radioactive waste in Precambrian crystalline rocks buried beneath Paleozoic sedimentary rocks in the area. The data indicate that (1) largest areas of deepest potential burial and thickest sedimentary rock cover occur in eastern Indiana; (2) highest concentrations of dissolved solids in the basal sandstone aquifer, suggesting the most restricted circulation, are found in the southern part of the area near the Kentucky-Ohio State line and in southeastern Indiana; (3) largest areas of lowest porosity in the basal sandstone aquifer, low porosity taken as an indicator of the lowest groundwater flow velocity and contaminant migration, are found in northeastern Indiana and northwestern Ohio, central and southeastern Indiana, and central Kentucky; (4) the thickest confining units that directly overlie the basal sandstone aquifer are found in central Kentucky and eastern Indiana where their thickness exceeds 500 ft; (5) steeply dipping faults that form potential hydraulic connections between crystalline rock, the basal sandstone aquifer, and the freshwater circulation system occur on the boundaries of the study area mainly in central Kentucky and central Indiana. Collectively, these data indicate that the hydrogeology of the sedimentary rocks in the western part of the study area is more favorably suited than that in the remainder of the area for the application of the buried crystalline-rock concept. (USGS)

Lloyd, O. B.; Davis, R. W.

1989-01-01

357

Hydrogeology of karst aquifer systems in SW Turkey and an assessment of water quality and contamination problems  

NASA Astrophysics Data System (ADS)

The aim of this research is to determine the relationship between groundwater flow and water quality of different ground and surface water basins in the southwest Turkey. In addition, groundwater vulnerability is assessed taking into consideration groundwater flow and quality. The autochthonous Beydaglari limestone is the major karstic aquifer in the region. According to the groundwater level map of alluvium aquifers in the basins, groundwater discharge toward the carbonate aquifer is direct and indirect. The hydrogeological connection between ground and surface water basins occurs via the karstic aquifer located at the bottom of the alluvium bottom. In Egirdir lake, water also discharges in the karstic aquifer via karstic sinkholes at the western border of the lake. In the research area, general groundwater discharge is toward the Mediterranean Sea by means of autochthonous carbonate system, according to hydrogeological investigations, research of lineament and hydraulic conductivities. This result is supported by the locations of lineaments and shore springs discharging from the limestone. In addition, spreading of contaminants via karstic aquifer to great distance has been clearly identified.

Davraz, Aysen; Karaguzel, Remzi; Soyaslan, Iskender; Sener, Erhan; Seyman, Fatma; Sener, Sehnaz

2009-09-01

358

Hydrogeological and geophysical study for deeper groundwater resource in quartzitic hard rock ridge region from 2D resistivity data  

NASA Astrophysics Data System (ADS)

Electrical resistivity method is a versatile and economical technique for groundwater prospecting in different geological settings due to wide spectrum of resistivity compared to other geophysical parameters. Exploration and exploitation of groundwater, a vital and precious resource, is a challenging task in hard rock, which exhibits inherent heterogeneity. In the present study, two-dimensional Electrical Resistivity Tomography (2D-ERT) technique using two different arrays, viz., pole-dipole and pole-pole, were deployed to look into high signal strength data in a tectonically disturbed hard rock ridge region for groundwater. Four selected sites were investigated. 2D subsurface resistivity tomography data were collected using Syscal Pro Switch-10 channel system and covered a 2 km long profile in a tough terrain. The hydrogeological interpretation based on resistivity models reveal the water horizons trap within the clayey sand and weathered/fractured quartzite formations. Aquifer resistivity lies between ˜3-35 and 100-200 ?m. The results of the resistivity models decipher potential aquifer lying between 40 and 88 m depth, nevertheless, it corroborates with the static water level measurements in the area of study. The advantage of using pole-pole in conjunction with the pole-dipole array is well appreciated and proved worth which gives clear insight of the aquifer extent, variability and their dimension from shallow to deeper strata from the hydrogeological perspective in the present geological context.

Kumar, Dewashish; Rao, V. Ananda; Sarma, V. S.

2014-04-01

359

Hydrogeologic framework and geochemistry of the intermediate aquifer system in parts of Charlotte, De Soto, and Sarasota counties, Florida  

USGS Publications Warehouse

The hydrogeologic framework underlying the 600-square-mile study area in Charlotte, De Soto, and Sarasota Counties, Florida, consists of the surficial aquifer system, the intermediate aquifer system, and the Upper Floridan aquifer. The hydrogeologic framework and the geochemical processes controlling ground-water composition were evaluated for the study area. Particular emphasis was given to the analysis of hydrogeologic and geochemical data for the intermediate aquifer system. Flow regimes are not well understood in the intermediate aquifer system; therefore, hydrogeologic and geochemical information were used to evaluate connections between permeable zones within the intermediate aquifer system and between overlying and underlying aquifer systems. Knowledge of these connections will ultimately help to protect ground-water quality in the intermediate aquifer system. The hydrogeology was interpreted from lithologic and geophysical logs, water levels, hydraulic properties, and water quality from six separate well sites. Water-quality samples were collected from wells located along six ground-water flow paths and finished at different depth intervals. The selection of flow paths was based on current potentiometric-surface maps. Ground-water samples were analyzed for major ions; field parameters (temperature, pH, specific conductance, and alkalinity); stable isotopes (deuterium, oxygen-18, and carbon-13); and radioactive isotopes (tritium and carbon-14). The surficial aquifer system is the uppermost aquifer, is unconfined, relatively thin, and consists of unconsolidated sand, shell, and limestone. The intermediate aquifer system underlies the surficial aquifer system and is composed of clastic sediments interbedded with carbonate rocks. The intermediate aquifer system is divided into three permeable zones, the Tamiami/Peace River zone (PZ1), the Upper Arcadia zone (PZ2), and the Lower Arcadia zone (PZ3). The Tamiami/Peace River zone (PZ1) is the uppermost zone and is the thinnest and generally, the least productive zone in the intermediate aquifer system. The Upper Arcadia zone (PZ2) is the middle zone and productivity is generally higher than the overlying permeable zone. The Lower Arcadia zone (PZ3) is the lowermost permeable zone and is the most productive zone in the intermediate aquifer system. The intermediate aquifer system is underlain by the Upper Floridan aquifer, which consists of a thick, stratified sequence of limestone and dolomite. The Upper Floridan aquifer is the most productive aquifer in the study area; however, its use is generally restricted because of poor water quality. Interbedded clays and fine-grained clastics separate the aquifer systems and permeable zones. The hydraulic properties of the three aquifer systems are spatially variable. Estimated trans-missivity and horizontal hydraulic conductivity varies from 752 to 32,900 feet squared per day and from 33 to 1,490 feet per day, respectively, for the surficial aquifer system; from 47 to 5,420 feet squared per day and from 2 to 102 feet per day, respectively, for the Tamiami/Peace River zone (PZ1); from 258 to 24,633 feet squared per day and from 2 to 14 feet per day, respectively, for the Upper Arcadia zone (PZ2); from 766 to 44,900 feet squared per day and from 10 to 201 feet per day, respectively, for the Lower Arcadia zone (PZ3); and from 2,350 to 7,640 feet squared per day and from 10 to 41 feet per day, respectively, for the Upper Floridan aquifer. Confining units separating the aquifer systems have leakance coefficients estimated to range from 2.3 x 10-5 to 5.6 x 10-3 feet per day per foot. Strata composing the confining unit separating the Upper Floridan aquifer from the intermediate aquifer system are substantially more permeable than confining units separating the permeable zones in the intermediate aquifer system or separating the surficial aquifer and intermediate aquifer systems. In Charlotte, Sarasota, and western De Soto Counties, hydraulic

Torres, A. E.; Sacks, L. A.; Yobbi, D. K.; Knochenmus, L. A.; Katz, B. G.

2001-01-01

360

Hydrogeologic Framework, Groundwater Movement, and Water Budget in the Chambers-Clover Creek Watershed and Vicinity, Pierce County, Washington  

USGS Publications Warehouse

This report presents information used to characterize the groundwater-flow system in the Chambers-Clover Creek Watershed and vicinity, 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 study area covers about 706 square miles in western Pierce County, Washington, and extends north to the Puyallup River, southwest to the Nisqually River, and is bounded on the south and east by foothills of the Cascade Range and on the west by Puget Sound. The area is underlain by a northwest-thickening sequence of unconsolidated glacial and interglacial deposits which overlie sedimentary and volcanic bedrock units that crop out in the foothills along the southern and southeastern margin of the study area. Geologic units were grouped into 11 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 450 drillers' logs to construct 6 hydrogeologic sections, and unit extent and thickness maps. Groundwater in unconsolidated glacial and interglacial aquifers generally flows to the northwest towards Puget Sound, and to the north and northeast towards the Puyallup River. These generalized flow patterns likely are complicated by the presence of low permeability confining units that separate discontinuous bodies of aquifer material and act as local groundwater-flow barriers. Water levels in wells completed in the unconsolidated hydrogeologic units show seasonal variations ranging from less than 1 to about 50 feet. The largest groundwater-level fluctuation (78 feet) observed during the monitoring period (March 2007-September 2008) was in a well completed in the bedrock unit. Synoptic streamflow measurements made in September 2007 and July 2008 indicated a total groundwater discharge to streams in the study area of 87,310 and 92,160 acre-feet per year, respectively. The synoptic streamflow measurements show a complex pattern of gains and losses to streamflows that varies throughout the study area, and appears to be influenced in places by local topography. Groundwater discharge occurs at numerous springs in the area and the total previously reported discharge of springs in the area is approximately 80,000 acre-feet per year. There are, in addition, many unmeasured springs and the total spring discharge in the area is unknown. The water-budget area (432 mi2 located within the larger study area) received an annual average (September1, 2006, to August 31, 2008) of about 1,025,000 acre-ft or about 45 inches of precipitation a year. About 44 percent of precipitation enters the groundwater system as recharge. Almost one-half of this recharge (49 percent) discharges to the Puyallup and Nisqually Rivers and leaves the groundwater system as submarine groundwater discharge to Puget Sound. The remaining groundwater recharge discharges to streams (20 percent) and springs (18 percent) or is withdrawn from wells (13 percent)

Savoca, Mark E.; Welch, Wendy B.; Johnson, Kenneth H.; Lane, R.C.; Fasser, Elisabeth T.

2010-01-01

361

Digital surfaces and hydrogeologic data for the Mesozoic through early Tertiary rocks in the Southeastern Coastal Plain in parts of Mississippi, Alabama, Georgia, South Carolina, and Florida  

USGS Publications Warehouse

A digital dataset of hydrogeologic data for Mesozoic through early Tertiary rocks in the Southeastern Coastal Plain was developed using data from five U.S. Geological Survey (USGS) reports published between 1951 and 1996. These reports contain maps and data depicting the extent and elevation of the Southeast Coastal Plain stratigraphic and hydrogeologic units in Florida and parts of Mississippi, Alabama, Georgia, and South Carolina. The reports are: Professional Paper 1410-B (Renken, 1996), Professional Paper 1088 (Brown and others, 1979), Professional Paper 524-G (Applin and Applin, 1967), Professional Paper 447 (Applin and Applin, 1965), and Circular 91 (Applin, 1951). The digital dataset provides hydrogeologic data for the USGS Energy Resources Program assessment of potential reservoirs for carbon sequestration and for the USGS Groundwater Resource Program assessment of saline aquifers in the southeastern United States. A Geographic Information System (ArcGIS 9.3.1) was used to construct 33 digital (raster) surfaces representing the top or base of key stratigraphic and hydrogeologic units. In addition, the Geographic Information System was used to generate 102 geo-referenced scanned maps from the five reports and a geo-database containing structural and thickness contours, faults, extent polygons, and common features. The dataset also includes point data of well construction and stratigraphic elevations and scanned images of two geologic cross sections and a nomenclature chart.

Cannon, Debra M.; Bellino, Jason C.; Williams, Lester J.

2012-01-01

362

Calendar year 1994 groundwater quality report for the Bear Creek hydrogeologic regime, Y-12 Plant, Oak Ridge, Tennessee. 1994 Groundwater quality data interpretations and proposed program modifications  

SciTech Connect

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 at the US Department of Energy (DOE) Y-12 Plant. These sites lie in Bear Creek Valley (BCV) west of the Y-12 Plant within the boundaries of the Bear Creek Hydrogeologic Regime which is one of three hydrogeologic regimes defined for the purposes of groundwater quality monitoring. The Environmental Management Department manages the groundwater monitoring activities 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. The annual GWQR for the Bear Creek 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. Part 2 (this report) contains an evaluation of the data with respect to regime-wide groundwater quality, summarizes the status and findings of ongoing hydrogeologic studies, describes changes in monitoring priorities, and presents planned modifications to the groundwater sampling and analysis activities.

NONE

1995-10-01

363

The deep hydrogeologic flow system underlying the Oak Ridge Reservation -- Assessing the potential for active groundwater flow and origin of the brine  

Microsoft Academic Search

The deep hydrogeologic system underlying the Oak Ridge Reservation (ORR) contains contaminants such as radionuclides, heavy metals, nitrates, and organic compounds. The groundwater in the deep system is saline and has been considered to be stagnant in previous studies. This study was designed to address the following questions: is groundwater in the deep system stagnant; is contaminant migration controlled by

R. Nativ; A. Halleran; A. Hunley

1997-01-01

364

Statistical classification of hydrogeologic regions in the fractured rock area of Maryland and parts of the District of Columbia, Virginia, West Virginia, Pennsylvania, and Delaware  

USGS Publications Warehouse

Hydrogeologic regions in the fractured rock area of Maryland were classified using geographic information system tools with principal components and cluster analyses. A study area consisting of the 8-digit Hydrologic Unit Code (HUC) watersheds with rivers that flow through the fractured rock area of Maryland and bounded by the Fall Line was further subdivided into 21,431 catchments from the National Hydrography Dataset Plus. The catchments were then used as a common hydrologic unit to compile relevant climatic, topographic, and geologic variables. A principal components analysis was performed on 10 input variables, and 4 principal components that accounted for 83 percent of the variability in the original data were identified. A subsequent cluster analysis grouped the catchments based on four principal component scores into six hydrogeologic regions. Two crystalline rock hydrogeologic regions, including large parts of the Washington, D.C. and Baltimore metropolitan regions that represent over 50 percent of the fractured rock area of Maryland, are distinguished by differences in recharge, Precipitation minus Potential Evapotranspiration, sand content in soils, and groundwater contributions to streams. This classification system will provide a georeferenced digital hydrogeologic framework for future investigations of groundwater availability in the fractured rock area of Maryland.

Fleming, Brandon J.; LaMotte, Andrew E.; Sekellick, Andrew J.

2013-01-01

365

An overview of the Tertiary geology and hydrogeology of the northern part of the Arabian Gulf region with special reference to Kuwait  

Microsoft Academic Search

Tertiary sediments constitute the main source of usable groundwater in Kuwait. Tectonics, depositional environment, lithology and the hydrogeology of these sediments have been reviewed on a regional scale, with special reference to Kuwait. The review showed that Kuwait was situated at the boundary of the stable shelf towards southwest and the unstable shelf towards northeast throughout the Tertiary period. The

A. Mukhopadhyay; J. Al-Sulaimi; E. Al-Awadi; F. Al-Ruwaih

1996-01-01

366

Hydrogeologic Interpretations of Natural-Gamma Logs for 31 Shallow Wells in the Memphis, Tennessee Area. National Water-Quality Assessment Program.  

National Technical Information Service (NTIS)

The purpose of this report is to describe the stratigraphy of the hydrogeologic units at each of the 31 monitoring wells. The report presents the natural-gamma-log data that were measured for the Mississippi Embayment study unit monitoring wells in the Me...

E. W. Strom

1997-01-01

367