bluuebunny/crossref_metadata_2025_split huggingface dataset:
Algorithm for Surface/Ground‐Water Allocation under Appropriation Doctrine
Authors: Lllangasekare Tissa H. , Morel‐Seytoux Hubert J. 
Published: March 2006

ABSTRACTA stream‐aquifer simulation model was developed to evaluate different conjunctive use management strategies in the South Platte River in Colorado. A component of this model simulates the allocation of surface and ground water for agricultural use. The water law based on the doctrine of prior appropriation provides the basic framework for water allocation in the study area. The physical sequence in which the river diversions are located along the river is different from the sequence in which the water has to be allocated according to the priority of rights. An algorithm is designed to allocate the river flows computed by the physical simulation component of the model to the appropriators according to the water rights and other imposed criteria as specified by the conjunctive management scheme under study. The algorithm is demonstrated on a management problem involving the evaluation of a streamflow augmentation scheme in the study reach.
Determination of Aquifer Parameters by the Slope‐Matching Method
Authors: Sen Zekâi 
Published: March 2006

ABSTRACTA method has been developed by which the slope between any two successive data points on a time‐drawdown plot can be used for determining aquifer parameters in nonleaky and leaky aquifers. The method yields values of transmissivity and storage coefficient which are in good agreement with the results of the classically known techniques. The method of slope analysis offers several advantages in its use. These advantages include the following: Changes in values for the aquifer parameters that might occur during a pumping test can be identified. Confidence limits can be calculated for average values of aquifer parameters. The method yields meaningful aquifer parameter estimates even for short duration pumping tests. Subjective interpretation of the data is minimized.
Analytical Modeling of Ground‐Water Impacts by Mining
Authors: Koch Donald 
Published: March 2006

ABSTRACTThe equation for two‐dimensional, vertically averaged steady‐state flow to a finite‐length line sink, a semiempirical expression for the radius of influence, and the theory of superposition are used to predict the impacts of excavations on ground‐water flow patterns. The algorithm provides a rapid method for estimating the inflow to mine pits, and the impact of mines on the potentiometric surface. An accurate expression for the radius of influence is developed by comparison with analytical and finite‐difference model solutions. The algorithm is an accurate estimate of drawdowns at longer times, when the steady‐state approximation is appropriate.
A Solute‐Transport Simulation of Brackish‐Water Intrusion Near Baltimore, Maryland
Authors: Chapelle Francis H. 
Published: March 2006

ABSTRACTBrackish‐water contamination of the Patuxent aquifer has been a serious water‐quality problem in Baltimore, Maryland, since the early 1900's. The Patuxent aquifer presently contains a circular plume of brackish‐water contamination that is about 5 miles in diameter. This plume is centered on the Patapsco River estuary and is characterized by chloride concentrations that range up to 5,000 milligrams per liter. Borehole data demonstrate that the Arundel Clay Formation, which overlies the Patuxent and functions as a confining bed, has been breached by Pleistocene river channels in the Baltimore area. These erosional channels, which have been subsequently filled with relatively permeable sediments, provide conduits for brackish water to seep from the Patapsco River into the Patuxent aquifer when aquifer water levels arc lower than river water levels.A two‐dimensional areal solute‐transport model of the Patuxent aquifer was used to estimate the future movement of the brackish‐water plume based on alternative strategies of aquifer use. Model simulations suggest that the plume will not spread rapidly if present pumping patterns are continued. Furthermore, sharply curtailing pumpage in the Baltimore area will probably not reduce the size of the plume, although this strategy may slightly decrease the spreading rate. While the plume is presently remaining nearly stationary, new pumping centers southeast of Baltimore could cause brackish water to migrate in that direction, significantly increasing the size of the plume.
A Radial Injection Tracer Experiment in a Confined Aquifer, Scarborough, Ontario, Canada
Authors: Palmer Carl D. , Nadon Robert L. 
Published: March 2006

ABSTRACTA radial injection tracer experiment was conducted in Scarborough, Ontario, as part of a program to evaluate the feasibility of using a confined aquifer, underlying the Canada Centre building site for the storage of chilled and/or heated water for a seasonal thermal energy storage system. Water was injected into the aquifer for five hours before a salt solution was added as a tracer. This tracer was injected into the aquifer over a period of four hours at a rate of 22.7 1/s. Injection of the water into the aquifer continued for an additional 1 5 hours following injection of the salt solution. Samples were collected from a monitoring well located 6.54 meters from the injection well. A sampling device was installed prior to the injection experiment to permit the collection of water samples at different elevations within the screened portion of the monitoring well. The samples which were collected at five different elevations at various times, both during and following the salt injection, were analyzed for specific conductance and chloride concentration. The data suggest that the aquifer is inhomogeneous and that the ratio of the hydraulic conductivity to porosity increases from the lowest sampling port to the highest sampling port near the top of the aquifer. A linear relationship was obtained between the time of arrival of the tracer and the apparent resistivity of the formation. This linear relationship was used to calibrate the apparent resistivity log of the injection well to provide a continuous characterization of the vertical variation in the hydraulic conductivity/porosity ratio across the full thickness of the aquifer. Data analysis also suggests that the dispcrsivity parameter varies linearly with the time of arrival of the tracer. The combination of geophysical logs with tracer experiments may permit detailed characterization of the hydraulic properties of aquifers.
Diagnostic Hydrologya
Authors: De Wiest Roger J. M. 
Published: March 2006

ABSTRACTThis paper examines two eases of surface‐water/ ground‐water interrelationships, one in Beaufort County, North Carolina and one in Ramona, California. In each case the author has to make a differential diagnosis between alternate solutions rendered by hydrologic methods.In the first ease, the author proves that the pumping and subsequent wastage to the ocean of 65 mgd in order to operate the Texas Gulf Sulphur phosphate mine, in all likelihood poses no threat to the environment.In the second case, the author has attempted to obtain, by means of the theory of ground‐water flow, an estimate of the physiographic volume of the Santa Maria creek ground‐water basin in Ramona. He has submitted the outcome of his calculations to the test of compatibility with the results of an actual pumping test, and with pumping records made available by the Ramona Municipal Water District. The outcome shows a water storage capacity of the order of 4,600 AF for the entire basin.In order to correlate recharge of the basin directly with the precipitation on the basin, a hydrograph analysis has been done for the 20 largest runoff‐producing months of the streamflow records 1965–1982. From this study it follows that the average (annual) recharge to the basin is of the order of 1,340 AF/yr and that the physiographic volume, as derived previously, is amply adequate to absorb this recharge.
A Hydrologic Budget Analysis for the Nile Valley in Egypt
Authors: Attia Fatma A. R. , Allam Mohamed N. , Amer Abdel Wahab 
Published: March 2006

ABSTRACTA two‐dimensional finite‐element model has been adapted to simulate the aquifer underlying the Nile Valley of Egypt. Calibration of the model led to the determination of the interaction between the ground water and the Nile surface water. Results obtained from the model were compared with those obtained from simple hydrologic budget analyses and were found to be quite comparable. The model is, thus, considered to adequately represent the ground‐water system of the Nile Valley and may be used to forecast the effects of managing the integrated ground‐water/surface‐water system.
Ground‐Water Recharge and Its Effects on Nitrate Concentration Beneath a Manured Field Site in Pennsylvania
Authors: Gerhart James M. 
Published: March 2006

ABSTRACTGround‐water recharge to a shallow, unconfined, fractured dolomite aquifer underlying agricultural land in Lancaster County, Pennsylvania occurs by two mechanisms. Direct recharge occurs through pathways such as near‐surface bedrock fractures and sinkholes, and affects dissolved nitrate concentration of ground water within two to three days; its effects last only about one week. Gradual recharge occurs through small channels and pores in the unsaturated zone and affects dissolved nitrate concentration for several weeks or more after the effects of direct recharge have dissipated. Whether recharge causes an increase or decrease in dissolved nitrate concentration depends on the amount of nitrogen‐rich manure spread on the site prior to the storm. Direct recharge from a storm in March 1984, a month in which 18 tons of manure were spread, resulted in a rapid decrease in dissolved nitrate concentration of about 2.5 milligrams per liter (mg/1) as nitrogen. Direct recharge from a storm in May 1984, after 384 tons of manure had been spread in April, resulted in a rapid increase in dissolved nitrate concentration of about 3 mg/1 as nitrogen. Concentration changes caused by gradual recharge several weeks or more after the storms were of the same magnitude as those caused by direct recharge during the storm.
Finite‐Difference Grid for a Doublet Well in an Anisotropic Aquifer
Authors: Miller Robert T. , Voss Clifford I. 
Published: March 2006

ABSTRACTThe U.S. Geological Survey is modeling hydraulic flow and thermal‐energy transport at a two‐well injection/ withdrawal system in St. Paul, Minnesota. The design of the finite‐difference model grid for the doublet‐well system is complicated because the aquifer is anisotropic and the principal axes of transmissivity are not aligned with the axis between the two wells.An analytical solution for flow in a doublet‐well system in an infinite anisotropic aquifer was employed in the design of a grid with artificial boundaries placed in the midst of the flow field. Flow‐net analysis was used to determine water flux across an cquipotential boundary and to assign approximate flux values at model boundaries. This enabled the simulation of the effects of the entire flow field, although only a small part was modeled.The validity of the flux values at the model boundaries for the isothermal case was tested by simulation of an eight‐day injection test of ambient‐temperature water. Model‐computed pressures compared very favorably with field‐observed pressures. The validity of boundary‐flux values also was tested for nonisothermal conditions by simulation of injection of 300o F water at 300 gallons per minute for eight days.
The Use of Geophysical Logs for Determining Formation Water Quality
Authors: Kwader Thomas 
Published: March 2006

ABSTRACTIn situ water‐quality measurements, with respect to various ion and dissolved solids concentrations, have been closely approximated using open‐hole borehole geophysical logs. Analyses have shown good correlation between water resistivity (Rw, as determined from the logs) and dominant ion concentrations sampled from a wide range of water quality in Tertiary carbonate and granular formations.Rw can be accurately determined by cross‐plotting saturated formation resistivity (Ro), obtained from normal or lateral resistivity logs, against formation bulk porosity from neutron, density, or acoustic velocity logs. Plotting these data on Hingle Resistivity‐Porosity Cross Plot (RPCP) paper with the proper matrix cementation factor (m, commonly 1.4 for unconsolidated sands or 1.6 for noncompacted Tertiary carbonates), will yield a graphical solution for Rw based upon the relationship Rw=φm Ro. The graphical technique also provides information concerning water‐quality variations with depth, true matric resistivity, location of confining beds, and vertical changes in formation porosity.Once Rw has been determined, other ion concentrations can be estimated based upon chemical analyses of water samples from adjacent wells tapping a similar type water mass (i.e., calcium‐bicarbonate, sodium‐chloride water, etc.). Total dissolved solids (TDS), chloride, sulfate, potassium, sodium, magnesium, and hardness (as CaCO3) concentrations have consistently shown a high correlation with Rw.
Application of Continuous Seismic Reflection Methods to Hydrologic Studies
Authors: Haeni F. P. 
Published: March 2006

ABSTRACTOil and gas exploration and engineering studies in water‐covered areas routinely use continuous seismic profiling techniques to obtain subsurface geologic information. Such profiling also can be used effectively in hydrologic studies to define the geologic framework of aquifer systems, to locate hydrologic boundaries, and in some places, to interpret the lithologic character of aquifers and confining beds.High‐resolution continuous seismic profiling, through the use of nonexplosive sound sources, can be used to produce continuous records that require little data processing before hydrogeologic interpretation. High‐resolution tuned transducer, minisparker, Uniboom, and small airgun systems operating from small boats in shallow water are capable of transmitting energy that can penetrate up to a hundred meters of earth materials. The resulting analog records of the reflected seismic signal closely resemble geologic sections.Surveys on the Housatonic River in Connecticut and Massachusetts, and on the Connecticut River, in water from 1 to 10 meters deep, have defined the bedrock surface beneath 60 meters of stratified drift. Seismic‐reflection profiling also was used to determine the extent and thickness of recent lake‐bottom deposits in two Connecticut lakes.Surveys along 90 kilometers of river channels in the Sarasota‐port Charlotte, Florida, area defined in detail the stratigrapahy and continuity of the shallow aquifers.
Inverse Problem in Ground Water: Model Development
Authors: Khan Irfan A. 
Published: March 2006

ABSTRACTA model to solve the inverse problem in ground water has been developed. The model consists of an unconstrained multivariable optimization algorithm and a ground‐water simulation model. The optimization algorithm is a modified version of Newton's second derivative method. It is a ground‐water‐specific algorithm and was found to be more efficient than other more general unconstrained optimization algorithms requiring first‐ and/or second‐order derivatives and those requiring no derivatives. The groundwater simulation model is based on a finite‐difference technique but it can be replaced easily by a finite‐element model. The results of an application of this model to a real aquifer are discussed in a companion paper titled “Inverse Problem in Ground Water: Model Application.”
Aquifer Test Analysis in Fractured Rocks with Linear Flow Pattern
Authors: Şen Zekâi 
Published: March 2006

ABSTRACTA major vertical fracture in a permeable rock mass may act as an extended well and can provide water through pumping cither directly from the fracture itself or if the fracture width is not enough to install pumps, from an abstraction well drilled in the fracture. In such a case the ground‐water flow is not radial but linear toward the fracture and the flow lines are perpendicular to the fracture axis.A mathematical description of ground‐water flow toward vertical fractures is presented. The cases considered are: (1) an infinitesimally small fracture width corresponding to a planar source or sink, and (2) a finite width fracture in which the effects of ground‐water storage in the fracture are taken into account. The necessary type curves are presented for the main and observation wells. It is observed that the type curve in the linear flow pattern case is extremely different from the radial flow solution especially for long times. In addition, recovery type curves are also given. The application of the method is presented for some available data in the literature.
Depositional Environments of Buried‐Valley Aquifers in North Dakota
Authors: Kehew Alan E. , Boettger William M. 
Published: March 2006

ABSTRACTMany buried‐valley aquifers in North Dakota occupy narrow, trench‐like valleys incised through glacial sediment into bedrock. By analogy with nonburied valleys of similar size, shape, and geomorphic characteristics, the buried valleys are interpreted to be glacial‐lake spillways formed during glaciations prior to the last advance and retreat. Water‐bearing sediments that fill these buried valleys, although traditionally interpreted as glacial outwash, are commonly composed of nonglacial fluvial sediments deposited between glaciations. Interglacial fluvial systems that occupied the glacial‐lake spillways include major trunk streams draining the Rocky Mountains as well as sluggish, underfit streams with small drainage areas. Deposits associated with the latter type consist of fine‐grained fluvial and lacustrine sediments in the valley centers grading into coarser sediments of alluvial‐fan origin along the valley sides. Thus, in some buried valleys, the most productive aquifers may lie along the valley sides rather than in the valley centers.
Analysis of Geophysical Logs of Water Wells with a Microcomputer
Authors: Keys W. Scott 
Published: March 2006

ABSTRACTA microcomputer can be a significant aid in the analysis of geophysical logs of wells used in investigations of ground‐water systems. Geophysical logs, test data, and laboratory analyses present a large volume of data that can most efficiently be manipulated with a computer. Techniques for the analysis of logs using mainframe computers and minicomputers have been developed and used in the petroleum industry for a number of years. These techniques have not been used widely in ground‐water investigations because available programs were oil‐oriented, and both programs and computers were too expensive to be cost‐effective for most ground‐water investigations. These programs also tended to be too complex for the part‐time user to learn. The advent of the relatively inexpensive microcomputer and a number of inexpensive, easy‐to‐use generic programs made computer‐aided log analysis available to most hydrologists.A microcomputer can be used to transfer well logs by telephone and to correct the data received. The logs then can be collated, compared, and analyzed statistically. Two logs can be cross‐plotted in order to identify lithology or to provide porosity corrected for matrix effects. Logs can be plotted against laboratory analyses of cores or samples for purposes of log calibration.As an example of this technique, logs and core data from a test well completed in the Madison Limestone were analyzed using a microcomputer and generic programs. Computer‐aided log analysis facilitated the identification of the lithologic units penetrated and the intervals of secondary porosity that produced water. Plots of logs and other data included in the paper were reproduced directly from the graphics subprogram that is part of the spreadsheet program.
Problems Interpreting Samples Taken with Large‐Volume, Falling‐Suction Soil‐Water Samplers
Authors: Anderson Linda Davis 
Published: March 2006

ABSTRACTChemical data resulting from sampling heterogeneous, variably saturated soils with large‐volume, falling‐suction samplers must be cautiously interpreted. Nitrate and chromium data from a tannery waste‐disposal project illustrate the difficulties in distinguishing chemical and physical effects of sampling procedures from natural variability. Dramatically different interpretations of soil‐water chemistry can result if precipitation in the porous cup or influence of the sampler on the soil‐fluid flow is ignored. Additional laboratory studies are needed to assess adsorption on and screening of trace metals by the porous cup of the sampler. In the field, redox conditions as well as pH should be carefully monitored, soil structure noted, and pore‐size distribution quantified. Use of numerical simulations could aid in planning monitoring strategies and interpreting results.
Design and Cost Analysis of Rapid Aquifer Restoration Systems Using Flow Simulation and Quadratic Programming
Authors: Lefkoff L. Jeff , Gorelick Steven M. 
Published: March 2006

ABSTRACTDetailed two‐dimensional flow simulation of a complex ground‐water system is combined with quadratic and linear programming to evaluate design alternatives for rapid aquifer restoration. The design model ensures that a contaminant plume is removed and treated within four years at the least possible cost. Rapid restoration is accomplished by maintaining specified velocities around the plume perimeter toward a group of pumping wells located near the plume center. Ground‐water velocities are adjusted to include the effects of solute retardation due to sorption. As a simplification, the model does not account for hydrodynamic dispersion. Results show how treatment and pumping costs depend dynamically on the type of treatment process, the capacity of pumping and injection wells, and the number of wells. The design for an inexpensive treatment process minimizes pumping costs, while an expensive process results in the minimization of treatment costs. Substantial reductions in pumping costs occur with increases in injection capacity or in the number of wells. Treatment costs are reduced by expansions in pumping capacity or injection capacity. The analysis identifies maximum pumping and injection capacities.Maintenance of the high ground‐water velocities required by rapid restoration strategies is difficult and expensive. In order to meet the four‐year target date, about ten times the initial volume of contaminated water must be pumped and treated. Rapid restoration forces large pumping volumes and high costs.
BIOINDICATORS OF GROUND WATER IN VARAHAMIHIRA'S BRIHAT SAMHITA*
Authors: Prasad E.A.V. 
Published: March 2006

AbstractEvery year enormous amounts of wasteful expenditure are incurred due to faulty location of well sites in the hardrock terrains by either the most commonly adopted mystic methods of “water‐divining” or the geophysical methods.The strikingly visible and easily recognizable bio indicators of ground water, described in Varahamihira's Brihat Samhita, are ideally suited for rapid economic development of the drought‐prone areas.The prevailing wrong notions, regarding the efficacy of these bioindicators, are due to lack of sound theoretical and practical knowledge of applied ecology involved in “tropical ground‐water hydrology.”