ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01481.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTA technique is presented for the estimation of ground–water recharge in a region where the formations overlying an aquifer cannot transmit all of the available water to the aquifer. The method is based on a routing model which is derived from the physical nature of formations overlying the aquifer. The model takes into account precipitation, evapotranspiration, soil moisture balance and the passage of water through strata such as boulder clay. The validity of the model is tested by calculated and field stream flow hydrograph

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01482.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTIn order to understand the flow pattern around a pumping well partially penetrating a vertically extensive aquifer, a specially designed pumping test was carried out in Pakistan. In this paper salient features of the test have been described. The spatial distributions of drawdown have been shown graphically. Some of the preliminary conclusions made from the drawdown pattern include:•The distance beyond which the flow is likely to be horizontal increases with decrease in the degree of aquifer penetration.•In equidistant observation wells open at different depths, (1) the drawdowns tend to merge at larger times, provided the observation point is located within the screened section of the aquifer; (2) the less the depth of penetration is, the earlier the drawdowns start merging; and (3) the initial rate of drawdown near the aquifer top is slow but catches up with time to exceed those at deeper poi

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01483.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTThe ground‐water flow and ground‐water quality of extensive gravel deposits in the Lower Colne Valley, near London, England are described. The great demand for aggregates in southeast England over the past 30 years has resulted in extensive exploitation of these gravels, the worked‐out pits being either left water‐filled for recreational purposes, or filled with a variety of waste materials. Both after‐uses are shown to alter the ground‐water situation either by locally lowering or raising ground‐water levels, such effects having been described in both French and German literature, or by causing ground‐water and surface‐water pollution problems. If the scale of pit development or landfilling is large as in the Lower Colne Valley, then remedial measures have to be undertaken to minimize the pollution risk and to obviate problems caused by raised or lowered gr

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01484.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTConfined flow of ground water through a tunnel, which might be encountered in tunneling under the bottom of a sea or river, is numerically analyzed by a reductive finite element method formulated in our research. That is, the rate and potential distribution of the confined flow of ground water through an opening are obtained in connection with the permeability of rock masses, the thickness of covered ground, the location of impermeable bedrock, and other variables.In addition, flow through an opening in the ground with highly permeable masses and discharge of ground water through a tunnel in grouted masses are illustrated, and some useful results for the practical application of tunneling work are obtained.

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01485.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTThe ground‐water flow system in the Lower Susquehanna River Basin in Pennsylvania and Maryland can be considered as one complex unconfined aquifer in which secondary porosity and permeability are the dominant influences on the occurrence and flow of ground water. The degree of development of secondary porosity and permeability in the various lithologies of the lower basin determines the aquifer characteristics of each lithology. Based on qualitative evidence, the use of a porous‐media model was assumed to be appropriate on a regional scale and a finite‐difference ground‐water flow model was constructed for the lower basin.The conceptual model of ground‐water flow in the lower basin incorporates the major features of the flow system. Through the use of two layers, 21 hydrogeologic units, and five topographic settings, the conceptual model was systematically reduced to arrive at a simplified conceptual model. Further reduction produced a numerical model representation of the conceptual model, in which the essential features of the lower‐basin flow system were quantified for input into the numerical model.The model was calibrated under both steady‐state and transient conditions, and was used to evaluate the water‐supply potential of the 21 hydrogeologic units. The carbonate units have the greatest potential for ground‐water development and the Triassic sedimentary and crystalline units have the least potential. A total ground‐water yield potential of about 900 million gallons per day could be obtained from the lower basin with a consequent 50‐percent reduction of

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01486.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTDuring the two‐week period from March 12 through March 26, 1982, a preliminary conceptual design analysis on various remedial measures for the Lipari Landfill, New Jersey, was performed. This site is currently ranked at the top of the EPA's Superfund Cleanup List. This report demonstrates the practical benefits and limitations of applying models (both analytical and numerical) to a hazardous waste site in a restricted period of time. The numerical model was used to simulate current flow conditions at the site and provide initial conditions for a series of sensitivity simulations. These sensitivity simulations were designed to test (1) a slurry wall, (2) drain location, (3) drain depth, and (4) a clay cap. Analytical solutions were designed to analyze (1) water in place, (2) flow through an underlying layer, the lower Cohansey, (3) draining the lower Cohansey, (4) flushing the contaminated area using wells, and (5) convective arrival time of contaminants to drains. This analysis quantified discharge to drains, flow rates to a swamp downstream of the landfill, time required to drain the landfill, and contaminant travel times that would result from the implementation of each of the remedial measures that were suggested. The conclusions from this study were used by engineers and planners who incorporated, economics and engineering decisions for the various remedial measures considere

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01487.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTA zone of contaminated ground water has been identified in an unconfined sand aquifer adjacent to a pit into which spent pulp liquor was intermittently discharged from 1970 to 1979. A network of multilevel sampling, bundle‐type piezometers was installed. Up to seven depthspecific sampling points were incorporated into each piezometer providing a cost‐effective means for three‐dimensional mapping of hydraulic head and water quality in the unconfined sand aquifer. Ground‐water samples retrieved from this network showed an area of contamination 900 m long, 400 m wide, and more than 25 m deep. This plume is dispersed about the ground‐water flow lines passing beneath the waste disposal pit, and it terminates at a vigorous ground‐water discharge area located 800 m from the pit.The contaminated ground water is characterized by elevated concentrations of sodium (3,000 mg/1), chloride (590 mg/1), alkalinity (2,700 mg/1), total organic carbon (2,000 mg/1), chemical oxygen demand (10,800 mg/1), biological oxygen demand (2,000 mg/1), tannin and lignin (780 mg/1), and lower sulphate (1 mg/1) compared to background ground waters in the area. The apparent rate of sodium migration is more than 50 m/yr and is close to the average linear ground‐water velocity. Removal of some organic matter by biological transformation has produced the increased alkalinity in the contaminated ground water and somewhat reduced pH. Tannin and lignin are relatively inert compared to other organic compounds found in the waste liquor. Extremely low sulphate levels occurring in the highly contaminated ground waters indicate the existence of conditions favorable for microbially‐mediated sul

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01488.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTAn algorithm for the Theis solution of pumping test data has been developed taking into account the basic principles of graphical approach of curve‐matching. The method is simple and does not need initial approximation of transmissivity and storativity as required by approaches suggested by Saleem (1970) and McElwee (1980). As a measure of error of fitting, integral square error is computed between the observed drawdown and drawdown calculated from the theoretical equation with the values of coefficients estimated by the procedure. Also root mean square deviation in drawdown is calculated. The algorithm is capable of identifying data with errors in observation or recording. The reliability of the algorithm and its limitations are discussed on the basis of test runs with synthetic data having varying magnitudes of error and varying distributions of error points in the data set. The estimates of parameters by the proposed algorithm for a typical field test data compare very well with the estimates by the sensitivity approach developed by McElwee (1980

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01489.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1984.tb01490.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY