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 Author:
 Valdes, J.J.
 Source:
 Ground water 1996 v.34 no.4 pp. 745749
 ISSN:
 0017467X
 Subject:
 islands; hydrology; geology; lakes; surface water; simulation models; history; rain; evapotranspiration; water table; paleoclimatology; groundwater recharge; hydrogeology; Bahamas
 Abstract:
 ... Samana Cay, Bahamas, is a leading candidate among the sites proposed as the first landfall of Columbus in the New World. One main point of contention against this identification is that Samana lacks a feature matching the laguna observed by Columbus in the middle of his landfall island. However, this argument has failed to consider the paleogeographic aspects of the problem. A hydrogeologic comput ...
 DOI:
 10.1111/j.17456584.1996.tb02063.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02063.x
 Author:
 Ali, A.I.; Lall, U.
 Source:
 Ground water 1996 v.34 no.4 pp. 647658
 ISSN:
 0017467X
 Subject:
 aquifers; saturated hydraulic conductivity; groundwater flow; estimation; stochastic processes; sandy soils; sand; clay soils; clay; alluvium; probability analysis; sediments; Utah
 Abstract:
 ... A nonparametric statistical methodology based on kernel function estimation is developed for assessing the probability that a particular location in the aquifer has high or low conductivity using borehole information. The approach presented is an alternative to Indicator Kriging. Soils are classified through a binary indicator function defined as 0 for low and as 1 for a high conductivity soil. Es ...
 DOI:
 10.1111/j.17456584.1996.tb02052.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02052.x
 Author:
 Srinivas, M.; Sundararajan, N.
 Source:
 Ground water 1996 v.34 no.4 pp. 588592
 ISSN:
 0017467X
 Subject:
 aquifers; geology; deformation; soil parent materials; limestone; mathematics and statistics; electric field; India; Burkina Faso
 Abstract:
 ... An analysis of the deformation of a homogeneous electrical field caused by a long, thin inclined bed, which is of considerable importance in the exploration of ground water and minerals, is presented using the Hilbert transform. The thickness of the bed and the inclination are expressed as a function of the abscissae of the points of intersection of the horizontal and vertical derivatives of the f ...
 DOI:
 10.1111/j.17456584.1996.tb02044.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02044.x
 Author:
 Amokrane, H.; Villeneuve, J.P.
 Source:
 Ground water 1996 v.34 no.4 pp. 666674
 ISSN:
 0017467X
 Subject:
 unsaturated flow; equations; rain; evaporation; evapotranspiration; plants; water uptake; soil water movement; mathematical models; unsaturated hydraulic conductivity; soil water potential; soil water content; porous media
 Abstract:
 ... A numerical procedure based on the MacCormack method was used for the simulation of onedimensional isothermal transient movement of liquid phase water in an unsaturated soil including precipitation, evaporation, and moisture removal from soil by the roots of transpiring plants. The numerical model utilized finitedifference explicit predictorcorrector equations and it was applied to a few flow p ...
 DOI:
 10.1111/j.17456584.1996.tb02054.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02054.x
 Author:
 Falta, R.W.
 Source:
 Ground water 1996 v.34 no.4 pp. 750755
 ISSN:
 0017467X
 Subject:
 polluted soils; volatile compounds; pollutants; air flow; soil air; permeability; extraction; pumps; computer software; pollution control; equations; mathematical models; soil vapor extraction; vapors
 Abstract:
 ... Soil gas pump tests are commonly performed to identify important unsaturated zone parameters such as the effective gas permeability tensor and the influence of tight or leaky confining units. An interactive FORTRAN computer program called GASSOLVE has been developed for analyzing these tests under both transient and steadystate conditions. The code uses one of two general analytical solutions for ...
 DOI:
 10.1111/j.17456584.1996.tb02064.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02064.x
 Author:
 Osiensky, J.L.; Williams, R.E.
 Source:
 Ground water 1996 v.34 no.4 pp. 727733
 ISSN:
 0017467X
 Subject:
 aquifers; groundwater contamination; groundwater flow; pollutants; electrical conductivity; equations; simulation models; mathematical models; porous media
 Abstract:
 ... Twodimensional, finitedifference, saturated, groundwater flow models such as MODFLOW can be useful in simulating "misealamasse" electrical flow through conductive porous media. A new technique for using an existing numerical code to develop an approximate solution for point source electrical flow is presented. Incorporating a change in variables from groundwater flow to electrical flow with ...
 DOI:
 10.1111/j.17456584.1996.tb02061.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02061.x
 Author:
 Moline, G.R.; Beauchamp, J.J.; Wright, T.
 Source:
 Ground water 1996 v.34 no.4 pp. 579587
 ISSN:
 0017467X
 Subject:
 groundwater contamination; water quality; groundwater; temporal variation; radionuclides; statistical analysis; objectives; optimization; Tennessee
 Abstract:
 ... In the Data Quality Objectives (DQO) process, statistical methods are used to determine an optimal sampling and analysis plan. When the DQO decision rule for instituting remedial actions is based on a critical change in water quality, the monitoring program design must ensure that this change can be detected and measured with a specified confidence. Usually the focus is on the change at a single m ...
 DOI:
 10.1111/j.17456584.1996.tb02043.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02043.x
 Author:
 Schafer, D.C.
 Source:
 Ground water 1996 v.34 no.4 pp. 628639
 ISSN:
 0017467X
 Subject:
 groundwater contamination; aquifers; pollutants; wells; drainage; groundwater flow; equations; algorithms; saturated hydraulic conductivity
 Abstract:
 ... A method is presented for determining steadystate capture zones in three dimensions around horizontal drains and vertical wells in homogeneous, anisotropic aquifers in a uniform flow field. Equations are presented for determining drawdown and velocity vector components in three dimensions around drains and wells. Using these equations, a secondorder RungeKutta particle tracking algorithm is app ...
 DOI:
 10.1111/j.17456584.1996.tb02050.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02050.x
 Author:
 Brown, M.J.; Burris, D.R.
 Source:
 Ground water 1996 v.34 no.4 pp. 734744
 ISSN:
 0017467X
 Subject:
 groundwater contamination; polluted soils; soil pollution; sand; aquifers; surfactants; sorption; chlorinated hydrocarbons; tetrachloroethylene; trichloroethylene; adsorption; Ontario
 Abstract:
 ... Batch sorption and column transport laboratory experiments were performed to investigate the use of cationic surfactants to enhance sorption of dissolved organic contaminants in aquifer material with low organic carbon content. The experiments used sand from the Borden aquifer in Ontario, Canada, treated with hexedecyltrimethylammonium (HDTMA+) surfactant. Test results indicate that organic cation ...
 DOI:
 10.1111/j.17456584.1996.tb02062.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02062.x
 Author:
 Parks, K.P.; Bentley, L.R.
 Source:
 Ground water 1996 v.34 no.4 pp. 597604
 ISSN:
 0017467X
 Subject:
 aquifers; surveys; electrical conductivity; ions; groundwater; statistical analysis; water quality; total dissolved solids; Alberta
 Abstract:
 ... Groundwater chemistry data from wells are cokriged with ground conductivity measurements to quantitatively describe groundwater chemical quality at a site. The cokriged estimates are shown to be superior to both simple rescaling of ground conductivity by a linear regression model and to interpolation of groundwater chemistry data from wells using ordinary kriging. By extending the use of geophy ...
 DOI:
 10.1111/j.17456584.1996.tb02046.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02046.x
 Author:
 Simons, G.A.
 Source:
 Ground water 1996 v.34 no.4 pp. 683690
 ISSN:
 0017467X
 Subject:
 polluted soils; pollutants; soil pore system; gases; diffusivity; soil pollution; equations; permeability; mathematics and statistics; porous media
 Abstract:
 ... The "pore tree" model of pore structure was originally developed for catalyst and sorbent grains to allow coupled reactions and diffusion into and out of nonpermeable porous media in the absence of convection through the media. The pore tree model is extended herein to describe the permeable pore structure which characterizes the subsurface transport of gas and water in soil, the dispersion of con ...
 DOI:
 10.1111/j.17456584.1996.tb02056.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02056.x
 Author:
 Moench, A.F.
 Source:
 Ground water 1996 v.34 no.4 pp. 593596
 ISSN:
 0017467X
 Subject:
 aquifers; water table; wells; groundwater flow; equations; mathematics and statistics
 Abstract:
 ... An alternative Laplace transform solution for the problem, originally solved by Neuman, of constant discharge from a partially penetrating well in a watertable aquifer was obtained. The solution differs from existing solutions in that it is simpler in form and can be numerically inverted without the need for timeconsuming numerical integration. The derivation involves the use of the Laplace tran ...
 DOI:
 10.1111/j.17456584.1996.tb02045.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02045.x
 Author:
 Washington, J.W.
 Source:
 Ground water 1996 v.34 no.4 pp. 709718
 ISSN:
 0017467X
 Subject:
 pollutants; volatile compounds; soil water; soil air; soil temperature; equations; volatilization; entropy; thermodynamics; polluted soils; vapors
 Abstract:
 ... Enthalpy and entropy of volatilization from dilute aqueous solutions for 26 volatile organic compounds (VOCs) have been determined using Henry's Law values reported in published literature. Based on the linearity of van's Hoff plots, for the temperature ranges common in soils, the differences in heat capacities of volatilization for reactants and products are very small for the VOCs studied. When ...
 DOI:
 10.1111/j.17456584.1996.tb02059.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02059.x
 Author:
 Steinich, B.; Marin, L.E.
 Source:
 Ground water 1996 v.34 no.4 pp. 640646
 ISSN:
 0017467X
 Subject:
 aquifers; rocks; soil parent materials; permeability; groundwater flow; geology; saltwater intrusion; freshwater; salinity; water quality; saline water; Mexico
 Abstract:
 ... Eight Schlumberger soundings and four Wenner anisotropy measurements were conducted in the northwestern section of the Yucatan Peninsula for hydrogeological investigations of a karst aquifer. This system is influenced by a circular high permeability zone (Ring of Cenotes) probably related to the Chicxulub Impact Crater. Schlumberger soundings and Wenner anisotropy measurements show that the karst ...
 DOI:
 10.1111/j.17456584.1996.tb02051.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02051.x
 Author:
 Bethune, D.N.; Farvolden, R.N.; Ryan, M.C.; Lopez Guzman, A.
 Source:
 Ground water 1996 v.34 no.4 pp. 699708
 ISSN:
 0017467X
 Subject:
 groundwater contamination; pollutants; methylene chloride; chloroform; chlorinated hydrocarbons; aquifers; groundwater flow; lakes; water pollution; pollution control; Nicaragua
 Abstract:
 ... Laguna Asososca, a large groundwaterfed volcanic crater, is an important source of municipal water supply for the city of Managua. In 1990, after 65 years of pumping at increasing rates from the crater, the gradient between the Laguna and the highly contaminated Lake Managua had potentially reversed, leading to a scenario where the Laguna was possibly drawing in contaminated ground water from La ...
 DOI:
 10.1111/j.17456584.1996.tb02058.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02058.x
 Author:
 Tim, U.S.; Jain, D.; Liao, H.H.
 Source:
 Ground water 1996 v.34 no.4 pp. 618627
 ISSN:
 0017467X
 Subject:
 geographic information systems; groundwater contamination; insecticide residues; carbofuran; herbicide residues; atrazine; alachlor; computer software; equations; prairie soils; agricultural soils; agricultural land; simulation models; biological resistance; risk; computer graphics; Iowa
 Abstract:
 ... During the last several years, the geographic information system (GIS) technology has emerged as an extremely effective tool for analyzing and prioritizing natural resource management alternatives. Because natural resource management problems are spatial in nature, the GIS technology provides a tool for defining the extent of the problem, and facilitates the design and implementation of alternativ ...
 DOI:
 10.1111/j.17456584.1996.tb02049.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02049.x
 Author:
 Soerens, T.S.; Sabatini, D.A.
 Source:
 Ground water 1996 v.34 no.4 pp. 605609
 ISSN:
 0017467X
 Subject:
 pollutants; sorption; isomers; mixtures; dyes; soil; aquifers; benzene; toluene; xylene; aromatic hydrocarbons; polluted soils; groundwater contamination; equations; mathematics and statistics
 Abstract:
 ... For compound mixtures or compounds with two or more differently sorbing isomers which are not analytically distinguished, combined sorption parameters determined in the laboratory are dependent upon the ratio of different compounds or isomers and upon experimental methods and conditions. The purpose of this paper is to mathematically examine the effects of these factors on sorption parameters calc ...
 DOI:
 10.1111/j.17456584.1996.tb02047.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02047.x
 Author:
 Chapelle, F.H.; Bradley, P.M.; Lovley, D.R.; Vroblesky, D.A.
 Source:
 Ground water 1996 v.34 no.4 pp. 691698
 ISSN:
 0017467X
 Subject:
 aquifers; groundwater contamination; benzene; toluene; oxidation; biodegradation; mineralization; sulfates; reduction; sulfatereducing bacteria; nitrates; nutrient availability; groundwater flow; South Carolina
 Abstract:
 ... Rates of biodegradation were measured in a petroleum hydrocarboncontaminated aquifer using a combination of field and laboratory methods. These methods are based on tracking concentration changes of substrates (both electron donors and acceptors) or final products of microbial metabolism over time. Ground water at the study site (Hanahan, South Carolina) is anoxic, and sulfate reduction is the pr ...
 DOI:
 10.1111/j.17456584.1996.tb02057.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02057.x
 Author:
 Dodds, W.K.; Randel, C.A.; Edler, C.C.
 Source:
 Ground water 1996 v.34 no.4 pp. 756759
 ISSN:
 0017467X
 Subject:
 bacteria; aquifers; groundwater; silt; sand; gravel; particle size; oxygen; denitrification; denitrifying microorganisms
 Abstract:
 ... Flowthrough microcosms were constructed to conduct ecological experiments on aquifer organisms. The two 5channel microcosms were simple to construct, were fed by an artesian spring, and maintained close to in situ temperature and O2 concentrations. They were used to test relative microbial colonization of three substrate sizes: silt (0.063 mm), sand (0.9 mm), and gravel (3 mm). After 96 days of ...
 DOI:
 10.1111/j.17456584.1996.tb02065.x

http://dx.doi.org/10.1111/j.17456584.1996.tb02065.x