Publications

Groundwater flow modeling was used to quantitatively assess the hydrologic processes affecting ground water and solute movement to drain laterals. Modeling results were used to calculate the depth distribution of groundwater flowing into drain laterals at 1.8 m (drain lateral 1) and 2.7 m (drain lateral 2) below land surface. The simulations indicated that under nonirrigated conditions about 89% o

A study was undertaken to quantitatively evaluate the hydrologic processes affecting the chemical and isotopic composition of drain lateral water in a drained agricultural field in the western San Joaquin Valley, California. The results elucidate the process of mixing of deep and shallow groundwater (below and within 6 m from land surface) entering the drain laterals. The deep groundwater was subj

Five-hundred nineteen mammals were reported dead at cyanide-extraction gold mines in Arizona [USA], California, and Nevada from 1984 through 1989. Most numerous were rodents (34.9%) and bats (33.7%); 'bat' was the most often reported category among 24 species or species groups. There are an estimated 160 cyanide-extraction gold mines in these three states, and the number is increasing. Ten mammal

National Water Summary 1988-89 - Hydrologic Events and Floods and Droughts documents the occurrence in the United States, Puerto Rico, and the U.S. Virgin Islands of two types of extreme hydrologic events floods and droughts on the basis of analysis of stream-discharge data. This report details, for the first time, the areal extent of the most notable floods and droughts in each State, portrays th

A new three-dimensional model of solute transport in groundwater that is based on a widely used two-dimensional method of characteristics model and is coupled to a modular finite-difference flow model is under development. The model's accuracy for ideal aquifers having homogeneous properties, uniform boundary conditions, and steady flow along a grid direction is demonstrated by comparison with con

The Priestley-Taylor equation, a simplification of the Penman equation, was used to allow calculations of evapotranspiration under conditions where soil water supply limits evapotranspiration. The Priestley-Taylor coefficient, α, was calculated to incorporate an exponential decrease in evapotranspiration as soil water content decreases. The method is appropriate for use when detailed meteorologica

Recently compiled data on the composition of commercial Aroclor mixtures and ECD (electron capture detector) response factors for all 209 PCB congeners are used to develop estimates of the bias associated with determination of polychlorinated blphenyis. During quantitation of multlcomponent peaks by congener-specific procedures error is introduced because of variable ECD response to isomeric PCBs.

In 1983, the City of Indianapolis, Indiana, completed construction of advanced wastewater treatment (AWT) systems to enlarge and upgrade its existing Belmont Road and Southport Road secondary treatment plants. A nonparametric statistical procedure, a modified form of the Wilcoxon-Mann-Whitney rank-sum test, was used to test for trends in water quality at two upstream and two downstream sites on Wh

The occurrence of selenium in agricultural drain water from the western San Joaquin Valley, California, has focused concern on the semiconfined ground-water flow system, which is underlain by the Corcoran Clay Member of the Tulare Formation. A two-step procedure is used to calibrate a preliminary model of the system for the purpose of determining the steady-state hydraulic properties. Horizontal a

In the late 1950's, intense demands for water and growing concerns about declines in the quality of water generated the need for more water-resources data. About thirty Federal agencies, hundreds of State, county and local agencies, and many private organizations had been collecting water data. However, because of differences in procedures and equipment, many of the data bases were incompatible. I

No abstract available. 

No abstract available.