Publication Citation

USGS Series Water-Resources Investigations Report
Report Number 95-4202
Title Relations of nonpoint-source nitrate and atrazine concentrations in the High Plains aquifer to selected explanatory variables in six Nebraska study areas
Edition -
Language ENGLISH
Author(s) Druliner, A. D.; Chen, H. H.; McGrath, T. S.
Year 1996
Originating office
USGS Library Call Number (200) WRi no.95-4202
Physical description vi, 51 p. :ill. (some col.), maps (some col.) ;28 cm.
ISBN

Online Document Versions

In Stock at the USGS Store

Abstract

Statistical techniques were used to relate nonpoint-source ground-water contamination by nitrate and atrazine to a variety of explanatory variables for six study areas in Nebraska. Water samples were collected from 268 wells in 12 counties from 1984 through 1987 and were analyzed for nitrate concentrations; water samples from 210 of the wells were analyzed for atrazine. A number of hydrochemical, climatic, hydrologic, soil, and land-use explanatory variables, which were believed to affect the contamination of ground water by agricultural chemicals, were identified and quantified for each of the 268 wells. Multiple regression methods were used to determine which explanatory variables were statistically related to ground-water concentrations of nitrate and atrazine. Regression models predicting nitrate and atrazine concentrations were produced that explained from about 50 to 68 percent of the variation in the dependent variables. Geographic- information-system methods were used to produce maps predicting nitrate and atrazine concentrations in ground water for one study area using selected regression and logistic models. The results of this study indicate that multiple regression techniques coupled with geographic information systems can be an effective means of identifying areas of potential ground-water contamination by nitrate and atrazine.