Use of GIS to Identify and Delineate Areas of Fluoride, Sulfate, Chloride, and Nitrate Levels in the Woodbine Aquifer, North Central Texas, in the 1950s, 1960s, 1970s, 1980s, and 1990s
Description: ArcView and ArcInfo were used to identify and delineate areas contaminated by fluoride, sulfate, chloride, and nitrate in the Woodbine Aquifer. Water analysis data were obtained from the TWDB from the 1950s to 1990s covering 9 counties. 1990s land use data were obtained to determine the relationship with each contaminant. Spearman's rank correlation coefficients and Kruskal-Wallis tests were used to calculate relationships between variables. Land uses had little effect on distributions of contaminants. Sulfate and fluoride levels were most problematic in the aquifer. Depth and lithology controlled the distributions of each contaminant. Nitrate patterns were controlled mainly by land use rather than geology, but were below the maximum contaminant level. In general, contaminant concentrations have decreased since the 1950s.
Date: August 2001
Creator: Sanmanee, Sirichai