Abstract

Using GIS Techniques and Field Methods to Analyze Karst Terrain
Track: Environmental Management
Authors: David Ladd

Karst features such as closed depressions and their catchments present challenges to natural-resources management and topographic analysis. In karst areas, some surface-water runoff is diverted to closed depressions that recharge groundwater at various rates, thus affecting the amount of runoff reaching streams and providing potential pathways for contaminant entry to an aquifer.

The U.S. Geological Survey, in cooperation with the Tennessee Department of Environment and Conservation, conducted an analysis of karst features in the Red River basin of Tennessee and Kentucky. Closed depressions were delineated and their storage characteristics were quantified using digital elevation data, Arc Hydro Tools, and Spatial Analyst. Storage capacities were combined with flood-duration data collected after significant rain to characterize surface-water/groundwater connectivity of the karst features. The data were used to classify depressions based on their contaminant transport potential. Such classifications could be used by natural-resource managers to better protect streams and springs in karst areas.