SINKHOLE CLASSIFICATION AND LOCATION USING GIS IN THE CAVE SPRINGS AREA, CHATTANOOGA, TENNESSEE

In this study, Geographic Information system (GIS) was used to map sinkholes on the Cave Springs property of the Hixson Utility District (HUD) in Chattanooga, Tennessee to assist in the development of a Source Water Protection Program (SWPP). Sinkholes provide direct contact to ground water resources, so it is important to know where they are located to prevent contamination sources from entering the aquifer. All data for this project, including geology, aerial photos, water features, property boundaries, and sinkholes were collected in a geodatabase. A classification scheme was defined based on maximum diameter: large sinkholes > 15 m, medium sinkholes 5 to 15 meters and small sinkholes < 5 meters. Nineteen sinkholes were identified on the property, 3 medium and 16 small. There were no large sinkholes identified on this property. Using a map produced by ArcGIS, three potential trends in the distribution of the sinkholes were identified (north, northeast and east). Joint measurements were then taken on the property to determine if there was any geological control on these trends. Only one (northeast) showed any possible link to the geology. The other two appear to be artifacts of the sampling technique. This GIS can easily be modified to evaluate the environment and conditions around the Cave Springs area as urban development in the north Chattanooga area increases.