An automated method for locating sinkholes in Montgomery County, Virginia, using digital elevation models

Abstract

The prospect of using U.S.G.S. Digital Elevation Models (DEM's) to locate sinkholes has been investigated. Three quadrangle maps, those of Blacksburg, Ironto and Newport, were selected as these areas are dotted with sinkholes. An algorithm was developed to extract sinkholes from DEM's. Sinkholes were also digitized from the topographic maps to check the accuracy of those extracted by the program from DEM's. This was done by overlaying pits extracted from DEM's with digitized sinkholes. Discriminant Analysis was run to compare the characteristics of sinkholes identified by the program from those that were not. It was found that few sinkholes could be located using the available integer elevation data of 30m resolution. Noise in the data, even after running a filter, precluded satisfactory results. It was concluded that elevation data of finer resolution and in real format should be used for this analysis.