The Winchester 30 x 60 minute quadrangle, covering northern Virginia, West Virginia, and Maryland, hosts karsts within carbonate units of Devonian to Cambrian age. Lidar-derived elevation data, acquired between 2011 and 2019, were used to create a mosaic of 1-meter resolution working digital elevation models (DEMs), from which surface depressions were identified using a semi-automated workflow in ArcGIS. Depressions in the automated inventory were systematically checked by a geologist using aerial imagery, lidar-derived imagery, and 3D viewing of the lidar imagery. Distinguishing features, such as modification by human activities or hydrological significance (stream sink, ephemerally ponded, etc.), were noted wherever relevant to a particular depression. Statistics on the geometric morphometry of each depression were calculated, including perimeter, area, depth, length of major and minor elliptical axes, and azimuth of the major axis. Center points were created for each surface depression and were used to create a point density raster. The density raster displays the number of closed depression points per square kilometer.
|Title||Lidar-derived closed depression vector and density raster in karst areas of the Winchester 30 x 60-minute quadrangle|
|Authors||Cheyenne L Cox, Daniel H Doctor|
|Product Type||Data Release|
|Record Source||USGS Digital Object Identifier Catalog|
|USGS Organization||Florence Bascom Geoscience Center|