DELINEATION AND CLASSIFICATION OF KARST DEPRESSIONS USING LIDAR: OWL MOUNTAIN PROVINCE, FORT HOOD MILITARY INSTALLATION, TEXAS

The Fort Hood Military Installation is a karst landscape located in the Lampasas Cut Plain region of the Edwards Plateau, characterized by outcrops of Lower Cretaceous limestones and dolostones from the Fredericksburg Group. The study area is located in the northeastern section of the installation, a dissected plateau known as the Owl Mountain Province. This section is utilized as training areas for troop readiness, while more rugged and vegetated terrain is set aside as endangered species habitat. Traditional methods such as field surveying can yield accurate results; however, they are limited by time and physical constraints and within the study area, dense vegetation and military land use preclude extensive traditional karst survey inventories. Airborne Light Detection and Ranging (LiDAR) provides an alternative for high-density and high-accuracy three-dimensional terrain point data collection. The increasing capabilities of GIS (Geographic Information Systems) and accuracy of geographically referenced data has provided the basis for more detailed terrain analysis and modeling.

Spatial interpolation of the Owl Mountain Province provided depression data that were delineated and classified using geoanalytical methods. Filtering mechanisms were employed to remove natural and anthropogenic depression features resulting from terrain modifications by military use, road building and maintenance, and the natural influence of water bodies throughout the study area. Most of the remaining depression features within the study area were interpreted as predominantly surficial expressions of collapse features, creating windows into karst conduits with surficial exposures of epikarst spatially limited. The availability of high density data makes it possible to model karst terrains in great detail; however, high density data significantly increases data volume, which can impose challenges with respect to data storage, processing, and manipulation.