MORPHOLOGICAL CHANGE BASED ON LIDAR-DERIVED DIGITAL ELEVATION MODELS

The U.S. Geological Survey (USGS) and the National Park Service (NPS) have collaborated to use the Experimental Advanced Airborne Research LIDAR (EAARL) to collect data for ecological monitoring, storm-event assessment, habitat mapping, and evaluating geomorphic change. In this study, 1-m digital elevation models (DEMs) were created from EAARL point data to assess and monitor morphologic change. The analysis occurred along the following three national parks: Fire Island National Seashore, a 41.8-km-long barrier island located on the south shore of Long Island, New York, Assateague Island National Seashore, an undeveloped barrier island located off the coast of Maryland and Virginia, and Gulf Islands National Seashore, located along a 240-km stretch of Mississippi and northwestern Florida coast. Multiple, repeat surveys have been conducted over each study area as part of the NPS Inventory and Monitoring Program (I & M), that was designed for the conservation and monitoring of critical coastal habitat. Morphologic modification was determined between each of the LIDAR acquisition periods by calculating net volumetric change per unit area (m). The study areas exhibited short-term morphologic change along the beach face. Such changes are affected by the variability of sediment sources and sinks, episodic storms, and anthropogenic modification. Results from the study sites indicate that the beach-face may be erosional or depositional over a range of temporal and spatial scales.