Coastal 3-D Morphological Change Analysis Using LiDAR Series Data: A Case Study of Assateague Island National Seashore

Abstract

This article presents our observation and analysis results of coastal three-dimensional morphological changes using U.S. Geological Survey (USGS), National Aeronautics and Space Administration (NASA), and National Oceanic and Atmospheric Administration (NOAA) light detection and range (LiDAR) data. The study area is located in Assateague Island National Seashore, along a 63 km stretch of Assateague Island on the Eastern Shore of Virginia and Maryland. Digital elevation models from LiDAR data over various time intervals, e.g., year-to-year (1996–1997–1997–1998–1998–2000), season-to-season (September, January), and multiyear (1996–2000), were created to test our analysis methods. Six sections in our study area were partitioned in accordance with their historical changes and coastal conditions. Three profiles of each section were extracted from the digital elevation models, and the spatial patterns and volumetric amounts of erosion and deposition of each section on a cell-by-cell basis were calculated. The means of volumetric net change per unit area (m3/m2) of each section were derived. With the analysis of the deposition, erosion, or no change of the study area, the spatial patterns of three-dimensional morphological change pattern can be traced in both detailed and broad extent over varying time periods and frequencies. The analyzed results discovered that the two ends of the island experienced the most significant erosion and deposition, with the changes gradually decreasing toward the middle of the island. The south end of the island had the largest amount of erosion (16,274 m3). The recommendation for light LiDAR data collection frequency is also made.