Patterns of Shoreline Change and Hurricane Washover on Barrier Islands

Despite the dynamic nature of barrier islands and spits, they have been highly developed and continue to be developed along much of the U.S. coast. This activity has altered erosional and depositional patterns of shorelines. Development has placed property and lives at risk from coastal storms, sea-level rise, and long-term erosion and has affected habitats for coastal ecosystems. This three-year project is designing new topographic surveying techniques and applying them to the study of the morphodynamics of these coastal zones. The Bureau of Economic Geology (Bureau) and the Center for Space Research (CSR) at The University of Texas at Austin are jointly conducting the research.

The primary field area includes 190 km of the southeast Texas coast (Fig. 1). This shoreline has both natural and developed areas, and its characteristics are typical for barrier coasts. Thus, techniques developed during this project can be applied to sandy barrier coasts around the world. We are coordinating three topographic surveying methods: (1) airborne laser altimeter surveys (also known as LIDAR surveys) provide continuous coverage of the dune and upper beach, (2) kinematic, three-dimensional (horizontal and vertical accuracy of several centimeters) GPS surveys using a vehicle provide coverage of the upper and lower beach, and (3) conventional total stations' surveys extend selected transects from landward of the foredune into the surf zone. Overlap areas of the different survey data are compared to evaluate accuracy. We will merge these various data into an optimal digital elevation model.