DIGITAL SHORELINE DATA FOR COASTAL ANALYSIS AND MANAGEMENT: AN EXAMPLE FROM HISTORIC AND RECENT SHORELINES FOR SOUTH CAROLINA

Understanding long- and short-term shoreline change trends and the ability to join those data with other local and regional information is essential for understanding modern coastal dynamics. This project focuses on creating a digital, publicly accessible database for historical shoreline change and coastal erosion data. This type of data structure is useful for locating long-term critical areas of erosion along any coastline; for this project, the focus is on South Carolina and portions of Georgia and North Carolina. Anders et al. (1990), through a joint effort with NOS–CERC–SC/DRSS, published a series of thirty-two georeferenced shoreline maps based on historic charts (five to six shorelines between1851 and the 1960’s) and aerial photography (1983) for Cape Fear, NC to Tybee Island, GA. The maps were drum-scanned at the USACE Coastal And Hydraulics Laboratory in Vicksburg, MS, and the shorelines were digitized from the scanned sheets using ArcView and ARC/INFO at Coastal Carolina University. Orthorectified aerial photography from 1998 for the state of South Carolina (provided by the SC Office of Coastal Resource Management), have been used to determine the most recent shoreline position based on the wet/dry line; digitization of more recent aerial photos are in progress. The digitized shorelines have been transformed into geographic coordinates, and the original scanned Anders maps will be referenced into UTM coordinates (WGS84). The recent shoreline locations will be compiled with the historical shoreline data for long-term erosion rates that are to be calculated using DSMS/DSAS software of R. Thieler and W. Danforth (1994). The shoreline data and erosion analyses will be integrated with ongoing projects in the same geographic region, providing an additional knowledge base for educators, managers, and scientists to utilize. This portion of a geologic framework study serves as a template for other coastal investigations at the local and regional levels.