Modernizing Shoreline Change Analysis in Georgia Using Topographic Survey Sheets in a GIS Environment

Modern analytical methods, particularly geographic information system (GIS) analyses, provide more accurate estimates of shoreline change than previous research studies because of limitations in older methods and equipment. Topographic survey sheets (T-sheets) are the best, and often the only, source of historical shoreline data for many areas, which, although containing controllable errors, can be profitably analyzed in a GIS framework. After developing protocols for on-screen registration and digitization, T-sheets of the Georgia coast from the time periods 1852-1871 and 1911-1925 were georeferenced and digitized. These shoreline data were then used to generate a simplified analysis of shoreline change to quantify average shoreline change rates for two of Georgia's undeveloped barrier islands (Wasaaw and St. Catherines Island). Wassaw Island displays typical barrier island depositional patterns (i.e., erosion on the northern end and accretion at the southern end) whereas St. Catherines is undergoing erosion along the length of its ocean shoreline.