National_slc_ShortTerm

This map consists of short-term (~50 years) shoreline change rates for the lower 48 states of the United States and Hawaii. Rate calculations were computed within a GIS using the Digital Shoreline Analysis System (DSAS) version 4.1, an ArcGIS extension developed by the U.S. Geological Survey. Short-term rates of shoreline change for the lower 48 states were calculated using an end-point rate method based on shorelines from 1970 or 1978 and 2000 to provide an approximately 30-yr short-term rate. Short-term rates of shoreline change for Hawaii were calculated using a weighted linear regression rate based on all available shoreline data between 1950 and 2008. A reference baseline was used as the originating point for the orthogonal transects cast by the DSAS software. The transects intersect each shoreline establishing measurement points, which are then used to calculate short-term rates.