Rate of shoreline change of marsh units in eastern Long Island salt marsh complex, New York (ver. 2.0, March 2024)

This data release contains coastal wetland synthesis products for the geographic region of eastern Long Island, New York, including the north and south forks, Gardiners Island, and Fishers Island. Metrics for resiliency, including unvegetated to vegetated ratio (UVVR), marsh elevation, mean tidal range, and shoreline change rate are calculated for smaller units delineated from a Digital Elevation Model, providing the spatial variability of physical factors that influence wetland health. Through scientific efforts initiated with the Hurricane Sandy Science Plan, the U.S. Geological Survey has been expanding national assessment of coastal change hazards and forecast products to coastal wetlands with the intent of providing Federal, State, and local managers with tools to estimate the vulnerability and ecosystem service potential of these wetlands. For this purpose, the response and resilience of coastal wetlands to physical factors need to be assessed in terms of the ensuing change to their vulnerability and ecosystem services.
This dataset displays shoreline change rates for eastern Long Island. Shoreline change rates are based on analysis of digital vector shorelines acquired from historical topographic sheets provided by National Oceanic and Atmospheric Administration (NOAA). Analysis was performed using the Digital Shoreline Analysis System (DSAS), an extension for ArcMap, created by the U.S. Geological Survey,. Linear Regression Rates (LRR) and End Point Rates (EPR) of shoreline change were averaged along the shoreline of each salt marsh unit to generate this dataset. LRR rates were used in areas where three or more historical shorelines were available while EPR was used in areas were two were available. Positive and negative values indicate accretion and erosion respectively.