Coastal Changes and Impacts Contour Data Documentation

National contour dataset digitally derived from elevation and hydrography.  April 23, 2012.

These contour datasets were generated from the National Elevation Dataset (NED) and the National Hydrography Dataset (NHD) in a fully automated process.  The input raster data source was the 1/3 arc-second version of the NED.  The NED data were modified by the NHD flow lines, areas, and water bodies to facilitate improved integration between the hypsography and hydrography.  These contour datasets were generated from the National Elevation Dataset (NED) and the National Hydrography Dataset (NHD) in a fully automated process. The input raster data source was the 1/3 arc-second version of the NED. The NED data were modified by the NHD flow lines, areas, and water bodies to facilitate improved integration between the hypsography and hydrography. These datasets are not the ones that appear on the U.S. Geological Survey's USTopo GeoPDFs.