Hover over the list of files on the left side or click on Footprint to see the extent of each file.Click Search Products to display the elevation data.To download terrain data for the area of interest, select Elevation Products (3DEP) and select the desired resolution in the left-side menu as shown below.In the National Map Viewer, navigate to your location on the map.The watershed boundary will be used later to clip the extent of the terrain raster for smaller file sizes and faster processing. Terrain and watershed boundary data can also be obtained from other sources. In this example, terrain raster and the watershed boundary shapefile were download from the United States Geological Survey’s (USGS) National Map Viewer.

The watershed used in this example is the 122 square mile East Branch Brandywine Creek watershed in Pennsylvania.ĭownload Watershed Boundary and Elevation Data A DEM is a representation of the bare ground topography (elevations) excluding trees, buildings, and any other surface objects and will be used as an input to HEC-HMS to create a terrain dataset, which can then be loaded into a Basin Model for further analysis (see Creating and Linking Terrain Data into a Basin Model tutorial). In this tutorial you will use ArcMap to prepare a Digital Elevation Model (DEM) raster from open-source elevation and watershed boundary data.

Clip raster arcmap