Elevation-Derived Hydrography: The USGA's rich new hydrological features dataset

The US Geological Survey (USGS) is the main source of publicly available elevation data in the United States. One of the USGS’s major programs, the 3D Hydrography Program (3DHP), includes Elevation-Derived Hydrography (EDH), a detailed water features dataset that is derived from elevation data such as Digital Elevation Models (DEMs). EDH fills the need for hydrography data that align with elevation data, which is important for analysis such as flood modeling. It is difficult to use hydrographic and elevation data together if they do not align—for example, a hydrographic features dataset produced from imagery might indicate a different location for a river’s edge than an elevation dataset over the same area. Because EDH data consist of hydrological features derived from an elevation dataset, the two datasets will align, enabling more accurate analysis and hydro modeling.