Description: The High Resolution National Hydrography Dataset Plus (NHDPlus HR) is an integrated set of geospatial data layers, including
the best available National Hydrography Dataset (NHD), the 10-meter 3D Elevation Program Digital Elevation Model (3DEP DEM), and the
National Watershed Boundary Dataset (WBD). The NHDPlus HR combines the NHD, 3DEP DEMs, and WBD to create a stream network with linear
referencing, feature naming, "value added attributes" (VAAs), elevation-derived catchments, and other features for hydrologic data
analysis. The stream network with linear referencing is a system of data relationships applied to hydrographic systems so that one
stream reach "flows" into another and "events" can be tied to and traced along the network. The VAAs provide capabilities for upstream
and downstream navigation with linear referencing, analysis, and modeling. The elevation derived catchments are used to associate
other landscape attributes, such as land cover, with stream segments.
Copyright Text: The U.S. Geological Survey (USGS) and the U.S. Environmental Protection Agency (USEPA).