NRCS Geo-Hydro — ArcView GIS Interface to WinTR-20

The NRCS Geo-Hydro system will develop input for the Natural Resources Conservation Service (NRCS) WinTR-20 hydrologic model from GIS data. Required GIS layers which need to be developed by the user for import to the interface include elevation, land use, and hydrologic soil group. A stream location layer is optional but recommended. The user may also import any other layers which would be useful in locating a watershed such as political boundaries, roads, etc. These data are available for much of the United States through the NRCS Geospatial Data Gateway and other sources. The WinTR-20 computer program is used to estimate peak discharge and runoff volume from watersheds for use in designing water control structures and in determining impacts of changing land use on the hydrologic system. NRCS Geo-Hydro is based upon the ArcView GIS program from Environmental Systems Research Institute (ESRI). The following software requirements are necessary to operate NRCS Geo-Hydro: ArcView GIS Version 3.2 or 3.3, ArcView Spatial Analyst Extension version 1.1 or greater, NRCS Geo-Hydro ArcView project and databases. Even though the system is point-and-click, basic familiarity with GIS operations and hydrologic analysis is recommended. NRCS Geo-Hydro is organized to automate the process used in a typical watershed hydrologic analysis. Its operation is grouped into a series of menus, buttons, and tools which are designed to be used in a sequential manner. Further refining or use of advanced WinTR-20 options may then be accomplished through the use of the WinTR-20 Controller/Editor. NRCS Geo-Hydro and WinTR-20 systems have comprehensive user guides, training material, example data, and other technical documentation.