Track: Water Resources
The National Hydrography Dataset - Integrating the USEPA Reach File and USGS DLG
Thomas G. DewaldKeven S. Roth
The National Hydrography Dataset (NHD) is the culmination of the cooperative efforts of the U.S. Environmental Protection Agency (USEPA) and U.S. Geological Survey (USGS). It combines the best of the USEPA Reach File Version 3.0 (RF3) and USGS Digital Line Graph (DLG) hydrography files: hydrologic ordering, hydrologic navigation for modeling applications, a unique identifier (reach code) for surface water features from RF3, and the spatial accuracy and comprehensiveness of DLG hydrography. While based initially on 1:100,000-scale data, the National Hydrography Dataset is designed to incorporate - and encourage the development of - higher-resolution data required by many users. Users of RF3 or DLG will find the same data in a new, more flexible format. They will find the National Hydrography Dataset both familiar and greatly expanded and refined. This paper presents an overview of the NHD, its availability, and application.
Thomas G. Dewald
USEPA
401 M Street SW
Washington, DC 20460
USA
Telephone: 202-260-2488
Fax: 202-260-1977
E-mail: dewald.tommy@epamail.epa.gov