Abstract
Indexing Stream-Gauge Locations to the National Hydrography Dataset Track: Water Resources Author(s): David Stewart, Alan Rea The National Hydrography Dataset (NHD) contains geospatial information about mapped surface-water features. Defined flow relations between the NHD features allow users to determine what is upstream or downstream from a point of interest on the NHD flow network. The National Water Information System (NWIS) is the repository for stream-gage locations and streamflow data collected by the U.S. Geological Survey (USGS) for approximately 25,000 currently active and historical stream gages. The locations of the NWIS stream gages were indexed to locations, or addresses, along NHD reaches using an automated snapping process. The addresses are expressed by a reach code and measure. Initially, about seventy-five percent of the gages snapped to the appropriate NHD reach address. After review and adjustment of many stream-gage locations by local USGS district personnel, approximately 22,000 gages were successfully indexed to the NHD. David Stewart U.S. Geological Survey Water Resources 12201 Sunrise Valley Drive Mail Stop 437 Reston , VA 20192-0002 US Phone: (703) 648-4879 E-mail: dwstewar@usgs.gov Alan Rea U.S. Geological Survey Water Resources 230 Collins Road Boise , ID 83702 US Phone: 208-387-1323 E-mail: ahrea@usgs.gov |
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