This dataset represents point locations and flow characteristics for current (as of November 20, 2001) and historical U.S. Geological Survey (USGS) streamgages in the conterminous United States. The flow characteristics were computed from the daily streamflow data recorded at each streamgage for the period of record.
The attributes associated with each streamgage include:
Station latitude (decimal degrees in North American Datum of 1983, NAD 83)
Station longitude (decimal degrees in NAD 83)
First date (year, month, day) of streamflow data
Last date (year, month, day) of streamflow data
Number of days of streamflow data
Minimum and maximum daily flow for the period of record (cubic feet per second)
Percentiles (1, 5, 10, 20, 25, 50, 75, 80, 90, 95, 99) of daily flow for the period of record (cubic feet per second)
Average and standard deviation of daily flow for the period of record (cubic feet per second)
Mean annual base-flow index (BFI: see supplemental information) computed for the period of record (fraction, ranging from 0 to 1)
Year-to-year standard deviation of the annual base-flow index computed for the period of record (fraction)
Number of years of data used to compute the base-flow index (years)
Reported drainage area (square miles)
Reported contributing drainage area (square miles)
National Water Information System (NWIS)-Web page URL for streamgage
Hydrologic Unit Code (HUC, 8 digit)
Hydrologic landscape region (HLR)
River Reach File 1 (RF1) segment identification number (E2RF1##)
Station numbers, names, locations, and drainage areas were acquired through the National Water Information System (NWIS)-Web (http://water.usgs.gov/nwis) on November 20, 2001. The streamflow data used to compute flow characteristics were copied from the Water server (water.usgs.gov:/www/htdocs/nwisweb/data1/discharge/) on November 2, 2001.
The missing value indicator for all attributes is -99. Some streamflow characteristics are missing for: (1) streamgages measuring flow subject to tidal effects, which cause flow to reverse directions, (2) streamgages with site information but no streamflow data at the time the data were retrieved, and (3) streamgages with record length too short to compute the base-flow index.