METHODS FOR ESTIMATING THE MAGNITUDE AND FREQUENCY OF FLOODS IN ARIZONA

Regression equations for estimating flood magnitudes at ungaged sites for recurrence intervals of 2,5, 10, 25, 50, 100 and 500 years were developed for six flood-frequency regions. The equations relate flood magnitudes to one or more of the following statistically independent variables: size of drainage area, mean basin elevation, and mean annual precipitation. The regression equations are based on annual peak-discharge data collected at 221 gaging stations having 10 or more years of record. Flood magnitudes for selected Recurrence intervals were determined for each station form a log-Pearson Type II frequency distribution, and multiple-regression analyses were used to relate flood magnitudes to basin characteristics. The regression equations apply to streams that are not affected significantly by regulation, diversion, or urbanization. Flood magnitudes and frequencies for the main stem of the Little Colorado River from the Zuni River to the mouth and for the main stem of the Gila River can be estimated from graphs in which discharge is related to size of drainage area for the Little Colorado River and to miles upstream and downstream from Collidge Dam for the Gila River. /FHWA/

• Supplemental Notes:
  • Performed in cooperation with the Department of Transportation, Federal Highway Administration. Sponsored by the Arizona Department of Transportation.
• Corporate Authors:

  U.S. Geological Survey

  F Street Between 18th and 19th Street, NW
  Washington, DC    20244
• Authors:
  • Roeske, R H
• Publication Date: 1978-9

Media Info

• Pagination: 82 p.

Subject/Index Terms

• TRT Terms: Drainage; Estimating; Floods; Rainfall; Regression analysis
• Uncontrolled Terms: Flood frequency
• Old TRIS Terms: Basins
• Subject Areas: Data and Information Technology; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00185266
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: FHWA-AZ-78-121 Final Rpt.
• Contract Numbers: 1-15(121), 73-10
• Files: TRIS
• Created Date: Feb 27 1979 12:00AM