Flood-frequency characteristics of Wisconsin streams
Water-Resources Investigations Report 91-4128
Prepared in cooperation with the Wisconsin Department of Transportation
- W.R. Krug, D.H. Conger, and W.A. Gebert
Flood-frequency characteristics for 269 gaged sites on Wisconsin streams are presented for recurrence intervals of 2 to 100 years. Annual flood peaks for the period of record for each gaged site are included.
Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of these equations. The State was divided into five areas of similar physiographic characteristics.
The most significant basin characteristics are drainage areas, main-channel slope, soil permeability, storage, rainfall intensity, and forest cover. The standard error of prediction for the equation for the 100-year flood discharge ranges from 25 to 33 percent in the State.
A comparison of multiple-regression analyses by use of generalized least squares and ordinary least squares was made to determine the best method for analysis. A split-sampling technique was used for all the stations in the State. Differences in results of the two methods were minimal. The generalized least-squares method was chosen for use because its theoretical basis is superior to that of ordinary least squares and its estimates of accuracy of the equations for estimating flood-frequency characteristics at ungaged sites is better than that of ordinary least squares.
A method for estimating flood-frequency characteristics of regulated streams was developed from the relation of discharge and drainage area. Graphs for the major regulated streams are presented in the report.
Drainage-basin characteristics derived from satellite imagery and channel morphology data were tried in the regression equations but did not improve their accuracy.
Additional publication details
- Publication type:
- Publication Subtype:
- USGS Numbered Series
- Flood-frequency characteristics of Wisconsin streams
- Series title:
- Water-Resources Investigations Report
- Series number:
- Year Published:
- U.S. Geological Survey
- Contributing office(s):
- Wisconsin Water Science Center
- iv, 185 p.
- United States
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