Duane H. Conger Warren A. Gebert William R. Krug 1992 <p>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.</p> <p>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.</p> <p>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.</p> <p>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.</p> <p>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.</p> <p>Drainage-basin characteristics derived from satellite imagery and channel morphology data were tried in the regression equations but did not improve their accuracy.</p> application/pdf 10.3133/wri914128 en U.S. Geological Survey Flood-frequency characteristics of Wisconsin streams reports