Peak Flow and Volume Predictions Using Frequency-Equivalent Hydrographs

Abstract

A new method for calculation of frequency-equivalent storms and hydrographs is presented. This procedure is an extension of the frequency-equivalent nonlinear hydrograph (FENLH) methodology. Streamflow data records for a total of 129 basins in the state of Kansas have been used. A new storm criterion for generating frequency-equivalent storms was selected. Peak flow rates, hydrograph volumes, and peak reduction factors, produced by the storm criterion, were related to the basin physiographic and climatic data. The combination of index flood and multiple regression techniques were used to obtain predictive equations for peak flow rates and hydrograph volumes for six different return intervals. The use of the FENLH model as a prototype and the selection of the criterion utilized in this study to determine frequency-equivalent conditions, provided storm dimensions that appeared realistic. The accuracy of the results obtained indicated that the methodology presented in this study can be applied to other areas.