Prediction of DRH using simplified two-parameter gamma SUH

Abstract

The proposed procedure predicts the direct runoff hydrograph (DRH) employing the improved two-parameter gamma distribution based synthetic unit hydrograph (SUH). This method produces a hydrograph more conveniently and accurately than those due to available popular Snyder, Gray, and SCS methods by eliminating both manual and subjective fitting of a hydrograph through a few data points as well as the tiresome adjustments for unit runoff volume. Upon testing with the data of three watersheds, the model yielded average efficiency exceeding 94% and 71% in calibration and validation, respectively, indicating satisfactory model performance.