Comparison of rainfall-runoff models for design discharge assessment in a small ungauged catchment

Abstract

Design discharges in a small experimental catchment in Žarošice (Czech Republic) were evaluated using various methods for peak discharge assessment applying 24-h storm rainfalls reduced to short duration. Rainfall-runoff models HEC-HMS based on standard Natural Resources Conservation Service hydrologic methods and KINFIL, which combines the Morel-Seytoux infiltration and kinematic wave direct runoff transformation, were used to compute runoff hydrographs. The approach of technical standard and Froehlich's method determined the peak discharges only. The aim of this study was to assess the ability of these methods to predict design peak discharge in comparison with the data obtained from the Czech Hydrometeorological Institute (CHMI), which is the authority for providing hydrological data in the Czech Republic. The results demonstrate that the peak discharges computed by Froehlich's method are mostly closest to the data provided by CHMI. For the 100-year flood, HEC-HMS based on the Curve Number method showed the best agreement.

Keywords

• curve number
• design rainfall
• peak discharge