Estimation of the IHACRES Model Parameters for Flood Estimation of Ungauged Catchments in the Upper Ping River Basin

Abstract

The estimation of model parameters for ungauged catchments usually involves formulating relationships between model parameters and catchment characteristics from neighboring gauged catchments. This study examined the effectiveness of the IHACRES rainfall-runoff model for flood estimation in the upper Ping River basin (UPRB). As a first step, the model was calibrated for nine subcatchments in the basin. Relationships among catchment attributes (catchment area, drainage, slope and elongation) and six model parameters at nine runoff stations were derived using a multiple regression. A sensitivity analysis of the six IHACRES parameters at the P.4A station was carried out to determine the effect these parameters had on flood hydrograph characteristics. Regression relationships were then applied to estimate the model parameters at two independent runoff stations as if these catchments were ungauged and compared with model results if the parameters were chosen to give a best fit with recorded data. The results showed that the suggested relationships can be reasonably applied for flood estimation of the ungauged catchments within the UPRB.