HYDROLOGICAL MODELLING OF SURFACE RUNOFF FOR TEMENGOR RESERVOIR USING GR4H MODEL

Hydrological models are mainly used for predicting system behavior and understanding various hydrological processes, whereby, various parameters that define the characteristics of the model were used. In this study, a conceptual rainfallrunoff model Génie Rural à 4 paramétres Horaires (GR4H) was developed for Temengor catchment to provide an estimate of the inflow contribution and lake level of Temengor Reservoir. Inflow data was calculated from the differences in the lake storage at each time step and accounting for the discharge from the power station. Since the lake level data at sub-daily time scale was too noisy to result in reasonably smooth inflow series data, denoising technique using filtering methods in both time and frequency domains for inflow data were applied. The model was calibrated and validated using 3 years rainfall data from 5 stations. The model performance with the optimum parameters value was evaluated based on the regression coefficient and Nash Sutcliffe Efficiency. It can be seen that the GR4H model are able to perform well in simulating the amount of inflow into the Temengor reservoir.