Estimation of Peak Flow and Runoff Volume with Response Surface Method

Abstract

The probabilistic‐based calibration strategy developed in this paper was briefly reviewed and applied to derive the optimum values of eight calibration parameters. Three optimum sets are obtained: estimations of peak flow, runoff volume, and both peak flow and runoff volume. Data for each of three storms were used to calibrate and verify the model for a catchment in Singapore to demonstrate the application of the calibration methodology. The calibration results indicate that: (1) The derived optimal values approximate the global optimum; (2) a close agreement between the simulated and the measured catchment responses (peak flow or runoff volume) could be achieved when only one specific objective function is considered at a time; and (3) a reasonably good match between the simulated and the measured hydrographs could be achieved, however, when both catchment responses (the peak flow and the runoff volume) are simultaneously considered. The verification simulations also indicate reasonably good comparisons between the simulated and the measured data.