Application on One-at-a-Time Sensitivity Analysis of Semi-Distributed Hydrological Model in Tropical Watershed

Abstract

A soil and water assessment tool (SWAT) model has been employed for the Langat River basin, Malaysia to predict stream flows. The basin was divided into 27 sub basins comprising 193 hydrological response units. Monthly calibration and validation were performed using the measured discharge data of the Kajang station. One-at-a-time sensitivity analysis using Sequential Uncertainty Fitting (SUFI-2) algorithms was performed to examine the critical input variables of the study area. It was found that the SWAT model can be successfully applied for hydrological evaluation of the basin and the SCS runoff curve number, base flow alpha factor and groundwater delay were found to be the most sensitive parameters. The next step should be conducting a 30 years continuous hydrological modeling. It is needed to analyze the water balance and the hydrological trends of the basin due to the basin experienced major land used changes since 1980 for urbanization activities. Index