SWAT model for water balance and water yield study in Ulu Muda Forest Reserve, Kedah

Abstract

The hydrological mechanism in the river basin is vital to sustain and conserve water resources. Therefore, the study's main aim is to determine the applicability of ArcGIS version 10.0.2 with the Soil and Water Assessment Tools (SWAT) model in the assessment of streamflow in UMFR catchment with a total area of 975 km2 located on the western coast of peninsular Malaysia, Kedah. The statistical model outputs chosen to measure the correlation between observed and simulated flow in the study area are the coefficient of determination (R2), Nash - Sutcliffe efficiency (NSE), and percent of bias (PBIAS). The results demonstrate a good match between observed and simulated flows, demonstrating that the SWAT model can accurately predict streamflow at UMFR. The findings suggest that during calibration and validation, both NSE, R2, and PBIAS are more than 0.5, indicating a strong agreement between observed and simulated flow. The most sensitive parameter that may influence simulation outcomes are SOL_AWC, SOL_K and GW_REVAP. For soil parameters, the most sensitive parameter is SOL_AWC compared to the other soil indicators. These findings justify that the model can predict water balance and water yield in all other river basins in Kedah for sustainable water resources management where the water quantity becomes a critical issue in the states.