Author(s): Khairul Anuar Mohamad, Noorbaharim Hashim, Ilya Khairanis Othman
Linked Author(s): Khairul Anuar
Keywords: HSPF, Skudai Watershed, the coefficient of determination, HSPF parameters, mixed land use
Abstract: The Hydrological Simulation Program-Fortran (HSPF) is used to study runoff simulation of mixed land use of Skudai watershed, the heaviest polluted river in the district of Johor, Malaysia. The aof this study is to examine the sensitivity of HSPF parameters during runoff simulations for upstream of Skudai watershed. The model is calibrated using data from November 2013-February 2014 and validated with observed data from March-May 2012. Different land use types are shown to be sensitive to HSPF parameters especially to the index of the mean infiltration capacity of the soil followed by the fraction of groundwater inflow which will enter deep (inactive) groundwater, the upper zone nominal storage and the lower zone nominal storage. Statistical analysis comprising the coefficient of determination, Nash-Sutcliffe efficiency and the relative error are used as evaluation indicators between simulated and observed runoff. By examining the sensitivity analysis, it has been concluded the index to the mean infiltration capacity of the soil (INFILT) is most sensitive to runoff followed by the fraction of groundwater inflow which will enter deep (inactive) groundwater (DEEPFR), the upper zone nominal storage (UZSN) and the lower zone nominal storage (LZSN). It is found that the coefficient of determination (R2) for validation is better than calibration with an average 0. 88 compared with 0. 83 in daily time steps. Based on this study, HSPF is capable of simulating runoff using hourly time-step for mixed land use in Malaysia
Year: 2017