IMPACT OF LAND USE ACTIVITIES ON THE HYDROLOGICAL REGIME IN THE JUNJUNG RIVER BASIN, PENANG ISLAND, MALAYSIA

Abstract

Land use activities in the river basin have a very significant negative impact on the hydrological regime, especially surface runoff. The study of the impact of land use activities on the hydrological regime in the Junjung river basin aims to analyse changes in the rate of surface runoff due to current land use changes and land use planning in 2030. To achieve the goal of this study, curve number analysis was used as a determinant of hydrological parameters in the development of HEC HMS modelling in the study basin area. The results of the study found that the current land use in 2020 recorded an average curve number value of 85.77 and then increased to 86.36 in 2030 due to land use changes in 2030. The change in the value of the curve number has had an impact on the hydrological regime that is surface runoff because there is an increase in the percentage of impervious areas from 22.84 percent in 2020 to 31.14 percent by 2030. The rate of change in runoff is shown through the simulation of the peak flow rate that occurs according to the frequency of the event, which is between 0.7 to 4.9 percent. The results obtained from this study can be used as fundamental data for advanced studies of flood control and management for better sustainable flood risk management.