Improvement of the ESA CCI Land cover maps for water balance analysis in tropical regions: A case study in the Muda River Basin, Malaysia

The Muda River Basin (MRB), Malaysia. This study proposed a framework to improve the European Space Agency Climate Change Initiative Land Cover (ESA CCI LC) products through the integration with the Annual Oil Palm Dataset (AOPD). The improved land use land cover (LULC) maps were then used to produce five LULC scenarios as input maps into the Soil and Water Assessment Tool (SWAT) model for analyzing the impact of LULC changes on water balance in the MRB. The improved LULC maps have good performance in representing rubber and oil palm, with an overall accuracy up to 81 %. In addition, SWAT simulated monthly streamflow well for the MRB, with the highest R2 and NSE values of 0.84 and 0.86, respectively. During the 2001–2016 period, the MRB experienced an expansion of oil palm from 7.10%–17.36 %, a reduction of rubber from 34.93 % to 26.38 % and a slight decrease in forest from 54.23%–52.80 %. The urban expansion scenario showed significant increment in surface runoff, while the reforestation scenario helped to reduce surface runoff, while increase lateral flow and groundwater. Oil palm expansion led to a higher reduction in lateral flow and groundwater than rubber trees due to the higher soil water absorption rate. The proposed framework can be duplicated and applied in other tropical basins, particularly in Indonesia and Malaysia.