Effect of Climate Change to Flood Inundation Areas in Bertam Catchment, Pahang

Abstract

Bertam catchment is increasingly becoming a main concern area on flood disaster caused by the dam release. Further research is required to be conducted at this area. The objective of this study is to determine future flood inundation area at the downstream of Bertam catchment for several scenarios as a result of dam release and climate change. The scenarios are current land use with and without climate change scenarios and future land use with and without climate change scenarios. InfoWorks RS, Geographical Information System (GIS) application and Auto CAD was utilized in this study to develop river modeling. The current land use used in this study is referring to 2010, and future land use refers to 2025. The climate change parameters used in this study are rainfall using climate change factor (CCF) derived by NAHRIM as input data. The design storm used in this study is 24 h storm duration and 100-years Annual Recurrence Interval (ARI). The results obtained using four scenarios show the differences of inundation areas. The model is validated based on actual maximum flood depth on site which is 1.2 m. The highest percentage of inundation area is when the water depth is greater than 1.2 m. For current land use, the difference in inundation area between with and without climate change scenarios is 12.6 %, while for future land use the difference is about 12.80 %. The finding of this study shows that impact of climate change has exaggerated the effect of water release from the dam to the downstream catchment.