Flood risk in Kuala Lumpur, Malaysia: A consideration of flood defences in a broadscale hydraulic model

This article presents the development of 5 m flood maps for Kuala Lumpur, Malaysia. The hydraulic model framework covered two types of flood: direct rainfall and fluvial flooding. For this study, two scenarios of fluvial flood risk were developed: the simplified broadscale ‘undefended’ view and a ‘defended’ view that accounts for the infrastructure investments already made by the city of Kuala Lumpur to mitigate flood risk. Flood maps were created using a 2D full-SWE hydraulic model under broadscale model assumptions, calibrated to local defence features.

The defended fluvial flood map reduces the flood extent in Kuala Lumpur by 40% across all return periods, indicating overestimation of damage in an undefended scenario. Further, this study has demonstrated that existing model functionality is capable of reconstructing the impact of complex flood defence systems. Future broadscale model frameworks should aim to incorporate local-scale features using this approach, and advance on this work by adopting a data-driven decision-making schema that is capable of automating the application of heterogenous data formats.