Author(s): Yuk San Liew; Fang Yenn Teo
Linked Author(s): Yuk San Liew
Keywords: Flood modelling; Flood mapping; Hydrodynamics; Muar River Basin
Abstract: In developing flood maps, there are two common approaches namely one-dimensional (1D) and two-dimensional (2D) hydrodynamic modelling. The 1D approach is a conventional method utilized to simulate the flood behaviors in the river channel using 1D hydrodynamic in-bank model and to map the characteristics mainly on depth and extent of flood for a particular area. While the other approach is 2D hydrodynamic out-bank model covering floodplain to produce flood maps providing greater information such as time series flow direction and velocity in addition to the depth and extent of flood for different simulation scenarios. This paper aims to demonstrate a case study of flood mapping using 2D hydrodynamic approach for Muar River Basin, Malaysia. Lists of data including hydrologic, hydraulic and catchment characteristic data were collected and analyzed to serve as the input in various stages for model set-up, calibration, verification and simulation. Flood extent maps were delineated for different return periods of 2-, 5-, 10-, 20-, 50- and 100-year. Results indicated that 2D model is a potential approach to be widely used for a better quality of future flood mapping delineation with availability of a high quality ground model data. The findings are especially important and help to determine the platform level for various return periods while designing structural preventive measures like dam, detention pond and embankment which target to minimize flooding risk in the study area. These flood maps are also advantageous to assist the local authority and community in making convincing decisions by having detailed results. It is as well supportive as a design and planning guide in proposing a development and to recommend suitable flood mitigation measures.