The assessment of the proposed dams in reducing flood hazard by using hydrodynamic modelling approach

Abstract

This paper aims to assess the implementation of the proposed dams which is a structural approach at the upstream area to reduce flood hazard in Kelantan using a hydrodynamic model. A coupled of 1D and 2D hydrodynamic model have been tested to simulate the occurrence of flood events in Kelantan due to the proposed dams. The Digital Terrain Model (DTM) has been generated by combining the data sources; i.e. from Airborne LiDAR and SRTM. The design of proposed dams were defined and simulated into the DTM with different magnitudes of flood. The flow hydrograph and water level for 25, 100 and 200-year return period are generated as input data for initial and boundary conditions. River cross-sections and hydrodynamic roughness value of Kelantan catchment area are also used in the model. The flood that have been observed is focused on Kuala Krai area before and after the construction of the proposed dams. The results of maximum velocity and water depth from the hydrodynamic modelling are then generated to produce flood hazard maps. The results obtained from the preliminary study of the hydrodynamic modelling at Kuala Krai after the development of the proposed dams showed that no flood occurred at the downstream based on the streamflow input considered.