The validation of hydrodynamic modelling for 2014 flood in Kuala Krai, Kelantan

¹ Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia, 81310 Johor Bahru, Malaysia
² Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia

^* Corresponding author: shahabuddin@utm.my

Abstract

Flood catastrophe that struck Kelantan in 2014 has marked as the worst in history. The absence of structural approach such as dam has increased the risks of the flood to this state. In this paper, the simulation of 2014 flood event focuses in Kuala Krai area has been carried out before and after the occurrence of the proposed dams along Galas and Lebir rivers, respectively using hydrodynamic model. The Digital Terrain Model (DTM) from Airborne Light Detection and Ranging (LiDAR) combining with Shuttle Radar Topography Mission (SRTM) data resources have been used for hydrodynamic modelling. The flow hydrograph and water level are generated as input data for initial and boundary conditions. River cross-sections and Manning’s roughness coefficient values that been estimated based on landcover map obtained in 2010 also used in the model. The model produces the outputs of flood depth and velocity. To validate the simulation results, the flood depths were compared against the flood marks depth from field survey at 16 locations collected by researchers from Disaster Prevention Research Institute, Kyoto University, Japan and Department of Irrigation and Drainage (DID). From the validation, it reveals that the average accuracy percentage obtained was about 90% and it can be said that the flood model was acceptable.