2D FLOOD INUNDATION SIMULATION BASED ON A LARGE SCALE PHYSICAL MODEL USING COURSE NUMERICAL GRID METHOD

Abstract

The implementation of various 2D numerical modeling techniques in the flood inundation analysis is vastly explored. However, understanding of the flood inundation uncertainty of this technique still limited. This paper evaluates 2D hydraulic models (HEC-RAS) in term of ability to simulate the surface flow of the large scale physical model. A physical model was developed based on high-resolution DEM (0.5m resolution) data of Sungai Bertam with scale 1/25. A total area of 23 m × 7 m and 20.8 m channel length was constructed. The experimental physical model was run with various inflow value and used to calibrate and analyze the numerical simulation. Although the simulated result showed a good agreement with the physical model experiment, some uncertainty still needs to consider. This uncertainty happens due to the change in channel geometry which leads to the turbulence phenomenon.