Flood modelling evaluation in river meandering channel under tidal effect

Abstract

Flood is one of the disasters in this country where around 29,000 km2 of 9% of the country are exposed to flood disaster. The purpose of this study is to develope a physical model under tidal influence for meandering in river channel and to assess the floodplain and water level for various flow conditions and tidal influence. The scope of this study includes gathering the available data, construction of physical model for parts of Sungai Selangor stretch at NAHRIM physical laboratory. The physical model test was carried out for different flow values under various conditions. In the first part, the test was carried out for the various flow with fixed low water, mean sea and high water and with tidal effect simulated by the computer controlled tidal gate structure. In the second part of the study, cut off was intruduce at one stretch of the channel section and test cases similar to first part was carried out Readings for velocity and water levels were taken at 8 stations along the river channel and another 8 locations in the floodplain area. The results of the experiments shows that the water levels increases as the the flow increases and causes the flood. The velocity was inconsistent and fluctuates and does not directly dependent on flow, introducing the cut off may able to help alleviate the flood problems to certain extent but does not totally solve the flood problems and it also shows the flood does not occurs at the downstream under all conditions tested.