DISTRIBUTED HYDROLOGIC MODEL FOR FLOOD INUNDATION SIMULATION

Abstract

Many research studies have been carried out in the past to develop flood inundation simulation models. However, such models consider only overland and river flows components of hydrologic cycle and are designed to simulate floods in local scale only, not in basin scale.In real situation, infiltration and base flow to river have significant impacts on the occurrence or non-occurrence of floods due to a particular rainfall. Therefore, flows in unsaturated and saturated zones too should be considered for proper flood inundation simulation. In this study, a physically based distributed hydrologic model is developed for flood inundation simulation by combining a newly developed overland flow and river flow simulation models with unsaturated zone and groundwater models. The overland flow and river flow models are validated individually with test data and then, coupled with other models. The model is applied in a river catchment in Japan to simulate a flood event of 1996. Output of the model shows satisfactory agreements with surveyed flood inundation and thus, shows that the model is suitable for basin scale flood inundation simulation.