Gis Approach Of Inundation Analysis In The Dongjiang(East River) Drainage Area

Flood has kept causing disasters to the east river basin. This paper developed an inundation risk model to estimate the economic loss in the scenarios of events with different frequency. A method was used to estimate the flooding area in the east river basin, using the digital elevation model (DEM), GIS spatial analysis, and hydrology calculation. Since the flow in East River is partly controlled by several reservoirs, the flooding area has been greatly reduced. The model was also used to estimate the flooding area in the case of reservoir control. Results indicated that there is a logarithm correlation between the flooding area and the flood frequency. The decrease in flooding area due to reserviors will be about 25%. Some sediment problems that alter the fluvial process like sediment mining were also discussed with this model.