Flood hazard delineation in Greater Dhaka, Bangladesh using an integrated GIS and remote sensing approach

Abstract

The objective of this paper is to delineate flood hazard areas for the greatest flood of 1998 in Greater Dhaka, the capital of Bangladesh. Multi-date RADARSAT Synthetic Aperture Radar (SAR) and Geographical Information System (GIS) data were used for this purpose. Flood frequency and floodwater depth were calculated using SAR data for the development of flood hazard maps. Flood hazard maps were created using a ranking matrix with land-cover, geomorphic units and elevation data as GIS components. The result of the study demonstrated that a major portion of Greater Dhaka constitutes high to very high hazard zones while only a little portion is not exposed to the potentialflood hazard. It is expected that the proposed flood hazard maps will be useful to mitigate losses of lives and property from recurrent flood disasters in Greater Dhaka of Bangladesh.