Flood Risk Assessment using Remote Sensing and Hydrodynamic Model in the Xiang Jiang River, Hunan, China

This project aimed at preparing flood hazard, vulnerability, and risk map using Remote Sensing and hydrodynamic model.
The study area of this project was Xiang Jiang river in Hunan province of China.

      This study used a number of satellite images such as JERS/SAR (1998), JERS/AVNIR (1997), LANDSAT-ETM (1999), SPOT (2002), ASTER (2002), and RADARSAT (2004). The JERS/SAR image was acquired during the later part of the 1998 flood event. Inundation area and flood depth maps were prepared using the HEC-RAS model along with hydrologic and topographic data. The results were improved with the help of flood extent map generated from JERS/SAR and LANDSAT-ETM images. A model was developed for flood risk analysis using the Model Builder function available in the ArcGIS software. A flood hazard map was prepared by considering the flood depth and flood frequency. Vulnerability was assessed based on the economic value of land being flooded and population density. Statistical techniques were used to evaluate the relative importance of causative factors and for assigning suitable weights. Finally, a flood risk map was prepared by combining the hazard and vulnerability maps. Approximately 64,000 people were found to be living in the high-risk zone of the study area.