GIS-based Multi-criteria Analysis Method for Flood Risk Assessment under Urbanization

Flooding is one of the most common natural hazards in China, and many flood events have caused tremendous economic losses and casualties. Moreover, the process of urbanization aggravates the regional threat posed by flooding. Assessment of flood prone areas is of great importance for watershed management and reduction of potential losses. In this study, the spatial multi-criteria analysis (MCA) method coupled with geographic information system (GIS) is employed to assess flood risk based on topographic and hydrological factors. The land use change under urbanization is also taken into consideration to observe the temporal change of regional flood hazard. According to the results of risk index, the flood risk in the majority of study area is in low level range. The area that received a high risk level is in the urban region, and the risk presents an increasing trend in the years1993, 2003, and 2013.