Urban flooding risk assessment based on FAHP–EWM combination weighting: a case study of Beijing

Abstract

Urban flooding is a long-standing problem that greatly hinders the development of the city. As a means of flood risk management, risk assessment plays a significant role in reducing flood risk. In this article, a multi-criteria decision analysis (MCDA) model for assessing urban flood risk is proposed, and the assessment results can provide a more scientific basis for urban disaster management. The model innovatively uses the fuzzy analytic hierarchy process (FAHP) and entropy weight method (EWM) subjective and objective combination weighting methods to determine the weight, with risk, exposure, vulnerability and emergency capability as the criterion layers, and 13 representative elements such as rainfall and altitude as the index layers. Taking Beijing as the research area, the flood risk distribution map was made to provide relevant basis for the management department. The evaluation results are further compared with historical flood disaster information to verify the accuracy of the model. The results show that the accuracy of the analytic hierarchy process (AHP) and AHP–EWM methods is 62.07% and 66.38%, while the accuracy of the FAHP–EWM method can reach 75.68%. In this study area, the models and methods we proposed are more reasonable and effective.