Urban flooding risk assessment based on GIS- game theory combination weight: A case study of Zhengzhou City

Flood disaster is one of the most frequent and damaging disasters in the world. In the context of global climate change, urban flooding is occurring more frequently and has more severe consequences. Risk assessment has a certain effect on flood management and risk reduction. To facilitate the formulation of better flood prevention and disaster reduction strategies, a new urban flooding risk assessment model was proposed, in which six evaluation indicators were selected from flood hazard and vulnerability. The model was established based on the combination weighting method of game theory, and the risk map was generated based on the GIS platform. The model was validated by comparing the evaluation result with the disaster information in Zhengzhou city. The result showed that AHP-CRITIC·game theory combination weighting was more reasonable than the AHP and AHP-EWM weighting methods to determine the weight. The high-risk and the very high-risk areas are mainly distributed in the Jinshui district with lower elevation and highest economic development. The model framework proposed in this paper can be applied to the rapid assessment of urban flooding risk.