Flood disaster risk assessment of and countermeasures toward Yangtze River Delta by considering index interaction

An effective risk assessment and response to flood disasters will help ensure the sustainable development of a region. A perfect flood disaster assessment index system should consider the interactions between indexes. The Choquet integral method can effectively solve the problems of index interactions and information overlap and can be used to aggregate relevant decision criteria and express the preferences of decision makers, making it a useful supplement to traditional indicator integration methods. A flood disaster risk assessment model based on the Choquet integral was constructed by considering the meteorological factors, geographical conditions, economic development, population status, medical conditions, education level, and crop sowing in the Yangtze River Delta region (including Shanghai, Jiangsu, Zhejiang, and Anhui) from 2006 to 2017. The model quantified the interaction between the evaluation indexes, taking the minimum information redundancy as the goal; subsequently, a flood disaster risk assessment was performed. The results showed that the meteorological conditions, geographical factors, exposure, and vulnerability have negative interactions with emergency and recovery capabilities. Because of the influence of the first three criteria, the information contained in the criteria for emergency and recovery capabilities is weakened or underestimated. Anhui Province was the largest flood disaster risk area in the Yangtze River Delta region from 2006 to 2017. Zhejiang Province ranked second, and Jiangsu Province and Shanghai City ranked third and fourth, respectively. The assessment results can provide a useful reference for flood disaster risk management in the Yangtze River Delta region.