Risk Assessment of Flood Disaster in Cities Based on “Disaster-Pregnant, Disaster-Causing, Disaster-Forming and Disaster-Curing”

The risk assessment of urban flood disasters (UFRA) is an effective way to prevent urban disasters, which plays an important role in risk management. Urban floods have occurred frequently in recent years, it is necessary to carry out research on UFRA. Considering four main factors: disaster-pregnant, disaster-causing, disaster-forming, and disaster-curing, this paper established a risk assessment model for urban flood disasters. Firstly, constructing a city flood risk assessment index system, and calculating the optimal combination weight (CW) by determining the subjective weight (SW) and objective weight (OW). Secondly, by using the cloud model to reveal the uncertainty relationship between evaluation indexes and level, the comprehensive UFRA was obtained. Rainfall and water information of all kinds of building types could be collected through cloud model and SWMM, the index system of the disaster-causing information by GIS was improved. Taking the 100-year return period rainfall in the central urban area of Zhengzhou City as an example, the comprehensive flood risk level was obtained, and the factors contributing to the risk in each region were analyzed. The results indicated that Jinshui District (JD) was at a high risk level and all other districts in Zhengzhou were at a sub-high risk. This model provides new insights for flood risk management.