System Comprehensive Risk Assessment of Urban Rainstorm-induced Flood - Water Pollution Disasters

Abstract

Abstract Urban flood disaster itself brings casualties and property losses, and may induce secondary derivative disasters that can lead to more serious damage. The rainstorm-induced flood - water pollution disasters studied in the paper is a kind of systematic risk. On the basis of determining the flood risk level by using the fuzzy comprehensive evaluation method, the conditional probability in Bayesian theory is applied to explore and calculate the possibility of flood-induced water environment pollution, then the improved grid environmental risk evaluation method is used to evaluate the flood-induced water pollution risk, and the coupled superposition relationship of flood and water pollution risk is inscribed by constructing risk level matrix, finally the system comprehensive risk of rainstorm-induced flood - water pollution disasters is obtained. Shenzhen City is selected as the study area, and the results showed that the area with high-risk of both flood and water pollution only accounts for about 1.86% of the total area, mainly distributed in the eastern junction of Longgang district and Pingshan district, where the flood risk level is high and the enterprise risk sources are dense. The method proposed in this study can be used for the system comprehensive risk analysis of rainstorm-induced flood - water pollution disasters, which can not only quantitatively reveal the formation of the induced risk, but also provide reference for early warning.