Generation and evolution mechanism of systemic risk (SR) induced by extreme precipitation in Chinese Urban system: A case study of Zhengzhou “7 20” incident

With global warming, the risk of natural disasters is further aggravated, and extreme weather is becoming stronger and more frequent, which is more likely to induce SR. As a comprehensive and complex giant system, cities are typical vulnerable and risk areas affected by climate change. To promote the targeted prevention and control of SR induced by extreme weather in urban system, this paper studies the generation and evolution mechanism of SR induced by extreme precipitation in Chinese urban system. Firstly, from a multidisciplinary perspective, the general process of SR generation and evolution in urban system is proposed. Secondly, the causation analysis of SR generation and evolution in Chinese urban system induced by extreme precipitation is conducted from the perspective of system safety theory and systematic management theory, including causation factors and paths. Thirdly, combined with the reality, the generation and evolution mechanism model of SR induced by extreme precipitation in Chinese urban system is established. Finally, an empirical study is carried out with Zhengzhou “7·20” incident as an example. The results show that generation and evolution of SR is caused by the continuous impact of the Swiss cheese effect, the trajectory intersection effect, and the cascading effect. In the future, targeted responding measures should be made, including the balance of urban development and SR prevention, the design of SR generation prevention mechanism, the design of SR early warning mechanism, and the design of collaborative linkage mechanism.