Study On Dynamic Evolution Of Urban Waterlogging Disaster Risk Based On System Dynamics

Global warming is becoming more serious,causing more frequent short-term heavy rainfall events,which makes the risk of urban waterlogging disasters increase.In addition,the acceleration of urbanization has also led to great changes in the factors and environment of urban waterlogging,further aggravating the risk of urban waterlogging.The increasingly frequent and serious urban waterlogging disasters have caused great threats and troubles to people’s production,life,and urban economic development.Therefore,it is urgent to research the dynamic evolution of urban waterlogging disaster risk.In this paper,the dynamic evolution of urban waterlogging disaster risk based on system dynamics is carried out,an urban waterlogging disaster risk index system is established,an urban waterlogging disaster risk model based on system dynamics is constructed,and finally the dynamic evolution of waterlogging disaster risk in Zhengzhou City is simulated and analyzed by taking Zhengzhou City with typical urban waterlogging disaster characteristics as a sample city.The main research contents are as follows:(1)Establish an urban waterlogging disaster risk index system.Firstly,based on the disaster system theory,the urban waterlogging disaster system and its dynamic relationship are analyzed,and the urban waterlogging disaster system structure is composed of four parts:disaster-causing factor,pregnant environment,disaster bearing body,and disaster prevention and mitigation is established.Then,based on the literature review method and word frequency analysis,the index information of the relevant literature is proposed for processing,and the information processing results are discussed based on the disaster mechanism,system structure,and dynamic relationship of urban waterlogging disaster,the specific indicators of the risk system are determined,and the urban waterlogging disaster risk index system including 4 first-level indicators,9 second-level indicators,and 19 third-level indicators is established.(2)A risk model of urban waterlogging disasters based on system dynamics was constructed.Firstly,according to the established urban waterlogging disaster risk index system,combined with the disaster mechanism and system structure,the modeling purpose is clarified,the time boundary of the system model is defined,the causal circuit of urban waterlogging disaster risk is designed,and the urban waterlogging disaster risk stock-flow map containing9 horizontal variables,9 rate variables,and 28 auxiliary variables is drawn.Then,based on factor analysis and entropy method,the weight of risk indicators in the system flow graph is determined,the structural equations of the relevant variables are established,and the urban waterlogging disaster risk model based on system dynamics is constructed.(3)Simulation analysis of dynamic evolution of waterlogging disaster risk in sample cities.Firstly,taking Zhengzhou City with typical urban waterlogging disaster characteristics as the sample city,the effectiveness,and reliability of the risk model are tested according to the natural and social data of the sample cities.Then,Vensim PLE software was used to simulate the dynamic evolution of waterlogging disaster risk in Zhengzhou City and analyze the sensitivity of risk factors.It is found that the risk of waterlogging disasters in Zhengzhou from 2022 to 2030 will further develop at a decreasing growth rate.From 2022 to 2030,the risk of disaster-causing factors and the sensitivity of the pregnant environment will continue to increase,the exposure of disaster-bearing bodies will stabilize,and the level of disaster prevention and mitigation capacity of Zhengzhou City will continue to grow.Through the sensitivity analysis of risk factors,it is found that rainfall intensity,drainage system operation status,sponge city construction,and improved level of emergency response mechanism have significant impacts on urban waterlogging disaster risk.Finally,based on the results of this analysis,countermeasures and suggestions are provided to reduce the risk of urban waterlogging disasters,and a model sample is provided for the waterlogging prevention planning of domestic cities.In this paper,a system simulation is introduced into the risk assessment of urban waterlogging disasters,a research method for the dynamic evolution of urban waterlogging disaster risks based on system dynamics is proposed,a dynamic model of urban waterlogging disaster risk system is established,and simulation and sensitivity analysis are carried out based on sample city data,which clarifies the changes of urban waterlogging disaster risk in the time dimension and the main factors affecting waterlogging disaster risk,which has practical guiding significance for pre-disaster prevention and post-disaster governance of urban waterlogging disaster.