A Research On Risk Factors Of Sponge City Construction Based On Bayesian Network

In recent years,rapid urbanization process in China has led to a series of ecological issues,including intensified heat island effect,decreased surface permeability,frequent urban floods and severe water pollution,etc.In order to cope with these challenges,Chinese government started to promote the construction of sponge cities vigorously.As the construction of sponge city in China is still in the initial stage,many problems remain unresolved in terms of technology,capital and management,leading to huge potential risks in the construction process.Therefore,it is an important task in sponge city construction and promotion to comprehensively identify the risks and to clarify the internal relationship between risk factors so as to identify the key risk factors.Accordingly,5 National First-batch of Pilot Cities were investigated,including Pingxiang,Jiaxing,Chizhou,Suining and Baicheng.This study explored the risks of sponge city construction comprehensively in China,and identified the main risk factors in the construction of sponge city in six dimensions as the politics,finance,society,technology,laws and management.Secondly,it constructed a Bayesian Network model for the risk of the sponge city construction,clarified the inherent logical relationship between various risk factors and figured out the risk chain.Thirdly,it identified the key risk factors and the biggest risk source of sponge city construction effectively using reverse reasoning and most probable cause chain analysis.Finally,it put forward some strategy suggestions from the aspects of source control and key risk factor control.The results showed that:(1)Among the three risk states of high risk,medium risk and low risk,the probability is 30% higher than the early warning value that the sponge city construction in China is at high risk,and the risk level is so high that risk control is rather necessary.(2)One or more key risk factors existed in each of the six dimensions including politics,finance,society,technology,laws,and management.Both risk factors of the laws were key risk factors,which highlighted the importance of sound laws and regulations.(3)The key risk factors affecting the construction level of sponge city were,“incomplete local supporting laws and regulations system”,“lack of restriction of special laws and regulations at the national level”,“unreasonable planning and design scheme”,“insufficient financial support from the government”,“incomplete management system and working mechanism” and “inadequate propaganda and education”,which required close attention.(4)Among the key risk factors,the main causes were “lack of special legislation at the national level”,“imperfect local supporting laws and regulations system”,“imperfect management system and working mechanism” and “inadequate publicity and education”.These factors would lead to the generation of other key risk factors,which should be controlled and managed from the source,so as to minimize the risk of sponge city construction.