Study On The Dynamic Evolution Of Sponge City Construction Risk Based On System Dynamics

Urban stormwater management has become a major issue that the international community pays much attention to.The traditional stormwater management model not only causes economic losses,but also poses a threat to public health and urban safety.As an alternative to traditional stormwater management,Sponge City restores the hydrological and ecological functions of landscapes by utilizing the natural processes of soil and vegetation.After the State Council put forward the "Guidance on promoting the construction of Sponge City",relevant regulations and norms have been issued,a large number of projects have been put into construction,but a series of problems such as poor construction experience,imperfect system and low public awareness have been exposed in the process of construction,resulting in the declining of sponge facilities,unsatisfactory expected effect,the enthusiasm of the masses and many other risks.In this context,a comprehensive and systematic exploration of the construction of Sponge City risk evolution has become the focus of sponge city research.Based on this,the study follows the research idea of "theoretical analysis-mechanism analysis-model simulation".First of all,the study sorts and summarizes the existing literature,defines the concept of risk of Sponge City construction,and identifies the risk factors through the rooting theory,summarizes into the five subsystems of policy,management,capital,technology and society,and excavated the internal relationship between the subsystems.Since there are many factors involved in the construction of Sponge City,and each factor presents a dynamic change in the whole life cycle,the risk model of Sponge City Construction is constructed using systematic dynamics.The results show that: 1)Among the five subsystems,Sponge City has the highest sensitivity to management risk,followed by technology risk,which needs to be focused on in the future development.2)In the whole life cycle evolution process,the development trend of each subsystem is different.The management risk has always maintained a high level of risk.The regulatory risk has a high level of risk in the start-up stage.And the level of technology and social risk has been rising with the advancement of the whole life cycle.This means the key points of risk management and control should be adapted to the situation.3)The simulation analysis of the mechanism between the subsystems shows that the management risk has a direct impact on the technology,capital and social risks,highlighting the importance of improving the management mechanism system.4)In the further risk factor sensitivity analysis,"lack of national laws and regulations","insufficient attention of local governments","insufficient operation and maintenance funds","poor planning and design technology" and "the public does not understand the sponge city" have a relatively obvious impact on the construction of the Sponge City,which should be focused on in the process of risk prevention and control.