Study On Optimization Of Proportioning Structure Of Resettlement Modes In City Shantytowns Transformation Based On System Dynamics

City transformation of shantytowns is a complex system project.Its purpose is not only to improve the image of the city,but also to enhance the quality of urban development.The resettlement modes in urban shantytowns transformation are diverse.The proportion of different types of resettlement modes constitutes the structure of resettlement modes in shantytowns transformation.However,the structures of the current resettlement modes in shantytowns transformation in some cities are not suited to urban sustainable development,and hindered the further development of the cities.Therefore,it is of great significance to study the optimal path of the structure of the resettlement modes in urban shantytowns transformation.Firstly,the various resettlement modes in shantytowns transformation were summarized through the investigation and review of the literature.Based on qualitative analysis of the impact of various resettlement modes in shantytowns transformation to urban sustainable development,causality diagrams of the sub-systems of various types of resettlement modes affecting urban development was established.Secondly,combine the causality diagrams of various types of resettlement mode subsystems to construct a causality diagram of urban resettlement modes in shantytowns transformation systems.The method of combining associated digital matrix with computer programming was used to identify and quantify the system archetypes of the causality diagram.This step revealed the structural contradictions of various types of resettlement modes to urban development.The results of the analysis of system archetypes showed that to reduce the proportion of reversed resettlement mode,increase the proportion of monetization resettlement mode and relocated resettlement mode as the direction of optimizing the proportion structure of resettlement modes is the key to resolve the structural contradictions between various types of resettlement modes for urban development.Finally,based on the causality diagram of urban resettlement modes system,the equations between system variables were established and the system dynamics model was constructed by using the software of Vensim.According to the results of the analysis of system archetypes,the variables that affect the ratio of various types of resettlement modes were selected as the simulation policy adjustment variables,and the simulation experiment of the system dynamics model was conducted in Xi'an as a case.The simulation results can show the optimal control measures to optimize the proportion structure of resettlement modes in shantytowns transformation,and the optimal structure in each policy environment.The simulation results show that for Xi‘an,improving support for infrastructure construction is the optimal control measure to optimize the proportion structure of resettlement modes in shantytowns transformation.When the support coefficient of infrastructure construction,the employment level of residents in shantytowns,value assessment of house in monetization resettlement,and the social security level of shantytowns residents were increased by 20%,the optimal ratios of the monetization resettlement mode,reversed resettlement mode,and relocated resettlement mode are 18:62:20,30:60:10,24:68:8 and 20:72:8.