Research On The System Dynamics Model Of Urban Land-use And Transport

With the development of economy and society,the cities in China have a variety of urban diseases,such as environmental pollution,traffic congestion.Undoubtedly,the uncoordinated development of urban land-use and transport could be the source.In order to improve this situation,planners as a city’s doctor,it is necessary for them to predict the influence of the planning policy on the mutual feedback between urban land-use and transport.Therefore,it is urgent to establish a planning decision model which is suitable for China’s national conditions and considering urban land-use and transport interaction.In this paper,the method of System Dynamics is used to analyze the interaction between urban land-use and transport and its system dynamics features.The system boundary and system elements are determined,and the interactive system of urban land-use and transport is divided into five subsystems.According to the relationship of system elements,system flow chart was protracted,and the feedback structure was analyzed,found that the main feedback structure for urban land-use and transport system were the spread type development feedback loop and compact development feedback loop,competing with each other.In order to describe the system flow graph quantitatively,this paper established the structural equation of the system,and forms the qualitative and semi-quantitative system dynamics model which is suitable for domestic cities.In order to verify the validity and practicability of the model,this paper made a further quantification of the model by using the historical data of Wuhan.Through the statistical regression analysis,the system dynamics model of urban land-use and transportation in Wuhan was established,and operated in the system dynamics simulation software Vensim.The results of the error analysis shows that the main system variables is less than 5%,so that the model results are effective to follow-up policy experiments.Finally,by changing the planning policy into the changes of the model parameters,this paper demonstrates how to use the model to carry out the scenario analysis of the policy implementation by increasing the floor area rate and increasing the number of rail transit vehicle numbers.The results show that the system dynamics model conduct a reasonable impact analysis on the implementation of the policy,which achieved the modeling objectives.