Modeling And Simulation Of Urban Renewal Based On System Dynamics Methodology

Old city is the region with a relatively long history that forms a stable socio-economic structure and specific geographical customs and culture after many years of evolution and growth, all of which frame abundant resources for the sustainable development. And urban renewal is the city project that aims to make the old residential housing with quality to meet modern living standards and with the potential of sustainable development as well, all by means of replacing, supplementing and improving, reconstructing and making creation to the elements of obsolescent functions and deteriorated environment in the old city. As the most common living place, the city, a special system where people have resided with different living styles and production patterns along the time-and-space axes, reflects the characteristics of different group of people. With the transformation of economic development mode and construction of resources-saving and environmentally-friendly society, the emphasis of modern urban construction in China has been transformed from the quick development of scale-based expansion model to the continually improving environmental functions model. Compared with the development and construction in new area, the old city has lagged behind in the aspects of construction scale and speed, environmental functions and quality, application of advanced technologies, community development, and so on. What's worse, there are increasingly serious social problems causing by the economic recession and deterioration of social contexts in the old city.System dynamics theory is an important branch of systemic science and management science. It is comprehensively interdisciplinary and useful to recognize and solve systemic problems. From the perspective of system dynamics, the urban renewal system is a kind of complex and highly nonlinear system with the characteristics of high level of order and loop multiplicity. Such system is counter-intuitive, mostly not sensitive to the changes of parameters within and therefore with great resistance to the changes of policies. All these characteristics lead to the difficulty to reconcile the contradictions of system's interests from the view of long-term versus short-term and overall versus partial. This paper, drawing on the system dynamics theory together with the theory of urban renewal and sustainable development principles, firstly describes the urban renewal system based on the principle of sustainable development. Then it proposes the system dynamics causal feedback loops in the urban renewal system and analyzes the relationships within the system establishing the mathematical model. Finally, based on the system dynamics characteristics of the old city, the paper uses the Vensim software to carry on the socio-economic and policy simulation to the urban renewal system.Guided by the three main aspects, the contents are arranged as follows:(1) Integrate the system dynamics and sustainable development theory to research on the topic of urban renewal policy-making.In the beginning, the paper, on one hand combining the characteristics of system dynamics, presents the application of system dynamics in three fields, namely the urban and regional development policy evaluation, urban planning and construction management, and urban environmental management and public participation. On the other hand, on analyzing the principal feedback loops in different application field, the paper makes the comparisons among and focuses on the application of feedback loops in the urban renewal policy-making, the significance of which is introduced also.(2) Put forward the dynamic decision-making objectives in the urban renewal system based on the sustainable development theory.The dynamic characteristics of socio-economic structure in the urban renewal system are analyzed and the entropy principle based on the sustainable development theory introduced. Based on the development objectives function of the urban renewal system, the theory and metabolic mechanism framework of urban renewal system stressing on the urban functions is set up.(3) Bring forward the system dynamics action pattern in the urban renewal system by analyzing the systemic feedback loops and making quantity relationships among elements within the system.From the point of systemic theory, the urban renewal system is divided into a few of sub-systems. By analyzing the interaction and influences among the sub-systems, the paper establishes the feedback loops in the economic, social and environmental sub-systems respectively. All these feedback loops lead to the strengthening or balancing effects, which form the systemic dynamics behavior pattern in the urban renewal system, and on the basis of which, the quantity relationships among various factors and elements within the system are illustrated.(4) Construct the whole dynamic urban renewal system model with the sustainable development theory and system dynamicsWith theories of complexity and economics and the former analysis of feedback loops and the quantity relationships as well, the modeling of the three sub-systems are carried on, following the five basic steps of system dynamics modeling and controlling method. All together with the respective functions for the economic, social and environmental subsystems and the functional relationships inter-subsystem, the whole system dynamic model of urban renewal system is constructed eventually.(5) Use the system dynamics simulation software—Vensim to experiment and make optimization to the policy-making in the urban renewal.By using the system dynamics simulation software, Vensim, and the econometrics and statistical software, Eviews, the historical statistics of the case city are analyzed and processed structurally. The system dynamics model is processed and tested by Vensim and some necessary modifications are made to analyze the simulation results and make the sensitivity tests. Furthermore, ten experiments and simulation analysis to the policy-making decision in urban renewal system are carried out.(6) Lastly, the paper proposes the suggestion to optimize policies to renew and vitalize the old city based on the policy simulation results.Based on number of results from the policy experiments and simulation, the paper proposes some suggestion to optimize policies to renew and vitalize the old city during the present stage of development. In conclusion, the strengths and weaknesses of the model are discussed, and further research direction is pointed out.