A Method Research Of The Delimitation Of Urban Growth Boundary Based On The Simulation Of Urban Expansion

Urban growth boundary is a system of management boundaries,with rigidity and elasticity,which is decided by the ecological pressure and the demand of construction land in urban expansion. As a kind of effective political tool, it can guide urban development and city layout The delineation of urban growth boundary not only helps guide the further agglomeration of urban construction land, control the infinite expansion of the city, but also promote the coordination and integration of urban planning and land use planning. Therefore, in the context of the scarcity of land resources, how to promote the rational expansion and layout of cities through the delineation of urban growth boundary has become an urgent problem to study and solve.Through the carding of researchs of urban growth boundary, urban expansion simulation and other related study at home and abroad, this paper determines the influence factors of urban construction land expansion and puts forward an idea to constrain the urban construction land expansion. Based on the previous studies and empirical methods for delimitation of urban growth boundaries at home and abroad.This paper tries to construct a methodologies model of the delimitation of urban growth boundary based on the Constained Celluar Automata and Varible Weight.This research takes Nanjing city as a case ,which applies the model constructed in this paper to delimitate the urban growth boundary in research area. The main research contents are as follows.(1) Determining the idea and method to constrain the urban construction land expansion in scale and spatial distribution based on the previous studies of urban expansion simulation and urban growth boundary. Cross-benefit method in economics is used to determine the rational scale of urban construction land during a certain period.The spatial expansion of urban construction land is constrained by the simulation model based on Constained Celluar Automata.(2) Determining the cell space, cell state ,neighborhood and time of the simulation model of Constained Celluar Automata based on the design of the structure of urban growth boundary system. Designing the transition rule and the basic process flow of the model for simulation based on the exploration of infection elements of urban construction land expansion. Using Model Builder on the Arcgis platform combined with add-on function development with C# computer language to implement the model of Constained Celluar Automata.(3) Making a case study in Nanjing city by using related data. Simulating the urban construction land expansion in Nanjing with the model of Constained Celluar Automata constrcted in this paper and verifying the accuracy of the simulation model.Adjusting and modifying the model based on the result of simulation, and then delineating the urban growth boundary.Related research conclusions include:(1) It is determined in the paper to constrain the urban contruction land expansion from the aspects of land area and spatial expansion systematicly. The rational scale of urban construction land is determined by the anlysis of marginal cost and marginal revenue of urban construction land expansion. The initial weights of factors affecting the spatial distribution of urban construction land are determined by logistic regression.Carrying out varied weight processing and then evaluating the comprehensive suitability of urban construction land based on variable weights. On this basis,calculating the final probability of the change of state of each cell,(2) The establishment of urban growth boundary system is similar to the ring structure, from the inside to the outside is the rigid boundary, the status quo and the forecast boundary in the year. Among them, the forecast boundary is predicted through urban construction land expansion simulations. Influence factors which affect spatial management of urban construction land is divided into three parts: natural ecological suitability, geographical location suitability and neighborhood interaction. Designing the transition rule of the model of Constained Celluar Automata based on Multi-criteria Evaluation. The final model for simulation is implemented by using Model Builder on the Arcgis platform combined with add-on function development with C# computer language. Three functional modules are contained in the model constructed in this paper:variable weight processing module, cyclic iteration module, boundary generation module.(3) By calculating the speed, intensity, economic elasticity and population elasticity of urban construction land expansion, this paper analyzes the space-time characteristics of urban construction land expansion in Nanjing in recent years.Quantifying the influnce factors affecting urban constrction land expansion, including construction land suitability, various kinds of attraction, restriction factors. On this basis,conducting logistic regression analysis, together with applying Monoloop method to calculate the basic weights of all infuence factors., and then carrying out varied weight processing.(4) Analyzing the marginal cost and marginal revenue of urban construction land expansion in Nanjing. Calculating the reasonable scale of urban construction land under the scenarios of low speed, medium speed and high speed of economic development.Using the model constructed in this paper to simulate the expansion of urban construction land in Nanjing. Evaluating the simulation accuracy of the model. The evaluation result proves the model can be used to simulate the expansion of urban construction land in Nanjing and the introduction of Variable Weight theory can improve the accuracy of the simulation model. Finally, this paper determines the urban growth boundary system in Nanjing based on the simulation of urban construction land use in 2030.