Research On Evolution And Coupling Of Urban Functions Of Changchun Based On Diffusion And Replacement

Chinese cities have been in a stage of rapid development for a long time,there are a large number of unreasonable and unscientific urban land layout behind the rapid spread of urban space.In addition,the development of China's economy has entered a new normal state,and the urban growth model with incremental and stock coexistence will become the main way of urban functional space development in the future.The historical experience of international urban development shows that the diffusion and replacement of urban functions is the development process that cities must go through.It is one of the key research topics of urban geography,urban planning and urban economics,and is an important component of the research on urban spatial structure.Therefore,the research of urban function evolution and coupling,based on urban function diffusion and replacement,will become one of the important subjects of urban spatial theory and practice research.We need to carry out in-depth study on this subject.The system research of urban function evolution and coupling has strong theoretical and practical value.At the theoretical level,urban function and evolution research can promote the integration of urban geography,urban planning,urban economics and other multi-disciplinary and the show of multi-disciplinary cross-results,which has enriched the theoretical research results of urban functions and provided innovative achievements to improve China's urban space theory system.At the practical level,the evolution and coupling of urban functions can accurately grasp the spatial differences of urban functional changes and the regional model of urban function coupling,and provide some theoretical support for the incremental growth and stock growth of urban function,which can provide a certain reference significance and value for sustainable development of urban space.This paper will start from the perspective of urban function diffusion and replacement and put forward the theoretical research framework of "process-method-mode-mechanism".The main contents of the thesis include the historical process of urban function evolution and coupling,the diffusion and replacement of urban function,the evolution and coupling mode of urban function,the mechanisms of urban function evolution and coupling.The core content of the study is to build a database of urban land diffusion and replacement using the urban land use maps,and to construct the methodology system of urban function evolution and coupling,with the help of mathematical statistics methods and GIS means,which can reveal the spatial-temporal characteristics of urban function evolution and the geographical model of urban function coupling,and analyze the transformation mechanism and operation mechanism of urban function evolution and coupling.The main body of the paper is divided into six chapters:Chapter 1: A review of urban function evolution and coupling.This paper discriminates the related core concepts,analyzes the progress of the research about urban function at home and abroad,summarizes these researches,and puts forward the research perspective and research topic.Chapter 2: The basic theories of urban function evolution and coupling.The paper combings the basic theory related to the research topic,laying a solid theoretical foundation for the study of urban function evolution and coupling research.Chapter 3: Historical process of urban function evolution and coupling in Changchun.Based on the historical maps and related literatures,this paper analyzes the historical background and pattern characteristics of urban function evolution and coupling of Changchun in the three stages of the Manchukuo period,the planned economy period and the transition period.Chapter 4: Diffusion and replacement of urban function in Changchun.Based on the index and method of overlay analysis,the proportion of the spatial distribution and conversion matrix,this paper analyzes the temporal-spatial characteristics of the diffusion,transfer in and out,replacement of the four types of urban functions,such as residential function,public service function,commercial service function and industrial function,by means of the spatial analysis method of sector-ring.Chapter 5: Evolution and coupling model of urban function in Changchun.Using the quantitative relationship between urban function diffusion and replacement,this paper summarizes the evolution state of four types of urban functions,and studies the spatial pattern of the four types of urban functions in combination with sector-ring analysis.Then,the paper summarizes the geographical type and evolution characteristics of urban function coupling,using the spatial difference of evolution state of the four types of urban functions and the mutual substitution between them.Chapter 6: The mechanism of urban function evolution and coupling in Changchun.The article puts forward the concept and content structure of urban function evolution and coupling mechanism.From the two aspects of transition mechanism and operation mechanism,the paper reveals the mechanisms of urban function evolution and coupling by the method combing quantitative and qualitative analysis.The study shows that the perspective of diffusion and replacement can be used as a new perspective to study the evolution and coupling of urban functions.Based on this,the new method system of urban function evolution and coupling research is also feasible and reasonable.Starting from the new perspective,using the new method,the paper puts forward the urban functional coupling region type based on diffusion and replacement.