Multi-scale Study, The Evolution Of Urban Spatial Form

Urban morphology is an important performance in the spatial process of urbanization. The urban spatial process of different scales including urban expansion, functional space succession and group spatial integration, will lead to the dramatic evolution of urban spatial morphology inevitably. Therefore, it is of important practical significance to study the evolution of urban spatial morphology in the context of rapid urbanization. Based on GIS spatial analysis techniques and a variety of quantitative analysis method, the dissertation takes Huai'an City of Jiangsu Province as an example, analyzes the pattern of urban spatial morphology evolution, the process and mechanism by selecting three different spatial scales and different time scales, and put forward the countermeasures of optimizing the development of urban spatial morphology.The dissertation is composed of eight chapters. Chapterâ… is about the introduction, including the background, research significance, purpose, content, frameworks, research methods, study area & data sources, innovation, and it also discriminates and defines the concept of urban space, urban morphology and urban spatial morphology. Chapterâ…¡is about literature review and theoretical analysis. Based on the literature review home and abroad, the dissertation reviews and prospects the evolution of urban spatial morphology. On the basis of the theoretical analysis, the theoretical foundation has been constracted for the study of evolution of urban spatial morphology. Chapterâ…¢is about the scale features and research methods of the evolution of urban spatial morphology. Based on the analysis of the origin of urban spatial morphology and scale features of urban spatial evolution, multi-scale framework of the evolution of urban spatial morphology are constructed, and multi-scale analysis method of urban spatial evolution are employed. Chapterâ…£is about urban expansion and morphological evolution. On the basis of the analysis of the spatial and temporal differences in urban expansion, by calculating the compact, fractal dimension and morphology index, the dissertation analyzes the characteristics of urban spatial morphology, summarizes the mode of urban expansion and elaborates the mechanism of urban spatial expansion and external morphology evolution. Chapterâ…¤is about the change of urban land use and the succession of functional space. Based on the analysis of structural change in land use, the dissertation analyzes the features of succession of functional space such as the industrial, residential and public facilities, summarizes the model of spatial structure evolution, discusses land market mechanism of urban spatial function succession. Chapterâ…¥is about the combinative development and group spatial evolution. Based on qualitative analysis of the combinative development and evolution characteristics of Huai'an city, the dissertation analyzes time distribution discipline of the accessibility of main function land use, and studies the mechanism effect of the adjustment of administrative divisions, road traffic and new industrial space growth on of urban morphological evolution according to the real status of Huai'an city. Chapterâ…¦is about the characteristics and optimized control of the evolution of urban spatial morphology. Based on the evolution characteristics of urban spatial morphology from three perspectives of large, medium and small scale, analyzes the evolution of urban spatial morphology, the dissertation summarizes the characteristic spectrum of the evolution of urban spatial morphology. And it also discusses the objectives and principles of ideal spatial morphology, analyzes the evolution trends of urban spatial morphology and optimization focus. According to the development of Huai'an city, policy recommendations are proposed. Chapterâ…§is the conclusion and outlook. Based on the conclusions of the research, the dissertation points out the main innovation and problems, prospects the future direction for further research.According to the research mentioned above, it comes to the conclusion that:(â…°) In terms of medium scale, the characteristics of the time change and spatial differentiation of urban expansion is very clear. There is a strong correlation between urban spatial expansion and external morphological evolution. It is the alternation between Circle-type expansion and fan-wing extension that lead to the external outline evolutes from the star shape to the block shape. Urban expansion had been influenced by a variety of factors, and it has a linear correlation with road construction, real estate development, GDP, GDP per capita and the high education level; (â…±) In terms of small scale, land use structure of urban functions changes dramatically, which lead to the succession of the city function space. The function of urban core residence and commercial & financial services is highlighted. Industrial land in urban fringe and the land use of large-scale public facilities are in relative concentration, and there is a relatively balanced land use in middle zone. Land market mechanisms have driven the land use change and spatial succession; (â…²) In terms of large scale, combination development of urban space lead to urban group tends to be merged, and there is adhesion development in two urban axes. The characteristics of time distribution of accessibility of function land use is distinctive, and it is the administrative divisions, road traffic and the new industrial space that drive spatial evolution of city group; (â…³) There are strong interacting and interrelation, through urban land use change, between the evolution process of different scales of urban space, including urban expansion, functional space succession and group spatial integration. The mutual contact and mutual influence, interaction, lead to a profound impact on the evolution of urban spatial morphology; (â…´)There are significant differences between the dominant mechanism of different scales of urban spatial morphology evolution. Evolution of small-scale function space is driven mainly by market forces, large-scale spatial evolution of the urban group are mainly forced by the government and some big role in structural factors, and the scale of urban expansion is limited by the combined effect of many factors; (â…µ) The development of trinity of Huai'an is the basis for the evolution of Huai'an urban space, and the evolution of urban spatial morphology experiences such three different stages as urban decentralization, the downtown formation and city group formation. Optimal control of urban spatial morphology is based on the concept of ideal urban morphology, highlighting the historical heritage of urban space and spatial integration, playing the integrated role of economic promotion, planning and coordination, traffic guidance, land control, protection of ecological constraints and system security.The innovation of the dissertation is in the following:Firstly, based on the understanding of hierarchical structure of urban spatial scale and the dependence of evolution characteristics of urban spatial morphology, analysis framework of the evolution of urban spatial morphology is constructed from the perspective of the scale. Secondly, based on GIS platform that integrated spatial analysis techniques and methods of morphological evolution, such as HP filter, buffer analysis and accessibility techniques, are employed to analyze the evolution of urban spatial morphology.