Research On The Model And Evolvement Of Urban System Spatial Structure

The formation and evolution of towns is an important spatial manifestation in the development of human society,which reflects the change of the social spatial structure of human society and reveals the spatial patterns of the overall behavior of human society.These changes and their laws provide the base of spatial research on the sustainable development of the human society.Urban expansion is a global phenomenon,is the expansion of space.In the transition period(nearly 30 years)China,the expansion of urban system is the important performance of Urban expansion,which characteristic is the expansion of the land as the leading factor,and the spread of the spread faster than people.The structural evolution of urban system dominated by the land will lead the local imbalance of social and economic development,which is not conducive to the sustainable coordinated development of the city.So,under the advocacy of national urban development policy,researching the urban system structure evolution is of great significance and value.This paper selects the complete physical geography unit-the Huaihe river basin as a case study area,measuring the Huaihe river basin urban system evolution and spatial modeling.The research methods conclude bibliometrics,spatial analysis and modeling and geographic information system integration and development.In particular,Chapter 1 and chapter 2 respectively review the research status,the main problem,the concept and characteristics,theory and technology of urban system spatial structure.Chapter 3 introduces the data source of urban space information extraction and data processing method,the threshold dichotomy and the SVM algorithm are mainly elaborated,and by validating and analysing the results of the two methods,determining the more appropriate SVM algorithm.Finally,the urban expansion process of Huaihe river basin in 1998-2013 is extracted by using the SVM algorithm.Chapter 4 puts forward applying the urban tree to urban system network model building,and expounds the calculation methods and calculation steps of the network entropy and land entropy.In the Chapter 5,the Huaihe river basin's urban expansion process,urban system evolution process,urban system network entropy change process and land structure entropy process are carried the qualitative and quantitative analysis.Chapter 6 introduces social network analysis method,through the whole mesh density,degree centrality and center potential analysis equivalence,condensing subgroup analysis,structure analysis and core-edge structure analysis,quantitative analysing Huaihe river city spatial relations,the huaihe river network structure evolution characteristics and level of economic integration are summarized.Comparing the research result of overall network with the research result of urban tree,it is concluded that urban tree has applicability and superiority in regional urban system research.And last,on the basis of the Huaihe river in urban system evolution research by using urban tree and the whole network.Huaihe river basin's urban system spatial structure and evolution characteristics are systematically expounded,the huaihe river basin's urban system optimization suggestions are proposed.On the basis of extensive literature review at home and abroad,this paper all-sided analyzes the performance,measurement,and modeling.From the perspective of theoretical system,the definition,characteristic,development status and trends of urban system are stated;from the perspective of empirical research,the urban expansion of Huaihe river basin are qualitative and quantitative analyzed comprehensively and systematically;from the perspective of research methods,considering the space-time characteristics of the urban system evolution,a comprehensive and innovative experiment design is made,from the perspective of technology application,the application of remote sensing,geographic information system and spatial regression and other methods in urban system measurement and modeling is integrated and expanded.The research results have a certain reference value on urban expansion and regional urban system planning.In the future research,the characteristics comparison of the urban system at home and abroad,the theory analysis of our country's urban system,the comprehensive quantitative analysis on top-down urban system evolution,analysis,modeling of urban system under the background of time and space,the integration and expand of Remote sensing,geographic information system and spatial analysis methods are the important research tends.