Analysis Of Evolution Of Spatial Structure Of Ten Urban Agglomerations In China Based On Multivariate Data

China's regional economy is transforming from provincial economy,which is divided by administration,to urban agglomeration economy,and the spatial development model centered on urban agglomeration is gradually taking shape.The rapid development of urban agglomeration will attract a large number of people and capital and other spatial factors.Therefore,modern tools and methods are used to promote the study of the spatial structure of urban agglomerations,and to study the evolution path and layout pattern of the spatial structure of urban agglomerations in depth,which is of great significance to understand the overall economic form of urban agglomerations.It also plays an important role in promoting the development of urban agglomerations and the sustainable development of regional economy.Based on the new resume data and macro data(GDP,population density and permanent population),this paper systematically explores the spatial structure and evolution process of the ten major urban agglomerations in China,so as to have a clearer understanding of the spatial structure characteristics and evolution rules of urban agglomerations.Firstly,based on the new resume data,this paper explores the structural characteristics of migration network from two perspectives:within and between urban agglomerations.The spatial heterogeneity of population migration among urban agglomerations is studied by using the Gini coefficient of migration,and the cha-racteristics of spatial agglomeration of population migration in urban agglomerations are obtained.Then,the Local Moran's I is used to explore the heterogeneity of migration within urban agglomerations.Using Anselin Local Moran's I,it is found that the distribution of migration in urban agglomerations is in a balanced direction.In addition,based on the resume data,we use the "core-periphery" model to explore the evolution process of urban agglomerations' internal core-structure,and find that most urban agglomerations' internal central structure has changed from single-core to multi-core.Based on the new resume data and macro data(GDP,population density and permanent population),the spatial structure evolution of urban agglomeration is further studied by using spatial agglomeration and diffusion.A multi-core model is used to quantify the spatial agglomeration and diffusion effects within urban agglomerations.Based on the new resume data,the central cities of urban agglomeration are identified by comparing Getis-Ord G*(hotspot analysis)and Girvan-Newman algorithm.The macro data(GDP and population density)indicators corresponding to the central cities are substituted into the multi-core model,and the model is fitted and parameters are calculated by Levenberg-Marquardt and Universal Global Optimization method.The agglomeration and diffusion effects of intra-cluster economic and population spatial factors.Finally,based on the macro data of GDP and permanent population,this paper puts forward the method of combining the index of spatial agglomeration and diffusion of urban agglomeration with Gini coefficient of urban scale to study the spatial development trend of urban agglome-ration's overall economy and population,and to have a clearer understanding of the spatial development mode of urban agglomeration's economy and population.