Study On Urban Network Structure Of Yangtze River Delta Based On Multiple Perspectives

With the acceleration of world globalization and informatization,the physical connection based on transportation system and the virtual connection based on information system promote the cross-regional flow of people,materials,capital and information and closely link cities.The urban network based on the social network and complex network theory is replacing the traditional urban hierarchy based on the Central place theory and becoming a new spatial organization structure reflecting the interrelation between cities and regions.Under the background of the new normal of economy and new urbanization,"economic belt" and "city cluster" have become important spatial carriers for economic growth and regional integration.Yangtze River Delta as the highest level of China’s economic development is the most active,open,one of the strongest regional innovation ability,the spatial structure of urban system and organization more and more complex,an urgent need to from a network perspective of more detailed review from the Angle of network node of city position and function of city,the relationship between cities and spatial organization structure,etc.This dissertation describes the urban network structure of the Yangtze River Delta region from multiple perspectives,such as different scales,different weights and different enterprise levels.At the regional scale,we choose county as the basic unit of analysis,break through Alderson’s “branch-headquarters” model in world urban network,and build two-stage ownership linkages model to construct the directed weighted network.The weighted data of hierarchical enterprise amount and investment amount of regional top 500 listed companies in 2018 are adopted.By using the network density analysis,weighted centrality analysis,directed alternative centrality,directed alternative power and other methods through the social network analysis software UCINET and Gephi,the urban network structure and power space characteristics in the Yangtze River Delta are studied.On a national scale,the author takes the prefecturelevel city as the basic analysis unit to explore the hierarchical connection pattern of the Yangtze River Delta in the whole country.By integrating the data of the whole industry,manufacturing industry and producer service industry into a unified urban network research framework,the characteristics of the industry in external contact are retained.Research results show that: 1)From the perspective of spatial differentiation of domestic investment pattern,the lower level city connection based on enterprise amount investment frequency and investment amount presents the structural characteristics of local connection and remote connection respectively.Local investment is mainly constructed by small-scale enterprises,and inter-industry relations show different characteristics due to the difference in the organization level of enterprises.The lower the level,the higher the chance of cross-industry behaviors,and the more diversified and balanced the characteristics.2)In terms of the structure of city network,the urban network in the Yangtze river delta region is characterized by the longitudinal,horizontal and cross-provincial links.3)In terms of power space,it has been formed with Shanghai and Hangzhou as the typical cities,Ningbo and Nanjing as the hub cities,Hefei as the gateway cities,and other cities as the crony cities”.There are slight differences in power space under different levels and different attribute data.