Research On Urban Spatial Connection And Network Structure Of Urban Agglomeration In The Middle Reaches Of Yangtze River

With the rapid development trend of globalization,information and network in the global widely spreading,the exchange of contacts between regions and cities around the world is becoming increasingly close,and the network structures built between regional cities also have a new feature.Urban agglomeration as a dynamic area in the regional development space,the exchange of various elements within its scope is frequent,and the evolution trend of its development pattern is very important to the regions and even to the country.Urban agglomeration in the middle reaches of China is located in the middle area of our country,and relying on the Yangtze River,with the advantages of geographical location,while it is also the national "central rise" strategy mainly implementation area,is gradually becoming the country's new growth pole.Therefore,it is very important to understand the characteristics of the inter-city communication between the urban agglomeration in the middle reaches of the Yangtze River,and to analyze the characteristics of the related network structure.Based on the Baidu index data,this paper constructs the urban agglomeration network in the middle reaches of the Yangtze River based on the information flow perspective.Based on the calculation of the intensity of information flow,the social network analysis method is used to establish multiple regression model.This paper explores the relevant characteristics and temporal evolution of the information flow network formed between cities in the middle reaches of the Yangtze River and analyzes the influencing factors.The main conclusions are as follows:(1)In recent years,with the advancement of information,the information flow relations established between the urban agglomerates in the middle reaches of the Yangtze River have been significantly enhanced,but the intra-urban cities are not balanced,and the polarization of the metropolitan areas is still obvious.Many small cities in the periphery,their development is limited.Compared the total amount of information flow in cities,Wuhan,Changsha,Nanchang has the highest total flow of information,and the sum of the total flow of information accounted for more than one-third of the total amount of information flow.The proportion of information flow and the proportion of the three sub-urban agglomerations were compared,among which Wuhan's sub-region had the highest proportion,Chang-Zhu-Tan sub-region and Poyang Lake sub-region was similar,Chang-Zhu-Tan sub-region is higher.(2)The urban network level of the urban agglomeration in the middle reaches of the Yangtze River changed mode from "1+2+22+6" to "1+2+11+17".The number of cities with the lowest total information flow increased significantly,"pyramid"structure has a tendency to extend to the bottom.The variation coefficient of the total composition of the information flow in the cities is increasing,and the differences in the urban agglomeration are also increasing.Three sub-urban groups in the region,the network level are presented pattern for "a nuclear lead",and the number of cities are on the "spindle-shaped" distribution trend.(3)The backbone network of the urban agglomeration was "triangular" structure,among which the three vertexes were Wuhan,Changsha and Nanchang respectively.The overall network density of the urban agglomeration increased,and the network density in 2016 was high,and the members of the urban agglomeration had been established.And the information flow between the cities is relatively frequent.The phenomenon of small group gathering in the urban agglomeration is obvious,and the four subgroups of the two subgroups are basically divided into provinces,and the role of administrative divisions and the fixed geographical space position is still more obvious.The stratification of the three levels of stratum appeared in the space is not adjacent but still formed a small group,verify the "flow space" with the development of communication to break the space distance constraints.(4)Research shows that the number of Internet broadband access users,GDP,the end of the total population is the main impact of the Yangtze River in the middle reaches of the urban agglomeration information network characteristics.And the number of broadband access users among them has the greatest impact.In addition,the city's function and status,urban events,administrative divisions,history and culture and other factors,will also have an impact on the network between cities.