| As one of the most important river basin economic belts in China,the development of the Yangtze River Economic Belt is of great significance to the optimization of the regional economic pattern and high-quality development in China.The development of regional logistics plays a positive role in promoting regional economic growth.Rich transportation modes and three-dimensional transportation network have laid the foundation for the development of logistics industry in the Yangtze River Economic Belt.However,due to the level of logistics infrastructure,logistics industry layout,urban location and other factors,the spatial differentiation of logistics development in the Yangtze River Economic Belt is obvious.Therefore,fully understanding the spatial pattern of logistics industry and deeply revealing its differences and influening factors is significant for exploring the upgrading path of logistics industry development and promoting the high-quality and coordinated development of the Yangtze River Economic Belt.This paper takes 130 cities in the Yangtze River Economic Belt as the research unit,and selects the network distribution data from 2019 to 2021 of two express enterprises,Shunfeng Express and Baishi Express.Firstly,the distribution quantity and density of express delivery enterprises in the Yangtze River Economic Belt is summarized,and the clustering characteristics and evolution trend are characterized by using the exploratory spatial data analysis methods.Then,based on the chain network model,the express enterprise network of the Yangtze River Economic Belt is constructed.From the perspective of the overall structure and node connection,the first is to summarize the structural characteristics and connection characteristics of the express enterprise network using the network analysis method;The second is to calculate the connection degree of the total urban network and construct the urban hierarchy,and further analyze the status and role of urban nodes in the network;Thirdly,the evolution trend of express enterprise network is described by calculating network density and matching coefficient.Then,the obstacle factors affecting the development of urban nodes and the optimization of network structure are identified by building the obstacle degree model.Finally,based on the above analysis conclusions,this paper puts forward optimization strategies of network structure from three aspects of urban node construction,inter-city connection establishment and regional functional organization.And from the perspectives of factor allocation,industrial structure,urban positioning,regional linkage,and competitive cooperation,a feasible path to achieve coordinated development of the Yangtze River Economic Belt through the construction of express enterprise network and logistics industry was summarized.The main conclusions of this article are as follows:(1)From 2019 to 2021,the agglomeration of express delivery enterprises in various provinces and cities of the Yangtze River Economic Belt gradually strengthened,and the agglomeration characteristics of express delivery enterprises in the Yangtze River Delta region were the most significant.The distribution center of express delivery enterprises is gradually moving towards the southwest direction,that is,the middle and upper reaches of the region.Capital cities such as Changsha and Kunming in the middle and upper reaches of the region have gradually become important choices for express delivery enterprise layout;(2)From 2019 to 2021,the "diamond" structure of the express enterprise network in the Yangtze River Economic Belt expanded outward along the axis of Chongqing—Changsha and ultimately evolved into a radiation structure centered around Shanghai.The triangular network formed by Shanghai,Chongqing,and Chengdu has always been stable.The high-level connections in the network are mainly concentrated between regional central cities or provincial capital cities in developed provinces,and local cities in the middle and upper reaches have not been integrated into the core network;(3)From 2019 to 2021,the density of express enterprise networks in the Yangtze River Economic Belt was greater than 0.82 and was increasing year by year.The absolute value of the matching coefficient was increasing,and each city node showed strong heterogeneity.The trend of establishing cross regional and cross level connections in the network was gradually strengthening;(4)The urban hierarchy system based on the overall network connectivity of the city presents a distinct "pyramid" structure.From 2019 to 2021,the number of bottom tier cities is increasing,and the center of gravity of the entire structure is gradually sinking.The overall network connectivity of cities in the upper and middle reaches is generally low.And these cities are always at the bottom of the"pyramid" structure;(5)The obstacles to optimizing network structure are relatively high in terms of commercial structure,industrial structure,and logistics structure.The main reason for the low status of most cities in the upstream region in the network is the weak foundation of express delivery development,and the insufficient integration of the express delivery industry with multiple industries such as commerce and manufacturing is the main obstacle to the continuous expansion of the radiation effect of hub cities in the middle and upper reaches of the region such as Chengdu,Changsha,and Wuhan. |
