Research on the Structure of Regional Logistics Network Based on Improved Gravity Model and SNA-A Case of Beijing-Tianjin-Hebei Region

At present, various localities are actively promoting the construction of regional integration, and the role of logistics industry in regional economic development is becoming increasingly prominent. Through the study of regional logistics network structure, we can judge the status of regional logistics integration. In order to study the structural characteristics of regional logistics network, this article takes Beijing-Tianjin-Hebei region as an example. Firstly, the article calculates the logistics gravity between every two cities based on the improved gravity model. Then based on the social network analysis method, this paper constructs a quantitative analysis system of directed multivalued network, and analyzes the structure of regional logistics network from the perspective of intensiveness, correlation, centrality and connection mechanism by using correlation analysis and structural hole theory etc. The main conclusions are as follows: the intensity of the Beijing-Tianjin-Hebei regional logistics network is relatively high, but the level of logistics development is unbalanced; the region lacks bridge cities, and the logistics network has no obvious hierarchical structure; the network presents a significant core-edge structure, and the relation intensity between core cities and marginal cities is weak, as well as inside marginal cities. Therefore, it is necessary to break through the administrative restrictions of geographical location and give full play to the leading role of core cities and bridge cities in order to achieve the coordinated development of regional logistics in Beijing, Tianjin and Hebei.