Study on the Hierarchical Structure of the “Belt and Road†Aviation Network Based on K-Core Analysis

Since the “Belt and Road†Initiative, air transport has become the second largest mode of transport after ocean shipping and has contributed more and more to international trade between the countries. To explore the hierarchical characteristics of the aviation network of the “Belt and Road,†analyze the relationship between levels, and identify the core layer of the network, k-core analysis based on the “degree†value was designed and performed; the data of airports and air routes were collected to construct the “Belt and Road†aviation network model; then, k-core decomposition was conducted to reduce the size of nodes layer by layer from the outside to the inside, and a network structure model with 19 levels was obtained; the relationship between the coreness and centrality of nodes in the network was investigated, and the changes in the attribute of networks at different levels and the connection between networks were explored; according to the structural characteristics of the network, the “Belt and Road†aviation network was divided into three categories: the core layer, the middle layer, and the detail layer. The results showed that the highest-level network obtained by k-core decomposition was used as the core layer of the “Belt and Road†aviation network, including 53 airports in 37 countries, all of which have high degree centrality and eigenvector centrality; the core layer network exhibits strong “small world†characteristics; there is little difference between the degree values of nodes, and the network has high stability. The status of China’s airports in the core layer network is not prominent; the four regional sectors such as East Asia, Southeast Asia, Central Asia, and the Middle East are closely connected regarding air transport. Europe is relatively weakly connected with three sectors: East Asia, Southeast Asia, and Central Asia; geographical factors are still the dominant factors determining the status of hub airports along the “Belt and Road.â€