Spatial evolution of international air cargo network connectivity in China: 1996-2019.

The interconnection of transport infrastructure is a priority area under the Belt and Road Initiative and holds significant implications for global socio-economic development. Air network connectivity plays a vital role in shaping transport efficiency. From a global air transport network perspective, this study investigates the spatial evolution of China's international air cargo network connectivity between 1996 and 2019. Using OAG global flight schedule data from five representative years (1996, 2002, 2008, 2014, and 2019), we apply complex network theory and graph-theoretical methods, incorporating tools such as UciNet and ArcMap. Three key indicators, weighted degree centrality, betweenness centrality, and K-core decomposition, are employed to analyze changes, evolutionary patterns, and driving factors of network connectivity. The findings reveal that with shifting global economic and policy environments, China's air cargo network connectivity has gradually strengthened, with an increasingly hierarchical structure and more diversified and efficient network forms. Freighter and bellyhold cargo routes differ markedly in network evolution: freighter routes display a stable core-periphery structure shaped by industrial and policy factors, while bellyhold routes evolve path-dependently alongside passenger services, shifting from concentration to decentralization. This study demonstrates the dynamic restructuring of China's international air cargo connectivity under the dual forces of globalization and regionalization. It provides theoretical insights and decision-making references for enhancing China's air transport efficiency and supporting the implementation of the Belt and Road vision, thereby contributing to the advancement of global integration.