Complex network analysis of China's integrated air-high-speed rail network: topological characteristics, centrality measures, and cluster analysis

This paper presents a comprehensive complex network analysis of China's integrated air-High-Speed Rail (HSR) network by constructing a directed weighted network and comparing its complex characteristics with its sub-networks. The findings reveal that, beyond small-world properties, the networks exhibit broad-scale characteristics with a rapid decline in degree distribution, deviating from the traditional scale-free model due to operational constraints and market saturation. Centrality analysis highlights the rising importance of secondary hubs, such as Xi'an, Kunming, and Zhengzhou, as strategic transit points linking urban centres and peripheral regions. The integrated network achieves enhanced efficiency through hybrid modularity, combining the aviation network's centralised structure with the HSR network's corridor-focused design. While this integration fosters economic connectivity and regional development, resilience challenges emerge due to reliance on high-centrality nodes. These findings offer implications for intermodal transport planning and regional development.