Analysis of the freight transportation network in the Changjiang middle reaches megalopolis based on complex network theory

This study focuses on the urban agglomeration in the middle reaches of the Changjiang, a key region in China's "Rise of Central China" strategy, serving as a critical link between the eastern coast and the inland areas of central and western China. Based on complex network theory, this study employs the P-space method to construct an integrated freight transportation network. The network encompasses road, rail, and waterway sub-networks, and its topological structure is analyzed. The results indicate that the freight transportation network in the Changjiang Middle Reaches Megalopolis exhibits significant small-world characteristics. Specifically, the network's average path length is 2.647, and the clustering coefficient is 0.534, significantly higher than the 0.086 of a random network of the same scale, suggesting that the network maintains high connectivity while also possessing a strong clustering effect. Additionally, the network density is 0.09, with a uniform node degree distribution, a coefficient of variation of 0.506, and a Gini coefficient of 0.285, indicating the stability and balance of the network structure. Key nodes such as Wuhan (Highway Hub), Zhuzhou Railway Station, and Jiujiang Port play pivotal roles as central hubs within the network.