Abstract:

High-speed rail affects the structure, function, and relationship of urban network by changing the connectivity and connection strength between cities. With the extension and upgrading of China's high-speed rail network, understanding and interpreting urban network based on high-speed rail flow has become one of the important ways of research. Starting from the high-speed rail flow, this study analyzed the characteristics and process of change of China's county network structure with the help of the 2008-2018 high-speed rail passenger transport data and social network analysis method. The results show that: 1) the density of high-speed railway network is increasing year by year. The centrality values of the eastern and central regions are high, and the hub position is obvious. The core intersection of multiple high-speed railway trunk lines is likely to generate high and medium intermediate nodes. 2) The hierarchical structure of multiple networks identifies the hierarchical characteristics with evolutionary differentiation and complex and diverse connection patterns. The node effect of the first and second levels is significant and the location advantage is obvious, and the third level is the extension and refinement of the network. 3) The composition of agglomerating subgroups is determined by regional proximity and spatial connection strength. Affected by the layout of high-speed railway lines, the subgroups present a trend of "multi-cores", which is manifested in three types of change: extension, merger, and addition.

Key words: high-speed rail flow, high-speed rail network, social network analysis method, network structure characteristics, counties in China