基于铁路客运视角的长三角区域网络结构研究

区域网络结构研究是区域一体化发展规划的重要依据。基于铁路客运视角开展研究是区域网络结构研究的重要途径之一。本文结合社会网络分析方法和ArcGIS空间分析方法，依据2015—2019年长三角区域城际铁路客运班次数据，从网络密度、网络中心度、核心-边缘结构和凝聚子群4个方面对长三角区域城市网络结构特征及其演变趋势进行研究。结果表明：（1）长三角区域城市间铁路流数量呈不断增长趋势，铁路客运联系的空间分布不平衡，主轴与次轴相互交织共同构成整体网络；（2）城市网络密度显著上升，网络结构复杂，但处于弱连接状态，江浙沪省际联系紧密，安徽省有待进一步融入长三角区域一体化；（3）度数中心度两极分化显著、高低值区地域集聚特征明显、核心城市控制力强势；（4）由上海市、南京市、苏州市、无锡市、常州市等组成的宁沪主轴沿线城市群在长三角区域内关系最为紧密、一体化程度最高；（5）凝聚子群分布形态的组织性逐步增强，以区域内的中心城市为枢纽，形成了具有地理邻近性的铁路客运联系网络；（6）长三角区域总体网络结构特征为空间分布不平衡、城市首位度突出、形成各级凝聚子群，总体演变趋势为网络联系趋于紧密、网络结构趋于复杂、分布形态趋于优化。

Research on the regional network structure of the Yangtze River Delta from the perspective of railway passenger transport

Research on regional network structure provides an important basis for regional integrated development planning and the perspective of railway passenger transportation is recognized as an effective way to study the regional network structure. Based on the railway passenger data of the Yangtze River Delta region from 2015 to 2019, using social network analysis combined with ArcGIS spatial analysis method, this paper studies the urban network structure characteristics and its evolution trend in the Yangtze River Delta region from four aspects: network density, network centrality, core-edge structure and cohesive subgroups. The results show that: (1) The number of railway flows between cities in the Yangtze River Delta is increasing, the spatial distribution of railway passenger transport links is unbalanced, the main axis and secondary axis are interwoven to form an overall network; (2) The density of urban network is increasing significantly, and the network structure tends to be complex, but still in a state of weak connection, Jiangsu, Zhejiang and Shanghai are closely linked, and Anhui needs to be further integrated into the Yangtze River Delta regional integration; (3) The two-level differentiation of degree centrality is significant, the regional agglomeration characteristics of high and low value areas are obvious, and the control power of core cities is strong; (4) The urban agglomeration along the Nanjing-Shanghai main axis composed of Shanghai, Nanjing, Suzhou, Wuxi and Changzhou is the most closely related and most integrated part of the whole Yangtze River Delta region; (5) The organization of the distribution patterns of cohesive subgroups has gradually increased, and the regional central city is taken as the hub, forming a railway passenger transport network with geographical proximity. (6) The overall network structure of the Yangtze River Delta region is characterized by unbalanced spatial distribution, prominent urban primacy, and formation of cohesive subgroups at all levels. The overall evolution trend is that network connections tend to be closer, network structure tends to become more complex, and distribution patterns tend to be optimized.