铁路运输已成为客货流动的重要交通工具和影响城镇体系的重要因素,由铁路站点和铁路运输线构成的铁路网络在很大程度上影响着城市体系等级结构和空间格局特征。通过筛选出具有始发列车的186个地级以上城市作为研究对象,通过城市始发列车数据分析城市体系等级结构与分布格局。在证明铁路始发列车数量与城市体系的规模等级呈正相关关系的基础上,运用图表判别和聚类分析法,将中国186个具有始发列车的城市划分为四个等级,分别是全国性中心城市3个,区域性中心城市8个,省域性中心城市30个,地区性中心城市145个。结果表明,中国城市等级结构呈现金字塔型结构,并受行政级别、地形因子、经济发展水平影响显著。城市体系的分布存在明显的东西差异,高等级中心城市在中国东部均衡分布,构成了中国铁路运输网络的基本骨架,并与国家国土开发中的"T"型战略格局非常吻合。高等级中心城市由于铁路网络的紧密联系,形成了6对双核结构城市模式。

The rail transportation has become an important conveyance carrying passengers and cargos. Railway network which is comprised of stations and railways influences the hierarchical structure and distribution pattern of the national urban system. This paper screens out the study objects including 186 prefectural-level cities having starting trains by timetable, and analyzes the hierarchical structure and distribution pattern of the urban system based on the data of starting trains. This paper demonstrates that the number of railway trains at starting station is positively correlated with the hierarchy of urban system. On this basis, it uses the methods of charts discriminance and the clustering analysis to classify all the 186 cities into four hierarchies. There are 3 national central cities, 8 regional central cities, 30 sub-regional central cities and 145 local central cities. From a unique perspective of railway network, the article reveals the following characteristics of the hierarchical structure and distribution pattern of Chinese urban system. (1) The urban hierarchy system presents a typical pyramidal structure, which means the higher the hierarchy of the cities is in the system, the smaller the number of the cities is. (2) The administrative, topographical and economic factors affect the railway network markedly, consequently affect the urban hierarchy system greatly. (3) The distribution of cities in eastern China is different from that in western China, which means the higher-hierarchy cities are mainly distributed in the east, and the railways of the west cities are mostly in east-west direction. (4) High-hierarchy cities are evenly distributed in eastern China, which constitutes the fundamental framework of Chinese urban railway network and coincides with the "T"-shaped development strategy of the national land. (5) Six pairs of dual-core structure of urban patterns have been formed among high-hierarchy central cities due to the close connection of railway network.