| In recent years,large-scale investment and construction in high-speed railways(shorted as HSR)has pushed China into the “High-speed Railway era”,which has changed the transportation structure in China and has an important impact on the spatial structure of the urban system.Under the background of rapid urbanization,clarifying the impact of HSR on the spatial structure of urban system is of great significance in formulating urban development strategies,strengthening urban economic relations,and optimizing regional spatial structures.On the other hand,influenced by globalization and informatization,important changes have taken place in the research theory of urban systems.The traditional “central place theory” which emphasizes the vertical connection of cities is being replaced by the “city network theory” which focus on the cooperation between cities.The spatial organization of urban systems needs to be studied from the perspective of networks.As one of the natural networks in human society,HSR provides suitable data sources for city network research.Based on the background and problems above,the HSR timetable data from 2008 to 2016 in China were collected to construct a city network in the flow space.The network structure of the urban system in China was revealed from three aspects: city centrality,link strength,and community structure.In addition,this thesis further revealed the specific impact of HSR on the spatial structure of urban system by referring to the value of the city.The results show that:(1)The overall structure of the city network has evolved from “zigzag” to “diamond-shaped”.The intensity of HSR connections between cities has increased,and the relationships between cities have become more complicated.The network has formed a spatial pattern in which the east leads,the central rises and the western lags.The communities in the network extend along the main HSR line and expand to other areas.(2)There is a spatial difference in the improvement of city centrality by HSR.Provincial capital cities in the central region benefit the most,and cities in the northwest region are lagging.(3)The HSR strengthens internal connections in the eastern region and external connections in the western region,while both internal and external connection in the central region.(4)The HSR reduces the resistance effect of spatial distance,expands the scope of connections between cities,and the point that the rule of distance decay begins to work is promoted from 75 km to 625 km.(5)The HSR can not only support the development of urban agglomerations,but also break the boundaries of urban agglomerations,leading cities form “corridor” along HSR lines. |
