Research On Time-Space Pattern Evolution And Its Impact On Economic Space Expand Of Accessibility Along The Lan Xin High-Speed Railway

Located in the northwest of China,the Lanzhou-Xinjiang High Speed Railway is the only railway line that connects Xinjiang and the western part of Gansu.In this paper,the research scope is taking one-hour driving distance(60km)in the provincial highway as the radiation range of high-speed rail,and thus17 cities and 91 counties are extracted.Based on the accessibility of the grid,the basic road network and socio-economic statistics of the three provinces including Gansu,Qinghai and Xinjiang in 2015 and 2017 are adopted.Also,the methods and models of weighted average travel time,isochronous circle,economic potential and spatial variogram are used to comprehensively evaluate the temporal and spatial convergence effects and economic potential space changes of the weighted travel time within the research unit before and after the Lan-xin high-speed railway is opened.All done is expected to better serves the regional development and provide scientifically theoretical support for regional coordinated development.(1)Before and after the Lanzhou-Xinjiang high-speed railway was opened and speeded up,the weighted average travel time in the study area increased significantly,increasing from the core area of the high-speed railway to the periphery,showing a "core-edge" structure.From the perspective of the city level,the accessibility of high-speed rail stations and central cities has been significantly improved.There are obvious "node effects" and "corridor effects".Space-temporal convergence obeys the law of geographical distance attenuation to a certain extent.The central hub of provincial capitals status has been consolidated.From the perspective of county level,the optimization strength of high-speed rail to the underdeveloped counties in the fringe area of the study area is obvious,reducing the overall difference in regional accessibility.(2)Before and after the Lanzhou-Xinjiang high-speed railway is opened for operation and speeding up,the isochronous circle will change from discontinuous to continuous,the service scope of stations and central cities will be further expanded,and the connection between high-speed railway cities and surrounding cities will be strengthened.It is worth noting that the speed increase of the high-speed rail has not brought about the continuous increase of the three-hour isochronous circle.The improvement of transportation conditions is only one of the influencing factors.Corresponding policies and measures should be adopted in accordance with the actual conditions of the region to enhance its economic attractiveness.(3)Before and after the launch of the Lanzhou-Xinjiang high-speed railway and its speeding up,the economic potential of the study area as a whole is on the rise,which stimulates the economic development potential of the cities along the route,and the hierarchical and hierarchical characteristics of economic potential are becoming more prominent.The economic status of cities such as Lanzhou,Xining,and Urumqi has strengthened.Some remote and underdeveloped cities in the study area have closer links with other node cities,promoting regional resource sharing.The impact of high-speed railways on the economic space of cities at different levels will have both promotion and suppression effects.(4)The population and economic distribution pattern of Lanzhou-Xinjiang high-speed rail is basically the same as that of Lan-xin high-speed rail line before and after the operation of Lan-xin high-speed rail.The improvement of accessibility promotes the improvement of urban investment,consumption,industrial structure,and residents' income levels to varying degrees.It is an important driving factor for regional economic spatial agglomeration and the key to improving the economy of the research area.(5)Before and after the Lanzhou-Xinjiang high-speed railway is put into operation and speeding up,the impact of high-speed railways on the economic space of cities of different grades will have both promotion and suppression effects.With the improvement of the hierarchy and hierarchy of central cities,on the one hand,small and medium-sized cities around it are attracted in,generating a siphon effect,depriving small and medium-sized cities of their own development,and becoming the hinterland of provincial capitals such as Lanzhou,Xining,and Urumqi.Driven by the transformation into later adsorption and compression,the regional development model evolved from a concentric circle structure to an elliptical structure;on the other hand,developed cities have provided new development opportunities for small and medium-sized cities.Low-quality development changes to high-quality development.