Study On The Spatial Pattern Evolution Of "Western Triangle" Urban Agglomeration In The Era Of High-Speed Railway

The launch of Xi'an-Chengdu High-Speed Railway had broken the geographical barriers of Sichuan and Shaanxi provinces,effectively gathered the advantages of human resources,information,resources and science and technology of Sichuan,Chongqing and northwest regions,and formed a new strategic platform for the coordinated development of regional economy.The study of the western triangle is of great strategic significance,and the formation of the western triangle urban agglomeration will become an important focus of the western development strategy,which can effectively achieve regional balance.At present,the large-scale construction and operation of high-speed railway creat vital opportunities for the spatial pattern development of urban agglomerations in China.HighSpeed Railway construction has an important impact on the spatial pattern of urban agglomerations by improving the accessibility between cities,improving the urban location conditions,promoting the flow of factors and increasing regional urban links.Amid the background of High-Speed Railway network,this paper pay attention on the evolution process of spatial pattern of urban agglomeration,and analyzes the evolution mechanism behind it and the future development trend for optimizing the urban agglomeration network,which is conductive significantly for optimizing the urban agglomeration network and promoting the healthy development of urban agglomeration system and regional coordinated development.First of all,from the historical perspective and in combination with current policies,this paper reveals the important position of the western triangle urban agglomeration in the Chinese territory.Through literature review,the basic rules of urban agglomeration formation in China are sorted out,and the formation mechanism of urban agglomeration in the western triangle is analyzed based on the status quo of the west triangle.Then,the change of urban contact and combination state within the western triangle urban agglomeration before and after the opening of the High-Speed Railway is measured.The gravity model is used to measure the spatial interaction intensity and direction of the urban agglomeration,and the spatial pattern of the urban agglomeration is judged based on the social network analysis method.Secondly,the evolution mechanism of urban agglomeration spatial pattern under the background of High-Speed Railway was sorted out,and the influence of high-speed railway on the evolution of urban agglomeration spatial pattern is analyzed with the metrological method.Finally,according to the existing High-Speed Railway lines and the planned High-Speed Railway lines,the daily accessibility of the city is measured,the hourly economic circle of the central city is divided,and the spatial pattern evolution trend of the west triangle urban agglomeration is predicted.Through the analysis,the following important conclusions are drawn: After the opening of the High-Speed Railway,the overall network density of the west triangle urban agglomeration has been greatly increased,but the overall density is still in the stage of insufficient connection,there is still a big gap compared with other state-level urban agglomeration,and the connection between cities still needs to be strengthened.The economic structure of the west triangle urban agglomeration is still in the state of polarization.The opening of high-speed railway will reduce the population size of the west triangle city group,and promote the economic agglomeration of the west triangle city group.In the future,the High-Speed Railway planning will form a 4-hour commuter circle within the urban agglomeration,and a 3-hour economic circle in each central city.The scope of the hourly economic circle will continue to expand,and the connection between cities will become closer.