Research On The Agglomeration-Diffusivity Effect Of The City Nodes Along Lanzhou-Xinjiang High-speed Railway

Transportation is the main carrier of moving production factors and products.Better transportation system can both promote ties of regional economy and regional agglomeration effect,and enhance benefits of scale economies and the regional opening level.The construction of transport infrastructure has feedback and guidance to the regional economies' scale,structure and layout.Also,as economic advantages,inducing traffic advantages can promote regional development.Lanzhou-Xinjiang high speed railway is taken as an example in this paper.By comparing and analyzing,the changes of relative influence power and the accessibility of the cities along the track are obtained.Besides,the strength and scale of urban field are clarified.Firstly,according to the references of domestic and abroad research,the relationship between construction of traffic infrastructure even high speed railway and the node-city development is analyzed and discussed.Taking this as the breakthrough,the logical framework of qualitative analysis is established.Secondly,the node-city's agglomeration-diffusivity effect of high speed railway along it is studied theoretically.By qualitative analysis of high speed railway's affection to urban development,the way of agglomeration-diffusivity,and the time-space characteristics,it is concluded that the agglomeration and diffusion confront with each other but always coexist,and they play different roles in different social development stages.Thirdly,based on the physics theory of ‘field',the improved field model is established to test the influence index of node-city along high speed railway,with the index system of 15 indicators and 7 major indicators.Then the entropy method is used to confirm the weight of each index,and each influence index of those node-cities is calculated.Based on the method of traffic time cost,GIS is used to determine the accessibility of node-city.Moreover,the traditional field model is improved by calculating of the urban influence index and regional accessibilityLastly,Lanzhou-Xinjiang high speed railway is seen as the example,its track conditions,construction significance and necessities are researched.The year of 2008 and 2015 are chosen as time sections and 7 cities with large population along the railway are selected as the research node cities.Furthermore,the influence index of each city and each year is identified,and the node-city accessibility is measured by use of the improved field model with software of ArcGIS.Meanwhile,the change of the city's field intensity is obtained,and the development and evolution of those cities are analyzed.The agglomeration-diffusivity effect of node-city along Lanzhou-Xinjiang high speed way is measured with GIS,which is simple and easy to operate.Based on the comprehensive application of GIS measures,this paper measured the agglomeration-diffusivity effect of Lanzhou-Xinjiang high-speed rail node cities.The method is simple and easy to operate.Taking two factors into account,including the city's own scale and accessibility dual effect on the urban city's agglomeration-diffusivity effect,the conclusion can match better with the city's situation,which analyzes quantitatively the agglomeration-diffusivity effect between high speed railway and the node cities.