Research On Spatial Spillover Effect Of Sichuan Province's Transportation Infrastructure Based On Reachability

With the development of western region of China,the implementation of the Yangtze River Economic Region and the “Belt and Road” Initiative,Sichuan Province has been more and more important as an transportation hub in southwestern China.In recent years,the construction of high-speed railways in Sichuan Province has been accelerating.It has played an important role in the rapid development of regional economy and society and the optimization of urban spatial pattern.This paper takes Sichuan Province as an example to study the 21 cities in Sichuan before and after the construction of the high-speed railway with the help of the ArcGIS 10.5 spatial analysis platform.By using geography models such as weighted cost distances and field strength models,and space lags and other spatial econometric models,we analyzes the accessibility and the division of the hinterland,and further explores the economic ties between cities.Finally,the spatial econometric model is used to explore the spatial spillover effect of high-speed rail construction.The main conclusions are:First,in terms of accessibility,Sichuan Province opened five high-speed rail lines and connected five prefecture-level cities at the end of 2016.The opening of the highspeed railway has significantly improved the accessibility of cities along the route,especially in Chengdu,Mianyang,and Deyang in the northeastern part of Sichuan Province.The phenomenon of isochronous expansion has become evident.In contrast,Ganzi,Aba and other areas in the southwest of Sichuan Province,due to the topography,landforms and economic and social development,the backward transportation infrastructure,coupled with the absence of high-speed railways,accessibility is significantly behind.Second,with regard to economic ties,the growth rate of total economic links between the cities has increased substantially after the opening of the high-speed railways.This is due to the rapid economic development and the continuous upgrading of transportation infrastructure,especially the construction of high-speed railways,further forming the Sichuan Provincial Transportation Network.The road is perfected by the significant space-time compression effect.With the Lanzhou-Chongqing Line,the completion of the high-speed rail line on the Suining Line and the improvement of comprehensive transportation systems such as expressways and national highways have strengthened the external economic and social links between cities in the northeastern Sichuan and other prefecture-level cities,and the space-time distance has been reduced.The South Sichuan Economic Zone is relatively backward in Neijiang,except that it is difficult to accept high-speed rails to accept external economic and social radiation,while economic Panzhi Economic Zone and Sichuan Northwest Economic Zone are limited due to geographical location,the slow transportation and economic development.Third,we find that the spatially lagging regression coefficients p exceeds 0.8 and both are significant at the level of 1% by using the spatial lag model,indicating that the spatial dependence between cities is strong,and there is a clear spatial spillover effect in the economic growth of neighboring cities.At the same time,after controlling variables that affect economic growth,the p-value in the case of high-speed railways also increased by 0.1048 compared with the situation without high-speed railways,further testifying the spatial spillover effect of high-speed railways on economic growth,indicating that the construction of high-speed railways shortens the travel time between cities and strengthens the spatial spillover effect among cities.