Spatiotemporal evolution of land transportation networks and accessibility in inland mountainous areas 1917-2017: A case study of Southwest China

Located in the western hinterland,Southwest China is a typical mountainous area covered by plateaus, mountains and hills. Its ruggedness hinders regional internal and external connections, and its poor transportation infrastructure has long constrained the socioeconomic development of Southwest China. Based on the GIS transportation database, this paper explored the spatiotemporal evolution and characteristics of the land transportation networks and the accessibility of Southwest China from 1917 to 2017. Regional accessibility in Southwest China has significantly improved, and transportation infrastructure has gradually integrated the transportation circles of the52 central cities. The transportation network has followed an evolutionary process from a "hub-spoke pattern" to a "network pattern", while the construction of a high-speed railway(HSR) has brought about significant spatial polarization. We argue that innovation in transportation technology is one of the most effective factors for promoting a significant change in regional accessibility. In addition, the spatial distribution and evolution of accessibility in Southwest China presents a verticalcharacteristic that distinguishes it from the plains, as the spillover effects of new transportation infrastructure on accessibility improvement are partly offset by the mountainous terrain. Additionally, in Southwest China, there is significant "path dependence" in the evolution of the transportation network, since a large portion of the population is concentrated along transportation corridors in mountainous areas.