Villages in mountainous areas are under the risk of topography, geomorphology and frequent natural disasters in a long term. Rural transportation system is characterized by low network degree and weak capacity to resist disasters, and the problem of vulnerability of traffic environment is prominent. Taking Luonan county in the Qinling-Daba mountainous areas as an example and based on exposure, sensitivity and response capacity of human-environment system vulnerability, this paper constructed a basic framework of rural transportation environment vulnerability, which contained the key elements of risk events, geographical features, key travel path, road network structures, public and private vehicles, family capital etc., and established a targeted evaluation index system. With the aid of ArcGIS and GeoDa, this research examined the spatial structure and spatial autocorrelation of the transportation environment vulnerability in Luonan county at the village level. It also utilized a geographical weighted regression model to explore the factors of natural conditions, population, socio-economic development, which had influence on response capacity of traffic risk and its spatial difference. The results showed that the vulnerability of transportation environment took the county seat and the suburbs as the center increasing outward, which presents a circle structure featured by great difference in vertical direction. Simultaneously, the vulnerability of the transportation environment in village-level residential areas showed a significant positive spatial autocorrelation, but both exposure degree and sensitivity showed a significant spatial negative correlation with the response capacity. There were three patterns of local spatial correlation in transportation environment vulnerability: the vulnerability of the local "hot spots" areas was widely observed in the north- central mountainous area and fell into the dilemma of high exposure, high sensitivity and low response capacity, while the "cold spots" villages were founded in suburbs or areas adjacent to the towns with higher income, which had low sensitivity and high response capacity. There were a few "heterogeneity points", and these villages were adjacent to low-vulnerable villages, but they belonged to high-vulnerable areas. Moreover, topographical condition, industrial distribution, population structure, education level and family size had a significant impact on response capacity of transportation risk. In addition, the effect direction and intensity of the influencing factors had significant spatial differences.

Under the macroscopical background of "Polar Silk Route", the paper puts forward the land and river intermodal transport route from Dalian to Tiksi Port of the Arctic Ocean (hereinafter referred as land and river intermodal transport route). The land and river intermodal transport route is a line available, which vertically connects the two economic belts between the northeast of China and the Siberia of Russia. Through the comprehensive analysis of the latest researches upon river and land intermodal transport route, which are carried out by Heilongjiang University, Melnikov Permafrost Institute of Russian Academy of Sciences and North-Eastern Federal University. Among them, the river transport section is the waterway from Russian Yakutsk City to Lena River of Tiksi Port; the land transport section runs through China and Russia and the central part of Northeast Asia, mainly including the railway and highway transport from Dalian to Yakutsk. And the main cities along the river and land intermodal transport route contain: China Dalian-Harbin-Heihe-Russian Blagoveshchensk (Hailanpao)-Neryungri-Yakutsk-Tiksi Port. Every node of land transport section has mature transportation systems, transit nodes with complete facilities and great economic development prospects. From July to September, Lena River has at least 3 months suitable for shipment and allows ship navigation with a weight of over 3000 tons. In summer, the Sino-Russia Northeast Asia land and river intermodal transport route has advantages of both short transportation distance and time. Along the route, there are abundant mineral resources. When the economy along the route gets improved, the trades between Asia and Europe can be connected and enhanced.

"The Belt and Road Initiative" has activated the westward economic and trade route, and the state has entered a new integrated development stage of land and sea. Previous studies mainly focused on ocean-oriented urban circulation network, however the research on the inland-oriented area needs to be expanded in both content and methods. Using spatial analysis, the paper constructed a framework of "circulation cost-accessibility and the ratio of export-oriented trade-market competition and policy protection-circulation structure and organizational models", and conducted research on the structural features of westward circulation network and organizational models of the circulation of goods based on the west corridor. The research finds that the high grade circulation node shows the overall approximation on the path of the minimum time and the cost of the freight, and the production capacity of flow node shows significant difference under the market competition, the coastal areas nodes, especially the Yangtze River Delta and Pearl River Delta, have significant scale advantages of current flows, but inland nodes with local subsidy policies could radiate the coastal area and launched supply competition. Wuhan, Xi'an, Zhengzhou, Chongqing and Changsha are the best inland nodes of coastal source. According to the characteristics of westward circulation network in the aspects of nodes, lines and flow, the "delta structure" of the country's westward circulation can be extracted. Based on the key nodes of westward circulation network, the paper proposed four patterns: the unified marshalling pattern, key node cities model, "export cities" model and key port cities model. The westward circulation has experienced the initial stage, diffusion stage and dispersed stage, and will enter the integration stage. The leading power of westward circulation will eventually return to the cities located in the advantageous space.

The Qinghai-Tibet Plateau is a unique geography-ecology-population-traffic region on the earth. The characteristics and regularities of the transport network development are an important breakthrough for the coordinated development of man-land relationship, which is of great significance to the research in the Qinghai-Tibet Plateau. Accordingly, this paper analyzes the evolution of transport network in this region between 1976 and 2016, and explores its accessibility using a temporal distance calculation model based on network analysis by taking provincial capitals, prefecture-level cities and counties as transport nodes. Results suggest that, first, transport network is more complex and the regional connectivity is gradually enhanced in the plateau, preliminarily forming a grid-like transport network; second, the average minimum accessibility time between anchor cities and between counties has been vastly reduced to 11.89 hours and 18.84 hours, manifesting a gradually growing spatial pattern from east to west and remarkable effects of time-space convergence; third, anchor cities are the poles of regional development, with average accessibility time to around cities reduced to 16.49 hours, indicating that anchor cities tied with others have been improved; fourth, the traffic circles of anchor cities and counties are evolving consistently, accessibility time from various places in the study area to their nearest cities or counties are decreasing, presenting a contiguous pattern of short-time traffic circle with 4-hour access to central cities and 2-hour access to counties along important arterial roads, thus improving external transport connection of towns. And traffic corridors are gradually formed in the Huangshui River Valley, and the Middle Region of "One River and Two Streams" in Tibet.