关键词: 铁路货流, 省际网络, 网络联系, 凝聚子群

Abstract:

Based on the data of railway freight flow among provincial administrative regions of China (excluding Hong Kong, Macau and Taiwan), this article analyzes the characteristics of inter-provincial network by social network analysis and GIS in China from 1998 to 2016. The results show that: 1) The density of China’s railway freight network has been increased from 1998 to 2011 and it has been decreased from 2012 to 2016. In 2011, the density of China’s railway freight network reached its maximum, and it began to decline slightly in 2012. The density declined in 2016 and it is roughly the same as that in 2006. It shows that the contribution of railway freight to economic development has increased from 1998 to 2011, and the connection among provincial administrative regions has become closer. From 2012 to 2016, the demand for railway freight flow in economic development has decreased; 2) The provinces in the eastern China and in the Bohai economic rim are in the leading position in the railway freight network, and the railway freight connections among the provinces in the eastern China are decreasing; 3) There is a huge amount of coal in Shanxi Province; it has the largest connection with other provincial administrative regions. Therefore, Shanxi Province plays a very important role in China’s railway freight network. Inner Mongolia autonomous region also has a huge amount of coal, which is sent to North China and Northeast China by the railway. So it also plays a very important role in China’s railway freight network. Hainan province and Tibet autonomous region are marginalized in China’s railway freight network because of limitations of geographical location, a short history of railway operation and its low economic development level; 4) Guangdong in the southern coastal regions is a developed province and its economy development is prospering. And there is a very important Guangzhou port in Guangdong Province. A lot of freight is flowing between Guangdong Province and the provinces in Central China and Southwest China, so there are lots of close connections between them. Most provinces (autonomous regions) in the Northwest China are developing provinces (autonomous regions) and their density of the traffic network is low. Therefore, the northwestern provinces (autonomous regions) are weakly connected to each other and to the provinces in the other regions. 5) In the railway freight network, geographical proximity and economic connections largely determine the composition of the cohesive subgroup. With the economy development and the continuous changes of railway freight transportation, the cohesive subgroups of railway freight network increase, and their scales become smaller. For example, in China’s railway freight network, there are 4 cohesive subgroups in 1998; and the number of cohesive subgroups increases from 6 cohesive subgroups in 2011 to 7 cohesive subgroups in 2016. The members of cohesive subgroups have decreased from 4-10 members in 1998 to 3-5 members in 2016.

Key words: railway freight flow, inter-provincial network, network connection, cohesive subgroup