This article first analyzes the development of different types of natural gas flow zones, and then divides all the provinces into four flow types: non-flow zones, output centers, input centers and exchanging centers. Next, this article analyzes the concentration and diffusion characteristics, current spatial pattern and its evolution of source and terminal regions of natural gas resources flows. Conclusions are drawn as follows: 1) the numbers of no natural gas flow zones, one-way output zones, one-way input zones and two-way exchanging zones all stabilized during the Eleventh Five-Year Plan period. The number of output centers is small but the quantity of flow is large. The number of input centers is large and they are widely distributed. Generally speaking, it presents a significant characteristic of centralized output and dispersed input in geographic space. 2) Current situation of China's natural gas output source has a characteristic of random distribution. But the terminal regions of natural gas flows have strong positive spatial correlation, which presents a significant spatial agglomeration pattern. Shandong, Jiangsu, Zhejiang and Shanghai show a high-high agglomeration mode, but Yun-nan, Sichuan, Tibet, Qinghai and Gansu show a low-low agglomeration mode. 3) The spatial pattern changes of China's natural gas output zones have three different stages: was relatively stable during 2001-2003; moved northwestward, expanded in space, and widely dispersed during 2004-2006; transferred to the east, spatially contracted, and significantly concentrated during 2007-2011. The spatial pattern changes of China's natural gas input zones have two different stages: expanded in east-west direction while contracted in north-south direction during 2001-2005; and relatively stable in spatial structure, and had obvious trend of intensification during 2006-2011.
To summarize the flows of natural gas resources in China, the following conclusions can be drawn. 1) Regional natural gas resources abundance and the development sequence are major factors of the forming of the source regions of natural gas resources in China. 2) The spatial pattern of the terminal regions changes with the evolution of natural gas consumption pattern. 3) Based on current spatial pattern of source and terminal regions of natural gas resources and current status of natural gas pipeline construction, it is recommended that the planning and construction of natural gas main network should extend to the southeast coastal areas of China. Meanwhile, to meet the demand of natural gas consumption in these areas in a timely manner, more work needs to be done, such as layout and optimization of shore stations and pipeline infrastructures for imported liquefied natural gas.
Studying on the spatial pattern of natural gas resources, this paper takes provincial regions as homogeneous space nodes. In theory, this study should take natural gas pools as the sources of resources flows and take the locations of consumer terminals, such as natural gas power plants, as the terminals. In addition, as the import of liquefied natural gas from overseas is gradually growing, the disturbance of liquefied natural gas on natural gas resources flow in China is gradually increasing. However, this paper does not bring oversea liquefied natural gas into the system of natural gas resources. Therefore, future research should further strengthen the analysis on the influence of international liquefied natural gas market on natural gas resources in China.