Evaluation of Natural Gas Supply Security in China Based on Ecological Network Analysis

The model of China' s natural gas supply security network was established by ecological network analysis method. From the perspective of regional cooperation and system level, the boundary and node path of the natural gas supply system were determined, and the input, output and inter-group flow were quantified. Based on the perpective of network information, network structure and network utility, the stability level, contribution weight of different nodes and symbiosis level of natural gas supply system in China from 2006 to 2020 were evalated by using the constructed China natural gas ecological network model. Three scenarios were designed, namely, reducing external sources, reducing domestic consumption and increasing domestic natural gas production under the same control of other conditions. The influence of different scenarios on the security of China' s natural gas supply system was investigated. The results show that during the period of 2006—2020, the influences of different nodes on the whole atural gas supply system are supply source, consumer sector, refining and reserve department in order. With China' s import of pipeline and liquefied natural gas (LNG), the connection between nodes in the gas supply network becomes closer, and the overall security level of gas supply steadily is improved in China, and the network has a relatively stable level of symbiotic. China' s natural gas import sources are too concentrated, and the uncertainty of import safety needs to be improved. In order to improve the security of China' s natural gas supply, it is suggested that ensuring internal supply sources and improving the domestic natural gas production capacity, strengthening regional cooperation and adopting diversified import policies, optimizing natural gas consumption structure and reducing energy intensity, strengthening the construction of natural gas strategic reserves and reducing energy risks.