Research On Accessibility And Vulnerability Of Port-centric Coal Transportation Chain

As a strategic material and non-renewable natural energy,coal has a significant supply-demand imbalance characteristic on region and time domain.To construct a stable and efficient coal transport chain is an important part of energy security.The supply and demand pattern of China's coal will change from the former decentralized type to the current regional type.The western coal producing areas gradually show their important role and strategic position.Shanxi,Shaanxi,and Inner Mongolia will become the main sources of coal supply in China.As coal consumption is concentrated in central China and economically developed areas such as East China and South China,China's coal transportation presents a pattern of "North-South coal transportation,West-to-East coal transportation".In recent years,China's borders and inland areas have accelerated the pace of opening up,especially the implementation of the “One Belt,One Road” strategic policy,which has provided new development opportunities for the coal logistics industry.Combined transport of iron and water is currently the main mode of coal transportation.In this mode of transportation,the port is a very critical transit node and plays an important role in coal transportation.Considering the port operation adaptability,this paper comprehensively evaluates the accessibility of port-centric coal transportation chain(PCTC)and analyzes its vulnerability.First of all,this paper summarizes the related research and theoretical basis of accessibility and vulnerability.The accessibility evaluation method of PCTC based on gravity model and vulnerability analysis method of PCTC based on vulnerability source identification are proposed.Then,under the fluctuation of coal transport demand,the general travel cost,the port operational adaptability,annualized slot capacity for coal and other indicators are examined.The accessibility model of PCTC was established by gravity model method,and the accessibility of the coal transportation route is analyzed and evaluated.Finally,from the perspective of complex network,the vulnerable nodes of PCTC are screened out according to the parameters of vulnerability source identification,and vulnerability analysis is carried out for them.Taking China's “North-South Coal Transportation” as an example,the accessibility evaluation model of the PCTC proposed in this paper is used to evaluate the accessibility of the PCTC in the western region passing through ports in the Bohai Rim region.Sensitivity analysis is also carried out considering the carrier's transportation stability preference.Taking Jingtang Port as an example,the spatial distribution pattern and changes of the transportation accessibility of coal from the producing area through Jingtang Port from 2014 to 2018 are analyzed.Under the background of ensuring the smooth and orderly coal transportation,calculate the identification parameters of the vulnerability source of the coal transportation network nodes.Accurately identify the key nodes of the coal transportation in the western region through the ports in the Bohai Rim area,and compare the operation of the coal sea transportation chain after the node unit fails State changes.The accessibility evaluation model of PCTC proposed in this paper comprehensively considers the whole process of coal inland collection and distribution,port transshipment and maritime transport.The evaluation of the accessibility of the PCTC enables us to understand the vulnerable links of the coal transport network deeply,and is the decision-making basis for further optimizing the coal transportation network.It is of great theoretical and practical significance to accurately identify the key nodes in the PCTC network through the vulnerability analysis of coal maritime transport chain nodes,which can guarantee the stable supply of coal resources and construct a scientific and efficient comprehensive coal maritime transport system.