中断模拟下的中国沿海集装箱港口航运网络脆弱性

Vulnerability of the shipping network of China’s coastal container ports under disruption simulation

双循环背景下,国内消费市场的持续扩大有望进一步增加港口内贸集装箱比例,而海洋集装箱运输极易受到外界因素的影响,因此对国内海洋集装箱运输网络脆弱性的研究必要而紧迫。本文在港口中断模拟下,运用复杂网络特征指标从网络结构和节点抗干扰性能两方面,分析2005年和2017年中国沿海集装箱港口航运网络脆弱性,并探讨脆弱性的主要影响因素。结果表明:①相较于2005年,2017年有较高比例的节点分别失效,使网络集聚系数上升、平均路径长度减小和网络独立路径数量增大,这表明当网络中有较多节点分别中断失效,剩余节点仍具有紧密联系,具有较多备用路径,能够以较快反应速度顺利应对干扰。港口节点间的平均路径长度、支路数量和联系受到同步影响,产生叠加效应。②2017年,最大干扰状态下港口的抗干扰性能差异较2005年减小。轴辐模式下枢纽港作用增强,上海港和深圳港的中断使网络中节点处于最大干扰状态下的比例增加,脆弱性节点增多。③航运网络脆弱性的影响因素突出表现在外界多种不可抗拒的自然和人文因素导致网络节点瞬时中断、轴辐式航运组织模式的强化、区域竞合与一体化的发展三方面。本文结果对于认清国内航运网络的脆弱性及影响因素、保障港口间有效联通和提升航运网络安全性具有理论和现实意义。

Under the background of dual circulation,the continuous expansion of domestic consumer markets in China is expected to further increase the proportion of domestic trade containers in ports,and marine transportation is vulnerable to the impact of external factors.Using disruption simulation,this study analyzed the vulnerability of China’s coastal container port shipping network in 2005 and 2017 from two aspects—network structure vulnerability and node anti-interference performance—with complex network characteristic index,and the main factors of vulnerability were discussed.The results show that:(1)Compared with 2005,a higher proportion of nodes failed respectively in 2017,which caused the network clustering coefficient and the number of independent paths to increase,the shortest path to decrease.This shows that when more nodes were interrupted and failed respectively in the network,the remaining nodes still have close connections—more standby paths,faster response speed,and smooth response to disruptions.Path length,the number of branches,and connection among the port nodes are affected synchronously,resulting in a superimposing effect.(2)In 2017,the difference of anti-interference performance of port nodes under the maximum disruption state decreased.In the hub-spoke mode,the role of hub ports is enhanced.With the disruption of the Shanghai Port and the Shenzhen Port,the proportion of nodes in the network under the state of maximum disruption increases,and the number of vulnerable nodes in the whole network also increases.(3)The vulnerability factors of the shipping network are mainly manifested in three aspects:the instantaneous disruption of network nodes caused by a variety of irresistible external factors,the“two-way influence”formed by the strengthening of the hub-spoke shipping organization mode,and the“superposition effect”enhanced by regional competition and integration.