高铁网络空间组织模式及其脆弱性评估——以长三角为例

Spatial organization model and its vulnerability assessment of high-speed rail network:Taking the Yangtze River Delta as an example

当前,汛情、疫情等突发事件对于交通站点的影响愈发明显,作为当今旅客跨区域出行的重要交通工具,高铁网络的连通性也会遭受不同程度的冲击。基于此背景,本文以高铁网络相对完善的长三角为例,通过模拟连续节点失效、单个节点失效情景下网络特征值的变化,揭示其网络的脆弱性特点。结果发现:①长三角高铁网络已形成层级结构明显、社团组织结构清晰的网络化结构,同时整体呈现“小世界、多中心”的复杂网络特征。②当度值排序前20%、中间20%的节点失效时,高铁网络结构变得更加松散,节点间联系中转的次数明显增加,直接联系和相对可达性水平明显降低,网络呈现较高的脆弱性。而当度值排序后20%节点失效时,高铁网络结构变得更加紧密,网络集聚水平有所提升,节点间联系中转的次数有所减少,对整体网络稳定性的影响相对较小。③单个节点失效背景下,高铁网络受冲击程度相对可控,基本可以维系高铁网络的正常运行。但不同节点对于高铁网络的脆弱性影响呈现明显的异质性特点,上海、南京、杭州、合肥等中心城市节点失效背景下网络呈现较高的脆弱性,而宿迁、泰州、马鞍山、淮北等周边城市节点失效时对网络稳定性影响相对较小。未来,应立足高铁网络脆弱性的空间分异特征,针对性的布局应急处置设施、谋划替代通勤线路、打造高铁互联互通联盟等,提高长三角高铁网络应对突发事件的能力。

At present,the impact of emergency events such as floods and epidemics on transportation stations is becoming increasingly more obvious.As an important tool for passengers to travel across regions,the connectivity of the high-speed rail network will also suffer varying degrees of impacts.Under this background,this study took the Yangtze River Delta,where the highspeed rail network is relatively mature,as an example,to examine the vulnerability characteristics of the network by simulating the change of network characteristic values under the scenarios of continuous node failure and single node failure.The results show that:(1)The high-speed rail network in the Yangtze River Delta has formed a clear hierarchical structure and a clear networked structure of community organizations.At the same time,the network as a whole presents the complex network characteristics of“small world,multi-centers”.(2)When the top 20%and the middle 20%of the nodes in the ranking of degree values fail,the high-speed rail network structure becomes more loose,the number of connections between nodes increases significantly,the level of direct connection and relative reachability decreases significantly,and the network presents a high vulnerability.However,when the last 20%the nodes in the ranking of degree values fail,the highspeed rail network structure becomes more compact,the level of network agglomeration is improved,the number of connections between nodes is reduced,and the impact on the overall network stability is relatively small.(3)Under the failure of a single node,the impact on the highspeed rail network is relatively controllable,the stability is still high,and the normal operation of the high-speed rail network can basically be maintained.But the impact of different nodes on the vulnerability of the high-speed rail network shows obvious spatial heterogeneity.The network will be more vulnerability when central cities such as Shanghai,Nanjing,Hangzhou,and Hefei are affected,while cities such as Suqian,Taizhou,Ma’anshan,and Huaibei,when affected by emergencies,the impact on network stability is relatively small.In the future,based on the spatial differentiation characteristics of the vulnerability of the high-speed rail network,we should deploy emergency response facilities,plan alternative commuter routes,and build a high-speed rail interconnection alliance to improve the ability of the Yangtze River Delta high-speed rail network to respond to emergencies.