A Study On The Hierarchy Phenomenon Of High-speed Railway Stations In China

Since the first high-speed railway built in 2003,construction momentum of China's high-speed railway is very swift?With the proposing of four vertical and four horizontal development plan,high-speed railway has gradually formed a network of development pattern,and the advantages of high-spee railway network(HSRN)are also brought into play.However,the drawbacks of HSRN are gradually emerging.All sites and lines are directly or indirectly connected to form a network,when a critical site in the network is invalid,it may affect the normal work of other sites or lines,and even cause serious paralysis of the network.Therefore,it is an effective way to avoid the disadvantages of HSRN by correctly assessing the hierarchy of each site in HSRN,finding out the key sites,strengthening maintenance and reducing failure probabilities of these key sites.So,it is necessary to analyze the structural characteristics of HSRN in China,study on the hierarchy of high-speed railway stations,identify the critical sites and backbone network,and explore the key factors that affect the hierarchy of high-speed railway stations in China.Combined theoretical research and empirical analysis,this paper evaluates the hierarchy of high-speed railway stations and explores the key factors that affect the hierarchy of stations based on the structural characteristics of HSRN in China.Firstly,combined with the status quo and characteristics of China's high-speed rail network,we choose complex network theory to analyze the topology structure of HSRN,and determine to use reliability theory as theoretical basis to conduct reliability simulation analysis of HSRN in China.Secondly,according to the connectivity information of China's HSRN,L-space method is used to abstract the HSRN,and the complex network model of high-speed rail is constructed.The complex characteristics of HSRN are analyzed according to the calculation results of characteristic parameters of high-speed railway complex network.Then,combining with reliability theory,based on the complex characteristics of China's HSRN,four kinds of site failure strategies are designed to simulate the variation range of HSRN's reliability indexes under different failure strategies.According to simulation results,identify an index that can exactly describe the hierarchy of sites,and use this index to quantify the hierarchy of each site.Finally,we choose regression analysis method,take 23 prefecture-hierarchy cities along Beijing-Guangzhou high-speed railway as empirical analysis samples,and explore the key factors that influence the hierarchy of high-speed railway stations from two dimensions: development hierarchy of the city where station located,the sites' own conditions.Research results show that:(1)China's HSRN has the characteristics of scale-free network,showing the robustness of stations' random failure and the vulnerability of stations' deliberate failure.(2)In the case of site failure based on betweenness centrality ranking,decline rate of HSRN's reliability indexes are the fastest.Therefore,betweenness centrality is determined as an index that describe the hierarchy of sites.(3)There is a threshold for the change of the reliability indexes of HSRN.A few key sites play an important role in the network,and the hierarchy distribution of stations follows Pareto's law.(4)According to the quantitative calculation results of betweenness centrality index,Chengdu,Beijing,Wuhan,Guangzhou,Zhengzhou,Shenzhen,Shanghai,Nanjing,Nanchang and Hangzhou are the most important stations,they are the central hubs of HSRN.These central hubs and regional hubs which affected by the "cascading failure" effect constitute the backbone network of China's HSRN together.(5)The hierarchy of high-speed rail station is mainly affected by three factors: Development level of the tertiary industry in the city where site located,frequency of station departure,reachability of site.There are square relationship between three influencing factors and the hierarchy of site,and the impact of these three factors on the hierarchy of site has a magnifying effect.This paper provides a new idea for determining index that describe the hierarchy of high-speed railway sites.Quantitative assessment of the hierarchy of high-speed rail stations helps to identify hub sites in HSRN,and has a strong practical significance to avoid risks of HSRN.At the same time,this paper identifies the key factors that affect the hierarchy of high-speed railway stations in China,and provides clues and basis for the follow-up study.