Impact Of High Speed Railway Scale-Free Network On Node Cities

Following the opening of the first He-Wu High-Speed Rail in April 2009,Wuhan's high-speed railway increased at an average annual rate of-one new line per year.Compared with 2009,Wuhan added 5 high-speed rail lines in 2014,doubling its GDP and upgrading its national ranking from No.12 to No.8,making it one of the "Trillions of Clubs" in China's urban.In 2016,the number of high-speed rail lines opened in Wuhan increased to 7,with GDP growth ranking first in Central China.Similar to Wuhan,Chengdu,Nanjing and Zhengzhou also opened a number of high-speed rail lines,occupying an important position in the high-speed railway network in the region and even in the whole country.In 2017,in the national high-speed rail network cities,the node cities with no less than 3 high-speed rail lines accounted for only about 8%.In a scale-free network architecture,hubs that make up 5-15%of the total number of nodes will typically have more than half of all connections.Based on the characteristics of China's high-speed rail network,it is necessary to verify whether it meets the scale-free network structure and to study what impact such a network structure will have on node cities.To understand the impact of this network structure,can we use such network characteristics to better improve the high-speed railway network to make it better to help the city's development.In network theory,scale-free network has growth and priority connectivity,most nodes have fewer connections and a few nodes have a large number of connections,which are similar to the evolution of China's high-speed rail network.In this paper,by calculating the degree distribution of high-speed railways from 2009 to 2017 and verifying by power-law fitting,it is concluded that the scale-free network structure of high-speed railways in China has been presented since 2014.Under this premise,the theoretical framework of HSR scale-free network is established,and the mechanism of HSR network is analyzed.This paper defines the Wuhan high-speed rail urban agglomeration as the research object and its scope is the 2-hour traffic circle with Wuhan as the center,Wuhan-Guangzhou high-speed rail and the combined high-speed rail as the main trunk line.According to the principle of statistical grouping,the node cities are divided into three levels according to the network index,and the rank-scale distribution is used to analyze the effect of scale-free network structure on the accessibility,spatial distribution,and industrial development.The conclusions are as follows:(1)Urban hierarchical structure and economic spatial pattern show a high degree of coupling,which can better reflect the spatial distribution pattern of urban GDP,but can't reflect the spatial distribution pattern of population.(2)Scale-free high-speed rail network promotes the polarization of urban hierarchical structure.The differences in network indices among different nodes are expanding with the growth of high-speed rail networks,and the“”growth pole" status of the first-tier cities becomes more and more prominent.(3)Cities with higher levels have better accessibility and higher intensity of external relations.(4)The tertiary industry intensified the agglomeration of the first-tier cities and the second and third-tier cities entered the stage of the third industry diffusion.The cities in the third tier showed the tendency of secondary industry agglomeration and gradually surpassed the first and second grades.The secondary industry as a whole showed a balanced development pattern.