关键词: 全球城市网络, 航空客运, Gephi, “联系强度-空间距离”模型;

Abstract:

This article analyses the spatio-temporal evolution of connection strength on global city network by using Gephi, which is based on passenger flights data from April 2014 to August 2018. Although Gephi can be used to analyze many topological properties of city network, we mainly used Average Weighted Degree and Betweenness Centrality to depict the basic characteristics of global city network, which reflected the connection strength and spatial differences of network. In order to reinterpret the breakthrough of connection strength to spatial distance constraint on global city network, we propose a model of connection strength-space distance based on concept of definite integral. The study mainly draws the following conclusions: 1) The connection strength of global city network becomes stronger in general from 2014 to 2018 and its backbone is formed by three big urban agglomerations, including West Europe megaregion, North America megaregion and East Asia megaregion. New York and other important nodes play a key role in building a global city network and form a self-centered network framework, bearing the flow of elements of global economic development. The variation coefficient obtained from the Betweenness Centrality of each city reflects that the polarization of the global city network is slightly reduced, but the ‘pyramid’ hierarchical structure does not change fundamentally. In addition, the Average Weighted Degree first increases and then decreases, which indicates that the global city connection strength has been improved and the complexity of the global city network in the evolution process. 2) The fitting curve obtained by the connection strength-space distance model basically conforms to the distance attenuation law, and the distance range of the peak indicates that the global city network has the highest connection strength in the short and medium range. Furthermore, the peak value first rises and then falls, which also proves the complexity and periodical characteristics of the change of global city network on connection strength. The breakthrough value of distance (BVD), obtained by the connection strength-space distance model, reaches a peak in 2016 and then falls with fluctuation, which reflects the complexity and volatility of global city network in its evolution and reconstruction process. On the one hand, this article makes a detailed investigation of the global city network from a spatio-temporal perspective, and on the other hand, it makes a quantitative analysis of the distance decay law.

Key words: global city network, passenger flight, Gephi, Connection Strength-Space Distance Model