新冠疫情对中国国际航空网络连通性的影响及空间差异

航空运输在实现各国互联互通、推动全球经济发展中发挥着重要作用。突发公共卫生事件或恶劣天气等均易对航空网络的连通性造成影响。本研究以新冠疫情为例，从全球航空网络视角探讨新冠疫情对中国国际航空网络连通性的影响及地区差异。研究结果表明：疫情期间，中国境外通航城市、国际航班、国际航线数量均大幅缩减，航空网络连通效率显著降低，但其空间格局未发生根本性变化，东亚和东南亚仍是中国对外主要联系地区，经济联系与贸易仍然起着重要作用。航线停飞对中国与中亚、西亚和大洋洲航空网络的连通性影响最大，而航班缩减对中国与东亚、中亚和东南亚航空网络的连通性影响最大。在国内，北京、上海和广州仍然是中国对外联系的枢纽城市，且其聚集度在疫情期间得到提升。

The Impacts of COVID-19 on the Connectivity of China's International Air Transport Network and the Spatial Differences

Air transportation plays an important role in connecting countries and promoting global economic development. Recently, China’s international air transport network expanded rapidly in terms of navigable countries and cities and the number of air routes and flights. In this context, the connectivity and stability of the air transportation network attracted significant attention, which could be threaten by many factors such as public health emergencies, poor weather conditions, policies, etc. Focusing on COVID-19, this paper depicted the spatial patterns of canceled flights after the spread of the COVID-19 pandemic across Chinese cities and the impact on connected countries and cities overseas. Next, this paper investigated the impacts of public health emergencies on the connectivity of China’s international air transportation network by comparing the changes of the average shortest path and weighted average shortest path before and after the outbreak of the COVID-19 pandemic. The results could be summarized as follows. First, the spread of this pandemic has significantly impacted the connectivity of China's international air transport networks. The number of navigable cities, routes and flights has substantially reduced, as has the efficiency of China's international air transportation. However, the COVID-19 pandemic has not significantly influenced the worldwide air transport network in this period. Additionally, the degree of effect of COVID-19 on air transportation connection was various across regions. For example, the air route suspension has the greatest impact on China's aviation network connectivity with Central Asia, West Asia and Oceania, while flight reduction has the greatest impact on China's aviation network connectivity with Northeast Asia, Central Asia and Southeast Asia. Second, there are no significant differences between the spatial patterns of the connectivity of China’s international air transportation network before and after the outbreak of the COVID-19 pandemic; the connectivity between China and Northeast Asia, Southeast Asia, North America, and Europe remains better than other areas. The findings indicate that labor mobility, economic communication, and trade are vital in shaping the spatial pattern of the connectivity of China’ international air transport network. However, the flight aggregation degree for international flights has increased. The proportion of flights among the top 5 countries has increased from 58.1% to 67.2%, which is also closely related to factors such as the proximity and necessity of personnel, economy, and trade links. The international route networks in Beijing, Shanghai and Guangzhou are more reliable than other cities. Thus, following the outbreak of COVID-19, the distribution of China’s international routes and flights has been concentrated in these major cities. The proportion of international air routes increased from 28.8% to 38.9%. Moreover, the concentration of international flights increased from 46.6% to 76.4%, which is a higher concentration than international air routes. While expanding its focus on the depth and breadth of international air transport links, China should focus on strengthening the reliability of international air transportation networks to cope with the impact of various emergencies and ensure basic connectivity and stable operation of international air transportation networks.