China''s urban systems in terms of air passenger and cargo flows since 1995
1995年以来中国城市体系格局与演变——基于航空流视角

This paper examines patterns and changes of China's urban systems in terms of air traffic flows since the 1990s. The related analysis approach is mainly based on the gravity model and the fuzzy variable method. The main findings are as follows: Firstly, the pattern, the interaction and changes of China's urban systems conform to the law of"Distance Decay".The global cities, or the mega-cities, such as Beijing and Shanghai have enforced their position nationwide. While in some economic centers of the western region, such as Chengdu, Kunming, and Urumqi, the hub airports gradually grow up into regional centers. Secondly, cities of Beijing, Xiamen, Xi'an, Shenzhen, Guanghzou and Shanghai are evident as regional hubs. Most of these cities are located in the urban agglomerations,such as the Beijing-Tianjin-Hebei Region,the Yangtze Delta Region,the Xiamen-Zhangzhou-Quanzhou Region, the Pearl River Delta Region, the Guanzhong Region, and the Chengdu-Chongqing Region etc. While cities in Liaoning, Shandong and Hubei provinces, their airports do not show evident regional hubness. And also other cities, such as Nanjing, Hangzhou, Fuzhou and Chongqing have small hubness index, because of the influence of related gateway cities or primary cities, such as Shanghai, Xiamen and Chengdu. Thirdly, the types of changes of China's main economic centers include the following ones: the steady type (eg Shenyang, Shanghai, Nanjing), the growing type (eg Tianjing, Hangzhou, Qingdao), the decaying types (eg Guangzhou, Fuzhou, Xiamen, Wuhan, Xi'an), the "increasing-decreasing" types and the "decreasing-increasing" ones. Generally speaking, cities in the Yangtze Delta Region show strong roles of regional motors, while those in the Pearl River Delta and the Beijing-Tianjin-Hebei Region show steadiness. Hubness of cities in Liaoning Province, the coastal Fujian Province, the Guanzhong Region, and the Jianghan Region, show slow growth, even remarkable decreasing tendency.