4. Wide-area hub

Shanghai, which has advantages in waterway, air and road transportation, ranks first in the wide-area hub category with a much higher deviation than other cities. The cities ranking second to 10th are Guangzhou, Shenzhen, Beijing, Tianjin, Qingdao, Ningbo, Xiamen, Chongqing, and Nanjing. Compared with 2018, the top five cities remain unchanged. The rankings of Qingdao and Xiamen have climbed slightly. The ranking of Chongqing has increased from 11th in 2018 to ninth in 2019, with land transportation contributing a lot.

The transportation hub is an extremely important function of a core city, and it is also the basis for strengthening and amplifying other core functions. The wide-area hub is a major item that measures the conditions and transportation volumes of waterway, air and road transportation facilities.

Thus, this major item includes three sub-items, waterway transportation, air transportation, and road transportation. They are gauged by 10 sets of indexes and data, including convenience at container ports, container throughput of ports, waterway transportation volume, convenience at airports, air transportation volume, convenience of railways, railway density, highway density, national and provincial highway density, and highway transportation volume.

(1) Waterway transportation

Shanghai, Shenzhen, and Ningbo are the top three in this sub-item, and the other top 10 core cities include Guangzhou, Qingdao, Tianjin, Xiamen, and Dalian. Those ranking high in this sub-item are mostly coastal cities.

(2) Air transportation

Shanghai, Beijing, and Guangzhou, which are China's largest air transportation hub cities, are the top three in this sub-item. They have significant advantages in this regard as shown by their deviation values. The cities ranking fourth to 10th are Shenzhen, Chengdu, Kunming, Chongqing, Xi'an, Hangzhou, and Zhengzhou. The dependence on air transportation in China's southwest and northwest regions has made Chengdu, Kunming, Chongqing, and Xi'an air transportation hubs.

(3) Land transportation

Guangzhou, Shenzhen, and Guiyang are the top three in this sub-item, and the other top 10 core cities include Beijing, Shanghai, Nanjing, Chongqing, and Wuhan. Guiyang stands out in this sub-item.