Spatial Network Structures of Urban Agglomeration Based on the Improved Gravity Model: A Case Study in China’s Two Urban Agglomerations

Table 2

City links and network grades of cities in the BTHUA.

Grade	City network characteristics	Weighted degree	Cities
1	Network radiation center	190664-906065	Beijing, Langfang, and Tianjin
2	Advanced network node	56960-190663	Tangshan, Xingtai, and Handan
3	Intermediate network node	13725-56959	Shijiazhuang, Cangzhou, and Baoding
4	Primary network node	2347-13724	Hengshui, Qinhuangdao, Zhangjiakou, and Chengde