Table 3 Nearest neighbor index of NSIBs in Chinese urban agglomerations.
Urban agglomeration | 2018 | 2021 | 2023 | ||||||
|---|---|---|---|---|---|---|---|---|---|
Nearest neighbor index | z-score | Type of space structure | Nearest neighbor index | z-score | Type of space structure | Nearest neighbor index | z-score | Type of space structure | |
Yangtze River Delta | 0.833 | −1.781 | Agglomeration | 0.594 | −7.036 | Significant agglomeration | 0.518 | −9.036 | Significant agglomeration |
Pearl River Delta | 0.825 | −0.819 | Random | 0.836 | −1.086 | Random | 0.816 | −1.268 | Random |
Jing-Jin-Ji | 1.524 | 3.168 | Discrete | 0.788 | −2.222 | Agglomeration | 0.814 | −2.189 | Agglomeration |
Middle Reaches of the Yangtze River | 1.122 | 0.658 | Random | 0.845 | −1.567 | Random | 0.764 | −2.670 | Significant agglomeration |
Chengdu-Chongqing | / | / | / | 1.053 | 0.289 | Random | 1.025 | 0.169 | Random |
Shandong Peninsula | 1.060 | 0.305 | Random | 0.936 | −0.570 | Random | 0.979 | −0.199 | Random |
Guangdong-Fujian-Zhejiang Coastal | 1.793 | 5.257 | Discrete | 0.914 | −0.823 | Random | 0.8565 | −1.533 | Random |
Harbin-Changchun | / | / | / | 1.753 | 3.812 | Discrete | 1.938 | 5.949 | Discrete |
Zhongyuan | / | / | / | 1.259 | 1.313 | Random | 1.259 | 1.313 | Random |
Guanzhong Plains | / | / | / | / | / | / | 2.182 | 5.541 | Discrete |
