Table 6 Average nearest neighbor distances of the ancient cities from the late Yangshao to Xia and Shang Dynasties in the Central Plains region
Periods | Number of ancient cities | Average nearest neighbor distance (m) | Expected average nearest distance (m) | NNI statistics | Z score |
|---|---|---|---|---|---|
Yangshao Period | 18 | 24,640 | 34,608 | 0.712 | − 2.338 |
Longshan Period | 24 | 43,477 | 35,229 | 1.234 | 2.19 |
Xia and Shang Dynasties | 22 | 22,711 | 25,664 | 0.885 | − 1.03 |