Abstract:
It is crucial to evaluate the expansion of urban entities to implement sustainable urban
planning strategies in China. Thus, this study attempted to extract and evaluate the growth of
urban entities 270 prefecture cities in mainland China (2000–2020) using a novel approach based on
consistent night light images. After the urban entities were extracted, a rationality assessment was
carried out to compare the derived urban entities with the LandScan population product, Landsat, and
road network results. Additionally, the results were compared with other physical extent products,
such as the Moderate Resolution Imaging Spectrometer (MODIS) and urban built-up area products
(HE) products. According to the findings, the urban entities were basically consistent with the
LandScan, road network, and HE and MODIS products. However, the urban entities more accurately
reflected the concentration of human activities than did the impervious extents of the MODIS and HE
products. At the prefecture levels, the area of urban entities increased from 8082 km2 to 74,417 km2
between 2000 and 2020, showing an average growth rate of 10.8% over those twenty years. As a
reliable supplementary resource and guide for urban mapping, this research will inform new research
on the K-means algorithm and on variations in NTL data brightness threshold dynamics at regional
and global scales.
