Abstract:

Taking the Guangdong-Hongkong-Macao region as our study area, we first used the time series data fitting method in TIMESAT to improve the quality of VIIRS nighttime light remote sensing images. We then generated annually averaged nighttime light images from the repaired VIIRS monthly composite data from June 2012 to May 2019. These, combined with the LandScan ^TM population distribution map and administrative division data, were used to analyze the spatial and temporal patterns of urban development in the Guangdong-Hongkong-Macao region for the first time, using a spatial statistics method, rank-size distribution method, and the Nighttime Light Development Index (NLDI) constructed using the Gini coefficient. The experiment was performed at both prefecture and county levels. The following conclusions can be drawn from this study. 1) From 2012 to 2018, the total amount of nighttime light in all prefecture-level cities in the Guangdong-Hongkong-Macao region showed an increasing trend. The total amount of night light in Guangzhou has always been highest, with Shenzhen, Dongguan, Foshan and other economically developed cities maintaining steady increases. The growth rate of nighttime light in small and medium-sized cities was significantly higher than in large cities, and was as high as 310.35% in Shanwei City. Small and medium-sized cities located in the surrounding areas show great development potential. 2) In the rank-size distribution analysis, from 2012 to 2018, the q value at prefecture level and county level decreased by 16.86% and 13.52% respectively. At the prefecture and city level, the distribution of urban scale has gradually changed from a first-place distribution to a rank-size distribution. At the district and county level, it has remained a first-place distribution, but the tendency to disperse has been greater than the tendency to concentrate. The "Core-Edge" urban network structure that had prevailed in the Guangdong-Hongkong-Macao region for a long time has gradually been broken. The gaps between urban structure levels are gradually narrowing, and the scale development is gradually becoming more balanced across the whole region. 3) It can be seen from the analysis of the Nighttime Light Development Index that the differences in nighttime light levels and population distribution levels in the Guangdong-Hongkong-Macao region are gradually decreasing, with the imbalance between cities showing a decreasing trend year by year. The rate of decrease of NLDI in small and medium-sized cities is faster than in large cities, which indicates that the development of small and medium-sized cities is faster. The NLDI values of Jieyang City, Shanwei City and Shantou City, which are all in the east of the Guangdong-Hongkong-Macao region, decreased most significantly, indicating that the east of the region has shown a strong development trend in recent years. This paper presents an analysis the evolution of urban scale distribution in the Guangdong-Hongkong-Macao region from the perspective of spatial statistics, and its dynamic urban development in recent years is discussed herein. These findings have both theoretical and practical significance for optimizing development as well as for scientifically informed distribution of resources in the region.

Key words: nighttime light remote sensing, urban scale, rank-size rule, Nighttime Light Development Index, the Guangdong-Hongkong-Macao region