Characteristics of the Spatiotemporal Changes in Urban Agglomeration in the Guangdong–Hong Kong–Macao Greater Bay Area, China.

The Guangdong–Hong Kong–Macao Greater Bay Area urban agglomeration, one of the world's four largest bay area urban agglomerations, occupies an important position in China's national development. In this paper, the expansion hotspot model, an urbanization index, a gravitation model, and a socioeconomic location model are used to explore changes in the characteristics of the urban agglomeration in the Guangdong–Hong Kong–Macao Greater Bay Area. The research results can provide decision support for government urban agglomeration planning. The research reveals the following. (1) In the skeleton maps of the expansion hotspots in the Guangdong–Hong Kong–Macao Greater Bay Area, Jiangmen shows an irregular shape, Shenzhen shows an irregular H-shape, Dongguan and Hong Kong show a shape somewhat between a circle and a star, Zhongshan shows a gourd-shape, and Guangzhou, Foshan, Huizhou, Zhaoqing, and Zhuhai show a polygon shape. (2) In 2000, 2010, and 2018, the urbanization index for the urban agglomerations were 41.78%, 50.87%, and 54.41%, respectively. The level of economic development, household registration policy, and urban planning are important factors affecting the development of urbanization. (3) The city quality and spatial connection strength of urban agglomeration have significant spatial nonequilibrium distribution characteristics. The total city quality of Shenzhen, Hong Kong, and Guangzhou accounted for more than 41.5% of the total city quality of the city cluster at the same time, and that of the east coast of the Pearl River is much stronger than the west coast. (4) There are "faults" in the socioeconomic location of the 11 cities in the urban agglomeration, with significant polarization. The socioeconomic locations of Jiangmen, Huizhou, and Zhaoqing have been below the reasonable socioeconomic location range in the past 20 years. [ABSTRACT FROM AUTHOR]