[Table 4]
The urbanization level varied with 368 Prefecture-level units but presented similar spatial distribution pattern (Fig 3). The Beijing-Tianjin-Hebei (BTH, hereafter), Yangtze River Delta (YRD, hereafter), and Pearl River Delta (PRD, hereafter) areas were significantly better than other regions in all aspects of urbanization (i.e., population, economy, space and society). Moreover, provincial capitals and municipalities directly under the central government also exhibited higher urbanization levels, such as Tianjin, Wuhan, Chongqing, Nanjing, Hangzhou, Chengdu, etc. However, the values varied from period to period (Fig S1~Fig S5). Cities along the Yellow River basin, the Yangtze River basin and coastal areas became the main population agglomeration areas (Fig 3a). The population gravity center was in the north before 2005, and then moved to the center and south (Fig S1). Economic urbanization experienced a stage from local development to overall improvement, conversely, the northeast region exhibited a decline (Fig S2). Additionally, cities with high spatial urbanization levels were mainly concentrated in Henan Province, Chongqing City, and the middle and lower reaches of the Yangtze River (Fig 3c). In particular, the spatial urbanization level was significantly higher in 2005 than in other periods (Fig S3). Furthermore, the social urbanization level of 368 research units increased over time, with the values being higher in the east and the center than in the west (Fig 3d, Fig S4). In addition, UI exhibited similar spatial distributions with spatial urbanization (Fig 3c, e). In 2020, although the urbanization level of most cities was mediate or lower, it displayed relatively balanced wholly (Fig S5).
[Figure 3]
The least-square linear regression model was applied to analyze the spatial-temporal variations of PU, EU, SU, SCU and UI from 2000 to 2020 for each pixel, and the change trend was described by the modeled slope. Ultimately, five variation levels were divided as follows: significant decrease, slight decrease, no significant change, slight increase and significant increase (Fig 4). The population urbanization was dominated by slight increase and slight decrease, and the latter was in the minority, mainly distributed in Provinces such as Heilongjiang, Hebei, Xinjiang, Qinghai, Guangxi, Guangdong, etc. (Fig 4a). According to Fig 4b, the economic urbanization level in the region west of the Hu Line and in the three northeastern provinces (i.e., Heilongjiang, Jilin, Liaoning) decreased slightly, and the region east of the line mainly slightly increased. In particular, the economic urbanization level of individual provincial capitals increased significantly (Fig 4b). Furthermore, nearly half of the cities exhibited a declining spatial urbanization level, mainly in provinces and autonomous regions such as Gansu, Shaanxi, Tibet Autonomous Region, Henan, Hubei, the Guangxi Zhuang Autonomous Region, etc. (Fig 4c). In terms of social urbanization, most cities increased slightly, except for Beijing, Xi’an, Chongqing, Wuhan, Nanjing, Guangzhou which showed a significant increase (Fig 4d). In addition, the change rate of comprehensive urbanization index from 2000 to 2020 varied significantly (Fig 4e). Nearly 1/3 of the cities showed a downward trend, and nearly 1/5 of the cities increased significantly, mainly in Shandong Province, the middle and lower reaches of the Yangtze River and the Sichuan-Chongqing urban agglomeration.