[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.