Urban growth rates, trajectories, and multi-dimensional disparities in China

It is undeniable that the process of urbanization in China is a massive phenomenon of scale and speed in humanity history. The relentless march of urbanization poses a critical challenge for creating a comprehensive analysis of the integrated characteristics of contemporary cities. Here, we integrated 30 m continuous and consistent human settlement areas to quantify spatiotemporal dynamics of urban development in 344 prefectural-level cities of China from 1987 to 2017 via Gibrat's law. Results indicated that China had experienced a rapid urbanization process during the past three decades with annual expansion and annual growth rates of 3877.93 km2 and 5.84%, respectively. A key finding was that city growth rate was inversely proportional to initial city size, therefore contradicting Gibrat's law, whose performance was relevant to shifts in urbanization policies. Furthermore, results also highlighted interregional disparities between the southwest and northwest and other regions, as well as intra-regional differences within geographical, urban sizes, and administrative levels. Exploring the validity of Gibrat's law involving the links between city size and growth rate in China deepens our theoretical insights and, more importantly, will make policymakers aware of the need to adopt a holistic approach by considering the uneven nature of urbanization toward better sustainability.