Reinvestigating China’s urbanization through the lens of allometric scaling

Cities are complex systems; we expect the dynamics of the urbanization process to follow the power law, which alludes to the scaling properties of allometry. Urban scaling as a fundamental theory has drawn abundant attention in geography and urban studies literature over the past few decades; yet, there is uncertainty about its applicability in a global context, especially in a fast-transforming urban environment such as China. More importantly, there have been very few studies on the allometric scaling of Chinese cities. This study intends to show the importance of the concept of dynamic evolution in urban systems. We examined the most significant impacts of urbanization are explicitly manifested by the scaling laws, for which the scaling exponent is the key indicator. We applied the scaling law in examining the hypothesis that the actual scaling exponent is stable at different stages of urbanization compared to the static or isometric state. We found that Chinese government-led developments may upset the power law and scaling relations among urban factors but for a short time only. Despite the driving forces in the different categories of cities alter their effects at different urbanization stages; the exponents of growth processes (urban land use area and its population density) obey the laws and rules of self-similarity and scaling coherence. Analyses of double logarithmic linear regression and quantile regression reveal the actual and observed scaling relation of urban system will always evolve to align with the theoretical assumption (β=2∕3), which provides implications on future urban development and planning in terms of city size and urban density.