Abstract:

Urban scaling laws depict the nonlinear relationship between urban indicators and population size within an urban system, but its applicability and significance in China's urban system is not clear. This study applied the data of 275 prefecture-level cities in China to explore the scaling relationship between different urban indicators and population sizes. We also attempt to present an empirical analysis of spatio-temporal characteristics of urban scaling exponent (β) from 2000-2017 to enrich the understanding of urban scaling laws. The result shows that as a typical fast urbanizing country, China's urban development conforms to the urban scaling laws but presents some different characteristics from developed countries. There is a significant increasing return to population size of economic output brought by China's urban population agglomeration. Nevertheless, the economies of scale for land use, infrastructure and public service are supposed to be strengthened. Some infrastructure and living facilities indicators have a super-linear or linear relationship with the population size, which are contrary to the expected sublinear regime. The scaling exponents of education, medical and health care and other urban indicators are far below the sub-linear thresholds of developed countries, which reflects the uniqueness in a fast urbanizing country that large cities are given priority to infrastructure construction and the unbalanced development of different-sized cities. The spatial distribution characteristic of scaling exponent reflects the differences in the degree of coordination of urban development, with the most significant differences in Northeast China. We also analyzed the evolution of scaling exponents of major urban indicators over time. Economic increasing returns to population size effect of large cities in China was the most significant in 2009 before falling slightly. Urban land expansion in large cities has continued to accelerate since 2000 and still remains at a high level after 2008. It is urgent to control the extensive urban land expansion and improve land use efficiency, especially in large cities. This study on urban scaling in China contributes to fully understanding the characteristics and evolution of urban systems in the fast urbanizing country. This paper is supposed to provide a support for achieving a balanced regional development and implementing new urbanization development strategies as well.

Key words: urban scaling, allometric growth, scaling exponent, agglomeration benefits, economy of scale