Urban sprawl in China: Differences and socioeconomic drivers.

China's unprecedented urbanization has resulted in accelerating urban sprawl, which is threatening the country's eco-environmental quality and socioeconomic sustainability. In this study, we integrated urban land census data and urban district population data to examine the pattern of urban sprawl and identify differences, and to investigate the socioeconomic drivers of urban sprawl in China between 2006 and 2014. The results revealed that China has experienced drastic urban sprawl over almost all of the last decade with an average urban sprawl index (USI) of 3.16%. However, the rate of urban sprawl has decreased since 2010. In addition, regional distribution, urban size, and hierarchy have different effects on urban sprawl. In particular, cities with severe urban sprawl should be noted, such as large and medium cities in eastern China, large cities in central China, small-A and large-B cities in western China, and large-A cities in northeast China. We also found that urban sprawl was significantly associated with urban population density, gross domestic product (GDP) per capita, and industrial structure. Further, when the spatial heterogeneity was considered, the driving forces of urban sprawl exhibited different magnitudes and directions. Our results indicate that to formulate effective urban planning and land use policies, decision-makers should seriously consider the differences in urban sprawl depending on region, urban size, and hierarchy.