Urban sprawl in China: Evidence from multi-temporal urban land products using Landsat data

Urban sprawl characterized by low-density and unplanned pattern of growth has resulted in environmental, economic and social consequences during past decades of urban development. Understanding the trends and patterns of urban sprawl is crucial to the implementation of the 2030 Agenda for Sustainable Development and the framework of sustainable urban development in China. Leveraging on the data-intensive computing infrastructure and the Global Human Settlement Layer framework, we developed a multi-temporal urban land product based on Landsat images for the 1990–2015 period with a five-year interval covering mainland China. The overall accuracy, producer's accuracy and user's accuracy for the mapping results range from 0.91–0.97, 0.8–0.95 and 0.97–0.98, respectively. The Kappa values range from 0.81–0.94. By analyzing the new urban land product in conjunction with population data, the rates, patterns and trajectories of urban sprawl was analyzed in 29 provincial cities quantitatively. We found that the annual expansion area and annual rate of urban land expansion of 29 provincial cities were 555.35km2 and 5.16% respectively during 1990-2015. Among the 29 cities, 26 displayed urban sprawl with 17 displaying sprawl that exceeded the national average level. Our results provide a comprehensive view of urban development in provincial cities, as well as highlighting measures to control urban sprawl and promote resource-efficient land use during urbanization process in China.JRC.E.1-Disaster Risk Managemen