Studies on the temporal and spatial variations of urban expansion in Chengdu, western China, from 1978 to 2010

Analysis of the urban expansion and its driving forces is critically important for sustainable urban development. The majority of studies on Chinese urbanization have been focused on coastal areas, while with less attention given to urban centers in the west. Chengdu, western China, however is undergoing significant urban growth due to rapid economic development and demographic growth. This research examines urban expansion in Chengdu based on remotely sensed data, urban expansion model, buffer analysis of geographic information system (GIS) and quadrant orientation analysis. Driving forces of urban expansion are also examined based on principle component analysis (PCA). Results indicate that the urbanized area increased by more than 17 times, up to 1910.2 km2 from 1978 to 2010, the urban expansion rate and intensity increased significantly and exhibited the spatiotemporal heterogeneity. We found that urban expansion patterns changed from patch infilling to patch margin expansion, and the expansion direction is primarily toward the northwest, west and southwest. The results suggest an obvious trend of urban expansion in Chengdu witnessed in coastal cities of China. The information provided by this research ultimately helped impact on future policies and plans for better land management and urban sustainability.