Thirty-year expansion of construction land in Xi'an: Spatial pattern and potential driving factors

China has witnessed rapid urban growth over the past 3 decades resulting in vast ecological and environmental issues. Understanding the process of construction land (Cl) expansion and its driving factors are crucial for urban growth planning and management to mitigate the adverse impacts of such growth. Based on remote sensing data for 1975, 1990, 2000, and 2008, we monitored Cl changes in Xi'an City over the past 3 decades. The land use transform matrices were calculated. The results showed that from 1975 to 2008, remarkable changes in Cl occurred in Xi'an City. Over the past 30years, the Cl concentration spread from one centre to multiple centres. The elevation, slope, traffic condition, wetland, education industry, rebuilding of city village, and historical and cultural sites may be the most important driving forces. We therefore recommend discussing the interactions of these potential driving factors within the Cl sprawl.