Rapid urbanization and its driving mechanism in the Pan-Third Pole region.

Rapid urbanization increasingly influences ecosystem stability and regional urban sustainability. Pan-Third Pole cities located in high-altitude regions around the Tibetan Plateau, Pamir, and Indo Kush have experienced rapid urbanization during the last few decades; however, an understanding of the urbanization rate and its driving mechanism remains lacking. Here, we investigate the urban land transformation dynamics of 14 major Pan-Third Pole cities and analyse their driving factors over two periods (2000-2010 and 2010-2017) based on the interpretation of historical Google Earth imagery using deep learning techniques. Our results show that the urbanized area has increased from 2809 km(2) to 4380 km(2), with an annual growth rate of nearly 3% during 2000-2017, which is probably the largest increase in the world. The analysis of potential driving factors reveals that population growth dominates urban expansion, elevation is a constrained topographical factor, and neighbourhoods to roads facilitate urbanization. Our findingswould benefit policymaking for urban sustainability in the most fragile region on Earth. (C) 2020 Elsevier B.V. All rights reserved.