Ground subsidence geo-hazards induced by rapid urbanization: implications from InSAR observation and geological analysis

Due to the convenient transportation and construction, cities are prone to be situated in areas with flat terrain and unstable sediments, resulting in the concurrence of ground subsidence and urbanization. Here the interaction between geology, anthropogenic processes and ground subsidence geo-hazards were investigated in the Greater Pearl River Delta region of China. Geological evidences and 2006-2010 persistent scatterer data indicate that anthropogenic activities are dominant, although the distribution of river system and Quaternary sediments are also highly related to significant displacements (primarily at a rate of -15 to 15 mm a(-1)). The surface displacements derived by synthetic aperture radar interferometry suggest that the urbanization rhythm has to be routinely monitored. Considering analogous urbanization modes, particularly in developing countries, ground subsidence monitoring together with the analysis of its driving force are critical for geo-hazards early-warning, city planning as well as sustainable urbanization.