Surface Deformation Evolution in the Pearl River Delta Between 2006 and 2011 Estimated from the ALOS1/PALSAR

Abstract

This study monitors the land subsidence of the whole Pearl River Delta (PRD) (area: ~40,000 km2) in China using the ALOS1/PALSAR data (2006-2011) and the SBAS-InSAR method. We also analyze the relationship between the subsidence and the coastline change, river distribution, geological survey data as well as the geomorphology data. The results show that (1) the land subsidence with the average velocity of 50 mm/year occurred in the low elevation area in the front part of the delta and the coastal area; (2) the areas along rivers also suffered from surface subsidence, due to the fragile geological structure and frequent human interference; (3) the geological evolution is the intrinsic factor of the surface subsidence in the PRD, but human interference (reclamation, ground water extraction and urban construction) extend the subsiding area and accelerate the subsiding rate. This study would provide technique supports for the surface deformation and disaster warning in delta regions.