Monitoring of ground subsidence in Chengdu Plain using SBAS-InSAR

After Wenchuan earthquake , the aftershocks happened frequently .Coupled with the rapid development of cities, they are likely to cause ground subsidence .So monitoring the surface of Chengdu Plain and obtaining the deformation information could provide scientific basis for the relevant decisions .In this paper , based on ENVISAT ASAR data, the authors monitored the ground subsidence of Chengdu Plain from 2008 to 2010 using SBAS-InSAR technology .The results show that the average surface deformations were between -8 to 14 mm in major cities in the Chengdu Plain during the monitoring period , the deformation is not prominent , and the western part of the plain showed a uplift trend caused by earthquake .The subsidence area in the north of the Chengdu City and south to the Deyang City was up to -22 mm with the expansion of the subsidence area .The monitoring results were validated by measured data and the accuracy is 2.9 mm .The Chengdu Plain has no regional tectonic setting of subsidence and has abundant groundwater resources , so the natural cause of subsidence is not obvious; the city building activity might be the major cause of subsidence .