Using permanent scatterer InSAR to detect land subsidence and ground fissures: A case study in Xi´an city

The Permanent Scatterers (PSs) SAR Interferometry has become an operational tool in the context of spaceborne SAR interferometry for monitoring surface deformation with millimetric accuracy. In this contribution we presented a case study in Xi´an city for land subsidence monitoring and ground fissures detection by using PS InSAR. We applied a linear regression model to retrieval land subsidence velocity by using a series interferometric phase of the coherent target. For the displacement of ground fissures monitoring, which caused by the nonuniform displacement of land subsidence and fault motion, a time series interferometric analysis of coherent target has been carried out to retrieve the history of displacement. The results archived from ENVISAT ASAR images acquired from 2005 to 2008 has demonstrated the distribution and the magnitude of the land subsidence and ground fissures. We compared the result from PS InSAR with the field surveying data and the results shown good agreement.