Multi-sensor persistent Scatterer Interferometry land subsidence monitoring in the Alto Guadalentín Basin (Spain)

In this work SAR data obtained from ERS-1/2 & ENVISAT (1992-2007), ALOS PALSAR (2007-2010) and COSMO-SkyMed (2011-2012) sensors have been processed using the Stable Point Network (SPN) technique for monitoring the Alto Guadalentín Basin (southern Spain). This area is affected by the highest subsidence rate measured in Europe (>10 cm/yr-1) related to long-term exploitation of the aquifer system. The PSI data obtained from the different satellites from 1992 to 2012 have been validated with two available GPS time-series located in the study area and compared with some predisposing and triggering factors as geological units, isobaths of Plio-Quaternary filling, soft soil thickness and piezometric level. The main conclusions derived from the performed analysis are next: a) subsidence processes are directly related to soft soil thickness distribution; b) land subsidence distribution is the same over the monitored period, although a deceleration has been recorded during the period 2011-2012; c) deformation rates are not correlated with piezometric level trend, probably due to a delay time between piezometric level variations and ground deformations