Research Article Groundwater and Subsidence Modeling Combining Geological and Multi-Satellite SAR Data over the Alto Guadalentín Aquifer (SE Spain) Pablo Ezquerro, 1,2 Carolina Guardiola-Albert, 1,3 Gerardo Herrera, 1,2,4,5 José Antonio Fernández-Merodo, 1,2,4 Marta Béjar-Pizarro, 1,2,4 and Roberta Bonì 6 1 Geohazards InSAR Laboratory and Modeling Group (InSARlab), Geoscience Research Department, Geological Survey of Spain (IGME), Alenza 1, 28003 Madrid, Spain 2 Spanish Working Group on Ground Subsidence (SUBTER), UNESCO, 03690 Alicante, Spain 3 Environmental Geology and Geomathematics, Geoscience Research Department, Geological Survey of Spain (IGME), Alenza 1, 28003 Madrid, Spain 4 Research Partnership Unit IGME-UA on Radar Interferometry Applied to Ground Deformation (UNIRAD), University of Alicante, P.O. Box 99, 03080 Alicante, Spain 5 Earth Observation and Geohazards Expert Group (EOEG), EuroGeoSurveys, Te Geological Surveys of Europe, 36-38 Rue Joseph II, 1000 Brussels, Belgium 6 Department of Earth and Environmental Science, University of Pavia, Via Ferrata 1, 27100 Pavia, Italy Correspondence should be addressed to Pablo Ezquerro; p.ezquerro@igme.es Received 28 April 2017; Revised 19 July 2017; Accepted 25 October 2017; Published 18 December 2017 Academic Editor: Timothy H. Dixon Copyright © 2017 Pablo Ezquerro et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In the current context of climate change, improving groundwater monitoring and management is an important issue for human communities in arid environments. Te exploitation of groundwater resources can trigger land subsidence producing damage in urban structures and infrastructures. Alto Guadalent´ ın aquifer system in SE Spain has been exploited since 1960 producing an average piezometric level drop of 150 m. Tis work presents a groundwater model that reproduces groundwater evolution during 52 years with an average error below 10%. Te geometry of the model was improved introducing a layer of less permeable and deformable sof soils derived from InSAR deformation and borehole data. Te resulting aquifer system history of the piezometric level has been compared with ENVISAT deformation data to calculate a frst-order relationship between groundwater changes, sof soil thickness, and surface deformation. Tis relationship has been validated with the displacement data from ERS and Cosmo- SkyMed satellites. Te resulting regression function is then used as an empirical subsidence model to estimate a frst approximation of the deformation of the aquifer system since the beginning of the groundwater extraction, reaching 1 to 5.5m in 52 years. Tese rough estimations highlight the limitations of the proposed empirical model, requiring the implementation of a coupled hydrogeomechanical model. 1. Introduction Aquifer overexploitation and groundwater reservoirs deple- tion represent a problem impacting large areas worldwide [1, 2], especially over arid and semiarid areas. Agricultural and urban use of aquifers resources, especially during dry seasons, has led to water mining which ofen leads to reservoir depletion and saline intrusion [3, 4]. Tese problems have taken more relevance in a global climate change context that predicts intensive dry seasons over vulnerable areas [5, 6]. Ground subsidence, accompanying aquifer system depletion, is a common hazard that has important social and economic repercussions [7]. Te efect of piezometric level changes over aquifer systems and associated consolidation can be explained by Terzaghi’s efective stress principle [8]. Tis type of soil deformation may produce building and infrastructure damage [9, 10], changes in fooding risk areas, or loss of water storage capacity [11]. In order to prevent major problems, Hindawi Geofluids Volume 2017, Article ID 1359325, 17 pages https://doi.org/10.1155/2017/1359325