SENTINEL-1 INSAR ASSESSMENT OF PRESENT-DAY LAND SUBSIDENCE DUE TO EXPLOITATION OF GROUNDWATER RESOURCES IN CENTRAL MEXICO

Long stacks of Copernicus Sentinel-1 IW SAR images acquired in 2014-2019 are processed with the Small Baseline Subset ( SBAS) and Permanent Scatterers (PS) Interferometric SAR (InSAR) methods to retrieve present-day land deformation rates across major cities in central Mexico. InSAR-derived subsidence velocity reflects intense groundwater pumping from shallow and deep aquifers for public, agricultural and industrial use, and consequent water level drop and aquifer depletion. In the capital Mexico City, as well as in the valleys of Toluca and Tulancingo, which all belong to aquifers recognized by the National Water Commission as in deficit in 2018, vertical deformation rates are as high as 40, 8 and 6 cm/year, respectively. Most pronounced rates occur mainly on highly compressible, Quaternary clay and silt-rich deposits. Rates of 6.5 cm/year are also observed at well-defined subsiding zones in Puebla, in response to groundwater abstraction for public-urban and industrial use.