Groundwater deficit and land subsidence in central mexico monitored by grace and RADARSAT-2

In the context of a lack of reliable data in assessing groundwater overexploitation, space borne sensors bring useful information. While space-borne SAR and gravimetric data are now used to study groundwater, their interoperability is still poorly studied. In this paper, we apply two cutting-edge techniques for the deficit assessment of one of Mexico´s most important watersheds. Space-borne gravimetry is used to extract total and groundwater storage variations from 2003 to 2013 meanwhile InSAR techniques allow the detection of groundwater deficit areas in 2012 and 2013. GRACE reveals the large-scale combined effect of local unconfined aquifer overexploitation revealed by InSAR. Results show a non-anthropogenic water deficit within the northern half of the basin. Important local decreases in groundwater storage are observed by InSAR within several cities of the southern part of the basin, but groundwater storage loss is partially compensated by surface water storage increase.