Land subsidence and associated ground fracturing: study cases in central Mexico with ALOS-2 PALSAR-2 ScanSAR Interferometry

Abstract

Land subsidence affects highly developed urban areas in central Mexico, where inhabitants rely on groundwater for about 60 % of water supply and most of the cities are located in volcanic valleys filled with fine and coarse grained sediments. Compaction associated to groundwater depletion in areas with subsoil contacts sediments-rock have caused differential subsidence, ground fracturing and eventually the reactivation of pre-existing faults, depending on the local geological setting. Remote sensing monitoring methods of land deformation have proved to be useful tools to assess this geological hazard for urban planning. We used L-band ScanSAR data from the ALOS-2 PALSAR-2 mission to produce a regional land subsidence map over an area of about 350 km × 350 km over central Mexico. Our results indicate with a remarkable spatial coverage widespread land subsidence over the major cities, which is ranging from more than 30 cm yr−1 in Mexico City to 5–10 cm yr−1 in other locations.