Land Subsidence Hazards: A Case Study of Mexico City

Land subsidence occurs when fluids are withdrawn from the subsurface, causing lowering of the ground elevation. Inadequate management of groundwater resources, where extraction exceeds the natural recharge, has led to overexploitation of aquifer systems worldwide, generating compaction and, therefore, land subsidence. Over urban areas, land subsidence may lead to progressive damage to buildings and critical infrastructure in addition to decreased access to groundwater resources. Satellite geodesy has been used for over two decades for the spatial characterization of land subsidence processes and provides a synoptic view of subsidence in urban areas worldwide. In this section, we present applications of satellite geodesy to the study of land subsidence processes using Mexico City as a natural laboratory. Among others, the applications we present rely on Interferometric Synthetic Aperture Radar (InSAR) for high spatial resolution and Global Positioning System (GPS) or multi-constellation Global Navigation Satellite System (GNSS) for high temporal resolution. We focus on the following applications: (1) synergistic use of satellite geodetic techniques and historical surveys, (2) characterization of the physical processes governing subsidence, (3) analysis of hazards associated with ground subsidence, (4) characterization of subsidence-induced surface faulting, (5) water resources management and aquifer vulnerability, and (6) study of earthquake-subsidence feedback processes. Such applications of satellite geodesy could be implemented elsewhere, including in urbanized deltaic regions (see Sect. 3.3.5).