Institute for Groundwater Research, University of Guelph
Abstract
EbookRegional land subsidence accompanying groundwater abstraction in the Toluca aquifer-system is a challenge for managing groundwater resources and mitigating associated hazards. In order to improve this situation, groundwater management scenarios for the Toluca Valley are examined with a three dimensional groundwater flow model coupled to a one dimensional compaction module. Subsequently, the land subsidence evolution was investigated by integrating SAR interferometry and geological and hydrogeological data to shed insight on the underlying processes governing subsidence. The results indicate that continuing at current rates of water consumption will lead to subsidence of more than 1.6 m over a 40 year period (2010–2050). Completely stopping exports to Mexico City is not the most important factor in controlling subsidence because the pumping system is mostly located in regions with low clay content, where subsidence is lower. However, decreasing exports by half and relocating the pumping centres to low-clay-content areas does have a positive effect on the overall water budget and subsidence. From 2003 to 2016, groundwater level declines of up to 1.6 m/yr, land subsidence up to 77 mm/yr, and major infrastructure damages are observed. Groundwater level data show highly variable seasonal responses according to their connectivity to recharge areas. However, the trend of groundwater levels consistently range from −0.5 to −1.5 m/yr regardless of the well location and depth. By analysing the horizontal gradients of vertical land subsidence, we provide a potential ground fracture map to assist in future urban development planning in the Toluca Valley. The approach taken in this study could be applied to their locations with similar problems in order to determine the most viable option for water supply.CONACyT,
Institute for Groundwater Research, University of Guelph
UAE
