Estimation of the groundwater recharge in the aquifer of the Mexico City

This work used several methodologies to evaluate the vertical groundwater recharge from precipitation in the aquifer of the Mexico City, Mexico. Firstly, the spatial variation of the recharge was evaluated and then the temporal variation in the recharge was analyzed in a station located in the center region of the study area. Several independent methods were applied to evaluate recharge: water-table fluctuation method and groundwater flow modeling in steady-state and in transient conditions. The results obtained show that the temporal variation in the recharge, measured in annual periods, was considerably greater than the variability in the precipitation that generated it, for all the applied methods and all the analyzed periods. The annual mean groundwater recharge varied from over 20% of the annual mean precipitation in the upper basin to less than 3% of the precipitation in the plains. A conceptual model of the groundwater system is proposed and its relationship to the recharges in each sector of the basin. This model identifies a regional flow system and local systems of different sizes. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.