Assessing the Impacts of Climate Change on Aquifer Hydrodynamics Using a Coupled Surface–Groundwater Modelling Framework

At present, substantial uncertainty surrounds climate change impacts on groundwater recharge, piezometric heads, and regional hydraulic gradients. This uncertainty is particularly pronounced in deep aquifers in semi-arid environments. Therefore, this study assessed the present and future impacts of climate change on the hydrodynamics of the Valle de León aquifer in central México. This assessment coupled surface-aquifer hydrological processes within a single integrated modelling framework. The methodology integrates the TETIS distributed hydrological model with MODFLOW and incorporates climate projections under different representative concentration pathway scenarios and Artificial Neural Networks within a unified modelling framework. The results indicate a mean annual groundwater drawdown ranging from 1.24 to 1.34 m. The largest drawdowns occur in the south-central part of the aquifer, modifying the regional hydraulic gradients towards the center of the cone of depression. This impact considers a simulated recharge rate corresponding to 12.8% to 13.3% of projected precipitation. The results indicate that projected recharge changes will not offset the persistent piezometric drawdown under the evaluated groundwater extraction rates.