Groundwater Use as a Climate Change Adaptation Strategy in Six Prioritized Regions of Colombia: An Integrated Assessment Using Remote Sensing and Hydrogeological Characterization

Climate change poses increasing threats to water security in Colombia, particularly in regions where groundwater monitoring remains limited. This study evaluated groundwater potential as an adaptation measure across six strategic regions covering 16.5% of Colombian territory: Tolima-Huila, Boyacá-Santander, Caribe Oriental, Caribe Occidental, Cauca-Nariño, and Meta-Vichada. We integrated a multi-source methodological approach combining conceptual hydrogeological characterization, potential recharge estimation using the Thornthwaite–Mather method, and groundwater storage anomaly analysis through GRACE satellite data coupled with the GLDAS model for the period 1992–2022. Potential recharge was evaluated for the historical period (1992–2022) and projected under SSP2-4.5 and SSP5-8.5 climate change scenarios (2040–2070) using global circulation models. Results revealed significant regional heterogeneity, with critical recharge reductions reaching 230 mm/month in Cauca-Nariño and 202 mm/month in Meta-Vichada under SSP5-8.5 compared to the historical baseline. Positive groundwater storage anomalies identified sectors with exploitation potential even in low-recharge areas, particularly in northern Tolima-Huila. Priority zones were defined for implementing adaptation measures, including artificial recharge, strategic use of fractured media, and strengthened water governance. The proposed methodology provides replicable technical foundations for climate-resilient planning at regional and local scales, which is particularly relevant for contexts with scarce hydrogeological information.