Two Decades of Human and Climate Induced Groundwater Storage Shifts in Brazil

Abstract Brazil holds the world’s largest reserves of renewable freshwater—the country contributes ~ 20% of the planet’s inland water discharge into the oceans¹—, yet recurrent water crises expose its growing vulnerability under extreme events². While surface water dominates national supply, vast groundwater reserves remain underused and poorly monitored, representing a critical but untapped resource for climate resilience and national security. Here, we present a data-driven spatiotemporal reconstruction of Brazil’s groundwater behavior over the past two decades, integrating multi-satellite and in situ data into an artificial intelligence modeling framework. Results reveal groundwater variability, recharge, and trends under climatological and anthropogenic stressors across the nation’s ~ 8.5 million km² of land. Brazil’s 2002–2023 averaged aquifer recharge is 223 mm—12% of annual precipitation—totaling ~ 1,900 km³ of annual renewable groundwater volume. Persistent depletion or no recharge is observed in heavily exploited aquifers in eastern Brazil, further impacted by prolonged droughts¹,² and climate oscillations. Such aquifers present depletion trends mirroring patterns observed in intensively exploited aquifers in Bangladesh³, India⁴, Iran⁵ and the U.S.⁶,⁷. As a world’s major breadbasket, Brazil plays a vital role in global food security. Results presented here are therefore critical to the nation’s sustaining agricultural productivity under increasing climate stress.