Aquifers recharge faster than past estimate
January 18, 2023
Surface water & ag more dependent on groundwater in new model
New research published in the Geophysical Research Letter Journal finds that groundwater basin recharge rates might be double previous estimates.
North American and European scientists present a new climate-based model that uses a global synthesis of regional groundwater data. A calculation model was developed based on available regional groundwater measurement data and precipitation data from six continents.
Climate aridity was identified as a single factor to accurately estimate infiltration. Arid locations have lower recharge rates than humid places. “The aridity-based model results closely mirrored field measurements.” The research indicates that previous models “vastly underestimate recharge rates.”
Findings also show a higher dependence between groundwater and river flow or vegetation, via evapotranspiration. This correlation became evident when the other surface fluxes — such as overland flow, shallow subsurface flows and soil-moisture-fed evapotranspiration – were studied.
“Strengthening the groundwater connection to surface fluxes in these models is essential, given that models are the foundation of our understanding of our planet and underpin present-day environmental science and policymaking,” wrote Berghuijs et al.
Aquifers might recharge more quickly than estimated, groundwater overdraft is too common especially in arid regions, where recharge rates are lower.