Geography of groundwater use and depletion in internationally shared aquifers.

October 27, 2026| Source: Proceedings of the National Academy of Sciences of the United States of America

Transboundary aquifers (TBAs) underlie 35% of global groundwater-irrigated cropland, yet few are covered by formal cooperative arrangements. Whether this limited cooperation is consequential depends in part on where groundwater is used within shared aquifers, because pumping far from international borders may generate little cross-border impact. Combining [Formula: see text]116,000 well observations with global irrigation data across all 426 known TBAs, we assess how groundwater use and depletion differ from comparable domestic systems and how they are distributed relative to international borders. While we find no evidence of greater average depletion in TBAs, depletion is more strongly concentrated toward international borders in shared aquifers and varies substantially across systems. Irrigation is also more intensive and concentrated toward borders in shared aquifers, although much of this pattern is attenuated after accounting for border rivers. Groundwater-supplied irrigation remains more border-proximate after accounting for these rivers. A dyad-level typology distinguishes shared systems according to where groundwater demand is concentrated, linking their potential for cross-border interaction to different management options. These findings suggest that transboundary groundwater governance should be organized around the geography of groundwater use and potential cross-border interactions rather than treating shared aquifers as uniform governance units.

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Historical trends show more declining than increasing species among European pollinators.

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Physical/TechOctober 27, 2026

Extensive glacier loss in the coterminous United States.

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Physical/TechOctober 27, 2026

Scientists disrupt less but more persistently with career aging.

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Reaction-based cryo-EM resolves the continuous conformational spectrum of CTP synthase catalysis.

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Physical/TechOctober 20, 2026

GTP orchestrates CTP synthase via an allosteric effector-cycling mechanism.

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