Groundwater variability is strongly linked to soil temperature across global aquifers

Groundwater plays a critical role in land-atmosphere interactions by regulating soil moisture and surface energy fluxes, yet its contribution to land-surface processes and heat extremes remains poorly quantified globally. Here, we combine observation-based aquifer records with gridded groundwater table depth (GWD) model outputs (2000–2015) to assess how GWD annual fluctuations covary with soil moisture, evaporation, soil temperature, and heatwave frequency across 1,658 aquifers worldwide. Soil temperature shows the most frequently dominant correlation with GWD among statistically significant, robust relationships (37% of aquifers), followed by evaporation (28%), heatwave frequency (22%), and soil moisture (13%). Aquifers with declining GWD suggest different coupling patterns compared to stable aquifers, with more negative relationships between GWD and evaporation and positive associations between GWD and soil temperature. Our results highlight the importance of incorporating groundwater dynamics into assessments of climate extremes and land-surface processes.

Subjects

groundwater

heatwave

land-atmosphere interaction

soil moisture

DDC Class

551: Geology, Hydrology Meteorology

Funding(s)

United Nations University Hub on Engineering to Face Climate Change at Hamburg University of Technology

Lizenz

https://creativecommons.org/licenses/by/4.0/

Publication version

publishedVersion

Name

Geophysical Research Letters - 2026 - Vogelbacher - Groundwater Variability Is Strongly Linked to Soil Temperature Across.pdf

Type

Main Article

Size

1.94 MB

Format

Adobe PDF

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Groundwater variability is strongly linked to soil temperature across global aquifers