Work

Focused groundwater recharge is controlled by landscape and climate

Year: 2025

Type: article

Abstract: Focused groundwater recharge is widely accepted as the dominant recharge mechanism in arid climates. As climates become increasingly arid, groundwater recharge is expected to shift towards focused mechanisms. Yet the magnitude of focused recharge, its spatial distribution and controls across different climate zones remain poorly characterised at the continental scale. Here, we compare historical rainfall tritium with > 1,700 groundwater tritium measurements to assess the likelihood of focused groundwater recharge across the Australian continent. Over 40% of bores assessed show evidence of focused recharge, suggesting that conventional recharge estimates based solely on diffuse mechanisms may substantially underestimate total recharge. We show that appropriate landscape features strongly influence the likelihood of focused recharge. While focused recharge is most common in arid regions, it can occur across all climates where such features are present. As aridity and climate variability intensify, understanding the landscape-climate interactions that enable focused recharge will be critical to sustaining groundwater resources.

Source: Communications Earth & Environment

DOI: 10.1038/s43247-025-03063-w

Authors: Stephen Lee, Dylan J. Irvine, Gabriel C. Rau, Matthew Currell, Carol V. Tadros, Clément Duvert