Document Type
Article
Publication Date
5-2025
Publication Title
PNAS Nexus
Disciplines
Biology
Abstract
Groundwater depletion in agricultural-dominated regions is attributed to climate and irrigation withdrawals that support crop production. However, despite decades of effort, knowledge gaps remain in understanding the relative influence of drought and crop production on groundwater levels at the continental scale. Here, utilizing empirical observations, we simultaneously track how long-term trajectories of groundwater levels, crop production of seven crops, and drought have evolved over time, and then integrate these observations with a causality-based attribution framework to unravel the relative impact of drought and crop production on groundwater levels across the contiguous United States (CONUS). We find a dominant pattern of decreases in groundwater levels with increases (25-61%) or no change (1-15%) in crop production across the CONUS. We estimate a significant (P < 0.1) causal influence of crop production and drought on groundwater levels in similar to 32% (n = 101) and similar to 20% (n = 62) of counties, respectively. Further, the extent of impact of crop production on groundwater varies with region and is most pronounced for cotton (42%, n = 18) and wheat (17%, n = 39). The memory effects of crop production (median: 7 years) and drought (median: 3 years) on groundwater levels imply that their impact could last much longer than the annual crop production cycle or the drought exposure period. Further, these findings allude to circular causality between groundwater and crop production, where both entities depend on each other at different time scales. Our work builds on past work and contributes to the growing understanding of food security and groundwater availability to manage these commodities to meet future demands.
DOI
10.1093/pnasnexus/pgaf129
Version
Publisher's PDF
Recommended Citation
Singh, Nitin K.; Saia, Sheila M.; Bhattacharya, Ruchi; Ajami, Hoori; and Borro, David M., "Unraveling the Causal Influences of Drought and Crop Production on Groundwater Levels Across the Contiguous United States" (2025). Biological, Geological, and Environmental Faculty Publications. 290.
https://engagedscholarship.csuohio.edu/scibges_facpub/290
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Volume
4
Issue
5
Comments
N.K.S. was supported by Auburn University (Start-up). R.B. was supported by Cleveland State University (Start-up)