Understanding global groundwater-climate interactions

Christopher E Ndehedehe; Oluwafemi E Adeyeri; Alex O Onojeghuo; Vagner G Ferreira; Ikechukwu Kalu; Onuwa Okwuashi

doi:10.1016/j.scitotenv.2023.166571

Understanding global groundwater-climate interactions

Sci Total Environ. 2023 Dec 15:904:166571. doi: 10.1016/j.scitotenv.2023.166571. Epub 2023 Aug 28.

Authors

Christopher E Ndehedehe¹, Oluwafemi E Adeyeri², Alex O Onojeghuo³, Vagner G Ferreira⁴, Ikechukwu Kalu⁵, Onuwa Okwuashi⁶

Affiliations

¹ School of Environment & Science, Griffith University, Nathan, QLD 4111, Australia; Australian Rivers Institute, Griffith University, Nathan, QLD 4111, Australia. Electronic address: c.ndehedehe@griffith.edu.au.
² Australian Rivers Institute, Griffith University, Nathan, QLD 4111, Australia; School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region.
³ JOLEXY Enviromental Services Limited, Edmonton, Alberta, Canada.
⁴ School of Earth Sciences and Engineering, Hohai University, Nanjing, China.
⁵ School of Environment & Science, Griffith University, Nathan, QLD 4111, Australia; Australian Rivers Institute, Griffith University, Nathan, QLD 4111, Australia.
⁶ Department of Geoinformatics and Surveying, University of Uyo, P.M.B. 1017, Uyo, Nigeria.

PMID: 37647947
DOI: 10.1016/j.scitotenv.2023.166571

Abstract

Global warming is emerging as an important predictor of water availability and future water supplies across the world through inducing the frequency and severity in hydrological extremes. These extremes (e.g., drought) have potential impacts on groundwater, environmental flows, as well as increase social inequalities (limited access to water by the poor), among a range of other issues. Understanding the influence of global climate on groundwater systems is thus critical to help reshape global water markets through policies underpinned by the knowledge of climatic processes driving the water cycle and freshwater supply. The main aim of this study is to improve understanding of the influence of climate variability on global groundwater using statistical methods (e.g., multi-linear regression and wavelet analyses). The response of groundwater to climate variability are assessed and the feasibility of identifying climatic hotspots of groundwater-climate interactions are explored (2003-2017). Generally, climate variability plays a major role in the distribution of groundwater recharge, evidenced in the groundwater-rainfall relationship (r ranging from 0.6 to 0.8 with lags of 1-5 months) in several regions (Amazon and Congo basins, West Africa, and south Asia). Some of the areas where no relationship exists coincide with major regional aquifer systems (e.g., Nubian sand stone in north Africa) in arid domains with fossil groundwater. Our results also show that groundwater fluxes across the world are driven by global climate teleconnections. Notable among these climate teleconnections are PDO, ENSO, CAR, and Nino 4 with PDO showing the strongest relationship (r= 0.80) with groundwater in some hotspots (e.g. in South America). The explicit role of the Pacific ocean in regulating groundwater fluxes provides an opportunity to improve the prediction of climate change impact on global freshwater systems. As opposed to remarkably large productive hydrological systems (Amazon and Congo basins), in typically arid domains, groundwater could be restricted during prolonged drought, constraining the persistence of surface water in the maintenance of a healthy surface-groundwater interactions.

Keywords: Climate teleconnections; Droughts; Hydrology; Recharge; Surface water.