Diagrams showing the two effects of water storage change can be sensed by GPS.
Two effects of water storage change can be sensed by GPS: loading caused by heavy water mass on/below the Earth’s surface deforms the Earth’s crust (a-c) and groundwater extraction leads to a compaction of the material in a groundwater aquifer (d-f). Credit: Razeghi et al. [2022], Figure 2
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Solid Earth

Due to its importance for agricultural irrigation, drinking water supply, and industry, groundwater represents one of the most crucial resources on Earth. The quantification of its changes and availability is of critical significance to assure sufficient fresh water supply especially in vulnerable arid and semi-arid areas.

Razeghi et al. [2022] combine position measurements obtained from a network of GPS receivers with direct observations of groundwater level change from wells to investigate groundwater loss and gain in the Lachlan aquifer, located in central New South Wales (Australia). The position of a GPS receiver is influenced by water storage changes in two different ways: by surface deformation caused by the heavy water mass deforming the Earth’s crust and by compaction of the groundwater aquifers caused by the water from the pores of the surrounding medium. This study focuses on the latter effect while removing the earlier one using additional data.

The authors clearly show the relation of groundwater storage change to extreme climatic events that have taken place during the observation period: one drought (the so-called Millennium drought over 1996-2009), two floods (2012 and 2016), and the strong 2011/2012 La Niña event. Additionally, they quantify the seasonal oscillation in groundwater and find a strong, but time-lagged, correspondence between groundwater recharge and rainfall events.

Citation: Razeghi, M., Tregoning, P., Shirzaei, M., Ghobadi-Far, K., McClusky, S., & Renzullo, L. (2022). Characterization of changes in groundwater storage in the Lachlan catchment, Australia, derived from observations of surface deformation and groundwater level data. Journal of Geophysical Research: Solid Earth, 127, e2022JB024669. https://doi.org/10.1029/2022JB024669

—Annette Eicker, Associate Editor, JGR: Solid Earth

Text © 2023. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.