Title: The rapid disappearance of underground water reserves: a threat to access to fresh water and the emergence of land subsidence problems
Introduction :
Groundwater, found in cracks and pores in permeable rocks called aquifers, is an essential resource for billions of people around the world, especially in regions where precipitation and surface water resources are limited. However, new research reveals rapid depletion of underground water reserves in many countries, jeopardizing access to drinking water, crop irrigation and causing problems of land subsidence.
The results of this study, which is the first of its kind to analyze groundwater levels on a global scale, will allow scientists to better understand the impact of human activity on this valuable underground resource, whether through overexploitation or indirectly through changes in precipitation linked to climate change.
Widespread decline in groundwater levels:
According to the researchers, who analyzed millions of groundwater level measurements from 170,000 wells across more than 40 countries, groundwater levels declined between 2000 and 2022 in 71% of the 1,693 aquifer systems included. in the study. Among them, 36% recorded an annual decline of more than 0.1 meter.
One of the aquifers showing the greatest drop in level is that of Ascoy-Soplamo in Spain, with a median drop of 2.95 meters per year. Several aquifer systems in Iran are also among those experiencing rapid decline in groundwater levels.
Good news and continuing challenges:
The study also highlights some success stories, such as Bangkok, Arizona and New Mexico, where interventions have more effectively regulated water use or redirected water to replenish depleted aquifers. However, these success stories remain rare.
It is also interesting to note that declines in groundwater levels accelerated during the first two decades of the 21st century compared to the period 1980 to 2000 for 30% of the aquifers studied. These accelerations exceed the random fluctuations in water levels expected in the absence of a systematic trend. This highlights the urgency of taking action to preserve this precious resource.
Conclusion :
It is clear that the rapid depletion of groundwater reserves poses a major challenge for many countries around the world. Access to drinking water and crop irrigation are seriously threatened, leading to economic and environmental consequences.. It is essential that policy makers mobilize to raise awareness of the importance of preserving groundwater and put in place regulatory measures to better manage its use. Only in this way can we hope to build resilience and adapt to climate change, while preserving this vital resource for future generations.