Assessment of the groundwater critical times to predict the impact of climate change on aquifers

As the primary source of freshwater, groundwater plays a critical role in supporting agriculture, sustaining ecosystems, and enhancing climate resilience. In the context of climate change, understanding the processes that influence groundwater is essential to predict how shifting precipitation patterns, altered evaporation rates, and the increasing frequency and intensity of droughts and floods will impact aquifers. However, assessing these processes is complicated by the limited availability of direct observations.

In this work, we aim to investigate the response times of groundwater systems and identify the key processes driving their evolution over time. Understanding the critical time of groundwater is crucial for predicting how groundwater systems will react to climate change, especially in terms of recharge and discharge dynamics.

First, we start by assessing the critical times of groundwater. For this purpose, the spectro-analysis method, whose efficiency has been demonstrated by Houben et al. (2022), is extending to discharge data collected across Europe. Our data spans from 1950 to the present, allowing us to identify critical times across a wide range of scales.

Second, we assess how critical times are influenced by rheological factors, climate conditions, and soil properties. In particular, we describe the relationships between critical times and various parameters selected to characterize the rheology, climate, and soil. This information enables us to identify the aquifers that are primarily controlled by climatic conditions and that may therefore be more vulnerable to climate change in the future.

Finally, we develop a machine learning model to predict the evolution of critical times with the variations in precipitation and evapotranspiration induced by climate change. We are therefore able to bring new constrains regarding the response time of groundwater to climate change for the years to come.

Our work will provide new insights regarding the impact of climate change on groundwater.By identifying the key parameters that control the critical times of groundwater, we can pinpoint the aquifers most vulnerable to climate-related changes. This knowledge allows us to focus on regions where the development of targeted adaptation strategies will be beneficial. These plans could help mitigate the potential risks of groundwater depletion and ensure the resilience of water resources in the face of climate change