Megadroughts and Extreme Hydroclimatic Events

New strategies for water management and ensuring the long-term security of the water supply: The European Partnership Water4All - Water Security for the Planet aims to generate new knowledge on this crucial resource and discover innovative approaches to support evidence-based decision-making. The projects are funded by the European Union and national funding agencies such as the FWF.
May 28, 2024
A dried-up riverbed
The arid landscape of the Yeso river basin in the Cajón del Maipo in Chile is a result of the very low rainfall. © ISTA/Vicente Valasco

Two research projects are currently being conducted as part of the Water4All partnership, with Austrian participation and with funding from the FWF and other funding agencies: The “MegaWat” project is dedicated to researching European megadroughts, and the “Interlayer” project is investigating extreme hydroclimatic events.

Megadroughts in Europe

Francesca Pellicciotti, geoscientist and professor at the Institute of Science and Technology Austria (ISTA), is head of the joint project entitled “MegaWat - Megadroughts in the Water Towers of Europe.” From ISTA, Pellicciotti is coordinating an international consortium of researchers from ETH Zurich, the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Futurewater SL (Spain), Utrecht University (Netherlands), and the National Research Council (Italy).

Francesca Pellicciotti says, “Megadroughts are severe, prolonged periods of drought lasting several years. Over the last two millennia, they have occurred on all continents except Antarctica. The megadrought in Chile has been going on for ten years, causing the government to declare a state of emergency. The resulting dramatic water shortages and crop failures are what motivated me to carry out this research work. At the same time, the frequency of droughts in Europe in the early 21st century is higher than it has been for over 2,000 years. Europe could also be facing a future with increasingly dramatic periods of drought. That is why we need continent-wide research into the causes, risks, and effects of megadroughts in the European mountains, or ‘water towers’ as we call them, as well as into management strategies."

Water in the mountains – often in the form of glaciers – is an important source of water for all the areas downstream. While glaciers act as a buffer during shorter droughts – those lasting less than a few years – by providing much-needed meltwater for the summer, little is known about the impact of decades-long megadroughts and the role that glaciers and snow may play in mitigating them. Recent findings indicate that mountain systems could even have an increased water deficit after a series of drought years. “To close this knowledge gap, my team and I at ISTA will be using models to simulate extreme European droughts, and then the effects of future megadroughts on European water towers,” says Pellicciotti. “We hope to learn which of Europe's mountain regions are most vulnerable to extreme droughts in order to better understand how such droughts occur and to develop water management and mitigation strategies for European stakeholders.”