The Groundwater Drought Initiative (GDI): Analysing and understanding groundwater drought across Europe

• Published in: Proceedings of the International Association of Hydrological Sciences Vol. 383; pp. 297 - 305
• Main Authors: Brauns, Bentje, Cuba, Daniela, Bloomfield, John P., Hannah, David M., Jackson, Christopher, Marchant, Ben P., Heudorfer, Benedikt, Van Loon, Anne F., Bessière, Hélène, Thunholm, Bo, Schubert, Gerhard
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Gottingen Copernicus GmbH 16.09.2020; Copernicus Publications
• Subjects: Aquifers; Arid environments; Arid zones; Aridity; Catchment area; Decision analysis; Drinking water; Drought; Ecosystems; Environmental impact; Groundwater; Groundwater data; Groundwater levels; Groundwater management; Hydrologic cycle; Hydrologic data; Initiatives; Monitoring; River catchments; Security; Semi arid environments; Semiarid environments; Stream flow; Surface water; Temporal variations; Water management; Water security; Water shortages; Water supply; Water table; United Kingdom > UK; Europe
• ISSN: 2199-899X; 2199-8981; 2199-899X
• DOI: 10.5194/piahs-383-297-2020

In Europe, it is estimated that around 65 % of drinking water is extracted from groundwater. Worryingly, groundwater drought events (defined as below normal groundwater levels) pose a threat to water security. Groundwater droughts are caused by seasonal to multi-seasonal or even multi-annual episodes of meteorological drought during which the drought propagates through the river catchment into the groundwater system by mechanisms of pooling, lagging, and lengthening of the drought signals. Recent European drought events in 2010–2012, 2015 and 2017–2018 exhibited spatial coherence across large areas, thus demonstrating the need for transboundary monitoring and analysis of groundwater level fluctuations. However, such monitoring and analysis of groundwater drought at a pan-European scale is currently lacking, and so represents a gap in drought research as well as in water management capability. To address this gap, the European Groundwater Drought Initiative (GDI), a pan-European collaboration, is undertaking a large-scale data synthesis of European groundwater level data. This is being facilitated by the establishment of a new network to co-ordinate groundwater drought research across Europe. This research will deliver the first assessment of spatio-temporal changes in groundwater drought status from ∼1960 to present, and a series of case studies on groundwater drought impacts in selected temperate and semi-arid environments across Europe. Here, we describe the methods used to undertake the continental-scale status assessment, which are more widely applicable to transboundary or large-scale groundwater level analyses also in regions beyond Europe, thereby enhancing groundwater management decisions and securing water supply.