Propagation of meteorological drought to groundwater in Europe

Groundwater is a vital natural resource, providing the primary source of freshwater for billions of people across the globe and supporting a diverse range of groundwater-dependent ecosystems. Groundwater drought, which is defined as a prolonged period of below-normal groundwater levels, threatens our reliance on this important resource. This can lead to a wide variety of detrimental impacts on society, the environment and the economy. Despite this, our understanding of groundwater drought has historically been restricted. This can be attributed to the poor availability of in-situ groundwater data, as well as limitations in our understanding of how effectively existing models are able to simulate groundwater drought. By combining newly available in-situ observations from nearly 2,000 wells, provided by the International Groundwater Resources Assessment Centre (IGRAC), with a continental-scale model over Europe, this study addresses this knowledge gap. In addition to characterising groundwater drought, this study evaluates the capability of the model to propagate meteorological droughts to groundwater across the continent, using in-situ observations for validation.