Exploring the impact of low-frequency drought events in the Netherlands

19:00 Tuesday 28 May




Marjolein Mens (Netherlands) 1; Joost Delsman (Netherlands) 1; Ferdinand Diermanse (Netherlands) 1; Corine Ten Velden (Netherlands) 1; Martijn Visser (Netherlands) 1; Cor-Jan Vermeulen (Netherlands) 2; Bas De Jong (Netherlands) 3

1 - Deltares; 2 - HKV Consultants; 3 - Ministry of Infrastructure and the Environment

As exemplified by the recent dry summer of 2018, droughts can have a major impact on agriculture, shipping, industry and drinking water supply in the Netherlands. The recent drought also showed that the most effective water management decisions during a drought event depend on how the drought develops over time, and on the co-occurrence of large precipitation deficit and low river discharge.

In the policy domain the question arises which drought situations to prepare for. More extreme events may occur in the future under climate change. Although the frequency of occurrence of future drought events remains very uncertain, it is recommended to analyse the potential impact of other events and more extreme events than have occurred in the past, in order to be well-prepared for a variety of potential future events.

In this presentation we will show the potential impacts of extreme drought events, having estimated return periods of more than 100 years. Five synthetic events were simulated with a complex and detailed model and quantify potential water shortages, agricultural damage, and depletion of the main fresh water reservoir ‘IJssel lake’. In addition, a rapid assessment model was used to analyse 1000 synthetic but plausible events to obtain more insight into both probabilities and impacts of such events. Results show a large range of drought impact from events that have similar return period, highlighting that drought impacts largely depend on specific hydrological development over time. Furthermore, the results demonstrate the added value of synthetic time series to ‘stresstest’ the water management system in support of climate change adaptation.

The research is carried out within the European IMPREX project.