In 2021, the United Nations climate panel (IPCC) published the new version of the international climate report (the Sixth Assessment Report, AR6). The report presented the latest projections for climate change worldwide. The projections are based on the latest scientific knowledge and most recent climate models. On 9 October 2023, the Royal Netherlands Meteorological Institute (KNMI) presented the new Dutch climate projections – the KNMI’23 scenarios – which formulate the newest IPCC’s global climate projections in terms of the implications for the Netherlands and Meuse and Rhine river basin. These new scenarios show that in this region we will be faced with an acceleration in sea level rise, higher average temperatures, drier summers and wetter winters. At the same time, extreme weather events will occur more frequently, and the summers may experience heavier showers.
At the request of the Ministry of Infrastructure and Water Management in the Netherlands, and in collaboration with Rijkswaterstaat and the KNMI, Deltares analysed the effects of the KNMI’23 scenarios on the discharge regimes of the Rhine and Meuse. All the newly generated discharge scenarios show lower river discharges for the Rhine and Meuse in the summer half-year. The decrease varies between 10 and 30% for 2100. We can now therefore say with more confidence that discharges will be lower in the summer half-year. For both the Rhine and Meuse, the mean winter and spring discharges will be higher. Rising temperatures will lead to the gradual disappearance of the glaciers in the Alps. The thickness of the snowpack in the Alps will also strongly decrease over the course of the century.
Relative Changes in annual average discharge at Lobith-Rhine for the current (Ref = grey) and future climate (future time-horizons on the x-axis).
Relative Changes in annual 7-day minimum discharge at Lobith-Rhine for the current (Ref = grey) and future climate (future time-horizons on the x-axis).
In STARS4Water we will continue this chain of research for the Rhine river basin. We will assess the water use in the basin and confront it with the discharge regimes of the Rhine, now and in the future. This way we will assess the water resources availability risks under both climate change scenarios and socio-economic changes.
For a short summary on the impact of the latest IPCC scenarios on the river discharges of the Rhine and Meuse see: https://www.deltares.nl/en/news/future-discharges-rhine-meuse-lower-summer-higher-winter
The research report itself can be found here: https://publications.deltares.nl/11209265_002_0003.pdf
