Climate Variability and Change—Hydrological Impacts (Proceedings of the Fifth FRIEND World Conference held at Havana, Cuba, November 2006), IAHS Publ. 308, 2006, 401–406.

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Uncertainty in climate change impacts on low flows

Martijn J. Booij, Martijn Huisjes & Arjen Y. Hoekstra

Water Engineering and Management, Faculty of Engineering Technology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands

m.j.booij@utwente.nl

Abstract It is crucial for low flow management that information about the impacts of climate change on low flows and the uncertainties therein becomes available. This has been achieved by using information from different Regional Climate Models for different emission scenarios to assess the uncertainty in climate change for the River Meuse in Northwestern Europe. A hydrological model has been used to simulate low flows for current and changed climate conditions. The uncertainty in the hydrological model is represented by the uncertainty in its parameters. Climate change results in an increase of the average annual discharge deficit (a low flow measure) of about 2.6 10⁸ m³ or 35%. This impact is considerable, resulting in an increase of water shortages in the Meuse basin during low flow periods. The uncertainty in this impact is about 10% as a result of uncertainties in climate change and HBV parameters, and does not disguise the climate change signal.

Key words climate change; discharge deficit; fuzzy objective function; HBV model; low flows; Meuse basin; Monte Carlo analysis; Regional Climate Model; uncertainty

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