MOSARH21 (2015-2017)

This projects aimed at making an assessment of future impacts of climate change on discharge of the French part of the Rhine tributaries (Moselle-Sarre-Rhine), by using the last climate simulations produced with regards to the fifth Assessment Report of IPCC. An approach using two hydrological models was implemented and used jointly with an ensemble of climate projections.

The impacts were quantified on the basis of several indicators linked to regimes, flood and low flows. A specific focus has been put on the quantification of uncertainties associated to the modelling chain. The results were compared to those obtained from previous impact studies done on the basin.

The evolutions of average annual streamflows indicate a slight rise, which could even become important for the radiative scenario RCP 8.5 (the most pessimistic one in terms of climate warming). The flood alea should intensify in the near future (2021-2050). On the opposite, in the far future (2071-2100), the evolution of floods indicators is more uncertain, as the hydrological projections diverge. The low flows could be decreasing in the near future. Their evolution in the far future is more uncertain, going from drastic decrease to sensible rise according to the chosen scenario.

The results were compared to those obtained in the framework of previous impact studies done on the basin. Accordingly to methodological differences and obtained results, we can conclude that the previous studies are consistent with the conclusions of the MOSARH21 project.