Climate change impacts on discharges of the Rhone River in Lyon by the end of the twenty-first century: model results and implications

Abstract

We assess possible modifications in the hydrological behaviour of the Rhone River and its tribu- taries at Lyon (France). We identify changes during the late-twentieth century based on observations and charac- terise potential impacts of climatic changes on river response by the end of the century. Different scenarios of the latest generation of IPCC AR5 CMIP5 and hydrological modelling were used and included two scenarios for future outlet discharge of Lake Geneva (Switzerland). We show that discharges in the Rhone basin are likely to decrease significantly by the end of the century and that the sea- sonality of run-off will change substantially as well. In addition, projections point to smaller discharge during low flows, but higher low flows in its sub-basins. Regarding floods, high flows exhibit a general tendency to decrease, whereas potential upwards can be observed for the more extreme floods (less frequent). The approach reported in this paper will help to reflect on the governance modalities of a transboundary river such as the Rhone, especially when water management depends on concession contracts, which are usually granted for several decades and typically last between 60 and 90 years

Ce jour-là, à Genève, les moulins sur le Rhône auraient pu tourner à l'envers… La crue de l'Arve des 1-5 mai 2015

“…Enfin, d'une façon générale, la connaissance actuelle du lien entre la variabilité des événements extrêmes et le changement climatique touche aux limites des concepts et méthodes scientifiques d'aujourd'hui. S'il est montré que les débits du Rhône à la sortie du Léman sont susceptibles de diminuer d'ici la fin de ce siècle (Ruiz-Villanueva et al, 2015), ce qui pourrait renforcer les phénomènes d'étale à la sortie du Léman, la question de l'évolution de la fréquence et de l'intensité des évènements de crue de l'Arve reste ouverte.…”

Interdisciplinary approaches for analysing governance challenges across the Rhône basin

“…Through this issue, our aim is to contribute to a better understanding of the multiple social-ecological dynamics at play at different points of the basin and therefore to build a more comprehensive picture of the resilience of the basin as a whole. Ruiz-Villanueva et al (2014) analyse the effects of climate change on the Rhône River mean flows from 1960 till 2100. Authors focus on the perimeter going from Lake Geneva to the city of Lyon, which is highly relevant as it concerns the transboundary perimeter, which regroups coordination issues between Switzerland and France.…”

Parsimonious Modeling of Snow Accumulation and Snowmelt Processes in High Mountain Basins

“…The TETIS model is a free software available at http://lluvia.dihma.upv.es/ES/software/ software.html. This model has been implemented in a high number of basins in Spain [24] and Latin America [25], and also there are applications in France [26], USA [27], UK [28], and China [29].…”