Variability of Water Balance under Climate Change Scenarios. Implications for Sustainability in the Rhône River Basin

The Rhône basin is considered a complex river socio-ecological system, which houses numerous socioeconomic activities closely linked to its river courses, as well as competition between the different users of these water resources. Likewise, its increasing vulnerability to climate change highlights the need to assess the potential effects of a set of climate scenarios to assist the management of these resources. With this aim, we have analysed the effects of five scenarios on different environmental zones of the basin characterised by altitudinal features, using the “Water Yield” hydrological module of the InVEST model. The model outputs show that the Rhône basin will have significant discharge water variations and changes in the seasonality of the hydrological regime, being able to trigger serious economic and environmental effects under the simulated scenarios. Regarding these altitudinal environmental zones, results show important differences in the final water balance, resulting in the mountain and subalpine zones being the most affected by these scenarios. The uncertainty in the availability of water resources and the need for its sustainable management will require the establishment of important adaptations to the new challenges imposed by these scenarios, particularly in alpine zones, due to its sensitivity and fragility to climate change.