The objective of this project is to study the influence of climate change, through changes in direct anthropogenic constraints, on the water resource in the Seine watershed. This project aims beyond the hydrological implications of climate change; it also intends to analyse the direct and indirect effects of climate change on biogeochemical fluxes and on the quality of aquatic ecosystems.

The research is based on an analytical approach, which begins with the disconnection of the various components of the system and then proceeds with the analysis of their superimposed responses. We will thus consider separately: (1) the forcings of the hydrosystem, the trends of which will be outlined using general circulation models in the case of climate, and specially-devised prospective methods for other constraints; (2) the hydrosystem itself (the surface hydrographic network, including its associated reservoirs, aquifers, and cultivated catchment area), the processes of which will be simulated using the models from Piren-Seine.

It will be possible, with these models, to explore the impact of a variety of superimposed climate change scenarios and other constraints, and to identify the system’s breaking points in order to characterize the vulnerability of the Seine hydrosystem as a whole. This project also seeks to bring the analysis of the consequences of climate change within the framework of a wider prospective reflection taking into account other factors of change induced by human activities in this already man-shaped system. Particular attention has been paid to the agriculture sector (of which an explicit model is being developed), but other direct anthropogenic constraints have also been studied. Among them, we will distinguish those likely to be influenced by climate change (air conditioning, industrial water uptake for cooling purposes, water treatment, recreational activities, etc.) from those assumed to be independent of climatic trends (demography, urbanization, etc.).

A key step in this part of the research would be to estimate the order of magnitude of climate change impacts in comparison to impacts produced by other trends detected in the Seine system.

The last line of research in this project is to consider, beyond the ‘physical’ impacts of climate change on the hydrosystem, the consequences of climate change in terms of water management. This aspect, aimed at the provision of operational guidelines, was developed in collaboration with the professional water resource managers, who are partners in the Piren-Seine programme.

Website

http://www.sisyphe.jussieu.fr/Internet/gicc/index.html