The Explore 2070 project, aimed at:

• evaluating the impacts dof climate change on water resources by 2070, for anticipating the main challenges at stake and prioritize risks,
• elaborating and evaluating adaptation strategies in the domain of water by determining the adaptation strategies the most appropriate while minimising risks.

This project was lead by the Water and Biodiversity direction of the Ministery for ecology, with the participation of ONEMA, CETMEF, water agencies, DREALs, CGDD, DGEC and DGPR. It gathered a hundred of experts coming from research institutes and specialised consultants.

The participation of Irstea, in particular the HYDRO team in Antony, focused on the Surface water working group. The aim was to assess the impact of climate change of French river discharges. HThe GR4J hydrological model of Irstea was applied as well as the SIM model from Météo-France.

Over France, results indicate (look at the synthesis report to know more):

• a likely increase of mean air temperatures from +1.4 °C to + 3 °C depending on simulations
• an uncertain evolution of precipitations, most of models agreeing on a decreasing trend during summers, from -16 % to -23 %
• a significant overall decrease of mean annual discharges, from 10 % to 40 % depending on simulations, especially strong on Seine-Normandie and Adour-Garonne
• for a wide majority of rivers, a decrease of low flow values even stronger than for annual discharges
• more heterogeneous and less strong evolution of floods.