Developing climate change adaptation strategies in agricultural drainage basins (ESACC-AGRO)

Context and challenges

As a result of future climate change, most modelling results agree that hydrological regimes could evolve towards lower flows in summer and more uncertain flows in winter by 2050 in France. Agriculture currently accounts for almost 80% of net water consumption in summer in France. As a result of climate change, agriculture will tend to exert increased pressure on resources, the viability and acceptability of which are the subject of heated debate.

In this context, this project proposes to develop and apply a multi-model agro-hydrological approach in order to conduct an integrated evaluation of climate change adaptation and mitigation strategies in response to the expectations of territorial stakeholders. Two contrasting drainage basins, Aveyron and Seille, will serve as case studies for this project, making it possible to determine whether the conclusions obtained can be applied across the board.

Agro-hydrological modelling will make it possible to simulate the relationships between irrigated and rain-fed agriculture and the objectives of water resource conservation in a context of climate change. This type of modelling will make it possible to better anticipate and limit the risks posed by significant changes in hydrological regimes and agricultural practices and to identify adaptation and mitigation strategies for agriculture that could make it possible to reconcile the viability of farms, the good quantitative status of hydrosystems and carbon neutrality. One of the challenges is to assess the interactions between green and blue water flows linked to agricultural systems, particularly intermediate crop cover.

The originality of this project lies in the implementation of a multi-model approach in partnership with the stakeholders, which will make it possible to take into account the uncertainties related to modelling, to compare the variability between models and to qualify the other sources of uncertainty in the construction and evaluation of scenarios. The reaction and understanding of stakeholders to the modelling results presented and their associated uncertainties will be studied. Indicators will be developed to meet the needs of analysis and stakeholders to inform decision-making in an operational manner in a context of uncertainty.

Goals

To carry out the ESACC-AGRO project, hydrological (water resources) and agronomic (crop water requirements and GHG emissions) modelling will be set up and coupled. This agro-hydrological modelling will make it possible to assess the vulnerability of agricultural systems and water resources faced with climate change through to 2050. Adaptation and mitigation strategies envisaged in territorial and regional plans will be tested and evaluated by the modelling and will serve as a basis for discussion during interviews with local stakeholders and decision-makers. In addition, a multi-model approach will be used to assess the uncertainties associated with the modelling.

The project will develop regional scenarios and a generalised modelling approach.

INRAE units involved

• LAE, Colmar
• HYCAR, Antony
• GESTE, Strasbourg