Le réseau des Sites de démonstration pour évaluer l'efficacité des opérations de restauration dans différents contextes et différentes conditions environnementales.

[Departement_IRSTEA]Eaux [ADD1_IRSTEA]Systèmes aquatiques soumis à des pressions multiplesInternational audienceMany hydromorphological river restoration works have been achieved over the last 15 years under the impulse of the Water Framework Directive (WFD). However, an important lack in the monitoring and assessment of the efficiency of those works still remains and is often reported. In 2010, The French Biodiversity Agency (FBA), French water agencies and National Research Institute of Science and Technology for Environment and Agriculture (Irstea) developed a specific methodology to monitor river restoration projects, named "Minimal Scientific Monitoring" (MSM). The MSM focuses on the multi-annual evolution of three components of the river environment, namely hydromorphology, physico-chemical parameters and biota. On each site studied, a before-after-control-impact design is implemented, meaning monitoring is led before and after restoration, and upon restored sites and control sites. In addition, all field protocols implemented are standardized (WFD standards if available) to ensure homogeneous data collection on all stations. One of the most important challenges when analyzing the effects of river restoration is to consider the relevant explanatory variables. Often, scientific publications do not include restoration work details (sizing and heterogeneity of recreated watercourse for example), nor do they include environmental variables. MSM is an attempt to fulfil this gap, by including physico-chemical, hydrology and water temperature monitoring in addition to the biological and hydromorphological survey. Following these parameters across a long-term monitoring and upon control and restored sites will help (i) considering the great diversity of river types and pressures existing upon the watershed and (ii) understanding the river system and biological communities evolution due to local and large- scale modifications. All restoration projects on which the MSM is implemented constitute the "demonstration sites network". This approach aims thus to generate standardized data on the long term and, more generally, to increase knowledge about the efficiency of the river restoration works at the national scale