1 THE GESTRANS PROJECT Taking into account changing alluvial channels in flood risk assessment N° ANR-09-RISK-004/GESTRANS

2 Duration: 4 years ( ) Partners Cemagref Laboratoire de Transfert en Hydrologie et Environnement CNRS UMR5600 Institut de Physique du Globe de Paris Direction Départementale des Territoires de l’Isère Université de Colombie Britannique N° ANR-09-RISK-004/GESTRANS

3 A challenge… Make compatible the short-term flood risk assessment and the long- term environmental objectives (DCE 2000/60/CE) …. and conflicting objectives : for instance when a sediment deposit, which is fully part of the river equilibrium (or disequilibrium), locally modifies the river section’s flow capacity Overcome individualism… a decision motivated by considerations on the entire river catchment may locally be poorly understood and accepted by floodplain inhabitants … and acceptance problem: even the best technical solutions may be inefficient if they are not well explained N° ANR-09-RISK-004/GESTRANS The RiverThe people and

4 N° ANR-09-RISK-004/GESTRANS

5 More collaborations ? N° ANR-09-RISK-004/GESTRANS photograph enquiries and regional daily press analysis Are the variations in flood risk assessment related to professional characteristics? => semi-directed interviews Hydrophone (1 thesis) Bedload measurements (HS, Sediment traps) Flume experiments (Thesis IPGP, Cemagref) Saint-Venant Cellular automata Braiding Rivers trajectory (long term changes, regional diversity, role of vegetation…). => Aerial photograph analysis => Flume experiments A field-based investigation of macroforms mobility => Multidate Airborne LiDAR surveys Rivières en Tresses (funding by Water Agency RMC) « Créateur de Drôme » «Sediphone » with WSL John Laronne Fellowship Thursday

6 N° ANR-09-RISK-004/GESTRANS This workshop: The first of a 4 years project Objectives:Facilitate interactions between researchers Presentation of the project (to stakeholders) Encourage (new) collaborations The place: Ancien Monastère de Sainte-Croix The staff: Programm: Day 1: Invited speakers (English) Day 2: The « Braided river » project / Field trip Day 3: Geosciences and social stakes interactions