Jean-Marc Tacnet (Irstea-ETNA) is a senior researcher who received two Master Engineering Degrees (ENGEES, ENGREF), a M.Sc. degree in Applied Computer Science (Grenoble University) and a PhD thesis (ENSMSE) in Environmental Engineering Sciences. His activities focus on integrated risk management and expert assessment processes applied to natural phenomena in mountains. He is involved in applied research dealing with decision support systems for hazard, risk assessment but also risk reduction measures effectiveness analysis in a context of imperfect information and uncertainty. His disciplinary fields concern multi-criteria decision-making, information fusion, artificial intelligence (fuzzy sets, possibility, belief function theories), uncertainty analysis, and software engineerin. He manages a research team called DARE (Decision-Aid, Risk ans Expertise- ADRET in French). Simon Carladous received his Master Engineering Degree from ENGEES, France (2005) and Master of Sciences in Natural Risks Management from Montpellier University, France (2013). He has 8 years experience in program and project management in different fields, namely drinking and wastewater management, natural hazards management in mountains (torrential floods, avalanches, rockfalls). He is currently undertaking his PhD thesis at Irstea in natural hazards management fields to develop decision-aid methods, taking into account information quality. Guillaume Piton is currently undertaking his PhD in the area of torrential hydraulics at IRSTEA, Grenoble. From 2009 to 2013, he held the position of hydraulics engineer at ARTELIA ( ex - SOGREAH ), with a multidisciplinary study of hydraulic works including hydrology, hydraulic modeling, project design, site preparation, implementation monitoring and impact assessment. His research interests include torrential hydraulics, Sediment transport, Design works in rivers and physical modeling.