To cite this version:Thomas Houet, Marine Gremont, Laure Vacquié, Yann Forget, Apolline Marriotti, et al.. Downscaling scenarios of future land use and land cover changes using a participatory approach: an application to mountain risk assessment in the Pyrenees (France) . Regional Environnemental Change, Springer, 2017, 17 (8) Better understanding the pathways through which future socio-economic changes might influence land 19 use and land cover changes (LULCC) is a crucial step in accurately assessing the resilience of 20 societies to mountain hazards. Participatory foresight involving local stakeholders may help building 21 fine-scale LULCC scenarios that are consistent with the likely evolution of mountain communities. 22This paper develops a methodology that combines participatory approaches in downscaling socio-23 economic scenarios with LULCC modelling to assess future changes in mountain hazards, applied to a 24 case study located in the French Pyrenees. Four spatially-explicit local scenarios are built each 25 including a narrative, two future land cover maps up to 2040 and 2100, and a set of quantified 26 LULCC. Scenarios are then used to identify areas likely to encounter land cover changes 27 (deforestation, reforestation and encroachment) prone to affect gravitational hazards. In order to 28 demonstrate their interest for decision-making, future land cover maps are used as input to a landslide 29 hazard assessment model. Results highlight that reforestation will continue to be a major trend in all 30 scenarios and confirm that the approach improves the accuracy of landslide hazard computations. This 31 validates the interest of developing fine-scale LULCC models that account for the local knowledge of 32 stakeholders. 33