Downscaling scenarios of future land use and land cover changes using a participatory approach: an application to mountain risk assessment in the Pyrenees (France)

Abstract

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

A Novel Multi-Risk Assessment Web-Tool for Evaluating Future Impacts of Global Change in Mountainous Areas

“…Climate change scenarios: The climate change inputs correspond to two scenarios of emission of greenhouse gases. The simulations were performed with the Green House Gas (GHG) emissions scenarios; RCP (Representative Concentration Pathways) are greenhouse gas concentration The landuse/landcover scenarios: The assessment of future land use/land cover was adapted from Reference [26]. It is addressed through the construction of four prospective socio-economic scenarios up to horizons 2040 and 2100, which are then spatially modeled according to (1) land use and cover changes (LUCC) maps co-constructed with stakeholders.…”

“…It is addressed through the construction of four prospective socio-economic scenarios up to horizons 2040 and 2100, which are then spatially modeled according to (1) land use and cover changes (LUCC) maps co-constructed with stakeholders. These stakeholders were selected among municipalities, local authorities, consulting companies, and researchers working in the studied areas and interested enough to attend several workshops, as detailed in Reference [26];…”

Current practices and challenges for modelling past and future land use and land cover changes in mountainous regions

“…The authors referred to land use legacies as one of potentially important factors shaping future land change, a pre-requisite to build the basic future scenario (a trend scenario) and its variations to assess future LULCC. Houet et al (2017) built scenarios of future LULCC in 2040 and 2100 combining participatory and modelling approaches to assess mountain risks in the municipality of Cauterets in the Pyrenees. To assess the main LULCC trends, they used historical aerial photographs, sharing knowledge resulting from their interpretation with stakeholders.…”

“…Ensemble modelling was proved to be a powerful tool to assess uncertainty of historical forest change and quantify projection robustness by considering a suite of models rather than a single model type. To map LULCC, more complex modelling environments were used, for instance, Dyna-CLUE land use allocation framework (Price et al 2017), FORESCEM LULCC simulation model (Houet et al 2017) and integrated modelling system BackES relying on agent-based modelling (Brunner et al 2017).…”

“…This is even more critical in the context of mountain research where researchers still regard stakeholders as sources of information rather than fully capable partners in research projects (Gleeson et al 2016). These shortcomings might be overcome by carefully designed participatory approaches, where stakeholders are part of the research from its very beginning, as seen in Houet et al (2017). The participatory approaches not only ensure a better understanding of specific local drivers of LULCC, frequently blurred by land use legacies, but also raise awareness of non-scientists about the meaning of the outcomes of LULCC models, increasing chances that they might be considered in future decisions.…”