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

In our study, we present a proactive decision support tool able to compute the impacts of different possible scenarios for territories impacted by mountain risks. The objective of this work was to develop and test various hazard and risk assessment methods, and to implement them into a web-application platform able to show possible risks induced by global change on ecosystems and society. Four case studies were selected for their representativeness: One located in a Pyrenean valley, others in the French Alps. Methodology addressed several points. The first one was on the identification of the impacts of global environmental changes (climatic situations, land use, and socio-economic systems) on identified hazards. The second one was on the analysis of these impacts in terms of vulnerability (e.g., the places and the physical modifications of impacted stakes, as well as levels of perturbation). The third one was on the integration of developed methodologies in a single coherent framework in order to investigate and map indicators of vulnerability. The last one was on the development of a demonstration platform with GIS (Geographic Information System) capabilities and usable on the web. The architecture and the main features of the web-platform are detailed within several cases for which hazard and impact assessments are evaluated for not only past and present, but also future periods. This web-tool, mostly dedicated to stakeholders, has proven its usefulness to test various socio-economical pathways, because multiple scenarios, considered as probable in inhabited valleys, can be benchmarked, analyzed, and compared

Accounting for variability and uncertainties in NDT condition assessment of corroded RC-structures

La prévision quantitative du développement de la corrosion demeure difficile, ce qui limite le développement de stratégies de maintenance préventive efficaces. Parmi les sources de difficultés, on recense la variabilité spatiale des propriétés des matériaux, la variabilité temporelle des conditions environnementales et la sensibilité des contrôles non destructifs à ces conditions. Le pont en béton armé de Barra, au Portugal, a fait l'objet d'investigations approfondies. Les mesures ont été utilisées pour modéliser le développement de la corrosion et sa variabilité. Un modèle reposant sur l'exploitation de données de laboratoire complémentaires permet de tenir compte de l'influence des paramètres environnementaux et d'aider à la décision en ce qui concerne le diagnostic de la corrosion et de son évolution.The quantitative forecasting of corrosion development remains difficult, limiting the development of validated preventive maintenance strategies. Difficulties come from the spatial variability of material properties, the temporal variability of the environment and the sensitivity of non destructive measurements to changing environmental conditions. The reinforced concrete Barra Bridge, Portugal, has been thoroughly investigated, and on site data have been used for modelling the development of corrosion and its variability. A model has been derived from additional laboratory experiments, which enables to account for the influence of environment and to support the decision process regarding the corrosion state and the forecasting of its evolution