MOUNTAIN RISKS: FROM PREDICTION TO MANAGEMENT AND GOVERNANCE, cilt.34, ss.133-177, 2014 (SCI-Expanded)
Debris flow events yield a threat to different components of mountainous environments not only as the result of the process evolution but of the interaction with human systems and their coupled vulnerabilities. A variety of models exists for characterising the hazard that the different mass-flow phenomena present. In the case of dynamic run-out models, they are able to forecast the propagation of material after the initial failure and to delineate the zone where the elements at risk will suffer an impact with a certain level of intensity. The results of these models are an appropriate input for vulnerability and risk assessments. An important feature of using run-out models is the possibility to perform forward analyses and forecast changes in hazards. However, still most of the work using these models is based on the calibration of parameters doing a back calculation of past events. Given the number of unknown parameters and the fact that most of the rheological parameters cannot be measured in the laboratory or in the field, it is very difficult to parameterize the run-out models. For this reason the application of run-out models is mostly used for back analysis of past events and very few studies attempts to achieve a forward modelling with the available run-out models. A reason for this is the substantial degree of uncertainty that still characterizes the definition of the run-out model parameters. Since a variety of models exists for simulating mass-flows and for identifying the intensity of the hazardous phenomena, it is important to assess these models, perform a parameterization and reduce their uncertainties. This will enable to improve the understanding to assess the hazard and will provide the link with vulnerability curves that will lead eventually to generate risk curves and quantify the risk.