Mountain Risks: A Marie Curie Research & Training Network J. Corominas and the ‘Mountain-Risks’ research team Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia, Barcelona, Spain  SCOPE: MOUNTAIN RISK MANAGEMENT Contact: Jordi Corominas,  Guidelines for sustainable planning Data resources, analysis techniques and general experience in hazard assessment are extremely extensive but, this knowledge is rarely transferred to the relevant operational institutions and to the general public. The long-term monitoring of hazardous sites has the potential to provide a thorough understanding of related processes and mechanisms in order to forecast events and set up alert systems. This, in turn, may be combined with disaster preparedness, adaptation and mitigation. As a consequence, risk management measures may be planned to minimise future damage and loss of lives for specific event magnitudes. Risk management includes the definition of protection objectives, their cost/effectiveness, the type of land-use regulations and preventive actions, as well as the available sustainable protective measures, type of warning systems and formulation of emergency plans. These actions will be applied on highly documented case studies, located in five European countries (France, Italy, Swiss, Germany and Spain) where mountain hazards are currently evident. The themes which will be investigated by the project are detailed hereafter. Fig. 1: Example of risk management (development planning, remedial measures) used in the Spanish Pyrenées.  Evaluation of remedial measures  Criteria for warning systems and evacuation plans  Framework for cost/benefit analysis Sustainable development in areas affected by landslides has to be performed according to specific guidelines, which in turn need to answer sthe following questions: - When are the measures necessary? - What are the appropriate measures? - Are they affordable? (cost-benefit analysis) Many villages or buildings are also located on large landslides, or on alluvial fans exposed to the impacts of fast gravitational flows. In the first case, the stabilisation of the movement is often unaffordable while moving the population might be socially unacceptable. For this specific case, research for sustainable development planning needs: - The development of construction technology for buildings; - The development of standards for alert systems: - The set-up of evacuation procedures. Are the measures sustainable? Are the measures appropriate? The following questions will be more particularly addressed, in order to define broadly acceptable, tolerable and unacceptable level of residual risk: - What is the protection level attained (dynamic analysis)? - How long will they last? - Is maintenance required? - Are the remedial measures sustainable? What is the residual risk? Development of remedial measures is an important step in landslide risk management. The objective of such remedial measures is to reduce consequences of a given hazard. Examples of options for remedial measures for an area affected by landslide include: Fig. 2: Examples of risk management (remedial measures) used in the Spanish Pyrenées. Monitoring system Expert System EmpiricalModelling Indirect: eg. rainfall (trigger) Direct: eg. displacement (creep curves) Process-based models: scenarios Alert thresholds Fig. 5: Flowchart of a warning system. Fig. 6: Example of the warning system of the Vallcebre landslide in the Spanish Pyrenées, based on rainfall, groundwater and displacement monitoring (GPS, wire extensometer). Risk management in mountain areas forces stakeholders to make decisions on problems that they normally poorly understand. A decision support from technicians and scientists is therefore essential for good management, and should be addressed to the identification of different scenarios in terms of potential damage and probability of events (Crosta et al., 2004). In order to provide support to stakeholders and to identify the best mitigation strategy with the lowest cost/benefit ratio, cost-benefit analyses will be performed for selected hazard sites. Such type of analysis can be used to define levels of social acceptance of mountain risk for the endangered community. On the bases of the scenarios results, best mitigation strategy plans (remedial measures, warning system and evacuation plans, combination of both) will be proposed. In order to reduce the temporal and spatial vulnerability of a given element at risk, the installation of monitoring and warning systems is often performed. Warning systems are usually completed by evacuation plan and/or the relocation of buildings to be further from a given mountain hazard. Establishment of alert systems require predictive models, which have to be validate on real and well-documented events. Nevertheless, there is a great lack of standardized practices to set up the systems. The following questions have to be answered: - Do the warning systems work? - Can we predict the onset of the movement? - Can we predict the displacements? Fig. 3: Example of a societal risk management using a frequency analysis (from Geotechnical Engineering Office, Hong-Kong, 1998). UNACCEPTABLE ALARP BROADLY ACCEPTABLE THE MOUNTAIN-RISKS RESEARCH PROJECT: CHALLENGES IN RISK MANAGEMENT - To reduce the frequency of landsliding by stabilization measures such as groundwater drainage, slope modification, anchors; - To reduce the probability of the landslide reaching the element at risk – e.g. for rockfalls, build rock catch fences; for debris flows, build catchment dams. INTENSE SCRUTINY REGION Fig. 4: Example of mitigation plan to manage the risk associated to the Séchilienne landslide (scenario) (from CGPC/IGE, 2004).