A multi-scale tool for assessing the seismic risk of small dams during emergency preparedness and response phase

Small dams are critical infrastructures, which provide different kinds of benefits, such as water supply, flood control, hydropower generation. Existing small dams are typically embankment structures, built without complying with the regulations of well-engineered large dams. Being often located near inhabited areas, the failure under earthquake loading of such types of structures would entail serious consequences for community safety. This paper aims at proposing a multi-scale methodology to assess the seismic risk of small dams. An application is illustrated with reference to the dams located in the Valle d’Aosta Region (Italy). State-of-the-art indices for large-scale risk-based prioritization are computed by convolving the seismic hazard with the vulnerability and the exposure. According to the methodology, for the dams to which the worst values of seismic risk indices are assigned, specific analyses based on Monte Carlo simulations are carried out to express the seismic response of embankment dams by addressing the associated uncertainties. The outcomes computed in the preparedness phase could be adopted to evaluate in near real-time the response of small dams in the immediate aftermath of an earthquake. Indeed, an algorithm was developed by using Geographic Information System for near real-time assessment of earthquake-related damage to small dams. The proposed multi-scale tool may support decision-makers, from civil protection organizations at the national level down to regional administrations, dam owners, first responders, infrastructure operators, and environmental protection agencies.