| description abstract | The traditional approach to hydraulic engineering problems, such as the designing of dams or embankments or, specifically in the case of consideration, the designing of a settling basin for debris flows, is deterministic and uncertainties are not explicitly considered in the evaluation of the designed structure. Nowadays some effort is made to consider phenomena in a probabilistic rather than deterministic framework, in order to respond clearly to the demand for reliability. In this paper, failure, damage, and risk are exemplified for a debris-flow prone basin and considerations on the acceptable amount of risk are presented. The evaluation of debris flow hazard is carried out for a specific site (Acquabona, Italy). The standard methodology used to perform a risk assessment analysis is applied. All relevant failure modes are represented by failure functions and each of the function’s variables is described by a statistical distribution; all relevant uncertainties are included in a Level II probabilistic calculation and failure probability is evaluated with a first order reliability method. Finally, the probability of failure is compared with the acceptable amount of risk. | |