A contribution for the assessment of sliding susceptibility in Sarno area, Southern Italy: Fid-Bau Portal

A contribution for the assessment of sliding susceptibility in Sarno area, Southern Italy

Capparelli, Giovanna / Versace, Pasquale / Biondi, Daniela

Rainfall is accepted as a major factor in many types of slope movement, including rapid, shallow soil slips and deeper landslides. Actually, rainfall-triggered landslides constitute a serious hazard in many parts of the world. More efforts are needed to improve knowledge and understanding of the mechanisms that control the triggering landslides. The technical literature is rich in examples of study cases and analysis models. In general, the models can be traced to two categories: hydrological and complete models. Although with very different procedures, both models attempt to describe the relationships rainfall-landslides for defining conditions of triggering phases. The first ones involve simple empirical relationships linking antecedent precipitation to the time that the landslide occurs; the latter consist of more complex expressions that take several components into account, including specific site conditions, mechanical, hydraulic and physical soil properties, local seepage conditions, and the contribution of these to soil strength. This study shows the results obtained by using a model belonging to the second category. The analysis was carried out in a landslide-prone area in Campania region (South Italy), were disastrous mud-flows occurred on May 5, 1998. After the events, an analysis of the triggering conditions has been developed working with the complete model SUSHI (Saturated Unsaturated Simulation for Hillslope Instability). The obtained results made possible to better define the triggering conditions and differentiate the scenarios leading to instability of those slopes.