An Integrated Hydrological-Geotechnical Model in GIS for the Analysis and Prediction of Large-Scale Landslides Triggered by Rainfall Events

The proposed fully automatic procedure in a free and open source GIS, called GRASS, allows the evaluation of the propensity of a certain portion of land to slide due to rainfall events. Great attention has been devoted to define a proper infiltration model. Widespread slope stability analyses by a Global Limit Equilibrium method have been performed cell by cell. It is possible to take into account parameters that vary in vertical and horizontal directions. Moreover, the histories of rain (if necessary also of snowmelt) and the antecedent soil moisture condition are taken into account. There are no limits on the duration of the rain histories that can be considered. The computational effort is low even where large areas are divided into small pixels. The proposed procedure can be applied to any slipping site. In the present research an extensive kinematic phenomenon surrounding the city of Santo Stefano d'Aveto (Italy) was examined.