Spatial integration of thematic data for predictive landslide mapping: a case study from Oltrepo Pavese area, Italy

This study involves the integration of multiple thematic data sets for landslide susceptibility assessment through spatial prediction models, at different scale levels. The proposed methodology has been applied in the Oltrepo Pavese area, characterized by a very high density of landslides, mainly surficial slope failures triggered by intense rainfall events. Firstly, the susceptibility assessment has been based on an indirect bivariate statistical analysis performed in order to evaluate the relative weights of each factor contributing to the instability. Among the susceptible areas predicted by the statistical analysis, a test site was selected to apply the infinite slope model, using data derived from the application of a groundwater numerical model for unsaturated and saturated conditions on selected slope profiles. All the applied models have been integrated and implemented in a raster-based geographical information system (GIS), giving useful information both on present instability of the area and its possible future evolution.