GIS-Based Analysis of Landslide and Bridge Data for Risk Assessment

The study of the interaction between road networks and landslides is crucial for assessing the risk posed by these phenomena to transportation infrastructures. In particular, the risk associated with interactions between landslides and bridges or viaducts can be quantified through the concept of “Landslides Class of Attention” (L-CoA). This study aims to develop methodologies for deriving key susceptibility and vulnerability factors in cases of landslide–bridge interactions within a vast area. The geographic area selected to test the effectiveness of the procedures is the Province of Belluno, (Italy). The proposed procedures enable the extraction of parameters essential for determining the L-CoA across a large number of infrastructures. To achieve this, the databases related to the existing landslides and bridges are integrated and analysed within a GIS environment. The primary databases used are the IFFI inventory of landslides in Italy and OpenStreetMap, which provides extensive information about bridges. These datasets are processed to extract parameters necessary for the L-CoA evaluation, such as bridge length and crossed entity, while additional parameters, including landslide magnitude and velocity, are derived by applying relationships from the literature. Information not directly obtainable from the databases can be supplemented through databases of selected infrastructures. Given the large number of identified interactions, statistical analyses can be performed to investigate how various factors influence the L-CoA. The adopted approach also allows for the extraction of parameters not directly required for L-CoA assessment, such as the orientation of the bridge relative to the landslide direction or the slope of the landslide. These additional data enable further statistical evaluations aimed at identifying potential correlations between the characteristics of the interacting elements and their corresponding L-CoA.