Rainfall-Induced Shallow Landslide Susceptibility for Risk Management of Underground Services in a Mediterranean Metropolitan City

Shallow landslide susceptibility assessment is an essential research activity for land management and risk assessment. In this study, a GIS-based approach was developed to assess rain-induced landslide susceptibility in the Municipality of Genoa, a Mediterranean anthropized area historically characterized by intense rainfall events that frequently trigger shallow landslides with high destructive power. Based on a detailed inventory of historical landslides, a semi-quantitative method was applied to assess the influence of seven causal factors of natural and anthropogenic landslides. The areas were categorized into five classes of rain-induced shallow landslide susceptibility, indicating slopes where newly triggered landslides may occur. The landslide susceptibility map was subsequently integrated with the map of gas and water utilities, whose features were used to assess their vulnerability. Finally, an early-stage risk assessment of the two utility networks was developed to serve as a decision support tool for strategic planning and integrated asset management in the context of climate change. The results show that about 9.8% and 6.8% of the total length of water and gas pipelines are exposed to higher risk classes 4 and 5.