Multi – criteria methods to enhance the landslide risk management of small-medium Municipalities to plan sustainable mitigation strategies: the analysis of San Colombano Certenoli Municipality

Landslides constitute a major natural hazard in mountainous and hilly regions, generating significant impacts on infrastructures, settlements, and socio-economic systems. In contexts increasingly affected by extreme rainfall events, effective landslide risk management requires not only reliable technical assessments but also a solid integration with regulatory frameworks, territorial planning instruments, and administrative decision making processes. The doctoral thesis examines landslide susceptibility assessment as a strategic support tool for Public Administrations operating within complex legislative and planning systems. The research integrates a technical susceptibility analysis with a comprehensive review of the administrative and regulatory framework governing landslide risk management in Italy, with reference to basin planning instruments and public works procedures. The study mainly concerns on the Entella River basin in the Liguria Region, including the Municipality of San Colombano Certenoli and North areas of the Maritime Alps Department, which have recently experienced severe rainfall-induced landslides. From a methodological perspective, landslide susceptibility maps are produced using the statistical Weights Of Evidence (WOE) method with the Geographic Information System (GIS) support. The model is based on the integration of landslide inventory data with geomorphological, geological, hydrological, land-use, and topographic elements, as the predisposing factors. The reliability of the results is assessed through quantitative validation techniques, as well as qualitative field surveys. At the same time, the thesis analyses the regulatory role of planning instrument, such as the Hydrogeological Basin Plan (PAI) and design strategies for public works, translating susceptibility information into preventive and mitigation measures. A local-scale application in the Municipality of San Colombano Certenoli demonstrates how susceptibility mapping can support administrative decision-making processes, including compliance with regulatory constraints, prioritization of interventions, emergency planning, and allocation of public financial resources. The study highlights the importance of integrating technical susceptibility assessment with legal and administrative tools to enhance risk governance, ensure regulatory coherence, and promote resilient and sustainable territorial management.