A regional-scale framework for landslide susceptibility and risk management: application to urban areas with significant cultural heritage in Sicily

Abstract

This paper presents a heuristic methodology for the assessment of landslide susceptibility and for risk management, based on territorial data available at the regional scale. The method is designed to be flexible and applicable across large areas with diverse geomorphological and geotechnical conditions. It was tested in Sicily (Italy), a region characterised by widespread slope instability and a high concentration of small urban areas with historical and cultural significance. The approach combines geomorphological, geological, geotechnical, and anthropogenic factors to assess a landslide susceptibility index, which is then integrated with a risk exposure index derived from official hazard zoning data. A comparison matrix is then used to prioritise interventions and assign each urban area to a specific category of risk management measures. Applied to a sample of 80 urban areas, the methodology proved to be effective in identifying critical conditions and providing preliminary, context-specific guidelines for landslide risk mitigation guidelines. The analysis showed that 75% of the cases analysed fall within the high and very high susceptibility classes. Among these, only 14% of the urban centres required a specific risk management plan, identified in the study as Category A, in which risk mitigation measures are considered a priority to address the triggering causes of instability. The results confirm the effectiveness of the proposed framework, highlighting its potential as a practical decision-support tool for regional uthorities committed to the sustainable governance of landslide risk.