Shallow landslides in Tuscany (Central Italy) triggered by the November 2023 heavy rainfall event

On 2 November 2023, an extreme rainfall event struck Tuscany (central Italy), causing severe floods and triggering widespread landslides, which resulted in 8 fatalities, 300 evacuees, and an estimated economic loss of 2 billion. The intensification in recent years of these extreme rainfall events in Italy, driven by the ongoing climate change, has led to a significant increase in the occurrence of shallow landslides, posing growing threats to both infrastructure and communities. The development of detailed event-based landslide inventories represents a fundamental step in the perspective of climate change adaptation, being essential for emergency response, hazard assessment, and long-term risk mitigation. Integrating field surveys, high-resolution satellite imagery, and NDVI-based change detection analyses, 411 shallow landslides triggered during the event were identified, ranging in extension from a minimum of a few square meters to a maximum of 8,000 m2. 120 buildings were impacted, along with approximately 21.6 km of roads, with the most affected segments belonging to local and municipal networks, underscoring the vulnerability of secondary infrastructure. Spatial distribution of landslides was studied considering patterns of rainfall and predisposing factors. The results highlight that areas with moderate infiltration capacity, intermediate slope angles, moderate clay content, land uses featuring limited rainfall interception, and weak root reinforcement are especially susceptible to shallow landslides triggered by intense rainfall. This study provides event-based insights into rainfall-induced shallow landslides under extreme hydro-meteorological conditions, contributing to the understanding of their occurrence patterns and supporting susceptibility assessment, early warning activities, and climate-resilient land-use planning.