A novel prototype national-scale landslide nowcasting system for Italy combining rainfall thresholds and risk indicators

作者：Samuele Segoni, Nicola Nocentini, Francesco Barbadori, Camilla Medici, Alessio Gatto, Ascanio Rosi, Nicola Casagli · 发表于：Landslides · 年份：2025 · DOI：10.1007/s10346-024-02452-0 · 被引用次数：9 · 研究领域：Landslides and related hazards、Flood Risk Assessment and Management、Tree Root and Stability Studies

Abstract Regional- and national-scale landslide warning systems are usually based on rainfall thresholds that forecast the possibility of landslide occurrence over wide spatial units called alert zones (AZs). This work proposes a substantial improvement of the state-of-the-art by combining the rainfall threshold outcomes with a set of spatially explicit risk indicators aggregated at the municipality level. The combination of these two different techniques is performed by means of a dynamic matrix, which was purposely calibrated to provide an output in the form of five possible levels of risk (from R0 to R4), which are connected to the growing intensity of expected impacts and a pre-defined confidence in issuing warnings without omitting alarms. Italy (about 300,000 km 2 ) is used as a case study, producing a set of rainfall thresholds differentiated for 150 AZs and providing a specific calibration of the dynamic risk matrix for each of them. The verification of the matrix outputs was satisfactory as no AZs experienced landslides at the R0 level; only two of them had more than 10% of landslides at the R1 level, and most of the AZs had more than 90% of the landslides in the R2 to R4 risk classes. A comparison with a nation-wide dataset of very severe hydrogeological disasters further corroborated the consistency of the model outputs with real scenarios, as most part of the impacts occurred in places and times when the matrix outputs were at the highest levels. The proposed meth...