Author(s): Anna Prati; Andrea Menapace; Michele Larcher

Linked Author(s): Anna Prati, Michele Larcher, Andrea Menapace

Keywords: Data analysis; Debris flow; Trigger thresholds

Abstract: This work analyzes the large dataset of recorded debris flow occurred in the Alto Adige region, in the Italian Alps and, specifically focuses not only on the features of the sites where these events have taken place, but also and, more importantly, on the characteristics of the rain fall events that triggered these debris flows. While large river basins are relatively less affected, smaller basins, especially those in alpine regions, experience indeed severe damage due to the triggering of sediment transport phenomena like debris flows and mudflows by these intense storms. The complexity of terrain morphology in the Alps makes forecasting such events challenging. Debris flow events, primarily influenced by slope, terrain saturation, and rainfall intensity, pose significant threats due to their high velocity and unpredictable nature. The study focuses on the South Tyrol region, investigating factors influencing debris flow triggering and empirically calculating rainfall thresholds for event occurrence. Through a comprehensive analysis of debris flow events since 1960, cataloging geological and rainfall data, the study is preliminary but innovative step towards a better understanding and therefore mitigation of the risks associated with these phenomena. The main result of this work consists indeed of specific thresholds curves that establish which intensities and durations of rainfall events may cause the triggering of a debris flow.

DOI: https://doi.org/10.64697/HIC2024_P388

Year: 2024