MASS MOVEMENTS OF AN ALPINE ROCK GLACIER

Due to climate change, the hazard for debris flows originating in glacier forefields or areas dominated by seasonal to perennial frost is increasing. Hazard assessment for this type of debris flows is especially difficult as records of past events are typically scarce or inexistent. We therefore developed a multi-methods approach for scenario building and runout modelling for pro- and periglacial debris flows triggered by precipitation events and applied it to a catchment in the Swiss Alps.

Debris flows are complex, surging movements of sediment and water. Discharge observations from well-studied debris-flow channels were used as inputs for a numerical modelling study of the downstream effects of chaotic inflows. The results show that downstream impacts are sensitive to inflow conditions. Inflow conditions for predictive modelling are highly uncertain, and our method provides a means to estimate the potential variability in future events.