Climate triggering of mass movements contributing to alpine sediment erosion


Date

2024-11-09

Publication Type

Conference Poster

ETH Bibliography

yes

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Abstract

Gravitational mass movements are key contributors to alpine sediment erosion, sediment connectivity, and ultimately global source-to-sink sediment pathways. Sediment production and transport by these processes are concentrated in confined areas characterised by steep slopes and fractured geological structures. The physical processes driving alpine mass movements are complex, which poses significant challenges in tracking the triggering and failure of individual events and particularly in upscaling across large catchments. Instead here we characterise mechanisms of sediment erosion in mountain basins by predisposing and triggering factors derived from climate variables, and analyse these statistically with mass movement inventories. We model rainfall patterns, snowmelt, antecedent wetness conditions, and rock weathering history as climate-driven indices for mass movement sediment supply. The analysis is carried out in the Alpine Rhine catchment (GR) over a 50-year period using daily gridded precipitation and temperature data from the Federal Office of Meteorology and Climatology MeteoSwiss and soil data from the SoilGrids database. By correlating the interplay of these climate variables with the initiation of mass movements, we explore their role as triggers for sediment production. To this end we utilize records of frequent rapid mass movements, such as shallow landslides, debris flows, and rockfalls from the Swiss natural hazard database (StorMe, Swiss Federal Office for the Environment FOEN). Our methodology builds on established approaches for modelling rainfall-induced shallow landslides (Leonarduzzi et al. 2017), the concurrent state of soil wetness (Leonarduzzi et al. 2021) and the influence of catchment hydrological conditions on debris flow initiation (Prenner et al. 2018) and aims to expand the understanding of climate-induced erosion triggering mechanisms in the Alps. The findings can offer a framework for better predicting climate-related changes in sediment erosion by mass wasting. REFERENCES Leonarduzzi, E., Molnar, P., McArdell, B.W. 2017: Predictive performance of rainfall thresholds for shallow landslides in Switzerland from gridded daily data. Water Resour. Res., 53, 6612–6625. Leonarduzzi, E., McArdell, B.W., Molnar, P. 2021: Rainfall-induced shallow landslides and soil wetness: comparison of physically based and probabilistic predictions. Hydrol. Earth Syst. Sci., 25, 5937–5950. Prenner, D., Kaitna, R., Mostbauer, K., & Hrachowitz, M. 2018: The Value of Using Multiple Hydrometeorological Variables to Predict Temporal Debris Flow Susceptibility in an Alpine Environment. Water Resources Research, 54(9), 6822–6843.

Publication status

published

External links

Editor

Book title

Journal / series

Volume

Pages / Article No.

Publisher

ETH Zurich

Event

22nd Swiss Geoscience Meeting (SGM 2024)

Edition / version

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Geographic location

Date collected

Date created

Subject

Sediment erosion; Alpine mass movements; Climate triggering

Organisational unit

08739 - Molnar, Peter (Tit. Prof) / Molnar, Peter (Tit. Prof) check_circle

Notes

Funding

213085 - Hydrogeomorphological Prediction of Source to Sink Sediment Pathways in the Alpine Rhine (SNF)

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