Possible impacts of climate change on debris-flow activity in the Swiss Alps
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This study uses a long dataset of past debris flows from eight high-elevation catchments in the Swiss Alps for which triggering conditions since AD 1864 have been reconstructed. The torrents under investigation have unlimited sediment supply and the triggering of debris flows is thus mainly controlled by climatic factors. Based on point-based downscaled climate scenarios for meteorological stations located next to the catchments and for the periods 2001–2050 and 2051–2100, we study the evolution of temperature and rainfall above specific thresholds (10, 20, 30, 40 and 50 mm) and durations (1, 2 or 3 days). We conclude that the drier conditions in future summers and the wetting of springs, falls and early winters are likely to have significant impacts on the behavior of debris flows. Based on the current understanding of debris-flow systems and their reaction to rainfall inputs, one might expect only slight changes in the overall frequency of events by the mid-21st century, but possibly an increase in the overall magnitude of debris flows due to larger volumes of sediment delivered to the channels and an increase in extreme precipitation events. In the second half of the 21st century, the number of days with conditions favorable for the release of debris flows will likely decrease, especially in summer. The anticipated increase of rainfall during the shoulder seasons (March, April, November, December) is not expected to compensate for the decrease in future heavy summer rainfall over 2 or 3 days.
KeywordsDebris Flow Regional Climate Model Extreme Precipitation Event Rock Glacier Trigger Debris Flow
This work has been undertaken partly in the context of the EU-FP7 project ACQWA (project no. 212250) and Era.Net CICRLE Mountain project ARNICA (10-MCGOT-CIRCLE-2-CVS-116).
- Beniston M, Stephenson DB, Christensen OB, Ferro CAT, Frei C, Goyette S, Halsnaes K, Holt T, Jylha K, Koffi B, Palutikof J, Scholl R, Semmler T, Woth K (2007) Future extreme events in European climate: an exploration of regional climate model projections. Climatic Change 81:71–95CrossRefGoogle Scholar
- Borga M, Stoffel M, Marchi L, Marra F, Jakob M (in press) Hydrogeomorphic response to extreme rainfall in headwater systems: flash floods and debris flows. Journal of Hydrology.Google Scholar
- Frei, C., R. Scholl, S. Fukutome, J. Schmidli, P. L. Vidale (2006), Future change of precipitation extremes in Europe: Intercomparison of scenarios from regional climate models, J. Geophys. Res.-Atmos., 111(D6), doi: 10.1029/2005jd005965.
- Gobiet A, Kotlarski S, Beniston M, Heinrich G, Rajczak J, Stoffel M (2013) 21st century climate change in the European Alps – A review. Science of the Total Environment, in press.Google Scholar
- Heinrich G, Gobiet A (2012) The future of dry and wet spells in Europe: a comprehensive study based on the ENSEMBLES regional climate models. Int J Climatol 32Google Scholar
- IPCC (2012) Managing the risks of extreme events and disasters to advance climate change adaptation. A special report of working group I and II of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge UKGoogle Scholar
- IPCC (2013) Summary for Policymakers. Working Group I Contribution to the IPCC Fifth Assessment Report Climate Change 2013: The Physical Science Basis. Cambridge University Press, Cambridge, UKGoogle Scholar
- Lendernik G, Meijgarrd E (2008) Increase in hourly precipitation extremes beyond expectations from temperature changes, Nature Geoscience, 1, doi: 10.1038/ngeo262
- MeteoSwiss (2013) On-line database from MeteoSwiss. http://www.meteoswiss.ch/en/.
- Pal J, Giorgi F, Bi X (2004) Consistency of recent European summer precipitation trends and extremes with future regional climate projections. Geo Phys Res Lett 31, L19836Google Scholar
- Rajczak J, Pall P, Schär C (2013) Projections of extreme precipitation events in regional climate simulations for Europe and the Alpine Region. Journal of Geophysical Research - Atmospheres 118:1–17Google Scholar
- Salzmann N, Noetzli J, Hauck C, Gruber S, Hoelzle M, Haeberli W (2007) Ground surface temperature scenarios in complex high-mountain topography based on regional climate model results. Journal of Geophysical Research-Earth Surface 112:F02S12Google Scholar
- Sattler K, Keiler M, Zischg A, Schrott L (2010) On the connection between deris flow activity and permafrost degradation: A case study from the Schnalstal, south Tyrolean Alps, Italy. Permafrost Periglac Process 22:254–265Google Scholar
- Schmidli J, Goodess CM, Frei C, Haylock MR, Hundecha Y, Ribalaygua J, Schmith T (2007) Statistical and dynamical downscaling of precipitation: An evaluation and comparison of scenarios for the European Alps. J Geophys Res-Atmos 112Google Scholar
- Schneuwly-Bollschweiler M, Stoffel M (2012) Hydrometeorological triggers of periglacial debris flows in the Zermatt valley (Switzerland) since 1864. Journal of Geophysical Research - Earth Surface 117, F02033Google Scholar
- Schneuwly-Bollschweiler M, Corona C, Stoffel M (2013) Improvement of dating quality and reduction of noise in tree-ring based debris-flow reconstructions. Quaternary Geochronology,.Google Scholar
- Solomon S et al (2007) The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge Univ. Press, Cambridge, 996 ppGoogle Scholar
- Stoffel M, Lièvre I, Monbaron M, Perret S (2005a) Seasonal timing of rockfall activity on a forested slope at Täschgufer (Swiss Alps) - A dendrochronological approach. Zeitschrift für Geomorphologie 49:89–106Google Scholar