Debris Flow Analysis: From Lithological Classification of the Basin to Deposition
The aim of this study is the development of an integrated approach for definition of scenarios of debris flow deposition. The approach has been applied to basins located in the North-western Alps. Firstly the basins are classified on the basis of the bedrock lithology. Hence the features of debris flows are related to different bedrock lithologies: basin area/fan area ratios, alluvial fan architectures, depositional styles and triggering rainfall characteristics. This method permits to capture the essential features of flow phenomena and to address the choice of proper constitutive laws for the numerical modelling of debris flow propagation and deposition. The numerical model calibration is based on the observed styles of deposition of debris flows and architecture of the alluvial fans (shape, slope, grain-size distribution, etc.). The simulations do not match the deposit of a given past event, but the results are in terms of scenarios and supply a more realistic tool for risk mitigation.
KeywordsCatchment lithology Sedimentary processes North-western Alps Numerical modelling Cellular Automata
This research was supported by PARAmount project of Alpine Space Programme of European Union (2-2-2-AT) – http://www.paramount-project.eu/.
- Deangeli C, Grasso P (1996) The evolutive mechanism of debris flows: analysis and protection works. In: Proceedings of 7th international symposium on landslides, Balkema, Trondheim/Rotterdam, pp 1183–1188Google Scholar
- Deangeli C, Giani GP (1998) Physical and numerical models to rehabilitate a waste disposal site. In: Proceedings of 8th international congress IAEG, Balkema, Vancouver/Rotterdam, pp 1813–1818Google Scholar
- Deangeli C, Gregoretti C, Paltrinieri E, Rabuffetti D, Tiranti D (2011) An integrated approach to simulate channelized debris flows from triggering to deposition. In: Proceedings of 5th international conference on debris-flow hazards mitigation: mechanics, prediction and assessment, University of Padua, Italy, 14–17 June 2011, pp 661–668,Google Scholar
- Moscariello A, Marchi L, Maraga F, Mortara G (2002) Alluvial fans in the Alps: sedimentary facies and processes. Spec Publ Int Assoc Sedimentol 32:141–166Google Scholar
- Takahashi T (1978) Mechanical characteristics of debris flow. J Hydraul Div 104(8):1153–1169Google Scholar
- Takahashi T (1991) Debris flow, IAIIR monograph. Balkema, RotterdamGoogle Scholar
- Tiranti D (2008) The sediment gravity flows triggering mechanisms, evolution and sedimentary processes in Western Italian Alps. Ph.D. thesis, Department of Earth Sciences, University of Torino (Italy) and the Cambridge Quaternary, Department of Geography, University of Cambridge (UK), pp 100Google Scholar