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| Titel |
Numerical simulation of the debris flow dynamics with an upwind scheme and specific friction treatment |
| VerfasserIn |
Guillermo Sánchez Burillo, Santiago Beguería, Borja Latorre, Javier Burguete |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250086965
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| Publikation (Nr.) |
 EGU/EGU2014-915.pdf |
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| Zusammenfassung |
| Debris flows, snow and rock avalanches, mud and earth flows are often modeled by means of a particular realization of the so called shallow water equations (SWE). Indeed, a number of simulation models have been already developed [1], [2], [3], [4], [5], [6], [7]. Debris flow equations differ from shallow water equations in two main aspects. These are (a) strong bed gradient and (b) rheology friction terms that differ from the traditional SWE. A systematic analysis of the numerical solution of the hyperbolic system of equations rising from the shallow water equations with different rheological laws has not been done. Despite great efforts have been done to deal with friction expressions common in hydraulics (such as Manning friction), landslide rheologies are characterized by more complicated expressions that may deal to unphysical solutions if not treated carefully.
In this work, a software that solves the time evolution of sliding masses over complex bed configurations is presented. The set of non- linear equations is treated by means of a first order upwind explicit scheme, and the friction contribution to the dynamics is treated with a suited numerical scheme [8]. In addition, the software incorporates various rheological models to accommodate for different flow types, such as the Voellmy frictional model [9] for rock and debris avalanches, or the Herschley-Bulkley model for debris and mud flows.
The aim of this contribution is to release this code as a free, open source tool for the simulation of mass movements, and to encourage the scientific community to make use of it. The code uses as input data the friction coefficients and two input files: the topography of the bed and the initial (pre-failure) position of the sliding mass. In addition, another file with the final (post-event) position of the sliding mass, if desired, can be introduced to be compared with the simulation obtained result. If the deposited mass is given, an error estimation is computed by means of the Nash-Shutcliffe statistic [10]. This error estimation can be used to calibrate the input friction coefficients, providing an efficient tool for risk analysis in many regions of the world and specially in areas with steep topographic gradients such as mountain ranges, heavily incised river networks, coastal cliffs, etc.
References:
[1] H. J. Koerner, "Reichweite und geschwindigkeit von bergstürzen und fleisschneelawinen". Rock Mechanics, 8, 225–256 (1976)
[2] P. J. McLellan and P. K. Kaiser, "Application of a two-parameter model to rock avalanches in the mackenzine mountains". 4th International Symposium on Landslides, 135–140 (1984).
[3] A. Kent and O. Hungr, "Runout characteristics of debris from dump failures in mountainous terrain: stage 2: analysis, modelling and prediction". British Columbia Mine Waste Rock Pile Research Committee and CANMET (1995).
[4] O. Hungr and S. G. Evans, "Rock avalanche runout prediction using a dynamic model". 7th International Symposium on Landslides, 233–238 (1996).
[5] D. Rickenmann and T. Koch, "Comparison of debris flow modelling approaches". First International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment. ASCE, ed. New York. C.L. Chen (1997).
[6] P. Bertolo and G. F. Wieczorek, "Calibration of numerical models for small debris flows in Yosemite Valley, California, USA". Natural Hazards in Earth System Sciences (5) 993–1001 (2005).
[7] S. Beguería and Th. J. van Asch and J. P. Malet and S. Gröndahl, "A GIS-based numerical model for simulating the kinematics of mud and debris flows over complex terrain". Natural Hazards in Earth System Sciences (9) 1897–1909 (2009).
[8] G. Sánchez Burillo, S. Beguería, B. Latorre and J. Burguete, "Numerical treatment of the friction term in upwind schemes in debris flow runout modelling". ASCE Journal of Hydraulic Engineering (sent for publication).
[9] A. Voellmy, Über die Zerstörungskraft von Lawinen. Schweizer. Bauzeitung (1955).
[10] J. E. Nash and J. V. Shutcliffe, "River flow forecasting through conceptual models part I – A discussion of principles". Journal of Hydrology, 10 (3) 282–290 (1970). |
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