Multivariate parameter optimization for computational snow avalanche simulation

Fischer, Jan-Thomas; Kofler, Andreas; Fellin, Wolfgang; Granig, Matthias; Kleemayr, Karl

doi:10.3189/2015jog14j168

Cited by 51 publications

(59 citation statements)

References 65 publications

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“…From the ratio of simulated snow depth in the Alpine3D point between the release and deposit area, the gradient in the layer depth of snow available for possible erosion was derived. The median gradient in this layer depth available for erosion for the 169 cases was found to be 0.7 m/km of elevation, congruent with earlier reported values of 0.8 m/km (Fischer et al, ). From the release and deposition snowpack simulations, linear gradients in snow temperature were derived and also provided to the RAMMS‐Extended model.…”

Section: Methodssupporting

confidence: 90%

Coupled Snow Cover and Avalanche Dynamics Simulations to Evaluate Wet Snow Avalanche Activity

Wever

Valero²,

Techel

2018

JGR Earth Surface

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We present physics‐based snowpack simulations for four snow seasons with detailed wet snow avalanche activity records. The distributed, spatially explicit simulations using the Alpine3D and SNOWPACK model show that the simulated snowpack in the release areas of documented wet snow avalanches often exhibits its first wetting of the season on the release day. This first wetting is accompanied in the simulations by liquid water accumulating on capillary barriers, often formed by depth hoar layers. The strongest water accumulations and largest increases in percolation depth are found on the day of avalanche release. For individual avalanche paths, however, this only holds in 25%–30% of the cases. Assuming that the depth of the strongest water accumulation corresponds to the avalanche fracture depth, the avalanche dynamics model RAMMS‐Extended was run using simulated snowpack properties as initial conditions in the release area and boundary conditions along the avalanche path. On average, the simulated affected area by the avalanche and runout distance for the release day are statistically significant in closer agreement with the observations than two days before the release. This does not hold for the simulations of 1 day before and 1 and 2 days after the release. This suggests that fracture depths and the temporal evolution of percolation depths are adequately simulated within a ±1‐day period. The results show a large potential for distributed snow cover and avalanche dynamics simulations to assess wet snow avalanche hazards, although predictions for individual avalanche paths remain challenging.

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Section: Methodssupporting

confidence: 90%

Coupled Snow Cover and Avalanche Dynamics Simulations to Evaluate Wet Snow Avalanche Activity

Wever

Valero²,

Techel

2018

JGR Earth Surface

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“…In yellow areas, enduring contacts, forming elastic networks between particles, are dominant (referred to as quasi-static regime in da Cruz et al, 2005;Berzi et al, 2011; Vescovi et al, 2013, or elastic-quasi-static regime in Campbell, 2002, 2005. In blue areas, collisional stresses are dominant (referred to as collisional regime in da Cruz et al, 2005;Vescovi et al, 2013;Berzi et al, 2011, kinetic regime in da Cruz et al, 2005Forterre and Pouliquen, 2008;Vescovi et al, 2013;Berzi et al, 2011, or inertial-collisional regime in Campbell, 2002, 2005. The flow is purely collisional for concentrations below the random loose package: ν < ν rlp .…”

Section: Model Formulationmentioning

confidence: 99%

Snow avalanche friction relation based on extended kinetic theory

Rauter

Fischer

Fellin

et al. 2016

Nat. Hazards Earth Syst. Sci.

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Abstract. Rheological models for granular materials play an important role in the numerical simulation of dry dense snow avalanches. This article describes the application of a physically based model from the field of kinetic theory to snow avalanche simulations. The fundamental structure of the so-called extended kinetic theory is outlined and the decisive model behavior for avalanches is identified. A simplified relation, covering the basic features of the extended kinetic theory, is developed and implemented into an operational avalanche simulation software. To test the obtained friction relation, simulation results are compared to velocity and runout observations of avalanches, recorded from different field tests. As reference we utilize a classic phenomenological friction relation, which is commonly applied for hazard estimation. The quantitative comparison is based on the combination of normalized residuals of different observation variables in order to take into account the quality of the simulations in various regards. It is demonstrated that the extended kinetic theory provides a physically based explanation for the structure of phenomenological friction relations. The friction relation derived with the help of the extended kinetic theory shows advantages to the classic phenomenological friction, in particular when different events and various observation variables are investigated.

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“…() or Fischer et al . (). Their application would be imperative, but represents a challenge due to the multi‐dimensional parameter space, including the spatial pattern in some parameters. Considering what was said in (1), systematic back‐calculations of multiple events may lead to a set of guiding parameter ranges.…”

Section: Discussionmentioning

confidence: 97%

How well can we simulate complex hydro‐geomorphic process chains? The 2012 multi‐lake outburst flood in the Santa Cruz Valley (Cordillera Blanca, Perú)

Mergili

Emmer

Juřicová

et al. 2018

Earth Surf Processes Landf

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136

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Changing high‐mountain environments are characterized by destabilizing ice, rock or debris slopes connected to evolving glacial lakes. Such configurations may lead to potentially devastating sequences of mass movements (process chains or cascades). Computer simulations are supposed to assist in anticipating the possible consequences of such phenomena in order to reduce the losses. The present study explores the potential of the novel computational tool r.avaflow for simulating complex process chains. r.avaflow employs an enhanced version of the Pudasaini (2012) general two‐phase mass flow model, allowing consideration of the interactions between solid and fluid components of the flow. We back‐calculate an event that occurred in 2012 when a landslide from a moraine slope triggered a multi‐lake outburst flood in the Artizón and Santa Cruz valleys, Cordillera Blanca, Peru, involving four lakes and a substantial amount of entrained debris along the path. The documented and reconstructed flow patterns are reproduced in a largely satisfactory way in the sense of empirical adequacy. However, small variations in the uncertain parameters can fundamentally influence the behaviour of the process chain through threshold effects and positive feedbacks. Forward simulations of possible future cascading events will rely on more comprehensive case and parameter studies, but particularly on the development of appropriate strategies for decision‐making based on uncertain simulation results. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.

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Multivariate parameter optimization for computational snow avalanche simulation

Cited by 51 publications

References 65 publications

Coupled Snow Cover and Avalanche Dynamics Simulations to Evaluate Wet Snow Avalanche Activity

Coupled Snow Cover and Avalanche Dynamics Simulations to Evaluate Wet Snow Avalanche Activity

Snow avalanche friction relation based on extended kinetic theory

How well can we simulate complex hydro‐geomorphic process chains? The 2012 multi‐lake outburst flood in the Santa Cruz Valley (Cordillera Blanca, Perú)

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