@inproceedings{ChristenBarteltKowalskietal.2008,
  author    = {Christen, Marc and Bartelt, Perry and Kowalski, Julia and Stoffel, Lukus},
  title     = {Calculation of dense snow avalanches in three-dimensional terrain with the numerical simulation programm RAMMS},
  series = {Proceedings ISSW 2008 ; International Snow Science Workshop. Whistler 2008},
  booktitle = {Proceedings ISSW 2008 ; International Snow Science Workshop. Whistler 2008},
  pages     = {709 -- 716},
  year      = {2008},
  abstract  = {Numerical models have become an essential part of snow avalanche engineering. Recent advances in understanding the rheology of flowing snow and the mechanics of entrainment and deposition have made numerical models more reliable. Coupled with field observations and historical records, they are especially helpful in understanding avalanche flow in complex terrain. However, the application of numerical models poses several new challenges to avalanche engineers. A detailed understanding of the avalanche phenomena is required to specify initial conditions (release zone dimensions and snowcover entrainment rates) as well as the friction parameters, which are no longer based on empirical back-calculations, rather terrain roughness, vegetation and snow properties. In this paper we discuss these problems by presenting the computer model RAMMS, which was specially designed by the SLF as a practical tool for avalanche engineers. RAMMS solves the depth-averaged equations governing avalanche flow with first and second-order numerical solution schemes. A tremendous effort has been invested in the implementation of advanced input and output features. Simulation results are therefore clearly and easily visualized to simplify their interpretation. More importantly, RAMMS has been applied to a series of well-documented avalanches to gauge model performance. In this paper we present the governing differential equations, highlight some of the input and output features of RAMMS and then discuss the simulation of the Gatschiefer avalanche that occurred in April 2008, near Klosters/Monbiel, Switzerland.},
  language  = {en}
}
@article{ChristenBarteltKowalski2010,
  author    = {Christen, Marc and Bartelt, Perry and Kowalski, Julia},
  title     = {Back calculation of the In den Arelen avalanche with RAMMS: Interpretation of model results},
  series = {Annals of Glaciology},
  volume    = {51},
  journal   = {Annals of Glaciology},
  number    = {54},
  publisher = {Cambridge University Press},
  address   = {Cambridge},
  isbn      = {1727-5644},
  doi       = {10.3189/172756410791386553},
  pages     = {161 -- 168},
  year      = {2010},
  abstract  = {Two- and three-dimensional avalanche dynamics models are being increasingly used in hazard-mitigation studies. These models can provide improved and more accurate results for hazard mapping than the simple one-dimensional models presently used in practice. However, two- and three-dimensional models generate an extensive amount of output data, making the interpretation of simulation results more difficult. To perform a simulation in three-dimensional terrain, numerical models require a digital elevation model, specification of avalanche release areas (spatial extent and volume), selection of solution methods, finding an adequate calculation resolution and, finally, the choice of friction parameters. In this paper, the importance and difficulty of correctly setting up and analysing the results of a numerical avalanche dynamics simulation is discussed. We apply the two-dimensional simulation program RAMMS to the 1968 extreme avalanche event In den Arelen. We show the effect of model input variations on simulation results and the dangers and complexities in their interpretation.},
  language  = {en}
}