TY  - JOUR
A1  - Christen, Marc
A1  - Bartelt, Perry
A1  - Kowalski, Julia
T1  - Back calculation of the In den Arelen avalanche with RAMMS: Interpretation of model results
JF  - Annals of Glaciology
N2  - 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.
KW  - avalanche
Y1  - 2010
SN  - 1727-5644
U6  - https://doi.org/10.3189/172756410791386553
VL  - 51
IS  - 54
SP  - 161
EP  - 168
PB  - Cambridge University Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Bühler, Yves
A1  - Christen, Marc
A1  - Kowalski, Julia
A1  - Bartelt, Perry
T1  - Sensitivity of snow avalanche simulations to digital elevation model quality and resolution
JF  - Annals of Glaciology
N2  - Digital elevation models (DEMs), represent the three-dimensional terrain and are the basic input for numerical snow avalanche dynamics simulations. DEMs can be acquired using topographic maps or remote-sensing technologies, such as photogrammetry or lidar. Depending on the acquisition technique, different spatial resolutions and qualities are achieved. However, there is a lack of studies that investigate the sensitivity of snow avalanche simulation algorithms to the quality and resolution of DEMs. Here, we perform calculations using the numerical avalance dynamics model RAMMS, varying the quality and spatial resolution of the underlying DEMs, while holding the simulation parameters constant. We study both channelized and open-terrain avalanche tracks with variable roughness. To quantify the variance of these simulations, we use well-documented large-scale avalanche events from Davos, Switzerland (winter 2007/08), and from our large-scale avalanche test site, Valĺee de la Sionne (winter 2005/06). We find that the DEM resolution and quality is critical for modeled flow paths, run-out distances, deposits, velocities and impact pressures. Although a spatial resolution of ~25 m is sufficient for large-scale avalanche modeling, the DEM datasets must be checked carefully for anomalies and artifacts before using them for dynamics calculations.
KW  - snow
KW  - avalanche
Y1  - 2011
SN  - 1727-5644
VL  - 52
IS  - 58
SP  - 72
EP  - 80
PB  - Cambridge University Press
CY  - Cambridge
ER  -