Item: INFLUENCE OF DTM/DEM RESOLUTION AND DOMAIN DISCRETIZATION ON THE SNOW AVALANCHE DYNAMICS MODELLING
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Title: INFLUENCE OF DTM/DEM RESOLUTION AND DOMAIN DISCRETIZATION ON THE SNOW AVALANCHE DYNAMICS MODELLING
Proceedings: International Snow Science Workshop 2024, Tromsø, Norway
Authors:
- Marcos Sanz-Ramos [ Flumen Research Institute (Universitat Politècncia de Catalonya - International Centre of Numerical Methods in Engineering ]
- Pere Oller [ GeoNeu Risk, Barcelona, Spain ] [ Risknat group (University of Barcelona) ]
- Ernest Bladé [ Flumen Research Institute (Universitat Politècncia de Catalonya - International Centre of Numerical Methods in Engineering ]
Date: 2024-09-23
Abstract: Numerical modelling of snow avalanche dynamics requires necessarily the utilisation of terrain topography to update the elevation of the calculation mesh. Free distributed topographical data is currently available worldwide through digital terrain models (DTM), from coarse to fine resolutions. This work aims on investigating the influence of the DTM resolution, both in the horizontal and vertical accuracy, on the results of the bulk dynamics of dense snow avalanches. To that end, the numerical tool Iber, a depth-averaged hydrodynamic numerical tool recently enhanced for the simulation of non–Newtonian shallow flows such as snow avalanches, was used. Several calculation scenarios, based on two well-documented events, were carried out utilising combinations of different mesh sizes and DTMs. The findings reveal the importance of DTM resolution for mid-low size avalanches. When comparing identical mesh resolutions, the vertical precision of the DTM has a more significant impact on the avalanche dynamics than the horizontal resolution of the DTM. Even with a five-fold improvement in spatial resolution, which currently includes LiDAR techniques, the outcomes derived from the 5-meter DTM closely resembled those of the 2-meter DTM, the computational cost being reduced notably. LiDAR-based topographical data allows the generation of DTM and DEM (digital elevation models), being the latest useful to represent the obstructions on the flow dynamics due to the vegetation and providing a closest representation of the avalanche dynamics to the observations
Object ID: ISSW2024_P2.5.pdf
Language of Article: English
Presenter(s): Marcos Sanz-Ramos
Keywords: DTM/DEM, numerical modelling, Iber, smoothing, fill sinks
Page Number(s): 339 - 345
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