Numerical modelling of dense snow avalanches with a well-balanced scheme based on the 2D shallow water equations

• Published in: Journal of Glaciology
• Main Authors: Sanz Ramos, Marcos, Bladé i Castellet, Ernest, Oller, Pere, Furdada, Glòria
• Other Authors: Universitat Politècnica de Catalunya. Doctorat en Enginyeria Civil, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. Geo2Aqua - Monitoring, modelling and geomatics for hydro-geomorphological processes
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Àrees temàtiques de la UPC::Física::Física de fluids; Non-Newtonian fluids; Avalanches; Landslides; 2D Shallow Water Equations; Dense snow avalanches; Finite volume method; Non–Newtonian fluid; Roe scheme; Fluids no newtonians; Allaus; Esllavissades; Journal of Glaciology
• Online Access: http://hdl.handle.net/2117/400798; https://doi.org/10.1017/jog.2023.48

A common technique for simulating non–Newtonian fluid dynamics, such as snow avalanches, is to solve the Shallow Water Equations (SWE), together with a rheological model describing the momentum dissipation by shear stresses. Friction and cohesion terms are commonly modelled using the Voellmy friction model and, recently, the Bartelt cohesion model. Here, an adaptation of the Roe scheme that ensures the balance between the flux and pressure gradients and the friction source term is presented. An upwind scheme was used for the discretisation of the SWE numerical fluxes and the non–velocity-dependent terms of the friction–cohesion model, whereas a centred scheme was used for the velocity-dependent source terms. The model was tested in analytically solvable settings, laboratory experiments and real cases. In all cases, the model performed well, avoiding numerical instabilities and achieving stable and consistent solution even for an avalanche stopping on a sloping terrain. Postprint (published version)