Parallel simulations for fast‐moving landslides: Space‐time mesh adaptation and sharp tracking of the wetting front

• Published in: International journal for numerical methods in fluids 2023-08, Vol.95 (8), p.1286-1309
• Main Authors: Gatti, Federico, Fois, Marco, Falco, Carlo, Perotto, Simona, Formaggia, Luca
• Format: Article
• Language: English
• Subjects: Adaptation; Algorithms; Debris flow; depth‐integrated model; Discretization; Drying; Dynamic models; Finite element method; flow‐like landslides; Landslides; Landslides & mudslides; Mathematical models; Mudflows; Numerical methods; Oscillations; parallel computing; quadtree mesh; space‐time adaptation; Taylor–Galerkin scheme; Tracking; Wetting; Wetting front
• ISSN: 0271-2091; 1097-0363
• DOI: 10.1002/fld.5186

We propose a highly scalable solver for a two‐dimensional depth‐integrated fluid dynamic model in order to simulate flow‐like landslides, such as debris or mud flows. The governing equations are discretized on quadtree meshes by means of a two‐step second‐order Taylor–Galerkin scheme, enriched by a suitable flux correction in order to avoid spurious oscillations, in particular near discontinuities and close to the wetting‐drying interface. A mesh adaptation procedure based on a gradient‐recovery a posteriori error estimator allows us to efficiently deal with a discretization of the domain customized to the phenomenon under investigation. Moreover, we resort to an adaptive scheme also in time to prevent filtering out the landslide dynamics, and to an interface tracking algorithm to avoid an excessive refinement in noninterfacial regions while preserving details along the wetting‐drying front. Finally, after verifying the performance of the proposed numerical method on idealized settings, we carry out a scalability analysis of the code both on idealized and real scenarios, to check the efficiency of the overall implementation. We describe an efficient and highly scalable numerical framework for the simulation of the runout phase of rapid landslides. The implementation is a parallel space‐time adaptive implementation of the two‐step Taylor–Galerkin scheme on quadtree meshes, adaptions which rely on a metric‐based algorithm combined with a Lagrangian strategy for the prediction of the wet‐dry interface. The numerical framework is tested on a real scenario occurred in December 2002, the Bindo occurred in December 2002, the Bindo Cortenova landslide (LC, Italy).