Numerical Modeling of Generation of Landslide Tsunamis: A Review

Abstract

Depth-integrated wave models are widely used for simulating large-scale propagation of landslide tsunamis, with the generation of tsunami being simulated separately by various generation models to provide the required initial conditions. For a given problem, the selection of a proper tsunami generation model is an important aspect for tsunami hazard analysis. The generation of tsunamis by submarine or subaerial landslides is a transient multiphase process which involves important fine-scale physics. Depth-integrated generation models, while relatively easy to use, cannot simulate these fine-scale physics. Depth-resolved generation models can overcome the shortcomings of depth-integrated generation models but are computationally demanding. This paper first reviews existing depth-integrated generation models to show the need for depth-resolved generation models. Four classes of depth-resolved generation models are reviewed: computational fluid dynamics (CFD) models, approaches coupling CFD and discrete element method, multiphase flow models, and meshless particle models. Multiphase flow models, which are relatively new, can consider complex interactions between landslide materials and its surrounding fluids. Meshless particle models are appealing for simulating landslide tsunamis because of their convenience to deal with the violent motion of the water surface and ability to run on graphics processing units. The main strengths, weaknesses, and future research directions of the reviewed models are briefly discussed. The literature reviewed, which is by no means complete, aims to provide researchers updated and practical guidelines on numerical modeling techniques for simulating the generation process of landslide tsunamis.

Translational momentum of deformable submarine landslides off a slope

“…In this paper, the translational momentum of deformable submarine landslides off a non-erodible slope is numerically investigated with a two-phase smoothed particle hydrodynamics (SPH) model (Shi, Yu & Dalrymple 2017;Shi et al 2019Shi et al , 2021. Yavari-Ramshe & Ataie-Ashtiani (2016), Kirby et al (2022) and Lee et al (2022) have provided comprehensive reviews of numerical models for submarine and subaerial landslides. Specifically, for deformable submarine landslides, four main types of numerical models have been developed.…”

“…The velocity difference between the solid particles and the interstitial water was unsolved (Yavari-Ramshe & Ataie-Ashtiani 2016). However, in real landslide events, the two-phase nature of the slides could not be neglected (Yavari-Ramshe & Ataie-Ashtiani 2017; Lee et al 2022). Thus, the fourth main type of landslide models, i.e.…”

“…A few Eulerian-Eulerian models (phase-resolved Navier-Stokes equations for both the particle and the water phases in the slides, Meruane, Tamburrino & Roche 2010;Armanini et al 2014;Kaitna, Dietrich & Hsu 2014;Savage, Babaei & Dabros 2014;Bouchut et al 2016;Yavari-Ramshe & Ataie-Ashtiani 2017;Si, Shi & Yu 2018;Lee & Huang 2021;Rauter 2021;Rauter et al 2022) and Eulerian-Lagrangian models (phase-resolved Navier-Stokes equations for the water phase and Lagrangian particle tracking methods such as the discrete element method (DEM) for individual particles in the slides, Zhao, Utili & Crosta 2016;Jiang, Shen & Wu 2018;Yang et al 2020;Nguyen 2022) have been developed for deformable landslides. To capture the generated waves, meshless numerical methods such as SPH have been increasingly adopted to solve the governing equations (Ataie-Ashtiani & Shobeyri 2008;Tajnesaie et al 2018;Shi et al 2021;Lee et al 2022). In the present study, the momentum of both the particle and the water phases in deformable submarine landslides is investigated and hence a two-phase model is preferred.…”

“…(2022) and Lee et al. (2022) have provided comprehensive reviews of numerical models for submarine and subaerial landslides. Specifically, for deformable submarine landslides, four main types of numerical models have been developed.…”

“…However, in real landslide events, the two-phase nature of the slides could not be neglected (Yavari-Ramshe & Ataie-Ashtiani 2017; Lee et al. 2022). Thus, the fourth main type of landslide models, i.e.…”