Search

The overall objective of the present work is to benchmark the novel Multilayer-HySEA model using laboratory experiment data for landslide generated tsunamis. In particular, this second part of the work deals with granular slides, while the first part, in a companion paper, considers rigid slides. The experimental data used have been proposed by the US National Tsunami Hazard and Mitigation Program (NTHMP) and established for the NTHMP Landslide Benchmark Workshop, held in January 2017 at Galveston. Three of the seven benchmark problems proposed in that workshop dealt with tsunamis generated by rigid slides and are collected in the companion paper (Macías et al., 2020). Another three benchmarks considered tsunamis generated by granular slides. They are the subject of the present study. In order to reproduce the laboratory experiments dealing with granular slides, two models need to be coupled, one for the granular slide and a second one for the water dynamics. The coupled model used consists of a new and efficient hybrid finite volume/finite difference implementation on GPU architectures of a non-hydrostatic multilayer model coupled with a Savage-Hutter model. A brief description of model equations and the numerical scheme is included. The dispersive properties of the multilayer model can be found in the companion paper. Then, results for the three NTHMP benchmark problems dealing with tsunamis generated by granular slides are presented with a description of each benchmark problem. [ABSTRACT FROM AUTHOR]

The present work is devoted to the benchmarking of the Multilayer-HySEA model using laboratory experiment data for landslide generated tsunamis. This first part of the work deals with rigid slides and the second part, in a companion paper, with granular slides. The US National Tsunami Hazard and Mitigation Program (NTHMP) has proposed the experimental data used and established for the NTHMP Landslide Benchmark Workshop, held in January 2017 at Galveston. The first three benchmark problems proposed in this workshop dealt with rigid slides, simulated as a moving bottom topography, that must be imposed as a prescribed boundary condition. These three benchmarks are used here to validate the Multilayer-HySEA model. This new model of the HySEA family consists of an efficient hybrid finite volume/finite difference implementation on GPU architectures of a non-hydrostatic multilayer model. A brief description of model equations, its dispersive properties, and the numerical scheme is included. The benchmarks are described and the numerical results compared against the lab measured data for each of them. The specific aim of the present work is to validate this new code for tsunamis generated by rigid slides. Nevertheless, the overall objective of the current benchmarking effort is to produce a ready-to-use numerical tool for real world landslide generated tsunami hazard assessment. This tool has already been used to reproduce the Port Valdez Alaska 1969 event. [ABSTRACT FROM AUTHOR]

Summary: High‐order finite volume schemes for conservation laws are very useful in applications, due to their ability to compute accurate solutions on quite coarse meshes and with very few restrictions on the kind of cells employed in the discretization. For balance laws, the ability to approximate up to machine precision relevant steady states allows the scheme to compute accurately, also on coarse meshes, small perturbations of such states, which are very relevant for many applications. In this paper, we propose third‐ and fourth‐order accurate finite volume schemes for the shallow water equations. The schemes have the well‐balanced property thanks to a path‐conservative approach applied to an appropriate nonconservative reformulation of the equations. High‐order accuracy is achieved by designing truly two‐dimensional (2D) reconstruction procedures of the central WENO (CWENO) type. The novel schemes are tested for accuracy and well‐balancing and shown to maintain positivity of the water height on wet/dry transitions. Finally, they are applied to simulate the Tohoku 2011 tsunami event. Novel central WENO (CWENO) reconstructions from cell averages to point values are constructed: we present one third‐order and two and fourth‐order reconstructions that require very small stencils. Path‐conservative numerical schemes for shallow water equations based on CWENO reconstructions are introduced. The schemes are well balanced, essentially nonoscillatory, preserve the positivity of the water height, and treat correctly the wet/dry transitions. Applications to the SWE model in both Cartesian and polar coordinates are presented, including a simulation of the Tohoku event. [ABSTRACT FROM AUTHOR]