A two-layer non-hydrostatic landslide model for tsunami generation on irregular bathymetry. 1. Theoretical basis
Date of Original Version
We describe a two-layer, coupled model for landslide motion over irregular bathymetry and resulting water column motion and tsunami generation. The three-dimensional non-hydrostatic wave model NHWAVE (Ma et al., 2012) is applied as the upper-layer model to simulate landslide-generated tsunami waves. Here, we focus on the derivation of governing equations for the lower-layer model, where the landslide is described as either a viscous mud flow or a saturated granular debris flow. The governing equations are depth-integrated in a Cartesian coordinate system referenced to the still water surface. Vertical acceleration of the slide is taken into account by including non-hydrostatic pressure effects within the slide. The model is validated in comparison to analytic results of Mangeney et al. (2000) and the slope-oriented numerical approach of Ma et al. (2015). The numerical approach and further examples are described in the companion paper Zhang et al. (2021).
Zhang, Cheng, James T. Kirby, Fengyan Shi, Gangfeng Ma, and Stéphan T. Grilli. "A two-layer non-hydrostatic landslide model for tsunami generation on irregular bathymetry. 1. Theoretical basis." Ocean Modelling 159, (2021). doi:10.1016/j.ocemod.2020.101749.