Performance Assessment of NAMI DANCE in Tsunami Evolution and Currents Using a Benchmark Problem

Abstract

Numerical modeling of tsunami evolution, propagation, and inundation is complicated due to numerous parameters involved in the phenomenon. It is important to assess the performance of numerical codes that solve tsunami motion, as well as flow and velocity patterns. NAMI DANCE is a computational tool developed for the modeling of long waves. It provides numerical modeling and efficient visualization of tsunami generation, propagation, and inundation mechanisms and computes the tsunami parameters. In the theory of long waves, the vertical motion of water particles has no effect on the pressure distribution. Based upon this approximation and neglecting vertical acceleration, the equations of mass conservation and momentum are reduced to two-dimensional depth-averaged equations. NAMI DANCE uses finite difference computational method to solve linear and nonlinear forms of depth-averaged shallow water equations in long wave problems. In this study, NAMI DANCE is applied to a benchmark problem which was discussed in the 2015 National Tsunami Hazard Mitigation Program (NTHMP) annual meeting in Portland, USA. The benchmark problem features a series of experiments in which a single solitary wave propagates up a triangular shaped shelf which has an offshore island feature. The problem provides detailed free surface elevation and velocity time series in the vicinity of the island. The comparison of the results showed that NAMI DANCE is able to satisfactorily predict long wave evolution, propagation, amplification, and tsunami currents.

Simulation of large plausible tsunami scenarios associated with the 2019 Durres (Albania) earthquake source and adjacent seismogenic zones

“…A tsunami hazard assessment for Durres has been carried out using a scenario-based approach that incorporated information about two nearby seismogenic sources and available topo-bathymetry data. To accomplish the objectives, we used the NAMI DANCE code manual (Velioglu et al 2016;Yalçıner et al 2017;Yalçiner and Zaytsev 2017;Lynett et al 2017;Dogan et al 2021). This code is an extension and update of the TUNAMI-N1/N2 model and solves the non-linear form of the long wave equations considering the appropriate initial and boundary conditions.…”

“…In this work, tsunami hazard computations, in terms of coastal inundation and maximum tsunami wave amplitude, are performed deterministically by the NAMI DANCE numerical code (Velioglu et al 2016;Yalçiner and Zaytsev 2017;Lynett et al 2017;Dogan et al 2021), considering earthquake worst-case scenarios. NAMI DANCE allows accounting for seismic source properties, high-resolution bathymetry and topography, and non-linear effects in wave propagation.…”

Multi-hazard analysis of flood and tsunamis on the western Mediterranean coast of Turkey

“…The NAMI DANCE software that runs the continuity and momentum equations as shallow-water equations is used to perform tsunami simulations to compute the tsunami wave height (d t ) at the coast of Fethiye, Turkey. The shallow-water equations are expressed as follows (Velioglu et al, 2016):…”

“…where η is the disturbance at the sea surface due to fault displacement, t is time, x and y are the horizontal axes on the sea surface, n is Manning's roughness coefficient, M and N are the discharge fluxes, D is the total sea depth, g is the gravitational acceleration, u and v are the water particle velocities, and h is the undisturbed sea depth. The NAMI DANCE software has the capability to compute generation, propagation, and amplification of tsunami waves using the shallowwater equations given above (Velioglu et al, 2016). In this study, tsunami wave amplification cannot be calculated due to the coarse grid size of the bathymetry.…”

Capturing Physical Dispersion Using a Nonlinear Shallow Water Model

“…The model has the capability to switch off the nonlinearity and allows nested domains in Cartesian or spherical coordinate systems. NAMI DANCE has been verified and validated with standard benchmark problems as well as with several tsunami events worldwide [18][19][20][21][22][23][24][25][26]. The governing equations of NAMI DANCE are the nonlinear form of shallow water equations and hence, the vertical motions of water particles do not have any role on the hydrostatic pressure.…”