Development of A Fast Tsunami Simulation System Based on The Linear Boussinesq Theory

Abstract

A fast tsunami simulation system was developed which utilized the superposition of point source computations stocked as a database. The single point source was represented by the Gaussian distribution with s=5 km. The propagation of the point source was computed by using the linear Boussinesq theory. The accuracy of the model was discussed in representing the actual tsunami source profile as well as in the dispersive tsunami propagation. The system was applied to a hypothetical Japan Sea tsunami used in the disaster mitigation planning of Tottori Prefecture. The system successfully displayed the sensitivity of local tsunami height to the tsunami source location and thus demonstrated the performance to assist specific evacuation planning in individual towns and cities.

A numerical study on nearshore behavior of Japan Sea tsunamis using Green’s functions for Gaussian sources based on linear Boussinesq theory

“…This study evaluated H and σ to be 1 m and 5 km, respectively. These values are similar to the values used by Yamanaka et al (2014). Such a small Gaussian source must be very dispersive and should therefore be simulated by the linear Boussinesq equations (dispersive equations) rather than by the linear long wave equations.…”

“…They numerically solved tsunami propagations from the unit source based on the linear long wave equations. However, such sources, including waveforms expressed by delta functions, usually generate chaotic waveforms by numerical vibrations on simulated waveforms (Yamanaka et al 2014). Thus, this study follows the concept used by Ito, Tajima, and Sato (2013), but adopts an initial sea surface deformation (a unit source) expressed by the following Gaussian distribution (Yamanaka et al 2014;Saito et al 2011): ηðx; yÞ ¼ Hexp À ðx À x 0 Þ 2 þ ðy À y 0 Þ 2 2σ 2 " #…”