지진해일 전파모의를 위한 유한차분모형 개발

Abstract

The transoceanic propagation of tsunami can be adequately modeled by using the linear Boussinesq equations. However, the linear Boussinesq equations may consume a huge computer memory space and excessive computational time to deal with frequency dispersion terms expressed by higher order derivatives. In the previous studies, thus, the linear shallow-water equations are discretized for simulating transoceanic propagation of tsunamis instead of the linear Boussinesq equations. The physical dispersion is compensated by the numerical dispersion induces by discretization. However, the linear Boussinesq equations can be directly solved because the computational ability in the computer science has been improved dramatically. In this study, a new finite difference scheme is proposed to discretize the linear Boussinesq equations. The nested tsunami propagation model is developed by adopting the new scheme and applied to propagation of a Gaussian hump over a constant water depth. The predicted free surface displacements are compared with available analytical solutions. A very reasonable agreement is observed. The scheme can be directly applied to simulation of transoceanic propagation of tsunamis.