Finite element method for tsunami wave propagation analysis considering the open boundary condition

AbstractA method for the treatment of the open boundary condition in the shallow-water equation to analyze the propagation of tsunami waves using a finite element method is proposed. The key feature of this method is that the analytical solutions of the linear shallow-water equation can be linked with the inner values of the velocity and the water elevation on the open boundary. The two-step explicit method is used to discretize the time function, which has an advantage in problems treating large numbers of elements and unsteady state. Two test examples have been carried out. The numerical results are in good agreement with the analytical solutions. The tokachi-oki Earthquake tsunami has been computed. The computed results have been compared with the observed tide gauge records. From these comparative studies, it can be concluded that the present method is a useful and effective tool in predicting tsunami generation and propagation