Perpustakaan Digital ITB

In many cases, tsunami waveheights and effects show a high variability along the coast. One way to study this complexity is to simulate the tsunami above a certain area by using water wave models. Since a tsunami can be considered as a shallow water wave, we can choose the well-known Shallow Water Equations (SWE) as a non-dispersive water wave model for the tsunami. Dispersive wave means that harmonic waves of smaller wavelength propagate slower than waves of larger wavelength. For the dispersive wave model, we used the recently derived. Variational Boussinesq Model (VBM). In the SWE model the vertical variations in the layer of fluid is neglected, different from the VBM where the vertical variations lead to the effect of dispersion. These models are derived by using variational formulation. Consistently with the way of their derivations, these models will be solved numerically by using Finite Element Method (FEM). In FEM, the solutions are approximated by linear combination of the basis functions. In this thesis, we used linear basis functions. The radiation boundary condition and hard-wall boundary condition are implemented for both SWE and VBM. To simulate the tsunami, we use the available data of the bathymetry of Indonesia which is incorporated into our FEM schemes. The tsunami simulation in the two areas of Indonesia, which are the area in the south of Pangandaran and the area in the south of Lampung, will be presented as a result of FEM's implementation for the SWE and the VBM.