Abstract
A large amount of sediment is transported by tsunami. While there are many studies on the amount of sediment transport or bathymetry changes by tsunami under the condition of active sediment transport, there are only few studies in the lower regime. In addition, not many studies have focused on the unsteady processes of bathymetry changes due to the propagation of tsunami. This research aims to evaluate the tsunami force, and to study the relationship between the force and bathymetry changes in the lower regime by movable-bed experiments. It was observed that ripples are formed when waves subsequent to the tsunami front reach the bed. The bathymetry changes can be classified by the method used in rivers. The relationship between the spatial distribution of grain size and shear stress observed in the experiments is consistent to existing studies.
