Modelling of tsunami wave overtopping in a converging channel

Abstract

Field observations of tsunami show that tsunami waves travel faster and further along coastal rivers than inland due to reduced obstructions and converging boundaries, causing inundation and damage to hydraulic structures. Hence, the objective of the present study is to investigate tsunami wave heights and overtopping volumes along river walls in a converging channel. Experiments were conducted in a wave flume (using nonbreaking solitary waves and solitary breaking bores) with a 9.14m long, 0.2m high PVC sheet in the flume representing converging river wall. Later, simulation of the test cases was performed using two numerical models ANUGA and BASEMENT. The results from the numerical modelling were then compared to that of experiments to evaluate the performance of the models and their applicability for tsunami warnings in these scenarios. Different propagation and overtopping behaviour was observed for non-breaking solitary waves and solitary breaking bores.