NUMERICAL STUDY ON THE INFLUENCE OF TSUNAMI-INDUCED TOPOGRAPHIC CHANGES ON THE TRANSPORT AND ACCUMULATION OF DEBRIS

Abstract

 In this study, in order to clarify the influence of topographic changes caused by tsunami on the transport and accumulation of debris, we developed a numerical model considering both the topographic changes and debris transport, and conducted numerical studies on debris transport phenomena in a port and around a coastal area during tsunami attack. The simulations of debris transport in the harbor with movable bed showed that the debris remaining rate in the harbor may be low under the condition that the debris does not touch the ground. In addition, the simulations of debris transport on a uniform slope with movable bed showed that the effect of topographic changes on the debris remaining rate on land is relatively small. However, with topographic changes, debris may accumulate deeper into the land area than without the change. These results indicate that the necessity of considering topographic changes in predicting the transport and accumulation of debris in ports and coastal areas where the seabed is composed of fine sand.