Improvement of prediction methods of coastal scour and erosion due to tsunami back-flow

Abstract

The 2004 Indian Ocean tsunami caused large-scale erosion and scour on many coasts. If the coastal scour by the first tsunami wave caused the destruction of a dyke, the second tsunami wave may generate much more serious damage. Therefore, it is necessary to research on the improvement of prediction methods for erosion and scour by tsunami. This paper presents a numerical model for the above mentioned purpose. In the model, the sediment transport due to tsunami is simulated by using user-friendly prediction methods, and considering bed load and suspended load transport. Furthermore, prediction methods on the maximum scour depth and its position at the beach in front of a seawall are also proposed. © 2010 by The International Society of Offshore and Polar Engineers (ISOPE).