NUMERICAL SIMULATIONS OF THE 2004 INDIAN OCEAN TSUNAMIS — COASTAL EFFECTS

Abstract

The 2004 Sumatra earthquake and the associated tsunamis are one of the most devastating natural disasters in the last century. The tsunamis flooded a huge coastal area in the surrounding countries, especially in Indonesia, Thailand and Sri Lanka, and caused enormous loss of human lives and properties. In this paper, tsunami inundations in Trincomalee, Sri Lanka and North Banda Aceh, Indonesia were simulated by using a finite-difference model based on nonlinear shallow-water equations. The calculated tsunami heights and inundations in these two regions are compared with the field measurements and observations. Fairly good agreement is observed. Numerical results confirm again that the local bathymetric and topographic characteristics play important roles in determining the inundation area. Numerical simulations further indicate that although nonlinearity becomes important in many dynamic aspects when tsunamis approach the shore, its influence on determining the inundation area is relatively small in the regions examined for this tsunami event. Finally, the potential capability of sediment transport and a force index on a virtual structure in flooded areas are introduced and discussed.