Numerical Simulation of Morphological Changes due to the 2004 Tsunami Wave around Banda Aceh, Indonesia

Teuku Rasyif,Shigeru Kato,Takumi Okabe,Syamsidik Syamsidik

doi:10.3390/geosciences9030125

Abstract

The 2004 Indian Ocean tsunami caused massive morphological changes around the coast of Sumatra, Indonesia. This research investigates the coastal morphological changes in the Banda Aceh area via coupling a hydrodynamic model with a sediment transport module. The Cornell Multigrid Coupled Tsunami Model (COMCOT) was coupled with the XBeach Model to simultaneously simulate sediment transport and the hydrodynamic process during the tsunami. The coupled model is known as COMCOT-SED. Field bathymetric data measured in 2006 were used to validate the coupled model. This study reveals that the tsunami’s impact was more severe on the eastern part of the coast, where it hit directly. Meanwhile, the western part of the coast suffered a lower impact because of the sheltering effects from a series of small islands and a headland to the north. This study has shown that the model results from COMCOT-SED are consistent with field data and show where the tsunami waves caused offshore erosion.

Highlights

Extreme events, such as tsunami waves and storm surges, can cause severe change to coastal morphology
The tsunami wave flooded toward Banda Aceh city with a maximum inundation distance of about 4 km from the shoreline according to field observation [22]
This can be explained because Banda Aceh city had a lot of structures around the coastal area which were not reproduced in the simulation, and they can reduce the tsunami wave energy and limit inundation further inland

Summary

Introduction

Extreme events, such as tsunami waves and storm surges, can cause severe change to coastal morphology. Notwithstanding the latest developments in tsunami engineering, we still do not fully understand the massive sediment transport that occurs during tsunami waves. The 2004 Indian Ocean tsunami that eroded a large part of coastal areas in affected coasts provides important evidence on tsunami sediment transport. The hydrodynamics of tsunami waves can result in massive destruction of coastal areas [1,2,3]. Previous research has mainly focused on morphological changes from the tsunami wave by observing the change based on satellite images, aerial photo, and field measurements [4,5,6]. Very few numerical investigations of beach profile changes caused by tsunami waves have been performed [7,8]

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