Tsunami Wave Impacts on Coastal Morphological Changes and One-Decade Process of Coastal Line Recovery after the 2004 Indian Ocean Tsunami around Banda Aceh, Indonesia

摘要

The 2004 Indian Ocean tsunami has been leaving a number of scientificquestions related to sediment transport process. The questions are notonly about the involving process during the tsunami waves propagation,but also about the recovery process of the coastal morphology as shownaround Banda Aceh of Indonesia. The source of the sediment transportand location of the sediment deposition around the nearshore area areamong the questions that motivated this research. This study aims atestimating the sediment deposition location after the 2004 tsunami andat identifying factors contributing to the return of coastal line aroundBanda Aceh after one-decade process. Cornell Multi-grid COupledTsunami (COMCOT) model and Delft3D-Flow were used to simulatethe morphological changes due to the Indian Ocean tsunami. The faultmechanism of the 2004 tsunami adopted multi-fault mechanism asvalidated by Romano (2009). Meanwhile, to monitor the coastalrecovery process, we used time-series spatial analysis by means of GIS.It is found that the COMCOT and Delft3D have been successfully beencoupled to simulate the coastal line erosion due to the 2004 IndianOcean tsunami. The inundation limit obtained from the simulation isalso agreeable to the actual data digitized from January 2005 data. Theland use of the area has been mostly recovered after one-decade of thetsunami. However, aquaculture activities around this area could berecovered fully and there was a significant decrease of area for fishponds/shrimp ponds. The recovered coastal line was helped by thecoastal process and no significant hard structure was introduced in thisarea to recover the eroded coastal line.