文章基本信息

标题：Numerical simulations of the 2004 Indian Ocean tsunami deposits' thicknesses and emplacements
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作者：Syamsidik, ; Al'ala, Musa ; Fritz, Hermann M. 等
期刊名称：Natural Hazards and Earth System Sciences
电子版ISSN：2195-9269
出版年度：2019
卷号：19
期号：6
页码：1265-1280
DOI：10.5194/nhess-19-1265-2019
语种：English
出版社：Copernicus Publications
摘要：After more than a decade of recurring tsunamis,identification of tsunami deposits, a part of hazard characterization, stillremains a challenging task that is not fully understood. The lack of sufficientmonitoring equipment and rare tsunami frequency are among the primaryobstacles that limit our fundamental understanding of sediment transportmechanisms during a tsunami. The use of numerical simulations to studytsunami-induced sediment transport was rare in Indonesia until the2004 Indian Ocean tsunami. This study aims to couple two hydrodynamic numericalmodels in order to reproduce tsunami-induced sediment deposits, i.e., theirlocations and thicknesses. Numerical simulations were performed using theCornell Multi-grid Coupled Tsunami (COMCOT) model and Delft3D. This studyreconstructed tsunami wave propagation from its source using COMCOT, whichwas later combined with Delft3D to map the location of the tsunami depositsand calculate their thicknesses. Two-dimensional horizontal (2-DH) modelswere used as part of both simulation packages. Four sediment transportformulae were used in the simulations, namely van Rijn 1993, Engelund–Hansen 1967,Meyer-Peter–Mueller (MPM) 1948, and Soulsby 1997. Lhoong, in the AcehBesar District, located approximately 60km southwest of Banda Aceh, wasselected as the study area. Field data collected in 2015 and 2016 validatedthe forward modeling techniques adopted in this study. However, agreementsbetween numerical simulations and field observations were more robust usingdata collected in 2005, i.e., just months after the tsunami (Jaffe et al.,2006). We conducted pit (trench) tests at select locations to obtain tsunamideposit thickness and grain size distributions. The resulting numericalsimulations are useful when estimating the locations and the thicknesses ofthe tsunami deposits. The agreement between the field data and the numericalsimulations is reasonable despite a trend that overestimates the field observations.