碩士 / 國立中央大學 / 水文與海洋科學研究所 / 100 / Due to the frequent large-scale Tsunami events recently, attention has been drawn to the destruction brought by these events and the relevant scientific and engineering issues. Dissipation induced by coastal vegetation is an important and environment-friendly method for reducing the hazard caused by tsunamis. Due to locating on the Pacific ring of fire, Taiwan is under the threat of tsunami events. The present study focuses energy reduction caused by the coastal vegetation to the tsunami events in Taiwan. At first, the present study focuses on describing the bore behavior of dam-break cases. The experimental data are used to validate the numerical model, LES-VOF model. The interaction between a bore and a complex pillar array is presented. We found that the LES-VOF model is capable of precisely predicting breaking waves and energy dissipation that occur after the impact of the bore to the structure.
However, as considering the time-consuming issue on the 3D simulation, we develop a porous media model that aims at replacing the complex yet uniform vegetation structure with a porous structure. The applicability of different porous drag models with different porosities is analyzed, and validated with the experimental data. It is found that the simulation results and the experimental data are highly consistent.
At the last part of this study is to investigate the effect of energy caused by vegetation in Kenting area. A real-bathymetry numerical simulation is conducted, and a tsunami scenario which oriented from Manila trench is considered. The result shows that the dense vegetation will have significant effect on the maximum run-up height, inundation distance, flow velocity and maximum run-down. In this case, two porosities of the filed vegetation are considered. The result shows that run-up height of porosity 0.95 is increased by 5.36%, and porosity 0.75 is increased by 23.21%.
| Identifer | oai:union.ndltd.org:TW/100NCU05761014 |
| Date | January 2012 |
| Creators | An-Ho Ling, 凌安和 |
| Contributors | Tso-Ren Wu, 吳祚任 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 248 |
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