Application of HHT to Study the 311 Tsunami from Tidal Data / 應用 HHT 分析 311 海嘯波動之研究

碩士 / 國立高雄海洋科技大學 / 海事資訊科技研究所 / 101 / The Hilbert – Huang Transform (HHT) method is employed to analyze the 311 tsunami characteristics around Taiwan in this study. This study analyzes the sea water levels recorded at 5 stations (Keelung Harbor, Hualien Harbor, Houbihu Harbor, Kaohsiung Harbor, Taichung Harbor) around Taiwan throughoust March 2011, the tidal water level data sources from Central Weather Bureau and the Institute of Harbor and Marine Technology (IHMT). Due to the excellent time-frequency resolution of HHT, it is chosen to simulate the performance of frequency modulation interference suppression. It is based on the empirical mode decomposition (EMD) which generates a group of intrinsic mode functions (IMF). The Ensemble Empirical Mode Decomposition (EEMD) approach consists of sifting an ensemble of white noise-added signal and treats the mean as the final true result, so it prevents “mode mixing”. The Ensemble EMD (EEMD) is adopted to decompose the tidal elevation data to derive the intrinsic mod functions (IMF). This study also adopts HHT to study the phenomena of tidal elevation and tsunami characteristics, which are based on the observed tidal data. This work shows that HHT can reveal the Tsunami arrival on energy-frequency-time plot and time period of Tsunami. Therefore, according to Hilbert spectrum distribution of 311 Tsunami from tidal data, it can acquire accurately the moment of inception of maximum run-up height. Meanwhile, it can predict the duration of influence of 311 Tsunami around Taiwan from the variation of the IMF. All of these above results will provide better understanding of the 311 tsunami characteristics

Identiferoai:union.ndltd.org:TW/101NKIM0297008
Date January 2013
CreatorsLi Wen- Sheng, 李文聖
ContributorsHsieh Chih-Min, Yang Wen-Chang, 謝志敏, 楊文昌
Source SetsNational Digital Library of Theses and Dissertations in Taiwan
Languagezh-TW
Detected LanguageEnglish
Type學位論文 ; thesis
Format100

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