2021 Fiscal Year Final Research Report
Formation and prediction of coastal rogue waves
| Project/Area Number |
19K21981
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 22:Civil engineering and related fields
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| Research Institution | Hokkaido University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
猿渡 亜由未 北海道大学, 工学研究院, 助教 (00563876)
森 信人 京都大学, 防災研究所, 教授 (90371476)
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| Project Period (FY) |
2019-06-28 – 2022-03-31
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| Keywords | 水工水理学 |
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| Outline of Final Research Achievements |
A nonlinear wave model to estimate wave growth and maximum crest height of focussing wave groups was developed and validated with the experimental results. The shallow water wave focusing theory has been also extended to the one with wave-curent interactions. We found that the presence of opposing current significantly amplifies the focusing waves upto six times of the initial wave height, which depends on a wave spectrum of the initial wave group. We also performed physical and computational experiments to simulate planar focusing wave groups, and found that possible effects of nonlinear energy transfers among crossing waves and flip-through phenomenon caused by the crossing wave impacts to further growth of focussing waves expected in a coastal region.
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| Free Research Field |
海岸工学
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| Academic Significance and Societal Importance of the Research Achievements |
従来の外洋で発生する巨大波と同一のメカニズムでは，沿岸域では巨大波は発生し得ないことは知られており，それ故高波による海岸災害が幾度となく繰り返されてきたにも拘らず既存の海岸工学の統計的枠組みを超えた巨大波の影響について考えられたことはなかった．本研究は，既に導出済みである浅水包絡波集中理論をベースに，沿岸域における巨大波の発生機構を実験的，数値的に再現し，異常波発生気象条件とその予測を支持する学術的根拠を与えるものである．本研究成果は，海岸防災に関わる新たなイノベーションを誘導するだけではなく，既存体系では予期できない超巨大波による未曽有の海外災害に備え強固な防災体系の実現を促すものである．
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