| Project/Area Number |
21K04273
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 22040:Hydroengineering-related
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| Research Institution | Osaka University |
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Principal Investigator |
Nakatani Yusuke 大阪大学, 大学院工学研究科, 准教授 (20635164)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Project Status |
Completed (Fiscal Year 2023)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2023: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2022: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2021: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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| Keywords | 瀬戸内海 / 化学的酸素要求量 / 外洋起源有機物 / 数値シミュレーション / 流動水質シミュレーション / 外洋起源 / 難分解性有機物 / 化学的酸素要求量COD |
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| Outline of Research at the Start |
瀬戸内海では40余年にわたり陸域から流入する汚濁負荷を削減してきたにも拘わらず，近年は化学的酸素要求量CODが横ばいあるいは微増しており，多くの湾灘で環境基準を未だ達成していない．この水質異変の原因の一つとして，難分解性の外洋起源有機物の動態が影響している可能性が指摘されているが，実態は明らかにされていない．
本研究では，瀬戸内海における外洋起源有機物の動態を解明し，近年のCOD異変への影響を明らかにする．得られる成果を基に，海域CODの制御可能性とその限界を定量的に示すことで，瀬戸内海における今後の水質管理方針の抜本的見直しを提案する．
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| Outline of Final Research Achievements |
In the Seto Inland Sea, the achievement rate of the environmental standard for chemical oxygen demand (COD) is low, and there is a need to clarify the cause of this low COD. In this study, a three-dimensional flow and water quality model was used to analyze the dynamics of organic matter of open-ocean origin in the Seto Inland Sea and to clarify its influence on the recent COD anomaly. As a result, it was found that the amount of oceanic COD that cannot be artificially controlled is up to 60% and at least 20% of the total COD in the Seto Inland Sea, and it is considered to be an amount that cannot be ignored in the water quality management of the Seto Inland Sea.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究において，瀬戸内海における外洋起源有機物の動態を解明し，CODの制御可能性とその限界を定量的に示したことで，今後の水質管理方針の抜本的見直しに資する知見を得た．
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