2019 Fiscal Year Final Research Report
Observational Evidence and Mechanistic Insight on the Regeneration Process of Riverine Forestation from a Massive Flood Impact
| Project/Area Number |
16H04422
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Hydraulic engineering
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| Research Institution | Shibaura Institute of Technology |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
戸田 祐嗣 名古屋大学, 工学研究科, 教授 (60301173)
赤松 良久 山口大学, 大学院創成科学研究科, 准教授 (30448584)
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Keywords | 河川工学 / 環境水理 / 河道管理 / 河川樹林化 |
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| Outline of Final Research Achievements |
This study focused on the regeneration process after a massive flood impact in the phenomenon of river vegetation overgrowth, which was significantly related to the flood damage prevention and fluvial ecosystem management. The Kinu river survey revealed that the bed shear stress, and the relative height difference well affected the vegetation invasion. In the Suzuka river survey, the number of buried seeds was massive at the edge of the watercourse and behind the dune. However, the actual germination tended to occur only in locations where suitable physical conditions were satisfied. An ecological model analysis indicated that a river had a high tendency of the vegetation invasion and growth. In contrast, another stream tended to be a bare land due to a flood impact and riverbed reduction. These findings clarified that the interaction of discharge, topography, and vegetation greatly influenced the initial regeneration process of vegetation in rivers.
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| Free Research Field |
水工学
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| Academic Significance and Societal Importance of the Research Achievements |
日本を含めた世界各地の河川流域において経年進行する河川の樹林化は、河川を管理するうえで様々な問題を引き起こす。これは、近年の地球温暖化で頻発している洪水の流下能力低下に加えて、河川下流域での流木被害、さらには、礫川原・砂州生態系の生物多様性の喪失にも繋がっている。本研究は、特に樹林化される河川において洪水後の初期再生過程の解明に焦点を絞ったものであり、河川本来の、砂州・礫河原が洪水により自律的に保全・維持されるための基礎過程の一部を実証的に明らかにしている。本研究の成果は、治水と環境のバランスを的確に考慮した、これからの新しい河川管理技術の確立のために重要な基礎的知見を与えるものとなっている。
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