| Project/Area Number |
21H01434
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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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| Review Section |
Basic Section 22040:Hydroengineering-related
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
武藤 裕則 徳島大学, 大学院社会産業理工学研究部(理工学域), 教授 (40263157)
角 哲也 京都大学, 防災研究所, 教授 (40311732)
小柴 孝太 京都大学, 防災研究所, 助教 (80883157)
竹門 康弘 京都大学, 防災研究所, 准教授 (50222104)
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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 |
¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000)
Fiscal Year 2023: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2022: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2021: ¥8,580,000 (Direct Cost: ¥6,600,000、Indirect Cost: ¥1,980,000)
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| Keywords | Sediment Replenishment / Morphological changes / Erosion processes / 2D numerical modeling / Optimization of SR / Imaged- based-technique / Habitat restoration / 土砂還元 / 流砂連続性 / 画像解析 / 側岸侵食過程 / 生態機能評価 / Numerical simulation / TELEMAC2D / Model calibration / Suspended sediment / Buech River / flood pulses / Sediment pulses / Replenishment Scenarios / LSPIV and STIV / Basegrain / Naka River / Sediment erosion rate / Flushing flow / SR assessment method |
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| Outline of Research at the Start |
ダムで遮断された流砂連続性の回復手段として、ダム下流への土砂還元（置き土）が実施されている。ここでは、粒径集団ごとの土砂収支に加えて、流量－流砂レジームを自然に近い形でいかに再現するかが大きな課題となる。本研究では、土砂還元手法の高度化に向けて、洪水波形中の土砂供給のデザイン手法や下流で新たに形成される砂州の生態機能をいかに評価するか、などの課題に取り組む。具体的には、徳島県那賀川（長安口ダム）における置土の侵食過程をモニタリングカメラによる現地観測により記録し分析するとともに、TELEMAC3Dをベースとした置土侵食と砂州形成の数値解析を、同様な試みを実施しているフランス電力と共同で行う。
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| Outline of Final Research Achievements |
The project aimed to create a real-time monitoring system and assessment approach for sediment replenishment (SR) in Naka River, Tokushima prefecture, Japan. The main practice involves adding sediment using artificial deposits or injections to restore downstream geomorphic ecology. We developed an image-based approach to detect the replenishment site's flow velocities and sediment erosion rates. We conducted a field visit and collected data from the Buech River in France. We established a two-dimensional model to simulate the hydro-morphological changes of SR in the Naka River. The impacts of flushing flow, replenished sediment, and the SR arrangement were assessed using morphological alterations and two scientific indicators (the transport ratio (TR) and the bed change indicator (BCI)). This project's findings can help predict the SR erosion processes and downstream geomorphological alterations of the SR.
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| Academic Significance and Societal Importance of the Research Achievements |
The project offers valuable suggestions for improving the SR in the Naka River, including increasing the frequency of sediment flushing, improving the materials used in the SR, and building new SR stockpiles to ensure a consistent sediment supply during dry periods.
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