2019 Fiscal Year Final Research Report
Decision support method for planning fish nests and fish pool based on prediction of spatiotemporal canal bed evolution caused by sedimentation
| Project/Area Number |
16K07935
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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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| Research Field |
Rural environmental engineering/Planning
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| Research Institution | Ibaraki University |
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Principal Investigator |
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| Project Period (FY) |
2016-10-21 – 2020-03-31
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| Keywords | 生態環境 / 農業用排水路 / 数値計算 / 路床変動 / 土砂水理 |
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| Outline of Final Research Achievements |
Field observations and numerical simulations of flow and canal bed evolution were carried out for a section of agricultural drainage canal where fish nests and fish pool were introduced. The amount of sediment change in fish nests and fish pool was estimated from the distribution of bed elevation for four years. Sedimentation and scouring in fish nests changed in a yearly cycle. Although the increase in sedimentation in all 6 fish nests was small, there were fish nests in which sedimentation was significant and the fish habitat decreased. The remarkable sedimentation in the left bank fish nest could be reproduced by numerical simulation. Furthermore, numerical computations showed that sedimentation and scouring tended to change significantly depending on the size of fish nests, and clarified the issues to be dealt with in order to design a more effective eco-friendly structures.
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| Free Research Field |
生態水理学
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| Academic Significance and Societal Importance of the Research Achievements |
農業用排水路における環境配慮工の価値は，水路の生態系保全機能だけでなく，営農，治水，維持管理，経済性等の観点からも評価する必要がある．しかし，複数の観点から環境配慮工を評価するための方法論は確立されていない．一方，流れと路床変動の数値計算を用いれば，水深，流量，堆砂量の変化を系統的に発生させることができるため，営農，治水，維持管理性を踏まえつつ生態系保全機能を定量化できる．本研究ではこの点に着目し，環境配慮工のより良い設計のために既存の数値モデルにより何ができ，何ができないかを整理した．
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