Development of upstream inclined weir fishways for fishes around paddy fields

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K07652
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Rural environmental engineering/Planning
• Research Institution: Ishikawa Prefectural University
• Principal Investigator: Ichion Eiji 石川県立大学, 生物資源環境学部, 教授 (10320912)
• Co-Investigator(Kenkyū-buntansha): 藤原 洋一 石川県立大学, 生物資源環境学部, 准教授 (10414038) ; 長野 峻介 石川県立大学, 生物資源環境学部, 講師 (90646978)
• Research Collaborator: NAKANO mitsunori ; TANAKA kenji
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 傾斜隔壁 / V字ノッチ / 農業水路 / フナ類 / ドジョウ / メダカ類

Outline of Final Research Achievements

Nine types of sloped-weirs for fishways were made by changing the angle of the weir slope (α) and that of the V-shaped notch on the upper surface of the weir (β). Several volumetric flow rates (1.58-14.43L/s) were used in the experiments for each weir type.The ascent rates for Oryzias sakaizumii, Misgurnus anguillicaudatus, and Carassius sp. were determined for each type weir in the experimental flume. We identified the suitable types of weirs for each species. In addition, our results suggest that the weir with α=45°, β = 30° was suitable for all three species.
In the experiments comparing the number of weirs, we obtained similar approximate expressions betwenn the number of weirs and normalized indices for ascent rates of fishes.

Free Research Field

農業農村工学・農村計画学

Academic Significance and Societal Importance of the Research Achievements

水田周辺のフナ類、メダカ類、ドジョウを用いて、実験時間を統一して、いくつかの流量条件で室内実験を行うことで、種によって遡上数が多くなるV字ノッチ傾斜隔壁の形状が異なることと3種の遡上に総合的に高い性能を有する隔壁を示すことができた。また、隔壁枚数を変化させて、3種の魚類を用いた遡上実験を行ったところ、隔壁枚数と遡上率の正規化指数の間で類似の近似式を示すことを確認し、1～2枚の隔壁を用いた実験から、複数枚の隔壁から構成される魚道の遡上率を推定できる可能性を示した。