Suggestion of suitable design standard of pool and weir fishway

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06580
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Kouki Onitsuka 九州工業大学, 大学院工学研究院, 教授 (20293904)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 魚道 / 遡上 / 遊泳能力

Outline of Final Research Achievements

The dams and weirs were installed in Japanese rivers for the purpose of water supply for the human activity. In such situations, fish can not migrate to the upstream of the river. It means that the anadromous fish such as salmon, mass, ayu and so on become to extinction. It is necessary to construct the fishway side of dams and weirs. However, the suitable geometric shape of fishway for fish migration is unknown. In this study, the suitable geometric shape of pool-and-weir fishway was made clear. Further, if a little improvement,i.e., rough stones installed on the bed of existing fishway, is conducted, the migration rate became higher.

Free Research Field

水工水理学

Academic Significance and Societal Importance of the Research Achievements

1997年に河川法が改正され，「河川環境の整備と保全」が法に明文化された．2006年には多自然型川づくりを見直した多自然川づくり基本方針が河川局長より通達された．ところが，河川に横断構造物が設置されると魚類の縦断移動が困難になる．この問題を解決するために魚道が設置される．しかし，魚の遡上に適した幾何学形状や水理条件などはほとんど明らかにされていない．本研究によって，魚の遊泳能力および魚の遡上に適した幾何学形状や，既設魚道において魚道内に突起物を設置するなど微細な工夫をすることによって魚の遡上率が向上することが解明された．そのため，特にサケやアユなどの遡上魚の種の保存につながる．