Author(s): Youichi Yasuda; Takashi Ohnishi
Linked Author(s): Youichi Yasuda
Keywords: Fishway; Migration Route; Local Flow; Multi-aquatic animals
Abstract: In Japan, pool-type fishways with vertical weirs in rectangular section have been installed in most drop structures. In this case, most swimming fish jump to migrate upstream through the vertical weir of the fishway. Recently, pool-type fishways with trapezoidal weirs in trapezoidal section were proposed by Yasuda. For a wide width of fishway, a symmetric trapezoidal section has been applied. For a narrow width of fishway, a half trapezoidal section (one side is sloping, and other side a vertical wall) has been applied. The proposed fishways enable the upstream migration for swimming fish, crab, shrimp, eel, and shell. In this paper, velocity fields in pool-type fishways with trapezoidal weirs in trapezoidal section have been shown by using measurement results from a proto-type. And, the migration route for swimming fish in the fishways has been made clear for both physical model and proto-type.
Year: 2009