Author(s): Taisei Sato; Tomoaki Funakoshi; Muneyuki Aoki
Linked Author(s): Muneyuki AOKI
Keywords: Stream-type fishway; Steep slope; Run up ratio; Swimming behavior of fish; Triborodon hakonensis
Abstract: The purpose of this study was to research a column arrangement a lot of fish can run up stream type fishway of a steep slope. To complete them, using a stream type fishway with a longitudinal slope of 1/20 in Case1, and 1/10 in Case2.Therefore, the experiments were carried out to measure the hydraulic quantities (flow velocity, water depth) and to observe the movement of real fish. The element of flow resistance used the column, because to increase the water depth. There were two patterns of column arrangement what were zigzag and aligned arrangements. The real fish used in the experiments were Ugui; Triborodon hakonensis. The average body length was 8.4 cm (7.4 to 9.3 cm) all of them. The average water temperature was 20.5 degrees (19.8 to 22.6 degrees). The Results showed the Followings; Results show that: 1) The run-up ratio of Case2 was much lower than Case1 in both zigzag and aligned arrangements. Comparing the zigzag and alignment arrangements slope of 1/10 in Case2, the former had a greater number of the fish that run up the fishway. 2) As a whole, the flow velocity V was faster in Case2 than in Case1, however Triborodon hakonensis swam along at the wall side in both Case1 and Case2, the flow velocity of the wall side was the same degree in both cases. Therefore, by devising a column arrangement, it is possible that fish can run up even if the stream type fishway is steep.
Year: 2020