Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4388827 | Ecological Engineering | 2015 | 10 Pages |
In this study, the attraction efficiency in the natural-like fishways which were installed at the Dalseong and the Gangjeong-Goryeong weirs located at the Nakdong River of Korea was assessed according to riverbed changes, with or without the attraction flow, and operation of movable weirs. A two-dimensional physical habitat model, especially River2D, was used as a tool of the evaluation for the fishway efficiency. And weighted usable area (WUA) was eventually considered as the indicator of the attraction efficiency. The Zacco platypus which is dominant species of the Nakdong River was selected as a target fish. From the simulation results based on various scenarios, it confirmed that while operating the fishway of the Dalseong weir, the attraction efficiency increased only when the sluice gate of the movable weir was closed. Additionally, the attraction channel in its current form was not significantly effective in attracting the fish. In respect to the Gangjeong-Goryeong weir, it was confirmed that because of the bed change after the flooding, the efficiency of attraction to the fishway had been reduced sharply. The attraction efficiency was improved because the reverse flow heading to the entrance of the fishway was eliminated when the movable weir opening, although the degree of improvement in the efficiency was insignificant. Eventually, in order to increase the attraction efficiency of the Gangjeong-Goryeong weir, the movable weir was operated, even during the low flow season. An alternative could be considered, namely re-locating the fishway from left to right bank, where stable overflow occurs because of the fixed weir.