FUNCTIONAL EVALUATION OF FISHWAY USING CHECK-SHEET AND IMPRUVEMENT OF THE EXIXTING FISHWAY

Abstract

This study has analyzed factors for recovery of the fishway by cluster analysis and main component analysis using check-sheet data of fishway in Gifu prefecture. Directionality to connect with a repair method of construction using the result was examined. It is pointed out that the function of the fishway decreases, when the item of the damage of the structure, stream route, step of the flow, partial scour in a riverbed are one. In Ono fishway of the Yoshida River, the need of continuous flow quantity monitoring to connect it with the life cycle of fish was shown. All the fishways that an evaluation of the Yoshida River has worse are erosion control dams. The function of the fishway decreases by complex factors such as the sedimentation of riverbed material and the drifting wood. It is clarified that the function of Futamate fishway was restored by simple repair, and the improvement of the maintenance system.