242 / 2024-02-28 15:17:50

Experimental Study on Fish Attraction Arrangement in the Tailwater Channel of the Fish Lift in the Kaihua Reservoir Project

fish lift, tailrace, fish channel, turbulence energy, fish test

The construction of hydroelectric projects plays a significant role in flood control, power generation, and navigation, bringing about substantial economic and social benefits. However, it also impedes river connectivity, changes the habitat environment of aquatic organisms such as fish, limits gene exchange, and reduces genetic diversity. The fishway facilities in the Kaihua Reservoir project adopt a fishway arrangement with fish lifts, with two fish attractants placed within the tailwater channel. Tailwater channels are often prone to fish aggregation due to the attraction of hydroelectric tailwaters. However, the flow structure within tailwater channels is complex, with strong turbulence in local areas, and the flow of power generation water blurs the fish attractant flow, weakening its guidance for upstream fish. To improve fish passage effectiveness, experimental research on the arrangement of fish attractants in the tailwater channel was conducted using a 1:12 scale physical hydraulic model. The results show that the mixing and turbulence of the tailrace on the left and right sides can be reduced by setting up partition wall in the tailrace slope downstream of the main unit and the ecological unit. The width of velocity barrier of tailrace outlet larger than 1.2m/s decreases obviously when the main unit generates electricity, and clear fish trap channels can be formed in the tailrace of the side of the ecological unit, and during fish release experiments, fish fry could smoothly enter the fish attractant mouth of the fish aggregation system.