374 / 2024-02-29 22:51:05

Ecological Operation Research Based on Habitats Recovering of Spawning Grounds of Fishes with Drifting Eggs in Reservoir

baima navigation and hydropower station,eco-hydrology,fish propagation,drifting eggs

River damming alters the hydrological conditions of rivers, transforming lotic habitats to lentic habitats in the reservoir, seriously affecting the spawning and propagation of fishes spawning drifting eggs. Taking the Baima navigation and hydropower station on the Wujiang River in Chongqing as the research object, this paper aims to maintain the navigation function while restoring the hydrological processes required for spawning of fishes that produce drifting eggs in the reservoir through ecological operation, and maintaining the spawning ground function. Through the simulation of one-dimensional hydrodynamic model, the water level, flood process, and velocity changes of representative sections of spawning ground for fishes that produce drifting eggs under different conditions in the reservoir were analyzed. Combined with the analysis of fish propagation requirements for hydrological conditions, the impact on spawning ground function was assessed. The results showed that after the completion of the Baima navigation and hydropower station, the water level at representative sections in the reservoir increased, the flow velocity slowed down, and the amplitude of the rise and fall of water levels decreased or disappeared. From the front to the tail of the reservoir，the function of the Yangjiao and Taozigou spawning ground basically disappears, the function of the Shibizi spawning ground decreases, and Yangjiatuo spawning ground can basically meet the needs of the reproduction of the fish with pelagic eggs. By creating artificial flood peaks through ecological operation, there was a significant rise in water levels at each spawning ground, and the flow velocity increased, which ensured the drifting velocity and distance for egg hatching to some extent.