The study of fish eggs'movement is a mechanical basis for understanding the rule of fish eggs' drifting and dispersing in natural rivers. It is of great significance in the estimation of early-stage fish abundance, the evaluation of spawning ground location and the ecological restoration of fish habitat. In order to reveal the characteristics, the main impact factors and impact mechanism of fish eggs'movement under the steady uniform flow in open channel, 20 groups of flume experiments with varying water depths and velocities were carried out and 200 videos of fish eggs' movement (eggs' diameter=4mm, specific gravity=1.01) were recorded and processed by particle tracking velocimetry (PTV) technique, a theoretical derivation of eggs' movement equations was also performed in this paper. The results show that the main impact factors of fish eggs' movement are the flow velocity, the fish eggs' specific gravity, the eggs' diameter and the egg'initial velocity. The eggs'longitudinal velocity is linear increasing with the increasing flow longitudinal velocity and the fitting linear coefficient is 0.73 which meant the eggs' longitudinal velocity is about 0.73 times to the flow longitudinal velocity. The eggs' vertical velocity is mainly affected by the eggs' specific gravity and diameter, and has no significant relationship with the flow longitudinal velocity. In the lower velocity condition, the trajectories of eggs' movement had a linear decrease trend and the slope of trajectories slowed down with the increasing flow velocity. When the velocity increased to 0.93 m/s, the trajectory changed from simple linear sinking to the wave-and-roll type sinking, and some individual eggs jumped suddenly. The impact of flow depth on the eggs' velocity and trajectory is relatively small. The effect of eggs'initial velocity on the eggs'longitudinal vertical velocities were only in the initial short time. © 2018, China Water Power Press. All right reserved.
