Author(s): Zhonghang Wu; Ran Li; Jingjie Feng; Xiaolong Cheng And Kefeng Li
Linked Author(s): Jingjie Feng, Ran LI
Keywords: Entrainment Fish eggs and larvae River intake Hydraulics
Abstract: Various types of river intakes play a crucial role in implementing the national water network strategy and constructing integrated water, wind, and solar energy systems. These intakes range from small riverine pumping stations to intake structures in pumped-storage reservoirs. The operation of river intakes can result in the entrainment of drifting fish eggs and early-stage larvae (fish fry) with limited swimming capabilities, adversely affecting riverine aquatic ecosystems. To investigate how hydraulic conditions near intake structures -- such as flow velocity, direction, and resistance -- affect fish fry entrainment, this study focused on a typical riverine pumping station intake. A turbulence model for the entrainment effect was developed using the Euler-Lagrange approach and validated with results from a 1:50 scale physical model experiment. Considering fluctuations in river flow during spawning periods for fish species producing drifting fish eggs, simulations were conducted for different river flow scenarios and intake operation conditions to calculate the entrainment of fish fry under various scenarios. The results indicated that the entrainment volume of fish fry varies with river flow rates and fish fry density and increases with the ratio of intake flow to river flow. Based on an analysis of fish spawning patterns in the study river reach, this research proposed recommendations for timely suspension of intake operations during critical periods. The findings provide valuable insights for ensuring intake operation safety and protecting fishery resources.
Year: 2025