基于水力学条件的江家口坝#br# 下集诱鱼进口流场研究

建设过鱼设施是减缓河流大坝修建对鱼类不利影响的重要措施。本文以江家口坝址至坝下580 m处的河段为研究区段，构建基于MIKE21的平面二维水动力模型，根据工程的水文情势选用典型工况对坝下流场进行分析，探究不同工况下鱼类可能的上溯路径。结果表明：主流流量在5.40~40.74 m3/s，集诱鱼流量在2.50 m3/s情况下，主流受集诱鱼进口流量约束，将偏向右岸往下游流动。在仅考虑2号机组下泄17.67 m3/s流量下，河道存在目标鱼类洄游的上溯路线，距集诱鱼进口30～100 m处，河道中间满足鱼类适宜流速和水深，鱼类将沿着河道中间洄游；距集诱鱼进口0～30 m处，右岸流速逐渐升高并成为鱼类适宜流速，鱼类将从右岸洄游并最终到达集诱鱼进口；集诱鱼进口处，右岸水深高于中间水深约10%～40%，高于左岸水深90%～170%，集诱鱼进口处的高水深将有利于鱼类进入。对于“T”形集诱鱼进口汇流，集诱鱼流量占12%左右能产生较好的集诱鱼进口水力学特征。研究成果可为集诱鱼进口处鱼类上溯提供参考依据。

Study on the Inlet Flow Field of Fish-trapping under Jiangjiakou Dam Based on Hydraulic Conditions

The construction of fishing facilities is an important measure to mitigate the adverse effects of river dams on fish.Taking the section from the dam site of Jiangjiakou to 580 m below it as the research area, a two-dimensional hydrodynamic model based on MIKE21 is constructed. According to the hydrological situation of the project, the paper analyzes the flow field of the river under typical working conditions, and explores the possible upward tracking path of fish under different conditions.The results show that: Under the condition of mainstream flow rate is 5.40~40.74 m3/s and trapped fish flow rate is 2.50 m3/s, the mainstream will flow downstream from the right bank constrained by the outflow of fish-trapping.Considering only 17.67 m3/s discharge from Unit 2,the upstream route of target fish migration is provided by simulated river course.From 30 m to 100 m away from the entrance of fish-trapping, the optimum flow velocity and water depth of fish are satisfied in the middle of the river, and fish will migrate along the middle of the river;From 0 m to 30 m, the flow velocity on the right bank increases gradually and becomes the optimum flow velocity for fish. Fish migrate from the right bank and finally reach the entrance of trapping fish.At the distance of 0 m,The water depth of the right bank is 10%~40% higher than that of the middle bank,and 90%-170% higher than that of the left bank. The high water depth at the entrance of the trapping fish will facilitate the entry of the fish.For the import confluence of “T” shaped trapping fish, the trapping fish flow accounting for about 12% can produce better hydraulic characteristics of trapping fish import.The research results can provide a reference for fish tracing at the entrance of trapping fish.