基于过鱼效果评估的涵洞鱼道堰式挡板性能研究与分析

Investigation and Analysis on the Characteristic of Weir Baffle System in Culvert Fish-Way Based on Passage Efficiency Evaluation

为研究涵洞式鱼道的内部结构对鱼道水力特性和过鱼性能的影响,利用FishXing软件对江西昌栗高速公路涵洞的过鱼障碍进行了预测与评估,并针对评估结果提出了涵洞内部结构的水力特性优化方案。改造后的涵洞鱼道监测数据证实,通过在内部铺设高低相间的堰式挡板系统,能够将涵洞池室内的水流速度相对平滑涵洞提升约30%,同时相邻池室间的水位差也整体下降。不同体积流量下涵洞鱼道过鱼效果的RFID(Radio Frequency Identification)射频识别结果显示,草鱼的成功通过率要明显高于鲫和鲤,其值分别为50%,26. 41%和7. 6%;涵洞的水流流量由0. 378 m3/s增至0. 429 m3/s,草鱼上行至涵洞上游入口处的平均所需时间和最短时间均有一定幅度的下降,而鲫平均消耗时间则延长了35. 15%,同时草鱼和鲫的折返率也有小幅上升。

In order to study the influence of internal structure in culvert fish-way on hydraulic characteristics and fish passage performance,a culvert evaluation software named Fish Xing was applied to predict and evaluate the existing passage barriers of the culvert crossing the Nanchang high way,an optimized hydraulic solution was presented as well,which was aimed at the results of barrier evaluation for internal structure in culvert. The data of flow field monitored in the retrofitted culvert fish-way confirms that the watervelocity in each pool increases by about 30% compared to that of the smooth culvert with no baffle system,while the water level difference between adjacent pool declines after the construction of high-and-low weir baffle system. According to the results of fish passage efficiency using RFID( Radio Frequency Identification) technology under different flow discharges,it can be seen that the rate of successful passage for grass carp( Ctenopharyngodon) significantly exceeds that of native crucian carp( Carassius auratus) and carp( Cyprinus carpio),the corresponding rates are 50%,26. 41%and 7. 6% respectively. As the water flow rate in culvert increases from 0. 378 m3/s to 0. 429 m3/s,both the average time and shortest time for grass carp to pass through the upstream entrance of culvert decline to a certain extent,while the average time consumed by native carp in passing through the whole culvert extends by 35. 15%,and the rates of retracing back increase slightly for both grass carp and crucian carp.