排序方式： 共有119条查询结果，搜索用时 15 毫秒
1.
大渡河枕头坝一级水电站鱼道设计研究 总被引：1，自引：0，他引：1
枕头坝一级水电站位于大渡河干流上,为减缓工程对鱼类的不利影响,提出了修建鱼道来改善大坝上下游鱼类种群交流.枕头坝一级水电站鱼道工程设计总长1 241.74 m,是目前国内已建和在建规模最大的鱼道工程.在鱼类游泳能力测试和水力学模型试验的基础上,对鱼道的过鱼对象、鱼道建筑物设计进行了研究.最终确定,枕头坝一级水电站采用单侧竖缝式鱼道,鱼道内过鱼孔流速建议为1.10～1.25 m/s;进口流速应大于0.15～1.3 m/s;鱼道设置3个进口,并增设诱鱼系统;还在鱼道进口和出口分别设置1个观察室,以便指导调整鱼道运行方式. 相似文献
2.
While dams cut off the migratory route of fish, and affect their growth and breeding, fishways are built to restore the connectivity of rivers and facilitate the life cycle of these migratory fish. This paper proposes a new kind of fishway called the "T shape fishway", and studies it by using both numerical simulations and physical experimental methods with the aim to design a fishway in China for migratory fish with swimming and jumping capability much poorer, such as schizothorax davidi and schizothorax prenanti, as compared with migratory fish in other places of the world, like trout and salmon. It is indicated that the range of velocity in each regular pool of the T shape fishway is from 0.42 m/s to 1.22 m/s when the flow discharge Q is 350 L/s, and there are no large vortex zones found there. This study shows that the T shape fishway can meet the requirements of these migratory fish quite well in terms of velocity and flow patterns in China. 相似文献
3.
通过对国内外鱼道发展现状和趋势的分析,对几种常用鱼道的优缺点做了比较,结合都日根水电站所在秦诺哈拉依赫河鱼类生长繁殖特点,采用了垂直竖缝式加小底孔相结合形式的鱼道设计。实践证明此鱼道设计有效保护了鱼类及河流生态的预期作用,具有一定的科学性、实用性和可推广性,对我国中小河道枢纽建设具有一定的参考价值。 相似文献
4.
《水动力学研究与进展(B辑)》2024,36(1)
Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic projects.The vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water levels.However,the resulting vortex current disrupts the fish passage hence directly affecting fish migration.This study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on fish.We conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)method.Moreover,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish migration.The results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish migration.Fish experienced significantly increased resistance when encountering strong vortices.This suggests that the vortex may act as a physical barrier to fish migration.These findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental management.As an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms. 相似文献
5.
Aiming at improving the hydraulic properties and enhancing the fish passage efficiency, this study proposes a novel bilateral-symmetric multi-slot fishway (BMSF) by combining the structural features of a double-sided vertical-slot fishway, multi-slot fishway and T-shape fishway. Eight BMSF cases are further designed by adjusting the slot width and the distance between the short baffle and the front end of the central wall, in order to achieve the relatively best hydrodynamic characteristics. The flow fields of two vertical-slot fishways and eight BMSF fishways are obtained by numerically solving the Reynolds-averaged Navier–Stokes equation, the volume-of-fluid equation and the k-ω-SST turbulence model. Numerical results manifest that the recommended BMSF-8 provides the smallest values in terms of the maximum time-averaged velocity magnitude (1.42 m s−1), the maximum time-averaged turbulent kinetic energy (0.132 m2 s−2), the maximum time-averaged Reynolds shear stress component (44 Pa), the spatial-mean time-averaged velocity magnitude (0.58 m s−1), and the spatial-mean time-averaged turbulent kinetic energy (0.042 m2 s−2) in the middle pool at Q = 1000 L/s. Even for the depth-mean time-averaged velocity magnitude at the slot and the volume percentages of some critical physical quantities, BMSF-8 is also superior to the other cases. To sum up, BMSF-8 leads to the relatively lowest flow velocity and turbulence, being more suitable for the passage of the whole fish community (especially for small-sized fishes with weaker swimming ability). In addition, the generalizability of the aforementioned superiority of BMSF-8 is displayed by providing the numerical results of four operating conditions (i.e., Q = 600, 800, 1000 and 1200 L/s). 相似文献
6.
E. Pereira B. R. Quintella C. S. Mateus C. M. Alexandre A. F. Belo A. Telhado M. F. Quadrado P. R. Almeida 《河流研究与利用》2017,33(1):16-26
In 2011, a vertical‐slot fish pass was built at the Coimbra Açude‐Ponte dam (Mondego River, Portugal), approximately 45 km upstream from the river mouth. The performance of this infrastructure for sea lamprey passage was evaluated between 2011 and 2015 using several complementary methodologies, namely radio telemetry [conventional and electromyogram (EMG)], passive integrated transponder (PIT) telemetry and electrofishing surveys. During the study period, the electrofishing revealed a 29‐fold increase in the abundance of larval sea lamprey upstream of the fish pass. Of the 20 radio‐tagged individuals released downstream from the dam, 33% managed to find and successfully surpass the obstacle in less than 2 weeks, reaching the spawning areas located in the upstream stretch of the main river and in one important tributary. Fish pass efficiency was assessed with a PIT antenna installed in the last upstream pool and revealed a 31% efficiency, with differences between and within migratory seasons. Time of day and river flow significantly influenced the attraction efficiency of the fish pass, with lampreys negotiating it mainly during the night period and when discharge was below 50 m3 s?1. Sea lampreys tagged with EMG transmitters took 3 h to negotiate the fish pass, during which high muscular effort was only registered during passage, or passage attempts, of the vertical slots. The use of complementary methodologies provided a comprehensive passage evaluation for sea lamprey, a species for which there is a considerable paucity of valuable data concerning behavioural, physiological and environmental influences on obstacle negotiation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
7.
Fishways are hydraulic structures that allow passage of fish across obstructions in rivers. Vertical slot fishways—VSFs—are considered the most efficient and least selective type of technical fishway solutions, especially due to their ability to remain effective even when significant upstream and/or downstream water level fluctuations occur. The scope of the present study is to perform numerical simulations in order to investigate and compare the hydraulic turbulent flow field in a standard and a simplified version of the most common VSF design. Implications in relation to fish swimming behaviour and fish passage performance are discussed. Different water depths (as well as discharges) were investigated, using a bed slope of 5%, as a reference for low‐gradient VSFs with a very limited selectivity that can be used in multispecies rivers in grayling‐barbel regions. Results show that maximum values of velocity, turbulent kinetic energy, and Reynolds stresses are higher in the standard design. However, corresponding to slot geometry and orientation, the direction of the main jet in the simplified design is more inclined towards the left side of the pool. This causes the eddy to split into 2 smaller ones; the minimum eddy dimension is reduced from 0.4–0.5 to 0.2–0.3 m. These dimensions are detrimental for fish passage efficiency, being more comparable with fish length (0.15–0.40 m), thus affecting migrating fish stability and orientation. Furthermore, the standard design provides a more straightforward upstream path and wider areas of low flow velocities and turbulence, useful for fish resting. Therefore, it is recommended that the standard design should be preferred over its simplified version, even if its construction costs are around 10–15% higher than the simplified one. 相似文献
8.
M. A. Wilkes J. A. Webb P. S. Pompeu L. G. M. Silva A. S. Vowles C. F. Baker P. Franklin O. Link E. Habit P. S. Kemp 《河流研究与利用》2019,35(10):1688-1696
Worldwide, fishways are increasingly criticized for failing to meet conservation goals. We argue that this is largely due to the dominance of diadromous species of the Northern Hemisphere (e.g., Salmonidae) in the research that underpins the concepts and methods of fishway science and management. With highly diverse life histories, swimming abilities and spatial ecologies, most freshwater fish species do not conform to the stereotype imposed by this framework. This is leading to a global proliferation of fishways that are often unsuitable for native species. The vast majority of fish populations do not undertake extensive migrations between clearly separated critical habitats, yet the movement of individuals and the genetic information they carry is critically important for population viability. We briefly review some of the latest advances in spatial ecological modelling for dendritic networks to better define what it means to achieve effective fish passage at a barrier. Through a combination of critical habitat assessment and the modelling of metapopulations, climate change‐driven habitat shifts, and adaptive gene flow, we recommend a conceptual and methodological framework for fishway target‐setting and monitoring suitable for a wide range of species. In the process, we raise a number of issues that should contribute to the ongoing debate about fish passage research and the design and monitoring of fishways. 相似文献
9.
鱼道设计离不开鱼类行为特性的研究,智能监控是观测、记录和量化鱼类行为的主要手段,但由于鱼道紊动的水流环境对鱼体精确跟踪造成了困难。本研究提出一种适用于鱼道研究的鱼类游泳行为提取方法,通过高斯混合模型（GMM）和卷积神经网络模型（CNN）对鱼体图像语义分割,再根据鱼体像素计算上溯轨迹、游泳速度和摆尾幅度。方法的验证以草鱼为试验对象,分别进行基于UNet和SegNet的鱼体语义分割对比试验和鱼类游泳行为提取试验。试验结果表明：（1） UNet模型的图像语义分割结果（MPA=95.9%,MIoU=93.3%）优于SegNet模型（MPA=95.5%,MIoU=92.8%）;（2）应用GMM-CNN模型进行过鱼轨迹跟踪,其坐标平均相对误差（MREx=7.1%,MREy=2.4%）低于单独使用GMM方法23.1%、11.6%;（3） GMM-CNN模型测算鱼类行为能够准确定位鱼体特征点,应用于提取鱼类游泳行为时具有较高的精确度。基于GMM-CNN鱼类游泳行为提取方法可以为鱼道设计提供技术支持。 相似文献
10.
竖缝宽度对竖缝式鱼道水流结构的影响 总被引：4，自引：0，他引：4
竖缝式鱼道具有流态稳定、对上下游水位变动自适应性强、过鱼效率高等技术特点,是目前国内外比较流行的鱼道布置方式之一,得到了广泛的工程运用。已有研究表明,影响竖缝式鱼道水流结构的参数主要包括各级水池的长宽比、导板长度、导向角度、以及隔板墩头体型等。本文在已有研究基础上合理取用竖缝式鱼道的长宽比、导板长度、导向角度等参数,采用数值模拟方法,进一步研究了竖缝宽度对水池内水流结构的影响,并给出了其合理取值范围。 相似文献