鱼道进口研究综述

Review of Fishway Inlet Research

防洪、灌溉、发电等需求的日益增加,使得全球范围内诸多国家在江河上修建了大量的大坝、堰、水闸等水工建筑物。鱼类需要通过洄游来满足不同时期他们对群落生境结构的要求。而这些水工建筑物的修建,破坏了河流纵向的连通性,造成了河流生境的片段化,阻断了鱼类的洄游通道和基因交流,造成了鱼类生境的破碎化,使鱼类无法完成洄游这一自然过程,引起鱼类种群数量减少。鱼道是恢复鱼类洄游通道的有效工程措施,是沟通鱼类破碎化生境的桥梁,设置的主要目的就是让鱼类顺利通过其障碍物。其作用除了减缓工程对鱼类的不利影响外,更使得许多的鱼类免于灭绝,保障了河流的连通性和生物多样性。因此,运行良好的鱼道具有重要的生态意义、经济意义和工程意义。鱼道进口是鱼道设计时必须充分考虑的关键问题,但以往在进行鱼道设计时,却又并没有得到足够重视;尤其在中国,研究人员设计鱼道时主要将他们的注意力集中在鱼道内部的结构水力设计参数的研究及型式选择上,而由于对鱼类生活习性和洄游规律等方面的认识还不完善,对鱼道进口位置布置及结构的研究相对薄弱,导致鱼类进入鱼道困难甚至根本无法进入鱼道,诱鱼效果差。总之,鱼道的进口是否能够吸引过鱼目标,是决定鱼道成败的关键因素之一。本文总结了国内外鱼道进口的研究现状,在此基础上,结合对鱼类游泳能力及集群等习性的分析,提出了未来研究设计鱼道进口的思路。

The construction of dams, weirs, sluices, and other hydraulic structures in rivers has rapidly in-creased due to the development of water conservancy and the increasing demands for flood control, irrigation, and the generation of power. Through migrations, fishes meet requirements with regard to the structure of the biotope during their life cycle. These hydraulic structures break down the connectivity of rivers, block the migration of fish, and fragment the fish habitat, which could result in a population decrease for many fish species. Fishway has been an effective way used to restore fish migration passages, and bridge fragmented habitats. The purpose of a fishway is to assist fish in smoothly bypassing an obstacle and alleviate the negative effects of the hydraulic structure. More importantly, fishways prevent the extinction of fishes, by protecting river connectivity and biodiversity. Therefore, well-functioning fishways have important significance. One of the key points in designing fishway is inlet, which was not given full consideration in the past, especially in China. Designers mainly focused their attention on the internal structure and flow conditions. Due to lack of recognition of the fish habits and migration law, researches on the location layout and structure of fishway inlet are seldom reported. In engineering applications, it is difficult or even impossible for fish to enter the fishway. In a word, one of the key factors of fishway design lies in whether fishes can quickly and accurately enter the fishway inlet. On the basis of recent researches on fishway inlet, combining with analysis on swimming capacity of fish and fish school, this paper provides the future direction of fishway inlet research.