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受三峡蓄水的影响,长江中下游水文生态系统发生明显变化,导致四大家鱼产卵适宜度下降以及像中华鲟这类生殖洄游性鱼类鱼卵孵化率降低。建设人工鱼礁是缓解长江渔业资源衰退、保护长江物种多样性、保持长江渔业可持续发展的一项重要措施。基于水槽模型实验,以透空正六面体型人工鱼礁为研究对象,将鱼礁块体与护岸相结合铺设在河道岸坡上,构成鱼礁型生态护岸。通过对鱼礁型护岸周围水面线及水流流速等水力特性进行测量分析,得到了鱼礁型护岸的鱼类产卵场水力因子。结果表明:在长江中下游河道两岸铺设透空型人工鱼礁其周围水流流速可维持在0.84~1 m/s之间,处于四大家鱼产卵繁殖最适宜的流速范围内;且由于鱼礁的存在,使岸坡附近水流流速梯度增大并产生上升流及背涡流等一些复杂的水流流态,这些水力因素又刺激了四大家鱼的交配活动,增加鱼类的产卵量。
Affected by the impoundment of the Three Gorges Reservoir, the hydrological ecosystem in the middle and lower reaches of the Yangtze River changed significantly, resulting in a decrease in spawning suitability of the four major domestic fish and a decrease in hatching rate of reproductive migratory fish such as Chinese sturgeon. The construction of artificial reefs is an important measure to alleviate the decline of fishery resources in the Yangtze River, protect the species diversity in the Yangtze River and maintain the sustainable development of the Yangtze River Fisheries. Based on the tank model experiment, the open-air regular hexahedron artificial reef was taken as the research object, and the reef block and revetment were laid on the bank slope to form the reef-type ecological revetment. By measuring and analyzing hydraulic characteristics such as waterline and flow velocity around the reef revetment, the hydraulic factor of the spawning grounds of fish reef revetment was obtained. The results show that the flow velocity of perfused artificial reef can be maintained at 0.84-1 m / s in the middle and lower reaches of the Yangtze River, which is within the most suitable flow rate for the spawning of four major domestic fish. , The water flow velocity gradient near the bank slope is increased and some complicated water flow patterns such as upwelling and back vortex are generated. These hydraulic factors stimulate the mating activities of the four major domestic fish and increase the fecundity of the fish.