长江中游水位下降引起的浅滩出露及其对产粘性卵鱼类繁衍的潜在影响探讨——以2020年春季为例

Shoal exposure caused by water level drop in the middle reaches of the Yangtze River and its potential impact on stickiness spawning fish:a case study in spring 2020

2020年春季长江中游干流出现了低水位的异常现象,通过收集长江中上游的降雨量与三峡水库的水文信息,分析2020年春季长江中游水位下降的过程和原因;同时,利用卫星遥感技术,分析长江水位下降导致的城陵矶河段、鄱阳湖和洞庭湖的浅滩大面积出露情况;最后探讨了这些变化可能对产粘性卵鱼类繁衍的潜在影响.结果表明:1)2020年春季长江中上游的降雨量减少是造成本次水位下降的主要原因;2)长江中游干流水位下降导致了鄱阳湖与洞庭湖浅滩出露面积分别达到670 km^(2)和480 km^(2),浅滩的大面积出露可能已经对这些鱼类的繁衍产生了系统和深刻的影响;3)建议有关部门和单位密切关注产粘性卵鱼类资源的动态变化情况,加强监测评价,同时长江三峡以及上游梯级水库群的联合调度应该充分考虑到中下游产粘性卵鱼类的自然繁殖习性,制定更合理的方案,以最大程度地保护长江鱼类资源.

In the spring of 2020,there was an abnormal phenomenon of low water level in the middle and upper reaches of the Yangtze River.By collecting the precipitation in the middle and upper reaches of the Yangtze River and the hydrological information of the Three Gorges Reservoir,the process and reason of the water level decline in the middle reaches of the Yangtze River in the spring of 2020 wer analyzed.At the sametime,satellite remote sensing technology is used to investigate the large area of shoal exposure in the Chenglingji reach,Poyang Lake and Dongting Lake caused by the water level decline of the Yangtze River.Finally,the potential effects of these changes on the reproduction of stick-producing fish were discussed.The results are shown as follows.1)The decrease of rainfall in the spring of 2020 in the middle and upper reaches of the Yangtze River is the main reason for the water level decrease.2)The decrease of water level in the main stream of the middle reaches of the Yangtze River resulted in the shoal outcrop area of Poyang Lake and Dongting Lake reaching 670 km^(2) and 480 km^(2) respectively,which might have a systematic and profound effect on the reproduction of fishes.3)It's suggested that related departments should pay close attention on the dynamic changes of the viscid egg spawing fish resources and strengthen the monitoring and evaluation.At the same time,the joint scheduling of the Three Gorges of the Yangtze River and the upstream cascade reservoirs need take into full account the natural breeding habits of viscid egg spawing fish in the middle and lower reaches and develop a more reasonable scheme is required to be devoloped in order to maximize the protection of fish resourses in the Yangtze River.