摘要
梯级大坝建设阻隔了自然河流水温的连续性,导致明显的水温累积效应,产生系列的生态效应。本文通过分析金沙江下游及三峡库区沿程水温的时空变化特征,揭示了建坝前后不同尺度水温的变化特征及累积效应,并分析了水温变化对鱼类产卵的影响。研究结果表明,金沙江下游在溪洛渡和向家坝建成后沿程年均水温差变小,沿程水文站年最大水温呈下降趋势,而年最小水温显著抬升,其中1月和12月最为明显。建坝后年水温变幅缩小且水温分布天数有“聚拢”趋势,水温分布天数由M型转为V型。累积效应指标发现建坝后时间拥挤效应显著,极值水温出现时间滞后,水温推迟达1~2个月,统计了攀枝花段27种和向家坝下游段46种鱼类产卵习性,发现水温变化导致受高度影响的鱼类分别占比48%和44%。本文丰富了梯级大坝建设的水温累积效应及对鱼类产卵的影响研究,对加强管理大型梯级运行引起的温度变化与保障下游生态恢复具有一定的科学意义。
Cascade hydropower development disrupts the continuity of natural river water temperature,leading to a significant cumulative effect on the temperature and a series of ecological effects.This study examines the water temperature along the lower Jinsha River and in the Three Gorges reservoir area,and reveals its spatial and temporal variations on different scales before and after dam construction and the cumulative effects.The impact of water temperature changes on fish spawning is also discussed.The results show that after the Xiluodu and Xiangjiaba dams were constructed,the annual mean water temperature difference along the lower Jinsha becomes smaller;along the river,the annual highest temperature at the hydrological stations shows a decreasing trend,while the annual lowest is significantly elevated,especially in January and December.After the construction,the annual temperature variation is reduced,and the time period featuring water temperature distribution has a trend of‘convergence’-the days of water temperature distribution changed from M-type to V-type.An examination on the cumulative effect indicator finds that after dam construction,a significant time crowding effect occurs-a lag time in the extreme water temperature,water temperature delayed up to 1-2 months,the fish of 48%and 44%affected to a high degree at the Panzhihua section and the section downstream of Xiangjiaba dam respectively-thereby affecting severely the fish spawning and reproduction in the downstream and the fish protection sections.The study demonstrates the cumulative effects of water temperature impacted by cascade dam construction and its impact on fish spawning,laying a basis to enhance the role of temperature changes caused by large-scale cascade dams and the downstream ecological restoration.
作者
周扬
王宁
温潇雄
闫龙
唐彩红
朱玉龙
张尚弘
易雨君
ZHOU Yang;WANG Ning;WEN Xiaoxiong;YAN Long;TANG Caihong;ZHU Yulong;ZHANG Shanghong;YI Yujun(College of Water Conservancy and Hydropower Engineering,North China Electric Power University,Beijing 102206,China;China Academy of Water Resources and Hydropower Research,Beijing 100038,China;Key Laboratory of Water and Sediment Science,Ministry of Education,School of Environment,Beijing Normal University,Beijing 100875,China)
出处
《水力发电学报》
CSCD
北大核心
2024年第11期1-16,共16页
Journal of Hydroelectric Engineering
基金
国家重点研发计划(2022YFC32020002)
国家自然基金委项目(52379065
52209087)。
关键词
梯级大坝
水温
累积效应
鱼类产卵时间
生态效应
cascade dams
water temperature
cumulative effect
spawning time
ecological effect
