摘要
湖库水体在热分层时期的缺氧现象将严重影响底层水体水质,破坏底层水生生物栖息环境,导致湖库整体水质及生态环境质量的下降。本文以引滦入津源头工程大黑汀水库为例,研究了水库热分层及缺氧区的时空演化特征,识别了在一定的水质及底质污染状况条件下,水库缺氧区形成与演化的主要驱动因素。研究表明,大黑汀水库缺氧现象出现时间为每年6月份至10月份,最严重时全库有60%的回水区域会出现缺氧问题,坝前延伸距离可达12.0 km。缺氧区内水体溶解氧浓度低于2.0 mg/L。研究认为,热分层状况是决定水体溶解氧状况及缺氧区演化的主要驱动因素;藻类浓度通过对溶解氧结构及底层水体耗氧条件的影响驱动了缺氧区的年内演化规律;水库的地形条件变化是水体缺氧区形成的重要辅助性因素;水动力学条件则主要影响水库缺氧区的稳定性。
The anoxic phenomenon of the reservoir during the thermal stratification period will seriously affect the water quality of the bottom water and destroy the habitat of the bottom aquatic organism,resulting in the decline of the water quality and ecological environment quality of the reservoir. Taking Daheiting Reservoir as an example,this paper studies the temporal and spatial evolution characteristics of reservoir thermal stratification and anoxic zone,and identifies the main driving factors for the formation and evolution of reservoir anoxic zone under certain conditions of water quality and sediment pollution. Studies have shown that the anoxic phenomenon of Daheiting Reservoir occurs from June to October. In the worst case,60% of the area in the whole reservoir will have anoxic problem,and the extension distance in front of the dam can reach 12.0 km. The dissolved oxygen concentration in the anoxic zone is less than 2.0 mg/L. The study suggests that the thermal stratification is the main driving factor determining the dissolved oxygen state and the evolution of the anoxic zone. The algae concentration drives the evolution of anoxic zone through the influence of dissolved oxygen structure and oxygen demand conditions of the bottom water. Topographical conditions are important supporting factors for the formation of anoxic zone. Hydrodynamic conditions mainly affect the stability of the anoxic zone of the reservoir.
作者
刘畅
刘晓波
周怀东
王世岩
李步东
LIU Chang;LIU Xiaobo;ZHOU Huaidong;WANG Shiyan;LI Budong(China Institute of Water Resources and Hydropower Research,State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,Beijing 100038,China)
出处
《水利学报》
EI
CSCD
北大核心
2019年第12期1479-1490,共12页
Journal of Hydraulic Engineering
基金
国家重点研发计划项目(2016YFC0401701)
中国水科院基本科研业务费项目(WE0145B592017,WE0145B342016,WE0145C032018)
关键词
热分层
缺氧区
时空分布
演化机理
驱动因素
thermal stratification
anoxic zone
temporal and spatial distribution
evolution mechanism
driving factors
