长江科学院院报 ›› 2024, Vol. 41 ›› Issue (9): 35-43.DOI: 10.11988/ckyyb.20230454

• 水环境与水生态 • 上一篇    下一篇

低温来流对深水水库过饱和总溶解气体输移的影响

周哲成1,2,3(), 石浩洋1,2, 郭辉1,2,4(), 王智欣1,2, 李析男5, 杨文俊1,2, 金光球3   

  1. 1 长江科学院 水力学研究所,武汉 430010
    2 长江科学院 流域水资源与生态环境科学湖北省重点实验室,武汉 430010
    3 河海大学 水利水电学院,南京 210098
    4 河海大学 环境学院,南京 210098
    5 贵州省水利水电勘测设计研究院 科技创新部,贵阳 550002
  • 收稿日期:2023-05-04 修回日期:2023-08-21 出版日期:2024-09-01 发布日期:2024-09-20
  • 通讯作者: 郭辉
  • 作者简介:

    周哲成(1999-),男,浙江台州人,硕士,研究方向为生态水利。E-mail:

  • 基金资助:
    国家重点研发计划项目(2022YFC3203904); 国家自然科学基金项目(52130903); 国家自然科学基金项目(U2340218); 中国长江三峡集团科研项目(0704179); 贵州省科技计划项目(黔科合支撑[2021]一般467); 中央级科研院所基本科研业务费项目(CKSF2023401/SL)

Influence of Low-temperature Inflow on the Transport of Supersaturated Total Dissolved Gas in Deep-Water Reservoir

ZHOU Zhe-cheng1,2,3(), SHI Hao-yang1,2, GUO Hui1,2,4(), WANG Zhi-xin1,2, LI Xi-nan5, YANG Wen-jun1,2, JIN Guang-qiu3   

  1. 1 Hydraulics Department,Changjiang River Scientific Research Institute,Wuhan 430010,China
    2 Hubei KeyLaboratory of Basin Water Resources and Eco-environmental Science, Changjiang River Scientific ResearchInstitute, Wuhan 430010, China
    3 College of Water Conservancy and Hydropower Engineering, HohaiUniversity, Nanjing 210098, China
    4 College of Environment, Hohai University, Nanjing 210098, China
    5 Department of Technological Innovation, Guizhou Survey & Design Research Institute for Water Resourcesand Hydropower, Guiyang 550002, China
  • Received:2023-05-04 Revised:2023-08-21 Published:2024-09-01 Online:2024-09-20
  • Contact: GUO Hui

摘要:

梯级深水水库产生的水温分层现象可降低下游水库来流水温,导致泄洪水体总溶解气体(TDG)的过饱和程度随库区密度分层流的输移过程产生变化。以溪洛渡—向家坝区间为研究区域,基于原位观测和数值模拟相结合的研究手段,研究低温来流对深水水库过饱和TDG纵向和垂向输移过程的影响规律。研究表明:①来流水温降低2 ℃,TDG云团潜入位置提前36.4 km,峰值垂向位置下移55 m、垂向影响范围减少23%;②来流水温降低2 ℃,TDG饱和度110%以上云团输移至向家坝坝前阶段和后续阶段,包络面积衰减速率降幅分别为16%和44%;③从射流区到交换区过饱和TDG平均纵向迁移速度显著降低,降幅达92%;④来流水温降低2 ℃,向家坝表孔出流TDG饱和度峰值和均值的降低程度分别为机组出流的3.2倍和4倍;⑤水温降低对鱼类安全水深阈值的补偿效应可量化为0.20 m/℃。研究成果可为梯级深水水库汛期生态调度提供科学支撑。

关键词: TDG输移过程, 数学模型, 水库水温分层, 总溶解气体(TDG), 云团位置, 水温补偿, 生态调度, 梯级深水水库

Abstract:

The stratification of water temperature in deep-water cascade reservoirs reduces the inflow temperature of downstream reservoir, altering the supersaturation degree of total dissolved gas (TDG) in flow discharges. With the Xiluodu-Xiangjiaba cascade reservoirs as a case study, we investigated the impact of lower-temperature inflow on the longitudinal and vertical transport processes of supersaturated TDG in deep-water reservoir via field observation in association with numerical simulation. Finds reveal that: 1) a 2 ℃ decrease in inflow temperature advances the submersion position of TDG cloud by 36.4 km, shifts the peak TDG saturation down by 55 m, and reduces its vertical influence range by 23%. 2) With a 2 ℃ decrease in inflow temperature, as the TDG cloud with a saturation over 110% transports to front of the Xiangjiaba dam, the decay rate of enveloped area decreases by 16%; in subsequent transport stage, the decay rate reduces by 44%. 3) The average longitudinal transport velocity of supersaturated TDG from the jet flow zone to the interflow zone plunges by 92%. (4) As inflow temperature reduces by 2 ℃, the peak and mean TDG saturation of the outflow from Xiangjiaba’s surface orifices reduce by 3.2 and 4 times that of the outflow from power generating set, respectively. (5) The compensation effect of temperature reduction on the safe water depth threshold for fish can be quantified as 0.20 m/ ℃. The findings provide scientific support for ecological dispatching of deep-water reservoirs during flood seasons.

Key words: TDG transport process, mathematical model, reservoir water temperature stratification, total dissolved gas, cloud position, water temperature compensation, ecological dispatching, cascade deep-water reservoir

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