| 摘要: |
| 金沙江下游梯级水库群在流域水温调控中扮演着关键角色，然而，对于梯级水库联合运行对下泄水温影响的认识仍然不够充分。本研究基于金沙江下游龙街（三）、乌东德、白鹤滩、溪洛渡、向家坝水文站长序列实测水温数据，从水温基线偏移、相位偏移和极值变幅三方面定量分析了金沙江下游梯级水库在不同运行阶段对沿程水温的累积影响。结果表明:（1）金沙江下游梯级水库建成后“热源效应”显著，乌东德、白鹤滩、溪洛渡、向家坝年均下泄水温逐年升高，年内水温变幅较天然水温最大减小4.1℃、2.4℃、1.6℃、3.2℃，沿程增温率由天然状态的0.348℃/100km降至现阶段的0.256℃/100km。（2）随着建库时间的增长，金沙江下游梯级水库水温累积程度逐渐增强，变化速度趋缓，至2022年四级水电全部投产运行后，乌东德、白鹤滩、溪洛渡、向家坝与天然水温分别滞后19、58、49、65天。（3）金沙江下游四个水库中白鹤滩对水温的影响最大，且不同类型水库在水温传递和累积方面呈现出独特的规律，混合型水库作为“龙头”水库时表现为正效应，稳定分层型水库表现为正效应，不稳定分层型和过渡型水库在不同阶段分别表现出正效应和负效应。本研究对于优化水资源管理、提高水电效益具有指导作用，同时为维护下游生态系统的健康提供了科学依据。 |
| 关键词: 金沙江下游 梯级水库 水温 累积效应 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金(U2340216,52020105006,U2040210) |
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| Analysis of the Water Temperature’s Cumulative Effect induced by the construction of Cascade Reservoirs in the Lower Jinsha River |
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HU Guangyang,YANG Zhonghua,BAI Fengpeng,REN Yufeng,MA Yiming,LI Wenhui
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State Key Laboratory of Water Resources Engineering and Management, Wuhan University
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| Abstract: |
| Cascade reservoirs in the lower Jinsha River play a crucial role in watershed temperature regulation. However, there is still a lack of knowledge on how cascade reservoirs affect downstream temperature.. This study quantitatively analyzes the cumulative effect of the four cascade reservoirs in the lower Jinsha River—Wudongde, Baihetan, Xiluodu, and Xiangjiaba—on downstream temperatures. It examines overall temperature deviation, phase deviation, and extreme amplitude using long-term temperature data from Longjie (Three), Wudongde, Baihetan, Xiluodu, and Xiangjiaba stations. The results indicate: (1) After the completion of the lower reaches of the Jinsha River cascade reservoirs, the "heat source effect" is significant, and the average annual discharge water temperature of Wudongde, Baihetan, Xiluodu and Xiangjiaba increases year by year, the annual water temperature variation decreases by 4.1℃, 2.4℃, 1.6℃ and 3.2℃ compared with that of the natural water temperature, the rate of increase of the temperature along the reservoir decreases from 0.348℃/100km in the natural state to 0.256℃/100km at the present stage. (2) As the operational period of the cascade reservoirs along the Jinsha River increases, the cumulative effect on water temperature in the downstream reservoirs gradually intensifies, with a slowing rate of change. By the year 2022, following the full commissioning of the four hydropower stations, Wudongde, Baihetan, Xiluodu, and Xiangjiaba exhibit temperature lag times of 19, 58, 49, and 65 days, respectively. (3) Among the four reservoirs, Baihetan exerts the greatest effect on temperature, and different types of reservoirs exhibit unique patterns in temperature transmission and accumulation. A hybrid reservoir shows positive effect when acting as a "head" reservoir, stable stratification reservoirs shows positive effect, while unstable stratification and transitional reservoirs shows positive and negative effect at different stages, respectively. This study provides valuable guidance for optimizing water resource management and enhancing hydropower efficiency, while offering a scientific foundation for maintaining the health of downstream ecosystems. |
| Key words: Lower reaches of the Jinsha River Cascade reservoirs Water temperature Cumulative effects |
