狭长型水库蓄水至初期运行阶段水温演化规律研究

高拱坝建成后,上游将形成典型的狭长河道型水库,水库水温分层变化规律与大坝结构安全密切相关,对其进行跟踪反馈研究具有重要意义。本文基于溪洛渡水库近4年的水库水温及相关监测资料,同时考虑水库的实际地形信息、气象资料、水文资料和调度资料,引入CE-QUAL-W2模型,实现了水库从开始蓄水到初期运行阶段的水库水温模拟,计算结果与实测数据吻合良好,验证了水动力模型CE-QUAL-W2的适用性。研究结果表明,由于溪洛渡水库河道狭长且水深较深的特殊性,水库在初期蓄水成库过程中,水温一直与河水温度基本相同,水库蓄水接近正常水位后,将逐渐形成4个明显的区域:水位变动区、温度不稳定区、温度过渡区和温度相对稳定区,不同区域水温随季节变化的特性不同。其中,库底温度基本保持稳定,过渡区温度也相对稳定,主要受低温季节来水温度影响。研究结论可为类似高拱坝工程结构设计考虑温度荷载时提供参考。

Analysis of the water temperature evolution of long and narrow reservoir from impoundment to first operating period

After the completion of the high arch dam, a typical long and narrow channel reservoir will be formed in the upstream. The stratified variation of water temperature in the reservoir is closely related to the safety of dam structure,and it is of great significance to study its tracking feedback. Based on the water temperature and the relevant monitoring data of Xiluodu Reservoir in nearly four years,and meanwhile, taking into account the actual topographic, meteorological, hydrological and operational data of the reservoir, the CE-QUAL-W2 model is adopted, which can simulate water temperature in the reservoir from the initial storage to the early stage of operation. The calculated results are in good agreement with the measured data, and the applicability of the hydrodynamic model CE-QUAL-W2 is verified. The study results suggest that as a result of Xiluodu high arch dam with long and narrow channel reservoir and the deep water depth, the reservoir water temperature is basically the same as the water temperature in the process of initial water storage; after the reservoir water close to the normal level, the reservoir water will gradually formed four obvious zones, which can be named the water level fluctuation zone, the temperature instability zone, the temperature transition zone and the temperature stability zone, and the water temperature in different zones varies with the seasons. The prediction research of the reservoir''s long-term operation shows that the temperature in the bottom of reservoir is weakly affected by the upper water body,and the temperature in the transition zone is also relatively stable, which is mainly affected by the temperature of the incoming water in the cold season. The conclusions of this paper can provide reference for the structural design of similar high arch dams.