河流型深水库出流日调节诱导下的内波特征

溪洛渡水库是典型的河流型深水库,在库区水温分层的情况下,出流日调节引起温跃层内波。通过布设温度链对库区水温进行长期监测,同时建立了库区立面二维数值模型对内波进行模拟,并对库区的内波现象、形成机理和传播速度等特性进行研究。结果表明,变温层取水及出流流量波动导致取水区段变温层的厚度变化,进而形成了周期为24小时的内波;内波向上游传递,振幅在传播中衰减,模拟的波速与K-H内波理论的计算值基本吻合;出流日调节型内波对于深水层下降的速率没有显著影响。由于目前对河流型深水库内波现象的研究较少,文章有助于加深对于水库内波现象的理解,并为水库内波相关的工程应用提供分析工具和理论依据。

Internal waves in a deep run-of-river reservoir under hydro-peaking

The Xiluodu reservoir is a typical deep run-of-river reservoir where hydro-peaking under stratification induces internal waves at its metalimnion. In this study, we take long-term measurement of water temperature in the reservoir using a thermistor chain, and develop a longitudinal-vertical two-dimensional numerical model to simulate these waves, focusing on the internal wave phenomenon and its formation and propagation features. Results show that the waves have a period of 24 hours and are induced by epilimnetic withdraw and hydro-peaking. They travel upstream along the metalimnion with decaying amplitudes and their travelling speeds agree well with the calculations using the Kelvin-Helmholtz wave theory. Also, they have no significant influence on the hypolimnion deepening. Currently, only a few exiting studies about internal waves in deep run-of-river reservoirs can be found. This study would shed light on our understanding of internal waves in reservoirs and help the analysis and design of related engineering applications.