| 摘要: |
| 大型水库由于水温分层现象易对生态环境造成一系列不利影响，但由于水深较大现场测量困难，水温分层的实测资料极少，对其研究尚不够深入。通过物理模型试验模拟并测量了春末夏初水库库首水温分层的形成和演化过程，分析了流量和出水口位置对水温在垂向和水平分布的影响。结果表明：①由于分层流流动的特点和水动力条件的差异，水温垂向结构在温度分层的演化过程中表现为多种形式。②垂向温差取决于上下游位置、入库流量和水库出水口的高度。通常在垂直方向上，上游温差要比下游大。随着进水口流量的增加和出口位置高度的提高，垂向温差也随之加大。③水平方向上的水温分布与水深、进水口流量和出水口高度有着密切联系。在水库的表面和中部位置，上游水温要高于下游水温。然而在特定条件下，如进水口流量较大且出口位置在表面时，上游水温要低于下游水温。④水流的出口温度受进水口流量和出水口位置的影响。较低的出水口位置会导致出水温度较低，在初始时段尤为明显。 |
| 关键词: 水温 温度分层 物理模型 大型水库 |
| DOI： |
| 分类号:TV697.2 |
| 基金项目:国家自然科学基金资助项目(51479218) |
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| Experimental studies on water temperature stratified flow in front region of reservoirs |
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WU Yutao, REN Huatang, HE Jie, XIA Jianxin
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College of Life and Environmental Science, Minzu University of China, Beijing
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| Abstract: |
| The large reservoirs are prone to cause some ecological and environmental problems due to water temperature stratification. However, the water depth in the reservoirs is very difficult to measure and little on-site observed data concerning the stratified reservoir flow are available, which is thus difficult to disclose its mechanism thoroughly. An experimental testing system is developed to simulate the formation and development of the water temperature stratification in late spring and early summer. And analysis of the influences of the discharge and outlet position on the vertical and longitudinal distributions of the water temperature has been carried out. The research results show that: ①due to the characteristics of the stratified flow and the differences between hydrodynamic conditions, the vertical structures of the water temperature show various forms in the evolution of the temperature stratification; ② the vertical temperature difference depends on the lower or upper locations, reservoir inflow and outlet elevation. Usually in the vertical direction, the upstream temperature difference is larger than that of the downstream. The vertical temperature difference increases with the increase in the discharge of the intake and the outlet elevation; ③ the longitudinal distribution of the water temperature is closely related to the water depth, discharge and outlet elevation. At the surface and mid-depth in reservoir water, the upstream temperature is higher than that of the downstream. At the bottom water stratification, the downstream temperature is higher than that of the upstream in a certain period when the outlet is located over the surface and the discharge is larger; ④ the water temperature of the oulet is affected by the discharge of the intake and the outlet elevation. A lower outlet location may result in lower outflow temperature, especially in the beginning period. |
| Key words: water temperature temperature stratification physical model large reservoir |
