乌江梯级开发对东风水库水温分布影响分析

为探讨梯级电站联合运行对下游水库水温影响,以乌江梯级开发电站中的东风水库为研究对象,根据东风水库2002年及2006年实测水温数据,分析了东风上游水库建成前后东风水库水温的变化过程,同时运用EFDC模型计算了东风水库上游引子渡和洪家渡水电站下泄低温水对东风库区表层水温及坝前垂向水温的影响。结果表明:梯级水库运行对天然河道水温的累积性影响程度跟主要支流水体温度及流量均有关,入库流量越大,东风库区相同位置库表水温越低,与天然水温的温差越大;下泄低温水温度越低,相同位置库表水温越低,与天然水温的温差越大;入库流量越大、入流温度与天然水温温差越大,低温水影响越大,上游下泄低温水对库区累积性作用越明显。

Influence of cascade reservoirs operation on water temperature distribution inDongfeng Reservoir on Wujiang River Basin

In order to explore the influence of joint operation of cascade reservoirs on water temperature in downstream reservoir, taking Dongfeng Reservoir on Wujiang River as the research object, according to the measured water temperature data of the reservoir in 2002 and 2006, the water temperature change process before and after the development of upstream reservoirs were analyzed and compared. At the same time, EFDC model was used to calculate the influence of low temperature discharging water of upstream reservoirs on surface water temperature and vertical water temperature in front of dam in Dongfeng reservoir area. The results showed that: (1)the cumulative effect of cascade reservoirs operation on the water temperature of natural river was related to the temperature and flow rate of main tributaries. The larger the inflow was, the lower the surface water temperature was and the greater the temperature difference between the reservoir and the natural water temperature was; the lower the discharge water temperature, the lower the surface water temperature, and the bigger the temperature difference. (2) The bigger the inflow and the temperature difference between inflow temperature and natural water, the greater the influence of low temperature discharge water, and the more obvious the cumulative effect of upstream low temperature discharge water on reservoir area.