梯级电站水温累积影响研究

Cumulative impact of cascade power stations on water temperature

采用数学模型进行梯级电站的水温累积影响研究，预测了雅砻江锦屏一级和二滩两个梯级电站联合运行时的库区水温分布及下泄水温过程，并与二滩电站单独运行时的水温进行比较。结果显示，锦屏一级水库全年稳定分层，库底保持稳定低温8．6℃，坝前表层水温在12．7～24．2℃内变化，下泄水温明显延迟。二滩库区在单独运行和联合运行时均稳定分层，但联合运行较单独运行时库表水温降低，库底水温升高，水温分层有所减弱，而下泄水温过程的延迟和均化现象进一步加强，梯级电站的累积生态环境效应显著。

The cumulative impacts of the cascade power stations on water temperature are studied by using the mathematic model. The water temperatue of Jinping and Ertan in reservoir area and the outflow temperature are computed. Comparison is carried out between the joint operation and single operation of Ertan. The results show Jinping reservoir is steadily thermalstratified in the year round. The temperature at bed keeps cold steadily at 8.6℃. The temperature on the surface near dam varies from 12.7 - 24.2℃ in the year round. The course of the outflow temperature is obviously delayed. Ertan reservoir is thermally stratified both at the single operation and joint operation conditions. But compared with the single operation condition, the surface temperature declines and the bed temperature rises at the joint cooperation condition. The stratification in reservoir area is weakened. The delay and evenness of the outflow temperature course is further strengthened. The cumulative impact of the cascade power station on ecology environment is obvious.