乌东德水库水温预测及低温水减缓措施

乌东德水库为季调节水库,采用宽度平均的立面二维水温数学模型对水库水温结构进行预测,结果表明:乌东德水库水温结构呈季节性分层特征,电站运行对下游水温过程有一定程度的春季低温水和冬季高温水影响。如果采用单层取水方案,在2~8月的下泄水温低于坝址现状水温,最大降幅为2.0℃,下泄低温水将对坝下鱼类产卵繁殖产生不利影响。乌东德水电站拟采取分层取水的措施,对低温水较为敏感的鱼类产卵期3~6月采用叠梁门取水。相比于单层取水,叠梁门方案对低温水的改善效果较明显,下泄水温提高了0.8~1.1℃,能一定程度地减缓升温期水温延迟效应。

PREDICTION OF WATER TEMPERATURE IN WUDONGDE RESERVOIR AND MITIGATION MEASURES OF LOW-TEMPERATURE WATER

The Wudongde Reservoir is a seasonal regulating reservoir in Southwestern China, and the reservoir water temperature structure was projected by the laterally averaged 2D reservoir water temperature model. The result shows that the water temperature structure of the reservoir presents seasonal stratification characteristics. The reservoir operation has affected on the dam downstream water temperatures, which included low-temperature water discharge in spring and high-temperature water discharge in winter. Compared to the natural river conditions, lower temperature water can be discharged between February and August while the water intake scheme of single layer was adopted. The maximum downstream water temperature decline could be 2℃, and the low-temperature waters had produced opposite effects on fish reproductions. Stop-log intake works will be taken in the Wudongde Hydropower Station during the fish spawning period between March and June annually, because the fishes are sensitive to low-temperature waters. Compared to the water intake scheme for single layer, the stop-log intake works showed notable improvements on downstream water temperature changes. The discharged water temperature can be increased by 0.8～1.1℃，which can slow down the water temperature delaying effects.