干支流水库调度对三峡库区香溪河库湾垂线平均流速影响研究

Influence of Reservoir Regulation on Vertically-averaged Velocity in the Xiangxi Tributary Bays of the Three Gorges Reservoir

为探讨三峡库区干支流水库调度对三峡库区香溪河库湾垂线平均流速的影响,评判其抑制水华的可能性,构建了香溪河回水区平面二维水动力学数学模型。考虑三峡水库起调水位、水位变化方式、水位变化幅度、调度持续时间、支流水库下泄流量等水库调度参数,计算了24种工况。结果表明:三峡水库运行调度期间,香溪河回水区流速很小,为10^-3~10^-2 m/s量级。三峡水库单独调度导致水位抬升,流速减小;水位下降,流速增加;但对库湾垂线平均流速的影响效果不显著,按照影响作用的大小排序依次为:起调水位、水位变幅、持续时间。支流古洞口水库增加下泄流量对库湾垂线平均流速影响较显著。

In order to study the influence of reservoir regulation on the vertically-averaged velocity in the tribu?tary bays of the Three Gorges Reservoir,and to evaluate possibility of controlling algal bloom with velocity change,a two-dimensional hydrodynamic model was established for the area of the Xiangxi River.24 cases were computed under the consideration of initial water level,changing style and changing amplitude of water level,as well as regulating duration and discharge of tributary reservoir,etc..The results show that the vertically-aver?aged velocity in the backwater area is very small during the operation of the Three Gorges Reservoir with a mag?nitude of 10^-3~10^-2 m/s.The effect of the reservoir regulation on the vertically-averaged velocity is insignificant.When the water level rises,the velocity decreases,and as the water level falls,the flow rate increases.Accord?ing to the importance of these impact factors,the significance order is initial water level,water level changing amplitude and regulating duration.The vertically-averaged velocity can significantly influenced by the discharge of tributary reservoir.