三峡水库近坝支流水华预警及处置策略初探

Preliminary study on early-warning and countermeasure strategy for algal bloom in near-dam tributary of Three Gorges Reservoir

以三峡水库近坝支流香溪河为例,基于水华暴发特征规律,通过数值模拟手段,研究不同调度启动时间和执行周期下调度对水华暴发过程的影响,得到以下水华预警规则及处置策略:第一,水华易发时段,在香溪河上游河段(距河口25 km)设置叶绿素浓度连续监测站点;第二,在叶绿素浓度从较低水平连续上升至10μg/L时,保持日调峰泄流过程的条件下启动升水位调度,叶绿素浓度连续下降时可终止;第三,库水位在受上游来流或下泄流量限制而必须下降时,尽可能控制在叶绿素浓度连续下降以后。

By taking a near-dam tributary of Three Gorges Reservoir——Xiangxi River as the study case,the impact from the reservoir dispatch on the algal bloom process under various starting times and execution cycles of the operations is studied through numerical simulation in accordance with the characteristics and law of the algal bloom,and then the rule and countermeasure strategy for the early-warning of the algal bloom are obtained; i. e. firstly,a stations for continouslg monitoring chlorophyll concentration is to be arranged at the upstream section of Xiangxie River（ 25 km from the confluence）; secondly,when the chlorophyll concentration increases from a lower level to 10 μg / L,the dispatch of water level rising is to be started under the condition of remaining the discharge process of the daily peak-load regulation,which can be stopped if the chlorophyll concentration continuously decreases; thirdly,when the water level of the reservoir must be lowered under the limitations of the upstream inflow or the discharge flow rate,it must be made as after the continuous decrease of chlorophyll concentration as possible.