基于预报调度规则的云峰水库特大洪水调度研究

针对当前极端天气频发的形势,对极端暴雨洪水进行准确预报、合理调度是水库调度管理不可回避的问题。以应对云峰水库流域特大暴雨洪水、提前建立预报及调度预案为目标,基于现有的预报方案及精度,将云峰水库防洪调度规则中引入累积净雨量判别指标,提前预报入库洪水,采取预泄手段提前腾空库容,消纳入库洪水,使整个泄洪的流量过程比较平缓,并对典型年及各频率设计洪水过程线的洪峰值与对应的累积净雨量进行了相关分析。研究表明:洪峰滞后于净雨量峰值约18 h,同时累积净雨量与洪峰流量呈较好的线性相关性;采用累积净雨量作为防洪调度的判别指标可以延长调度的预见期,并提高防洪与兴利互相结合的程度。研究成果为优化云峰水库特大洪水调度方案创造条件。

Flood forecast and operation rule-based study on extreme flood control operation of Yunfeng Reservoir

Facing the conditions that extreme weather increases frequently，it is the accurate forecast and reasonable dispatch on extreme floodone problem that cannot be neglected for reservoir operation managers. Aiming at establishing the forecast and operation pre-scheme in advance for the extreme rainstorm flood possibly occurring within the watershed of Yunfeng Reservoir，the judging index of accumulated net rainfall is introduced into the flood control operation rule of Yunfeng Reservoir on the basis of the existing flood forecast scheme and its accuracy，so as to forecast the inflowing flood therein in advance，and then take the measure of pre-discharge to absorb the inflowing flood for making the whole flood discharge process more smooth. Moreover，the relevant analysis is made on the typical years and the flood peak values and the accumulated net rainfalls of the design flood hydrographs with all the frequencies. The study shows that the flood peak lags behind the peak value of the net rainfall for about 18 h，while the accumulated net rainfall presents a better linear correlation with the flood peak discharge. The forecast period for the operation can be prolonged by taking the accumulated net rainfall as the judging index for the flood control operation and enhance the combination of flood control and usable operation. The study result creates the condition to optimize the extreme flood control operation scheme for Yunfeng Reservoir.