考虑梯级水库库容补偿和设计洪水不确定性的汛限水位动态控制域研究

汛限水位动态控制本质上是风险调度的范畴，其最主要的风险源来自于入库洪水的不确定性。不仅包括由于预报误差带来的实时调度风险，还包括由于设计阶段对于设计洪水不确定性考虑不周而存在的潜在防洪风险。本文针对梯级水库，提出了一种考虑库容补偿和设计洪水不确性的汛限水位动态控制域求解新方法。通过分析梯级水库库容补偿调度原理，定义了水库极限汛限水位上限值，并给出了考虑设计洪水不确定性的防洪风险定量表达式。以Copula函数为工具建立上游和区间天然来水的联合概率密度函数，求出下游遭遇某一设计洪水时，上游可能出现的洪水范围，从而得到考虑梯级水库调蓄作用的不确定性设计洪水。通过反复迭代计算最终得到兼顾防洪风险与兴利效益的汛限水位动态控制域。将该方法运用在考虑潘口库容补偿作用的黄龙滩汛限水位动态控制域计算中，并与同频率法和典型年法比较，得到以下结论：1）所提方法能通过挖掘历史洪水信息，为模拟梯级水库设计洪水不确定性提供参考信息；2）相对于同频率法和典型年法，所提方法推求的汛限水位动态控制域更加的安全；3）黄龙滩水库汛期运行水位可以从[240，247]m变为[240，248.21]m。可使汛期来水较多的2000年和来水较少的1994年分别增加发电量0.13和0.11×10⁸ kW·h。所提方法能充分考虑梯级水库库容补偿和设计洪水的不确定性，能得到不增加防洪风险的水库汛限水位动态控制域。

Dynamic Control Bound of Flood Limited Water Level Considering Capacity Compensation Regulation and Design Flood Uncertainty of Cascade Reservoirs

The dynamic control of flood limited water level (DC-FLWL) belongs to the research field of risk operation.The risk source mainly comes from the uncertainty of inflows,including the risk from the forecasting error in real-time operation and the potential risk in the design phases from insufficient consideration about the uncertainty of design flood.A new model considering capacity compensation and the uncertainty of design flood for cascade reservoirs was developed to calculate the bound of DC-FLWL.Firstly,the probable maximum FLWL was defined by analyzing the principle of capacity compensation and an explicit expression of flood control risk was given.The joint distribution of the upstream and interval floods was established by a Copula function.When the downstream reservoir encountered a certain design flood,the possible range of upstream flood could be obtained,thus the uncertain design floods could be obtained.By simulating the operation of the cascade reservoirs under a risk constraint,the DC-FLWL could be calculated.The proposed method was applied to Pankou-Huanglongtan cascade reservoirs in Du River basin,and the results were compared with homogeneous frequency and typical year methods.It showed that:1) By employing empirical information from the historical flood data, the proposed method can provide reference information to the simulation of the design floods of cascade reservoirs;2) The bound of DC-FLWL obtained by the proposed method was much safer than the homogeneous frequency and typical year methods;3) The bound of DC-FLWL for HLT could be widened from[240.00,247.00] m to[240.00,248.21] m,which would increase 13 and 11 million kW·h extra hydropower generation during a wet year in 2000 and a dry year in 1994,respectively.The proposed method could give a sufficient consideration about the capacity compensation regulation and design flood uncertainty of cascade reservoirs, and the bound of DC-FLWL could be calculated while no flood control risk was increased.