基于多目标均衡优化的设计洪水推求方法

Calculation of design floods based on multi-objective equilibrium optimization

设计洪水是确定水利工程等别及水利工程运行管理策略的重要依据。为了准确推求设计洪水过程线,解决现有设计洪水推求方法修匀繁琐、不确定性大等问题,基于均衡优化思想提出多目标均衡优化方法。考虑洪峰流量、时段洪量和过程线形状等设计洪水要素误差,该方法构建了设计洪水误差向量,并建立起相应的均衡优化目标函数,采用改进布谷鸟算法求解设计洪水过程线。通过实例研究表明:采用多目标均衡优化法所推求的设计洪水过程线不仅满足洪水洪峰和时段洪量的约束,而且有效保持了典型洪水过程线的形状;多目标均衡优化法无需手动修匀计算或设置惩罚因子,不仅操作简便,还有效减少了设计洪水推求的复杂性和不确定性。因此,多目标均衡优化法可为设计洪水过程线推求提供一条新途径。

Design floods provide important bases for determining structure grades and operation strategies of water conservancy projects.In order to calculate the exact design flood hydrographs and reduce the smoothing complexity and the uncertainty of existing design flood calculation methods,a multi-objective equilibrium optimization(MOEO)method was proposed based on the idea of equilibrium optimization.According to this method,a design flood error vector was constructed based on the errors of the peak flow,interval flood volume and flood hydrograph shape,and then a corresponding equilibrium optimization function was established to resolve design flood hydrographs using the improved cuckoo search algorithm.The case study shows that the calculated design flood hydrograph by the MOEO method can satisfy the constraints of the peak flow and interval flood volume,as well as keep the shape of a typical hydrograph;the MOEO method gets rid of manual smoothing and penalty factor adjusting,which is not only user-friendly but also effectively reduces the complexity and uncertainty in calculating design floods.Therefore,the MOEO method can provide a new approach for the calculation of design floods.