水库供水调节计算优化模型研究与应用

Research and Application of Optimization Model for Reservoir Water Supply Regulation

水库供水调节计算是实现河流水资源时空合理分配的重要技术手段。常规水库供水调节计算方法流程清晰、操作简单,但计算所得供水量并非最优值。针对常规水库供水调节计算方法难以充分发挥水库供水效益的问题,以调节计算期内水库总供水量最大为目标,以各供水对象供水保证率和最大破坏深度为约束条件,构建水库供水调节计算优化模型;基于等价变换原理,将模型中供水对象供水保证率非线性约束条件进行线性化处理,采用Cplex线性求解器对模型进行求解。张峰水库供水工程实例分析结果表明:优化模型计算所得张峰水库多年平均供水量较常规方法增加948万m^(3),增加比例为7.5%,供水效益明显增加;水库多年平均水位较常规方法降低6 m,水库蓄泄变化次数更多,充分发挥了张峰水库多年调节作用;供水对象的最大破坏月份数量大于常规方法,但仍满足各供水对象的设计供水保证率要求,说明优化模型是通过增加最大破坏月份数量的方式,来到达减小最大破坏深度的目的;水库多年平均出库流量较常规方法减小0.2 m^(3)/s,但可保证长系列所有月份均满足河道内生态流量要求;1997-2002年、2008-2010年两个沁河流域典型的连续枯水时段缺水量及缺水过程与常规方法结果相似,符合实际情况,验证了模型的合理性;优化模型可根据实际需要修改优化目标和约束条件,能够精准控制各供水对象的供水保证率和最大破坏深度,且具备可移植性,使用更加灵活。

Reservoir water supply regulation calculation is an important technical means to achieve rational spatial and temporal allocation of river water resources.The conventional reservoir water supply regulation calculation method has a clear process and simple operation,but the calculated water supply volume is not the optimal value.Aiming at the shortcomings of conventional water supply regulation method,an optimization model is constructed in order to improve the calculation accuracy of the reservoir water supply scale.The model’s goal is maximizing the total water supply of the reservoir during the calculation period,and it’s constraint contains the water supply guarantee rate and maximum damage depth of each water supply object.Based on the principle of equivalent transformation,the nonlinear constraint conditions of the water supply guarantee rate for water supply objects in the model are linearized,and Cplex linear solver is used to solve the model.The analysis results of Zhangfeng reservoir water supply project show that:Compared with the conventional method,the average annual water supply volume of Zhangfeng Reservoir calculated by the optimization model increases by 9.48 million m^(3),with an increase of 7.5%,and the water supply benefits increases significantly.The average water level of the reservoir decreases by 6 meters compared with the conventional method,and the number of changes in water storage and discharge increases,which fully utilizes the multi-year regulation effect of Zhangfeng Reservoir.The number of maximum damaged months for water supply objects is greater than that of the conventional method,but it still meets the design water supply guarantee rate requirements of each water supply object,indicating that the optimization model achieves the purpose of reducing the maximum damage depth by increasing the number of maximum damaged months.The average annual outflow rate decreases by 0.2 m^(3)/s compared with the conventional method,but it can ensure that all months of the long series meet the ecological flow requirements within the river.The water shortage and water shortage process in two typical continuous dry periods from 1997 to 2002 and from 2008 to 2010 in the Qinhe River basin are similar to the results of the conventional method,which conforms to the actual situation and verifies the rationality of the model.The optimization model can modify the objectives and constraints according to actual needs,can accurately control the water supply guarantee rate and maximum damage depth of each water supply object,and also has portability,which makes it more flexible to use.