南水北调东线工程江苏段水资源优化配置

为更好地解决跨流域调水工程水资源配置问题,该文在水资源常规配置的基础上,将模拟技术与离散微分动态规划方法(DDDP)相结合,提出了"河-湖-梯级泵站"系统水资源优化配置模型。模型以整个系统的缺水量及抽水量最小作为综合目标:首先根据一定的湖泊运行规则按逆水流方向依次对各湖泊区间来用水进行模拟计算,以确定各湖泊区间在各时段的最大可供水量及可外调水量;在此基础上,以整个系统总抽水量最小为目标函数,各湖泊在每个时段的抽(弃)水量作为决策变量,建立多湖泊联合调度动态规划数学模型,采用DDDP法对其进行求解。以南水北调东线工程江苏段为例,采用该模型进行水资源优化配置,结果表明,该模型提高了整个系统的供水保证率,同时实现了可供水量在各区间各时段的均衡分配;在50%、75%和95%频率时,江苏可实现最大外调出省水量达14.08、14.18和12.70亿m3;同时,供水系统总抽水量分别可减少51.34、94.87和28.19亿m3,可见通过优化调度,降低了系统运行成本,实现了本地水和外调水的联合优化配置。

Optimal allocation of water resources for Jiangsu section of South-to-North Water Transfer East Line Project

In order to solve the problem of water resources allocation in inter-basin water transfer project, this paper puts forward an optimal water resources allocation model for rivers-lakes-pumping stations system by combining simulation technology and discrete differential dynamic programming(DDDP) on the basis of the conventional water resources allocation. The minimum water shortage and pumping water volume was taken as comprehensive objective function, and, the inflow and water use in different hydrological year were simulated and calculated based on certain operation rules of lake in order to determine the maximum available water supply volume and transferred water volume of each section. A dynamic programming model for joint operation of multiple lakes was proposed, in which the minimum pumping water volume of the whole system was set as the objective function, the water volume to be pumped into the lake or discarded water from the lake was expressed as decision variable and was solved by means of DDDP. The JiangSu section of South-to-North Water Transfer Project was taken as a study case, the results showed that not only the water supply guaranteed rate of the whole system can be improved but also the equilibrium allocation of water supply volume among each section and each period can be realized. The maximum transferred water volume 1408, 1418 and 1270 million m3 out of JiangSu province in 50%, 75% and 95% hydrological year were calculated, respectively. And the model decreased the total pumping water volume 5134, 9487 and 2819 million m3 in 50%, 75% and 95% hydrological year, respectively, which can reduce the cost of the water supply system through optimal operation, and finally realize optimal joint allocation of local and transferred water resources.