用多目标遗传算法优化设计水库分期汛限水位

水库分期汛限水位利用洪水的季节性规律,可在不降低水库防洪标准的前提下,显著提高水库兴利效益.论述了优化设计分期汛限水位的必要性、基于模拟调度优化设计分期汛限水位的可行性.以防洪、发电、航运等多目标来评价分期汛限水位方案,以不降低水库防洪能力为约束条件,建立了优化设计模型.对简单遗传算法进行了多目标评价、引入共享函数、线性变换适应度函数、优解保持策略、重新洗牌等改进,建立了一种改进的多目标遗传算法,用以优化设计分期汛限水位方案.以三峡水库为研究背景,采用混合编码方法描述分期汛限水位方案,利用1882~2003年宜昌站汛期的实测日流量资料进行模拟优化,得出了较优的分期汛限水位方案.计算结果表明,分期汛限水位优化设计能权衡防洪与兴利之间的关系,在满足防洪要求的前提下,显著提高水库兴利效益.

Optimal Design of Reservoir Seasonal Flood Control Level by Using Multi-objective Genetic Algorithm

The seasonal flood control level(FCL),which the storage allocation for flood control is varied seasonally,can be adopted to obtain more benefits under the condition of flood standard unchanged when the flood season is divided into several sub-seasons.For given design flood standards,the seasonal FCL isn't unique and should be determined optimally.With the constraints of the seasonal FCL risk less than the risk of current annual FCL,an optimal seasonal FCL model was developed based on simulation of the historical data.This optimal model is to maximize the beneficial use and to minimize the flood risk simultaneously.A modified multi-objective Genetic Algorithm with mixed integer-programming method was used to optimize the FCL for the Three Gorges Reservoir(TGR) and yielded a set of Pareto solutions.The application results indicate that the optimized model can make an effective tradeoff between the flood control,power generation and navigation,and enhance water resources utilization ratio as well as the economic benefit of the TGR.