基于宽浅式破坏原则的水库旱限水位优化方法

Optimal method of reservoir drought-limited water level based on principle of wide and shallow damage

针对旱限水位计算过程中干旱期需水多采用经验性调整系数确定存在主观性较强、合理性不足等问题,基于宽浅式破坏原则,以枯水年内月缺水率均值及其标准差最小为目标优化干旱期分行业需水,提出了水库旱限水位优化方法。以汾河水库与汾河二库为例进行优化效果分析,验证方法的合理性和可行性,结果表明:以优化后的旱限水位指导水库调度,可降低枯水年内的月缺水率均值及标准差;以50%作为严重缺水率阈值,优化后的旱限水位能够有效降低严重缺水月数;在连枯水年内,优化后旱限水位控制水库调度效果明显优于未优化的旱限水位,优化后旱限水位能够降低严重缺水情况的发生频率,符合枯水年内宽浅式破坏要求;旱限水位的设置保障了枯水年内各行业的用水安全,可减少极端缺水情况的发生,为旱灾防御指挥决策提供依据。

In view of the problems such as strong subjectivity and insufficient rationality in determination of water demand according to the empirical adjustment coefficient in calculation of the drought-limited water level in dry periods,this paper proposes a reservoir drought-limited water level optimization method based on the principle of wide and shallow damage,to optimize water demand of different users with the aim of minimum mean monthly water shortage ratio and its standard deviation in dry years.Taking the Fenhe Reservoir and the Fenhe-II Reservoir as examples,optimization effect analysis was carried out to verify the rationality and feasibility of the method.The results show that the mean monthly water shortage ratio and its standard deviation in dry years can be reduced by using the optimized drought-limited water level to guide reservoir operation.Taking 50%as the threshold for severe water shortage ratio,the optimized drought-limited water level can effectively reduce the number of months with severe water shortage.In consecutive dry years,the reservoir scheduling effect under the control of the optimized drought-limited water level is significantly improved,compared with that under the control of the non-optimized drought-limited water level,and the optimized drought-limited water level can reduce the frequency of severe water shortage,meeting the requirements for wide and shallow damage in dry years.The setting of the drought-limited water level can ensure water safety of various users in dry years,reduce the occurrence of extreme water shortage,and provide a basis for drought prevention command and decision-making.