分期设计洪水重现期计算模型研究

Models of the return period calculation for seasonal flood

年最大洪水与分期最大洪水序列是两个选样不同的样本,其重现期和设计值计算对于水库安全防洪、提高兴利效益和洪水资源安全利用至关重要。本文根据重现期的定义,运用数理统计法,推导了独立同分布单变量和多变量水文事件重现期的计算公式。在此基础上,结合现有的3种分期洪水概率模型,严格推导了年最大洪水重现期与分期最大洪水有关重现期计算模型和关系式。采用蒙特卡洛试验,经模拟计算,文中有关重现期模型计算值与经验重现期一致,表明文中推导的重现期模型是正确的。最后,以南四湖流域1963—2008年分期7日最大入湖洪量资料为例,给出了分期最大洪水分布参数估计、年最大洪水分布计算过程,说明分期最大设计洪水的计算问题。文中模型与计算方法以期为我国分期设计洪水计算提供理论支撑。

Annual maximum flood and seasonal maximum flood sequences are two different type samples.Their return periods and design values are very important to operate flood control safely, improve benefitand utilize flood resources of reservoirs. According to the definition of the return period, using mathemati-cal statistics, return period formulas of independent and identically distributed variable and multivariable hy-drologic events were derived. Then,the return period calculation models of annual maximum flood and maxi-mum flood of seasonal flood were presented. Employed the Monte Carlo test, the return periods are consis-tent with the empirical return periods. These results indicate that the return period models derived in thispaper are correct. Finally, taking the 7 days maximum flood volume of Nansi Lake during 1963-2008 asan example, the formulas of parameters estimation of seasonal maximum flood and probability distributionof annual maximum flood were given, illustrating the calculation problem of the design seasonal maximumflood. The models and calculation methods in this paper are expected to provide theoretical support for thedesign seasonal flood calculation in China.