基于混合抽样的洪水设计值抽样误差计算方法

为进一步提高洪水设计值的精度和可靠性,提出了一种新的混合抽样方法,以雅砻江甘孜水文站设计洪水为例,定量分析表明,在实际工作中推荐采用给定频率洪水设计值的分位数作为保证值,可使洪水设计值的安全保证率均相同;洪水设计值的概率分布函数为非对称的有偏分布,在频率曲线的上端或下端部分为一正偏分布,在频率曲线的中间部分为一负偏分布,其不确定性程度整体上随着设计频率的减小而增大。研究成果可为雅砻江流域水利水电工程规划建设提供参考。

Sampling Error Calculation of Design Flood Based on the Hybrid Sampling

A new hybrid sampling method is proposed to provide a basis for estimating the sampling error of the flood design value. Quantitative analysis of the uncertainty of flood design value can further improve its accuracy and reliability. Taking the design flood of the Ganzi hydrological station in the Yalongjiang River basin as an example, the quantitative analysis shows that in the actual work, it is recommended to use the quantile of the flood design value at a given frequency as the safety correction value, and the safety correction value is at each frequency. The safety guarantee rate is the same. The probability distribution function of the flood design value is asymmetrically distributed, with a positive partial distribution at the upper or lower end of the frequency curve, and a negative partial distribution at the middle of the frequency curve. The degree of uncertainty generally increases as the design frequency decreases. The search can provide reference for planning and construction of water conservancy engineering in Yalongjiang River basin.