基于次序统计量理论的洪水频率分析方法研究

针对目前参数估计方法存在稀遇洪水频率设计值偏大的问题,提出采用基于数值次序统计量期望值的适线法计算洪水频率设计初始值;针对目前参数估计方法存在常遇洪水频率设计值偏小的问题,提出采用周文德公式修正目前频率设计偏小的情形,计算洪水频率设计修正值;针对目前传统方法计算洪水频率设计值抽样误差大的问题,提出采用基于数值次序统计量标准差的方法计算洪水频率设计保证值。定量分析表明,提出的基于数值次序统计量期望值的优化适线法具有良好的无偏性和有效性;寸滩站洪水频率设计修正值大于频率设计初始值,且两者偏差随着频率减小而减小;寸滩站洪水频率设计保证值明显大于修正值。

Method for Flood Frequence Analysis Based on Order Statistics Theory

As for the problem that the rare flood frequency design value is too large with parameter estimation methods, this paper used the FIT method of order statistic expectation value to calculate the initial value of design flood. For the problem that the common flood frequency design value is too small with parameter estimation methods, this paper used the ZhouWende formula to calculate the correction value of design flood. As for the problem that the error of design flood is too large, this paper used the standard deviation of generalized order statistics method to calculate the safety value of design flood.The results show that the FIT method of order statistic expectation has a good unbiased and effectiveness properties. The correction value of design flood of the Cuntan station design flood is greater than the initial value of design flood, and both bias decreases as the frequency decreases. Obviously, the safety value of design flood of Cuntan Station design flood is greater than the correction value of design flood.