基于高阶线性矩法的洪水设计值研究

Application of high-order L-moments to flood quantile estimation

为了提高大重现期洪水设计值计算精度,研究高阶线性矩法在洪水频率分析计算中的应用。应用蒙特卡洛试验研究不同阶线性矩的统计特性和对设计值的影响。以陕西省5个测站年最大洪峰流量序列为例,进行广义极值分布高阶线性矩的参数估计,评价拟合效果和设计值的计算偏差。结果表明,高阶线性矩法具有良好的统计特性;与普通线性矩法比较,高阶线性矩法能更好拟合洪水序列的大洪水值,且设计值估计偏差小。因此,高阶线性矩法是一种合理可行的参数估计方法,以期为大重现期设计洪水值的计算提供依据。

To improve the calculation accuracy of design flood for long return period, this paper studies application of high-order L-moments to flood frequency analysis, focusing on Monte-Carlo simulations for statistical properties of the L-moments method and its influences on the return period flood quantile. Parameters of GEV distribution and high-order L-moments were estimated for five annual maximum flow series observed in Shaanxi province, and the fitting effect and calculation error of flood quantile evaluated. The results show that this method has good statistical performance in flood analysis of long return period and it gives a representation of the data series better than the lower-order methods.