降雨观测误差抗差估计方法比较研究

根据遥测系统雨量观测资料误差的类型和特点,在抗差最小二乘法的基础上提出了雨量观测误差的三步修正方法.其中,每一步都根据雨量资料误差的不同特点,用不同的权函数进行修正.权函数设计包括保权区、降权区、拒绝区的权函数设计3个部分.降权区降权函数的选择无统一标准,所以采用了线性降权函数和抛物线降权函数.同时,根据面平均雨量是否分级2种情况和权函数的类型,组成了4种方案并对其抗差计算结果进行了比较分析.此外,还选用危水水库乌溪沟以上流域1974~1999年间28场洪水的暴雨资料进行了抗差分析计算.结果表明,面平均雨量是否分级对抗差效果的影响较大,而降权函数的形式对抗差效果的影响并不显著.

Comparison of robust estimation method for correction of rainfall observation error

The types and characteristics of rainfall observation error of hydrological remote monitoring system were analyzed,and a three-step weight function correction method for observation error of the system was developed on the basis of the theory of robustified least square method.In each step of the method,different kinds of weight functions were adopted according to the characteristics of observation error,therefore,the weight function design for weight-keeping area,weight-declining area,and weight-zero area was involved.Without a uniform format for determination of weight-declining function in weight-declining area,the linear function and parabolic function were adopted in this area.Four schemes for correction of rainfall observation error were formed with different weight functions adopted under the condition of classification or without classification of mean areal precipitation,and the calculated results of different schemes were compared.The analysis and calculation of rainfall data of 28 floods from 1974 to 1999 of the upper Wuxigou Basin of the Weishui Reservoir show that whether the mean areal precipitation is classified or not is of great influences on robust estimation,however,the influence of format of weight-declining function is not notable.