年最大日雨量极值分布拟合与推算

摘要

Based on the annual maximum diurnal rainfall data from 12 metrological stations over Honghe of Yunnan Province in the recent 48 to 58 years, the extreme value distribution of annual maximum diurnal rainfall is fitted with the Pearson-Ⅲ distribution, Gumbel distribution, and logarithmic distribution, and their extreme values at various reappearance periods are calculated by the best probability distribution.The results show that these three probability distribution models can fit well the distribution of annual maximum diurnal rainfall; the fitting results with Gumbel distribution are the best for 7 stations, PearsonⅢ distribution for 4 stations, and lognormal distribution for 1 stations, and they all reached the standards of significance test. For various given reappearance periods, the distribution characteristics of annual maximum diurnal rainfall over Honghe are very similar, and maximum and minimum centers are consistent, higher in South and lower in north.%采用红河州12个站近48～58年的年最大日雨量资料,用PearsonⅢ型分布、耿贝尔分布、对数正态分布等3种概率分布模型分别进行了拟合,选择拟合最好的分布模型来估算最大给定重现期极值.结果表明:3种分布均能较好地拟合年最大日雨量的分布,在红河州12个站的拟合中,有7个站用耿贝尔分布,4个站用Pearson-Ⅲ分布,1个站用对数正态分布拟合最佳,且通过了显著性水平α=0.05的x2拟合优度检验.对于不同的给定重现期,红河州年最大日雨量极值分布形势均极为相似,最大值和最小值中心一致,均表现出南高北低的特征,最大中心位于最南端的河口,最小中心位于红河州中部一线.