摘要
本文叙述了矩、概率权重矩与线性矩之间的关系,并以Γ分布为例进行分析。线性矩的计算式为概率权重矩的线性组合,两者的计算结果完全相同。概率权重矩和线性矩均与指定的频率分布型式和作为权重的概率有关,结果的敏感性较差。详细分析了计算参数的近似公式及其精度。对水文应用而言,它们的计算结果仅是估计的初值,需经过合理性分析才能取用。
The relationship between moment, probability-weighted moment （PWM） and linear-moment （L-moment） is described and is il- lustrated with gamma distribution in this paper. The L-moment is the linear combination of the PWM and the computed results from both methods are exactly same. The PWM and L-moment are all related to specific distribution types and probabilities as weights, and their results have lower sensitivity. The approximated formula of the computed parameters and their accuracy are analyzed in detail. In hydrologic application, the computed results may only be used as initial values for estimation and should be used after the reasonable analysis.
出处
《水文》
CSCD
北大核心
2005年第5期1-6,共6页
Journal of China Hydrology
关键词
水文频率计算
概率权重矩
线性矩
Г分布
参数估计
hydrologic frequency computation
probability-weighted moment
linear-moment
gamma distribution
parameter estimation
