摘要
根据中国近40年逐日降水观测资料,分析了大范围空间域上不同等级日降水量与其占有面积的函数关系。研究表明,几乎每一年任何一天中国区域的不同等级日降水量场的统计分布都呈明显的左偏态型。利用负指数分布和Weibull分布的概率密度函数(PDF)拟合实测降水资料的结果表明,后者拟合效果优于前者。负指数分布型可能仅适用于同一天气系统控制下的一次降水过程或较小的区域范围,在更大的区域内(如中国区域),由于构成降水的多种天气系统在同一日相互叠加,可能用Weibull分布更适合。
A function relationship between the daily rainfall over a large area and its area has been researched using the observed precipitation data in China in recent 40 years. The result shows that the statistical distribution of the daily rainfall field over large coverage(like China) appear usually obvious leftward skew pattern. Comparing the negative exponential distribution with the Probability Density Function of Weibull distribution shows that the latters fitting result is better than the former one. The negative exponential distribution pattern might is only suitable for the precipitation process under the same synoptic system or smaller region, and in a larger region(say China), it is possible more suitable for Weibull distribution fitting because of the combination effects of the varieties of synoptic systems.
出处
《高原气象》
CSCD
北大核心
2005年第3期422-427,共6页
Plateau Meteorology
基金
河南省气象科技攻关项目"河南气候变化评估研究"(Z200402)资助
关键词
日降水量
水平分布
非均匀性
统计分布模式
Daily rainfall
Horizontal distribution
Precipitation inhomogeneity
Statistical distribution model
