我国汛期降水的特征结构、年际变化及气象跃变

THE TYPICAL STRUCTURE,THE ANNUAL VARIATION AND THE CLIMATIC JUMP O'F THE PRECIPITAION IN FLOOD SEASONS IN CHINA

本文用36年(1951～1986)我国汛期(4～9月)160个站的降水距平百分率资料,用RPCA(Rotated Principal Component Analysis))的方法对我国汛期降水进行研究,结果表明:我国汛期降水有六种典型结构,它代表了我国汛期降水的空间分布特征;而相应的时间系数代表着年际变化。如果将各主分量的时间系数做5年滑动平均,按文献所定义的气候跃变,则在六十年代,我国黄河流域、长江下游及以南、东北地区的降水发生了气候跃变。

Using the data of 160 stations in China from 1951 to 1986,the percent of precipitation departure in flood season (from Apr. to sept. ),is analyzed by RPCA (Rotated Principal .Component Analysis) method in this paper. Six typical sturctures showing space distributive specification of precipitation in China are divided. The annual variation may be shown by the time series. The climatic jump of precipitation in the Yellow River, the lower reaches and the south of Changjiang,and in the northeastern China in 1960' s has been found.