中文摘要：

选用1967～2012年青藏高原东部60个站点的降水资料,分析了该地区降水的时空演变特征,结果表明：高原东部降水呈由东南向西北递减的态势,高值区位于西藏东部和川西高原,低值区位于柴达木盆地;降水场可以划分为八个小区,分别是西藏东部和川西高原西部区、藏南谷地区、青南高原区、柴达木盆地区、藏北高原区、川西高原北部区、青藏高原东南缘区以及青海东北部区.年降水表现出强增加趋势,20世纪60年代后期到90年代后期相对偏少,20世纪末以来相对偏多;除川西高原北部区外,其余各区不同程度的表现出增加趋势.春季降水表现出“偏少～偏多”的年代际变化特征,在1995年附近发生由少到多的突变,20世纪60年代后期到90年代中期相对偏少,90年代后期以来相对偏多;八个分区均不同程度的表现出增加趋势.夏季降水呈增加趋势,20世纪60年代后期到90年代后期相对偏少,20世纪末以来相对偏多;八个分区均不同程度的表现出增加趋势.秋季降水的线性趋势趋近于零且没有表现出年代际变化特征;除川西高原北部区呈减少趋势外,各区均不同程度的表现出增加趋势.冬季降水表现出“偏少～偏多～偏少”的年代际变化特征,分别在1986和1996年附近发生由少到多和由多到少的突变,20世纪60年代后期到80年代中期相对偏少,80年代后期到90年代中期相对偏多,90年代后期以来相对偏少;除西藏东部和川西高原西部区及青海东北部区外,各区均不同程度的表现出“偏少～偏多～偏少”的年代际变化特征.

英文摘要：

By using the rainfall data set in 60 weather stations at the east of Qinghai - Tibet Plateau for the period from 1967 to 2012, we analyzed the temporal and spatial variations of rainfall. The results indicate the spatial variations of rainfall in the four seasons are almost the same, having a gradual reduction trend from southeast to northwest. These regions Of maximal rainfall are located in east of Tibet Plateau and Western Sichuan Plateau. These regions of minimal rainfall are located in the Qaidam Basin. Based on the REOF method, the rainfall have been classified into eight main patterns ： east of Tibet Plateau and west of Western Sichuan Plateau, the valley in Southern Tibet Plateau, Southern Qinghai Plateau, Qaidam Basin, Northern Ti- bet Plateau, north of Western Sichuan Plateau, the southeast edge of Qinghai - Tibet Plateau and northeast of Qinghai Plateau. The annual rainfall show strong growth linear trend, little before the later stages of the 1990s, rich after the end of 20th centu- ry. Except north of Western Sichuan Plateau, the annual rainfall of all other regions show growth linear trend in different de- gree. The spring rainfall show the obvious characteristics of interdecadal change, little before the middle stages of the 1990s, rich after the later stages of the i990s. The spring rainfall of all regions show growth linear trend in different degree. The sum- mer rainfall show growth linear trend, little before the later stages of the 1990s, rich after the end of 20th century. The summer rainfall of all regions show growth linear trend in different degree. The autumn rainfall show no linear trend and characteristics of interdecadal change. Except the autumn rainfall over north of Western Sichuan Plateau show reduction linear trend, that of all other regions show growth linear trend in different degree. The winter rainfall show the obvious characteristics of interdecadal change, little before the middle stages of the 1980s, rich from the later stages of the 1980s to the middle stages of the 1990