中文摘要：

用1959年-2008年云南降水和NCEP/NCAR资料,分析纵向岭谷区北部＂春汛＂降水典型站点福贡、贡山的气候特征,表明＂春汛＂降水过程具有雨量多、强度大的特征＂。春汛＂期间的降水远大于主汛期的降水,3月降水占年降水百分率最大,并且2月、3月的降水比前一个月突增一倍左右,大雨暴雨以上日降水频次远大于主汛期,近50年来＂春汛＂降水变化趋势基本不明显,在年际尺度上具有很强的年际震荡,以8年周期较为明显。在年代际尺度上,16年周期较为显著。合成分析和相关分析得出：形成＂春汛＂的主要原因是2月-4月对流层低层逐渐增强的南支西风受到南北向地形的阻挡和抬升,在纵向岭谷区北部产生降水。南支西风、南支槽是造成纵向岭谷区北部＂春汛＂降水的天气系统。阿拉伯海和孟加拉湾是＂春汛＂降水的水汽源地。2005年2月异常强盛的南支西风和3月活跃的南支槽是造成＂春汛＂降水异常偏多的原因,这可为预报员提供参考。

英文摘要：

Affected by monsoon, characteristics of wet and dry seasons are distinct in Yunnan Province. It starts to rain from the mid-February across the northern Longitudinal Range-Gorge, termed ＂the rainfall in spring＂, which differs greatly from the rainfall in spring occurring in other regions. During the processes of rainfall in spring, a variety of disasters are always accompanying, such as debris flow and landslide, especially in the year 2005. Climatic characteristics of the rainfall in spring at the western-northern stations Fugong and Gong jebel were analyzed in this study using wind and relative humidity from National Centers for Environmental Protection and the National Center for Atmospheric Research of the United States （NCEP/NCAR） reanalysis data sets and observed precipitation at weather stations in Yunnan Province from 1959 to 2008 in conjunction with methods of the linear trend, wavelet analysis, composite analysis and correlation analysis. Results indicated that persisting for a long time, higher intensity and abundance are major characteristics of rainfall in spring. The amount of rainfall in spring is generally greater than that in flood season over the study area. The precipitation in March accounted for most of the total precipitation. The precipitation in February and March doubled the precipitation amount of the previous month, respectively. However, the outbreak of monsoon rainfall began in May or June across most areas of Yunnan. Compared the characteristics of precipitation in the Longitudinal Range-Gorge with that in other areas, there exist three precipitation peaks in March, July and October in the northern Longitudinal Range-Gorge. In particular, the percentage of precipitation in March relative to the total precipitation of a year was largest. It was found that trends of rainfall in spring have not been obvious in recent 50 years, showing major periods of 8a and 16a. Through composite and correlation analyses, it was indicated that the rainfall in spring would be as a result of incr