中文摘要：

利用1971-2010年40a柴达木盆地8个气象站及盆地外缘托勒气象站的水汽压、月降水量资料，运用整层大气可降水量经验公式，计算了柴达木盆地大气可降水量和降水转化率。结果表明，近40a柴达木盆地可降水量、降水量、降水转化率均呈波动增加趋势。可降水量在20世纪70年代初到80年代中期相对较低，90年代后逐渐增多，总体呈先降后增的变化趋势。近40a春、夏季呈持续增长趋势，而秋、冬季20世纪80年代呈弱的减少趋势，90年代后呈持续增长趋势；可降水量变化趋势在空间上表现为自东南向西北增加的分布特征，这与可降水量多少的空间分布特征相反。气温是影响柴达木盆地可降水量变化的最主要气候因子，其次为日照，而相对湿度对柴达木盆地可降水量变化的影响相对较小。本文的分析表明，多雨年与少雨年可降水量保持相对稳定，可降水量与多雨、少雨年并无直接关系。降水量的多少是大尺度环流背景下的水汽输送、交换及降水转化率共同作用的结果。

英文摘要：

Based on water vapor pressure and monthly precipitation data from 1971 to 2010 recorded by eight weather stations in the Qaidam Basin, precipitable water （PW） and precipitation conversion efficiency were analyzed using an empirical formula of atmospheric total PW. The results show that PW, precipitation and precipitation conversion efficiency increased from 1971 to 2010. However, variation in PW was different over an inter-decade time scale for the last 40 years. PW shows a decreased trend in the first period but increased afterwards, specifically, PW in the Qaidam Basin was relatively low during the early 1970s until the end of the 1980s. PW in spring and summer shows a continued increase from 1971 to 2010, but the situation is different in autumn and winter. Spatial patterns in PW variation were revealed： the tendency of PW increases gradually from southeastern to northwestern. This pattern is reversed for PW amount. Changes in PW change were also analyzed and we found that air temperature has the most important influence on PW, followed by sunshine hour. Variation in PW is indirectly related to precipitation.