清涧河流域近50年降水变化特征分析

采用清涧河子长站1959—2008年实测月降水资料，对降水量年内分配的不均匀性、集中程度进行了详细的分析计算；应用Mann—Kendall检验方法分析了清涧河降水量的年际及季节变化趋势，并对降水量系列进行了突变分析。结果表明：降水量年内分配不均匀系数Cu年代之间变化不大，降水相对集中；降水年际变化丰枯交替周期较长；整体上年降水量呈减少趋势，在1964年和2005年共发生两次突变。

Analysis of variation characteristics of precipitation in Qingjian river basin during recent 50Years

The non - uniform coefficient of distribution of years and concentration degree of the Qingjian River precipitation were calculated in great detail based on the monthly precipitation data measured at Zichang station from 1959 to 2008. The method of Mann - Kendall rank correlation is used to analyze the annual and seasonal precipitation change trend and the mutation of precipitation series. Results indicated that uneven distribution coefficients of rainfall years change little and precipitation is relative concentration ; precipitation interannual variation and alternation cycle is longer than the other ; the year precipitation on the whole shows a trend of decrease and has two mutations in 1964 and 2005.