中文摘要：

利用山东省123个气象站1961—2015年逐日实测降水资料,采用小波变换方法,分析了山东省降水全年、4—9月汛期和10月—次年3月非汛期三种时间序列的周期变化特征。结果表明：山东省降水全年时间序列存在3-4、15-16、36-37 a三个变化周期,汛期时间序列存在5-6、11-12、43-44 a三个变化周期,非汛期序列存在3-4、12-13、30-31 a三个变化周期,第一周期（小周期）在空间上呈现由东北向西南逐步增大的趋势;降水全年时间序列变化周期同时受到汛期和非汛期的影响,但汛期影响起决定作用;根据分析的周期特征预测,山东省未来15 a内将处于枯水期,水资源形势不容乐观。

英文摘要：

Using measured daily precipitation data of 123 meteorological stations in Shandong Province from 1961 to 2015,the period changecharacteristics of three precipitation series in a year,flood season（from April to September）and non-flood season（from October to Marchof the following year）were analyzed based on wavelet transformation method. The results show that each precipitation series exhibits threechange periods,which are 3-4 year,15-16 year and 36-37 year in year series,5-6 year,11-12 year and 43-44 year in flood season se-ries,and 3-4 year,12-13 year and 30-31 year in non-flood season series. In space,the little period of three series presents an increasingtrend gradually from the northeast to the southwest. The change periods of year series are affected by those of flood season and non-flood sea-son at the same time,but the effects of flood season are decisive. According to the analyzed change periods,it can be predicted that Shan-dong Province will be in dry season in the next 15 years,and its water resources situation is not optimistic in the future.