利用1951~1997年华北地区26个测站的6~8月降水量资料,分析了各站夏季降水标准差的空间分布和降水距平百分率年际和年代际变化的地域性特征。在此基础上,根据各站降水标准差和旱涝的一致性,对华北夏季降水异常进行分区,研究了各区降水长期变化的趋势及其阶段性和跃变的特征。最后,探讨了华北地区目前这个少雨期何时结束的问题。

The spatial distribution of standard deviation of summer precipitation and the regional features of the interannual and interdecadal variations of precipitation anomaly percentage are analyzed by using monthly mean precipitation data from June to August during the period of 1951 to 1997 at 26 stations in North China.Then,based on the consistence of the standard deviation and the drought-flood appeared at various stations,the division of precipitation anomalies in North China is made,and the long-term variation trend of precipitation anomalies in various regions and their stage and climate jump are studied.Finally,it is an important problem when the drought period started from the mid-1960s over North China will end,we shall have a preliminary discussion on this problem.