本文用黄河上游(兰州以上)及其附近地区34个站25年以上的降水资料, 分析了本区多年平均的年、月、旬降水(变率)特征。指出本区的部份地区有初夏旱、伏旱和秋雨现象; 本区的月降水变率远大于年变率, 而旬降水变率又大于月变率, 特别强调了在盛夏和秋雨期, 主要产流区各月都有一个高变率中心。这些都给水文、气象预报带来很大困难。

Using the precipitation and variability materials(34 stations, over 25 years) of the upper reaches of the Yellow River, we've studied the characteristics of the secular mean yearly, monthly, decade precipitation and variability; we've set up the rainy season, the region of drought (Early Summer) and Autumn rain. We've pointed out that the secular mean monthly variability is much more bigger than the yearly variability and emphasised that there is a big center of the monthly variability nearby Ma Qu station(over 36%) from July to September. These caused a lot of difficulties of the hydro-meteor forecast.