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利用１９９２～１９９６年４～９月，黄河上游河曲段部分气象站，逐日０２、０８、１４、２０时云量，２０～０８时、０８～２０时降水资料，计算分析了４～９月黄河上游河曲地区云层特征，阴天、雨天出现频率，地理分布，总云量、低云量与降水的关系。结果表明：黄河上游河曲地区，４～９月阴天出现频率约４５％。地理分布以久治为高值中心，由南向北呈递减趋势。≥０１ｍｍ降水日数占阴天日数的比例约７０％，≥５．０ｍｍ的比例约２３％，≥２５．０ｍｍ的比例不足１％。并指出黄河上游地区以低云降水为多，但降水强度小，持续时间短，夜间降水多于白天
From April to September 1992 to 1996, some meteorological stations in the erqu section of the upper reaches of the Yellow River, daily precipitation data of 02, 08, 14 and 20 hours, precipitation data of 20 ~ 08, 08 ~ 20 o’clock, calculated from April to September the Yellow River The upper reaches of the Hequ area cloud characteristics, cloudy, rainy days frequency, geographical distribution, total cloud cover, low cloud cover and precipitation. The results showed that the frequency of cloudy days from April to September was about 45% in Hequ area of the upper Yellow River. The geographical distribution of long-governance center for high value, decreasing trend from south to north. ≥0 1mm The number of precipitation days in cloudy days is about 70%, the proportion of ≥5.0mm is about 23%, and the proportion of ≥25.0mm is less than 1%. It is also pointed out that precipitation in the upper reaches of the Yellow River is low with low precipitation, but rainfall intensity is short, duration is short, precipitation at night is more than that at daytime