石羊河流域中下游1961~2014年各级降水量别日数变化特征统计分析  

Statistical Analysis of Variation Characteristics of Precipitation Days at Different Levels in the Middle and Lower Reaches of Shiyang River from 1961 to 2014

作　　者：韩福贵 吴春荣[1,2,3,4] 何芳兰 赵赫然[1,2,3,4] 宋达成 李雪娇[1,2,3,4] 

机构地区：[1]甘肃河西走廊森林生态系统国家定位观测研究站,甘肃武威 [2]甘肃省荒漠化与风沙灾害防治国家重点实验室培育基地,甘肃武威 [3]甘肃民勤荒漠草地生态系统国家野外科学观测研究站,甘肃武威 [4]甘肃省治沙研究所,甘肃兰州

出　　处：《气候变化研究快报》2018年第6期510-517,共8页Climate Change Research Letters

基　　金：甘肃河西走廊森林生态系统国家定位观测研究站资助.

摘　　要：本文以石羊河流域中下游乌鞘岭、古浪、武威、永昌、民勤几个气象台站1961~2014年降水量数据为基础,对降水量基本特征、各级别降水日数和降水百分率、各级别降水季节分配、各级降水量别日数持续时间等演变特征进行了综合分析。结果表明:1) 该地区各级降水量别日数按大小顺序排列为乌鞘岭 >古浪 >永昌 >武威 >民勤,降水以阵性降雨较多,各级别降水日数多以日降水量 ≤ 10.0 mm的小雨为主、中雨以上的降水日数很多,而大雨和暴雨的日数极少。2) 各级别降水季节分配不均,主要集中在5~9月份,乌鞘岭、古浪、武威、永昌、民勤分别占全年降水量的85.3%、77.4%、79.2%、84.5%、83.6%,而夏季分别占60.1%、45.3%、53.8%、58.5%、57.8%,多以中、小雨的形式出现,从季节分布来看,夏季最多,约为年均总数的一半。3) 持续干旱日数长,发生频率高,冬季降雪量和降雪日数少,1~8月降水随时间的增加而不断的增大,而后随时间的变化降水又不断的减少。4) 从历年最长连续降水日数的季节分布看,石羊河流域最长持续降水日数多发生在夏、秋季8~10月,在春季3~5月持续干旱威胁最大,最长持续降水日数在2~3月从没出现过。In this paper in the middle and lower reaches of Shiyang river basin of Wuxiaoling, ancient sea, Wuwei, Yongchang, Minqin, several meteorological offices and stations based on the precipitation data from 1961 to 2014, the basic characteristics of rainfall and rainy days at all levels and precipitation percentage, at all levels seasonal distribution of precipitation, precipitation at various levels don’t stay duration of evolution characteristics are analyzed. Results showed that: 1) the region at all levels of precipitation don’t stay in order of size of Wuxiaoling >the ancient sea >Wuwei of Yongchang >Minqin, precipitation in the gustiness rainfall is more, at all levels more rainy days is given priority to with daily rainfall of 10.0 mm or less light rain, moderate rain, a lot of rainy days over, but very few rainy days of heavy rain and heavy rain. 2) At all levels uneven distribution of rainfall season, mainly concentrated in the May-September, Wuxiaoling, ancient sea, Wuwei, Yongchang, Minqin, accounted for 85.3% of annual rainfall, respectively, 85.3%, 79.2%, 84.5%, 83.6%, and summer respectively 60.1%, 45.3%, 53.8%, 58.5%, 53.8%, take the form of, in the light rain, from the point of seasonal distribution, summer for most, about half of the total annual aver-age. 3) The continuing drought days long, high frequency, winter snow and less snowfall days, January-August precipitation increases with the increase of the time constant, then the change of precipitation over time and decreased continuously. 4) From the past years the longest continuous rainy days season distribution, Shiyang river basin, the longest continuous rainy days in summer, autumn in August-October, 3 - 5 months in the spring drought persisted threat is the largest, the longest continuous rainy days in February-March never seen again.

关 键 词：石羊河流域 各级降水量 降水日数 季节分配 变化特征 

分 类 号：P4[天文地球—大气科学及气象学]