锦州地区逐日降水概率分布特征  

Characteristics of daily precipitation probability distribution in Jinzhou area

作　　者：温舟 温日红[2] 曲梓祎 娄芳蕾 常姝婷 史虹婷 王笑影[2] WEN Zhou;WEN Ri-hong;QU Zi-yi;LOU Fang-lei;CHANG Shu-ting;SHI Hong-ting;WANG Xiao-ying(Jinzhou Meteorological Service,Jinzhou 121000,China;Institute of Atmospheric Environment,China Meteorological Administration,Shenyang 110166,China)

机构地区：[1]锦州市气象局,辽宁锦州121000 [2]中国气象局沈阳大气环境研究所,辽宁沈阳110166

出　　处：《气象与环境学报》2020年第5期25-32,共8页Journal of Meteorology and Environment

基　　金：国家重点研发计划项目(2018YFC1506802);辽宁省气象局项目“基于卫星影像融合和面向对象的盘锦湿地提取技术研究”(BA202003);中国气象局沈阳大气环境研究所基本科研业务费项目(2020SYIAEMS1)共同资助。

摘　　要：利用锦州地区的逐日降水量观测资料对逐日降水量的概率分布进行了统计分析,采用最大似然估计法得到Gamma函数分布的形状参数α和尺度参数β,通过Gamma概率分布模拟观测站点逐日降水的概率分布。结果表明:锦州地区逐日降水频率整体趋势先上升后下降,基本呈对称式分布,降水概率有一定的振荡,个别日会出现远超相邻日期的降水频率,7月21日降水频率最高,在不计微量降水的情况下,最低逐日降水概率有多个日期为0。各季降水频率偏低是造成义县地区干旱的原因之一;北镇夏季平均降水频率最低,但其夏季平均降水量却为锦州地区最高,说明北镇可能易出现较大量级降水或易出现极端降水天气。清明期间降水频率在50%以上、高考期间降水频率在80%以上,符合大众日常对特殊日期降水情况的认知;逐日降水频率可以为公众气象服务提供新的思路。凌海、北镇更容易出现极端降水天气;锦州地区日降水出现小雨天气概率最高,暴雨以上降水概率较低,锦州地区各站极少出现大暴雨以上量级降水,对锦州降水量级预报,尤其是暴雨或大暴雨以上降水量级的预报起到一定的指示作用。Based on observation data of daily precipitation in Jinzhou area,we analyzed the probability distribution of daily precipitation in this region,and determined the shape parameter and scale parameter of the Gamma function distribution using the maximum likelihood estimation method.We used the Gamma distribution to simulate the probability distribution of daily precipitation.The results showed that the occurrence frequency of daily precipitation has a trend that increases first and then decreases,and exhibits a symmetrical distribution.Precipitation probability has some oscillation,with the precipitation frequency on some specific days much higher than that on the adjacent days at times.The highest precipitation frequency occurs on July 21,and the lowest value is zero on several days when ignoring small precipitation.Low precipitation probability during all seasons is one of the reasons responsible for the drought in the Yixian area.Beizhen area has the lowest precipitation frequency and the highest precipitation amount during summer,which means that heavy and extremely heavy precipitation events are likely to occur in Beizhen.The precipitation probability is higher than 50%during the Qingming Festival and higher than 80%during the national college entrance examination,which is consistent with the public knowledge on the precipitation on these special days.Daily precipitation probability can provide a new way for public meteorological services.Extreme precipitation events are prone to occur in Linghai and Beizhen.Small rainfall events have the highest occurrence probability in Jinzhou,heavy precipitation and above have a low probability,and extremely heavy precipitation hardly occurs at stations in Jinzhou area.It has some meaningful guidance for the precipitation level forecast,especially for the heavy precipitation or extremely heavy precipitation and the level above.

关 键 词：逐日降水量 GAMMA函数 概率分布 

分 类 号：P426.6[天文地球—大气科学及气象学]