基于Copula函数的甘肃河东短时强降水特征分析  

Characteristics of Short-Time Heavy Rainfall in Hedong Area of Gansu Based on Copula-Function

作　　者：杨银 李岩瑛 陈豫英 陈自艳[5] 刘蓉 YANG Yin;LI Yanying;CHEN Yuying;CHEN Ziyan;LIU Rong(Ningxia Meteorological Observatory,Yinchuan 750002;Key Laboratory for Meteorological Disaster Monitoring and Early Warning and Risk Management of Characteristic Agriculture in Arid Regions,CMA,Yinchuan 750002;Ningxia Key Laboratory of Meteorological Disaster Prevention and Mitigation,Yinchuan 750002;Wuwei Meteorological Office of Gansu Province,Wuwei 733000;Lanzhou Meteorological Bureau,Lanzhou 730000)

机构地区：[1]宁夏气象台,银川750002 [2]中国气象局旱区特色农业气象灾害监测预警与风险管理重点实验室,银川750002 [3]宁夏气象防灾减灾重点实验室,银川750002 [4]武威市气象局,武威733000 [5]兰州市气象局,兰州730000

出　　处：《气象》2019年第5期632-640,共9页Meteorological Monthly

基　　金：国家自然科学基金重点项目(41630426);国家重点基础研究发展计划(973计划)(2013CB430206)共同资助

摘　　要：利用1960-2014年兰州、临夏、合作、定西、武都、天水、平凉和西峰逐分钟降水资料,分析甘肃河东强降水频次的时空分布特征,建立基于Copula函数的持续时间和过程雨量的联合分布,基于该函数开展强降水发生概率分析研究。结果表明:(1)甘肃河东近55年来平均强降水频次为1.64次/(a·站),主要特征为持续时间短、过程雨量小,平均持续时间为2.88 h,过程雨量为23.4 mm,持续时间小于1 h的概率高达13.4%;(2)强降水主要发生在汛期(4-9月),月变化服从正态分布,墨西哥帽小波分析表明频次存在着显著的22~23 a和13~15 a的年代际和3~7 a的年际变化;(3)强降水发生概率从大到小依次为平凉、西峰、天水、定西、武都、临夏、兰州和合作,相应的陇东最大,陇南次之,中部地区最小。Based on minutely precipitation collected from Lanzhou,Linxia,Hezuo,Dingxi,Wudu,Tianshui,Pingliang and Xifeng weather stations in Hedong Area of Gansu Province during 1960-2014,the spatio-temporal distribution characteristics of heavy rainfall frequencies are analyzed.Besides,the risk analysis on duration and accumulated precipitation is obtained by Copula function based on a bivariate Copu-la distribution model for heavy rainfall variables.The results show that:(1)The main characteristics of heavy rainfall in Hedong Area during recent 55 years are short duration and low accumulated precipitation.The occurring frequency is 1.64 time/(a·station),average duration is 2.88 h,average accumulated precipitation is about 23.4 mm and the probability of duration less than 1 h is up to 13.4%.(2)Heavy rainfall occurs mainly from April to September,and the monthly variation is in the normal distribution.The Mexico Hat wavelet analysis shows that there are obviously interdecadal changes of 22-23 years and 13-15 years,and interannual changes 3-7 years in the heavy rainfall.(3)The frequency of heavy rainfall from large to small is Pingliang,Xifeng,Tianshui,Dingxi,Wudu,Linxia,Lanzhou and Hezuo in order.Correspondingly,the maximum frequency occurrs in eastern Gansu,second in southern Gansu,and the smallest central Gansu.

关 键 词：COPULA函数 强降水 发生概率 甘肃河东 

分 类 号：P468[天文地球—大气科学及气象学] P426