摘要
基于1961—2017年三江源地区14个气象站冬半年(10月至翌年4月)逐日降水资料,采用百分位阈值法定义极端降雪,并利用线性趋势、M-K突变检验、Morlet小波分析等统计方法,分析了冬半年降水以及极端降雪指数的时空变化特征。结果表明:三江源地区冬半年降水呈显著增加趋势,极端降雪阈值为2.6—7.8 mm,频数为1.6—3.8 d,呈现自西北向东南增大(多)的特征,高值中心位于清水河,低值中心位于兴海;极端降雪量以2.2 mm/10 a的显著趋势增加,突变增加发生在1993年,存在明显的准12 a变化周期;极端降雪集中在4月和10月,雪灾频次大值区位于中南部以清水河、杂多为中心的区域,并以发生中度雪灾的概率较大。
Based on daily precipitation data at 14 meteorological stations in the Sanjiangyuan region during winter period(from October to April)from 1961 to 2017,the spatiotemporal characteristics of precipitation and an extreme snowfall index defined by a percentile threshold method were analyzed,using some statistical methods such as the linear tendency analysis,the Mane-Kendal trend test,and the Morlet wavelet analysis.The results show that there is a significant increase in precipitation over the Sanjiangyuan region during winter period.The extreme snowfall threshold varies between 2.6 and 7.8 mm with an occurrence frequency ranging from 1.6 to 3.8 d.It also exhibits an increasing distribution from the northwestern region to the southeastern region,with the high-value center located in the Qingshui River and low-value center in Xinghai.The extreme snowfall increases significantly by 2.2 mm/10 a with a distinct abrupt change in 1993 and has an obvious quasi-periodic cycle of 12 a.The extreme snowfall mostly occurs in April and October,and the regions with a higher occurrence frequency of snow disaster are located in the middle and southern areas(centers located in Qingshui River and Zaduo)with a higher occurrence probability of moderate snow disasters.
作者
王玉娟
刘晓燕
白爱娟
祁栋林
肖宏斌
欧建芳
WANG Yu-juan;LIU Xiao-yan;BAI Ai-juan;QI Dong-lin;XIAO Hong-bin;OU Jian-fang(Qinghai Meteorological Disaster Prevention Technology Center,Xi'ning 810001,China;School of Atmospheric Science,Chengdu University of Information Technology,Chengdu 610225,China;Qinghai Institute of Meteorological Science,Xi'ning 810001,China;Qinghai Key Laboratory of Disaster Prevention and Mitigation,Xi'ning 810001,China)
出处
《气象与环境学报》
2018年第6期108-115,共8页
Journal of Meteorology and Environment
基金
国家公益性行业(气象)科研专项"青藏高原融雪与降雪过程镶嵌的雪灾动态预报预警技术研究"(GYHY201306054)
青海省科技厅项目"青海雪灾精细化监测预警及应急联动机制的建立"(2017-SF-131)共同资助
关键词
极端降雪指数
气候变化
三江源地区
Extreme snowfall index
Climate change
Sanjiangyuan region