近48年来湘江流域极端降水事件特征分析  

RESEARCH ON EXTREME PRECIPITATION EVENT CHARACTERISTICS OF XIANGJIANG RIVER BASIN IN RECENT 48YEARS

作　　者：肖艳[1] 黎祖贤 章新平[1] 周建君 

机构地区：[1]湖南师范大学资源与环境科学学院,湖南长沙410081 [2]湖南省气象局,湖南长沙410007 [3]湖南气候中心,湖南长沙410007

出　　处：《长江流域资源与环境》2010年第11期1356-1362,共7页Resources and Environment in the Yangtze Basin

基　　金：国家自然科学基金项目"我国西南地区降水中稳定同位素的代表性及影响机制研究"(40871094);湖南省重点学科建设项目(2008001)

摘　　要：基于湘江流域44个气象站1960～2007年的逐日降水资料,将第95个百分位值定义为各台站极端降水事件的阈值。同时,采用线性回归、突变分析和相似系数等方法,分析了该流域极端降水事件的变化特征,研究了不同强度降水事件的时空分布特征。结果表明:湘江流域近48a来极端降水事件的各指标(降水量、降水日、降水强度、降水指数、日最大降水量)均呈增加趋势。但在不同时期,极端降水事件表现了不同的变化趋势。1970s以前多大雨事件,1970s～1980s各类极端降水事件相对偏少,进入1990s开始明显增加,尤其是暴雨和大暴雨事件显著增多。此外,极端降水事件的分布还表现出明显的区域性特点:湘江上游多暴雨事件,中游多大雨事件,下游多大暴雨事件。Based on the daily precipitation data of 44stations in Xiangjiang River Basin during last 48years,the 95th percentile is defined as the threshold of extreme precipitation for each station.At the same time,the changing feature and temporal and spatial characteristics of the different grade rain events were analyzed by using the methods of Line Regression,Abrupt Changing Analysis and Similarity Coefficients.The result showed that every index（precipitation quantity,precipitation days,precipitation intensity,precipita-tion index and daily maximum precipitation）of extreme precipitation increased in last 48years.But in dif-ferent times,the extreme precipitation shows a different changing trend.The heavy rain events were more frequent before 1970s.During the 1970sand 1980s,each grade rain event was in a relatively weak stage. Since the 1990s,all precipitation obviously increased,especially the rainstorm and heavy rainstorm events. Besides,regional difference was revealed by analyzing the distribution of extreme precipitation in Xiangjiang River Basin.Rainstorm events were mainly in the upper reaches;heavy rain events were more in the middle reaches;heavy rainstorm events were in the lower reaches.

关 键 词：湘江流域 极端降水事件 阈值 时空特征 

分 类 号：P426.614[天文地球—大气科学及气象学]