长江上游流域秋季连阴雨时空变化特征  

Spatial and Temporal Variations of Continuous Autumn Rain in the Upper Yangtze River Basin

作　　者：陈晨 李波[2] 雷东洋 李子进 夏羽 

机构地区：[1]宜昌市气象局,湖北宜昌443000 [2]三峡梯调通信中心,湖北宜昌443000

出　　处：《气象与减灾研究》2015年第2期22-26,共5页Meteorology and Disaster Reduction Research

基　　金：中国长江电力股份有限公司委托项目(编号:2413020002)

摘　　要：利用长江上游259个气象站逐日降水资料,采用线性趋势分析方法,分析了近1961—2012年来长江上游流域秋季连阴雨的时空变化特征。结果表明,长江上游流域秋季连阴雨过程平均出现1.54次/a,其中9月出现次数最多,10月次之,11月出现较少。秋季连阴雨日数、累积降水量分别以2.3 d/(10 a)、13.7 mm/(10 a)的速率显著减少,连阴雨开始和结束日期平均为9月9日和9月30日均表现出推迟趋势。进入21世纪后,5—9 d、10 d以上连阴雨过程的次数、80.0 mm以上连阴雨过程的次数均表现出减少趋势。金沙江下游和四川盆地东部为秋季连阴雨累计雨量及其变化速率的大值中心,四川盆地西南部为连阴雨日数及其变化速率的大值中心。9月的降水中心、雨日分布情况与秋季总体情况基本一致,10月降水中心、阴雨日数的中心出现了明显东撤,11月东撤更为明显。Based on the 259 daily precipitation data of meteorological stations in Yangtze River basin during 1961-2012,the linear trend analysis method is used to study the spatial and temporal variations of continuous autumn rain in the upper Yangtze River basin. The results show that the continuous autumn rain process in the upper reaches of the Yangtze River basin occurs 1.54 times per year,which occurs most frequently in September,followed by in October,and appeared less in November. The autumn continuous rain days and accumulated precipitation amounts present significantly decreasing trend,with the decrease rates being 2.3days per decade and 13.7 mm per decade respectively,both the start and end dates which are September 9 and 30 present delaying trend. The numbers of continuous rain process with 5-9 days duration,more than 10 days duration and with more than 80 mm total precipitation present decreasing trends in the 21 st century. The maximum center for the accumulated precipitation amount and its change rate is located in the lower reaches of the Jinsha River and the eastern Sichuan Basin,and the maximum center for the continuous rain days and its change rate is located in southern Sichuan Basin. The center of precipitation and rainy days distribution in September are similar to those in autumn,however,the then center of precipitation and continuous rain days distribution in October and November move eastward obviously.

关 键 词：秋季连阴雨 时空分布 线性趋势 长江上游流域 

分 类 号：P426.6[天文地球—大气科学及气象学]