西南地区极端降水变化趋势  

Extreme precipitation trend of Southwest China in recent 41 years

作　　者：罗玉[1] 范广洲[1,2] 周定文[1] 华维[1] 李金建[3] 

机构地区：[1]成都信息工程学院大气科学学院高原大气与环境四川省重点实验室,成都610225 [2]南京信息工程大学气象灾害预报预警与评估协同创新中心,南京210044 [3]四川省农业气象中心,成都610072

出　　处：《气象科学》2015年第5期581-586,共6页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(41275079;41405069);国家科技支撑计划项目(2009BAC51B03);国家青年科学基金资助项目(41305077)

摘　　要：利用西南地区90个气象台站1970—2010年逐日降水量资料,依据世界气象组织(WMO)定义的连续5 d最大降水量、总降水量、强降水比等6种极端降水指数,采用F检验、11 a滑动平均等统计方法,研究了西南地区极端强降水变化趋势的时空变化特征。在时间上,西南地区近41年来冬、春、夏季连续5 d最大降水量缓慢波动上升,秋季连续5 d最大降水量呈下降趋势;强降水、降水强度及强降水比呈上升趋势,但总降水量和最长持续无降水日数呈减少趋势;另外,各极端降水指数还存在明显的年际、年代际变化。在空间上,西南地区极端降水变化趋势具有显著的地域差异,呈东西或西北东南向梯度变化特征。其中冬季连续5 d最大降水量、降水强度、强降水比及最长持续无降水日数,在西南大部分地区呈增加趋势。秋季连续5 d最大降水量与总降水量在西南大部分地区呈减少趋势。而春、夏季连续5 d最大降水量和强降水的增减区域大致相当。Based on the daily precipitation data from 90 meteorological stations in Southwest China during1970-2010, six extreme precipitation indices defined by the World Meteorological Organization such as RX5 d,ATP, PPER, et al were used to analyze the temporal and spatial distributions of variation trend of extreme strongprecipitation in Southwest China with methods like F test, 11-year moving average. Results indicated that in timescale the trend of RX5d（December-February; March-May; June-August） in Southwest China increased slowly,but decreased in September-November. R95 p,SDII and PPER showed increasing trend, but ATP and CDD showeddecreasing trend Moreover, each extreme precipitation indice presented obvious interannual and interdecadal varia-tions. In spatial scale, the extreme precipitation trend in Southwest China presents obvious geographical differenceof gradient change from east to west or northwest to southeast. There existed significantly increasing trend of RX5d（December-February）,SDII,PPER and CDD in most of Southwest China, but presented decreasing trend of ATPand RX5d（September-November） in most of Southwest China. The increasing/decreasing areas of RX5d（March-August）and ATP are appreximately equivalent.

关 键 词：降水 极端降水指数 变化趋势 滑动平均法 

分 类 号：P426.623[天文地球—大气科学及气象学]