20世纪我国东部地区的降水及极端旱涝事件变化规律  

Precipitation and Variations of Extreme Drought /Flood Events in the Eastern China in the 20th Century

作　　者：郭雪[1] 王志伟[2] 俞胜彬[3] 郭玉喜[4] 

机构地区：[1]兰州大学大气科学学院,甘肃兰州730000 [2]山西省气候中心,山西太原030002 [3]中国科学院南海海洋研究所,广东广州510301 [4]山西省气象局,山西太原030002

出　　处：《干旱气象》2013年第3期476-481,共6页Journal of Arid Meteorology

基　　金：山西科技攻关项目(20080312019)资助

摘　　要：根据我国东部地区（110°E以东）160个观测站100多a的降水资料对我国东部地区包括华北地区、长江流域和华南地区等100多a的降水变化趋势和降水极端偏多和极端偏少年份的分布进行了分析；并通过计算z指数，实现旱涝面积转化，分析我国东部100多a来的旱、涝范围变化和极端旱、涝年份的分布。结果表明：我国东部地区100多a的降水极端偏多年份随时间分布比较均匀，其间隔在20～40a间。降水极端偏少年份在减少。降水量的变化存在着大约40—50a的震荡周期。夏季降水增加明显，秋季降水下降明显。长江流域的年降水量和我国东部年降水量趋势保持较好的一致性，说明长江流域的降水对我国东部降水的贡献显著，华南区域的降水起次要作用。我国东部近100a来雨涝范围和干旱范围都没有表现出明显的增、减趋势，但存在着明显的年际和年代际振动。我国东部干旱覆盖面积最大的时间主要集中在1930年代以前，1969年以后变化趋势不明显。东北和华北极端干旱年份大都出现在1940年以前，长江流域和华南的极端干旱年份则随时间分布比较均匀。The precipitation data observed by 160 meteorological stations in the eastern China （the east of 110°E） in more than 100 years were used to study the changes of precipitation and the distribution of extremely more or less rainfall years in the eastern China in- cluding north China, Yangtze River Valley and south China region. The method of Z index was used to transform drought and flood area and study the changes of the dry or waterlogged area and the distribution of extremely dry or waterlogged years in eastern China in more than 100 years. Results show that the extremely more rainfall years in more than 100 years distributed evenly in eastern China and the interval was about 20 to 40 years, and the extremely less rainfall years decreased. There was an oscillating period about 40 - 50 years for the precipitation variation. The precipitation increased significantly in summer, and decreased obviously in autumn. The trend of an- nual rainfall along the Yangtze River Basin was consistent with the annual precipitation variation in the east China, which illustrated the Yangtze River Basin precipitation contributed significantly to the eastern China, and the secondary one was south China rainfall. There was no obvious increasing or decreasing trend for drought or flood area in the east China in more than 100 years, but there was obvious interannual and interdecadal oscillation. The maximum drought area mainly concentrated before the 1930s in east China, and after 1969 its change trend wasnt obvious. The extremely drought years in the northeast and north China mostly appeared before 1940, and ex- tremely drought years in the Yangtze River Basin and south China distributed evenly.

关 键 词：20世纪 中国东部 降水 极端旱涝 变化规律 

分 类 号：P426.614[天文地球—大气科学及气象学]