近60年中国不同区域降水的气候变化特征

Climatic Characteristics of Precipitation in Various Regions of China for the Past 60 Years

利用1951—2009年中国503站日降水量资料,研究了我国各季各地区降水年代际变化的特征,并分析了其对我国干旱演变的影响。结果表明:近60年来我国各区域年平均降水量大多为减少趋势,其中华北、西南地区减少明显;各地区秋季降水偏少的趋势最为显著,可能是导致秋季干旱增多以及秋冬连季干旱频繁的主要原因。2000年以后北方夏季降水呈减少趋势,其中华北夏季降水明显减少,而冬季降水趋于增加,南方秋季降水减少明显,而春季降水增多。云南等西南地区秋冬春连旱偏多的原因之一可能与孟加拉湾季风结束偏早有关。

Abstract： By using the precipitation data at 503 stations across China during 1951-2009, the evolution characteristics of drought in China are analyzed on the basis of spatial and temporal precipitation distribu- tions at each season and area. The results indicate that the precipitation in China during each seasonshowed not only a stable interannual change but also an interdecadal variability. The precipitation in au- tumn has a unified decreasing trend since the 1950s, suggesting that droughts become much frequent in this season. The North China easily has droughts in summer, while autumn droughts prefer the SouthChina since the year 2000. The extremely severe drought in the Southwest China after the year 2000 might have a close relationship with the earlier withdraw date of the Bay of Bengal （BOB） monsoon.