江汉平原降水变化趋势的气候分析

利用江汉平原1958年～2004年各气象站点降水量资料,对近47年来江汉平原降水量变化趋势进行了分析.结果表明:江汉平原绝大部分地区年降水量变化表现为明显的增加趋势,降水倾向率为5.7～78.9 mm/10a.江汉平原平均年降水量则呈明显的增加趋势,年降水量以39.9mm/10a的速率增加,尤其是20世纪90年代增幅较大.平原夏、冬季降水均呈增加趋势,春、秋季降水则呈减少趋势.另外,60年代和70年代旱年较多,而80年代以来涝年较多,且有增加的趋势.

Climatic trend of rainfall over Jianghan Plain from 1958 to 2004

Using the day by day precipitation data at 8 stations in Jianghan Plain from 1958 to 2004, the climatic change characteristics of yearly precipitation in Jianghan Plain in four seasons were analyzed. The results indicated that the annual rainfall trend in most parts of Jianghan Plain illustrated as the obvious straight trend and rainfall trend was 5.7-78. 9mm/10a. It was discovered that the trend of mean annual rainfall of Jianghan Plain was increase during the 47 years, and annual rainfall rose up with an increase of 39. 9mm/10a, especially since the 1990s. The rainfall increased during summer and winter, and decreased during spring and autumn. Droughts were more frequent in 60 and 70s, and more floods since 1980s. Furthermore, flood frequency seemed to be gone up since 1980s.