中文摘要：

旱涝气候灾害是中国最严重的自然灾害之一，它不仅分布广、发生频率高，而且造成巨大的经济损失。研究表明：随着全球变暖中国旱涝气候灾害的年际和年代际变化更加明显，这是由于包括海一陆一气各圈层相互作用的东亚季风气候系统的变异所造成。笔者利用IPCC－AR422个海－陆－气耦合气候数值模式的计算结果对在A1B排放情景下21世纪各时期东亚夏季风降水的变化趋势进行预估，结果表明：在全球变暖背景下东亚夏季风降水在21世纪不仅年际变率增强，而且从21世纪中期亚洲夏季风增强，它将引起中国华北和华南地区夏季降水明显变强，洪涝灾害增多。

英文摘要：

Climatic disaster of droughts and floods is one of the most heavy natural disasters in China. It not only has wide distributions and high occurring frequency, but also can cause huge economical losses in China. The studies show that with the global warming, the interannual and interdecadal variabilities of droughts and floods in China become increasingly significant, which is due to the variabilities of the East Asian monsoon climate system including sea-air-land interaction. Moreover, the future evolution trend of the East Asian summer monsoon （EASM） precipitation for various periods of the 21 th century under A1B emission scenary is predicted using IPCC-AR4 22 coupled models. The results show that under the background of global warming, the interannual variability of EASM precipitation will be intensified, especially the summer precipitation in North China and South China will become strong from the middle period of the 21th century, which can cause the increase of flood disasters in these regions.