2050年前长江流域极端降水预估

 20世纪90年代长江流域日最大降水增加主要出现在长江以南地区和金沙江流域，ECHAM5/MPI-OM模型也大致模拟出了这种趋势。在IPCC给出的3种不同的排放情景下，2000-2050年长江上游日最大降水均有上升趋势，2020年前A2情景下日最大降水最大，A1B最小；长江中下游日最大降水在2025年之前均有明显上升趋势，之后略有下降，波动较大。长江流域未来日最大降水增多的区域可能主要出现在长江以南地区，而极端降水减少的区域可能出现在长江以北地区。

Projection of Future Precipitation Extremes in the Yangtze River Basin for 2001-2050

Daily maximum rainfall (as an index for extreme precipitation) was higher in the Jialing River basin, Taihu Lake area, the mid-lower main stream section in the 1990s, and there was a good relationship between ECHAM5/ MPI-OM simulations and observed data about extreme precipitation. Under the A2, A1B, and B1 greenhouse gases emission scenarios of SRES, the extreme precipitation projected in 2000-2050 was compared, the daily maximum rainfall will be dominated by increasing trends in the upper reaches of the Yangtze River basin, with the largest magnitude of increasing tendency under the A2 scenario and the least magnitude under the A1B scenario before 2020. As for the middle and lower reaches, the daily maximum rainfall will increase prominently before 2025, and then decline slightly. There might be more floods in the south of the Yangtze River and more droughts in the north in the future.