全球和中国降水、旱涝变化的检测评估

持续严重干旱和暴雨洪涝对全球社会经济发展有明显影响,近些年来随着观测记录的加长和对更多的复杂气候模式和人为温室气体排放情景的观察统计,对全球和中国的降水与旱涝变化评估和预估有了更深入研究,注意到20世纪全球和中国降水有多年代际波动,近几十年洪涝和干旱在局部地区频繁发生,如我国的长江流域多发生洪涝,华北地区持续干旱。预估21世纪由于人为温室气体排放增加和全球变暖,全球和中国的降水将可能增加,尤以北半球中高纬度大部分地区降水强度增加明显,而中低纬度部分地区干旱日数将可能增加,应该引起水利、农业、林业、交通、卫生等有关部门的关注。

Assessment and Prediction of Precipitation and Droughts/Floods Changes over the World and in China

The serious impacts of both sustaining and serious droughts and severe rainstorm and floods on the life and social and economic development over the world and in China are well-known. Many studies are focused on the assessments and predictions with the extended data of the precipitation and droughts/floods and with the complicated climate models, as well as with the observation of a number of human emission scenarios. A review of the key results shows that the precipitation over the world and in China sees a multi-decadal oscillation during the 20th century. The regional floods and droughts occurred frequently over the world and in China during the last 50 years, such as floods along Yangtze River Valley and droughts over North China. The precipitation over the world and in China during the 21st century is predicted to be on the increase due to increased human emissions and global warming, especially an increasing intensity of precipitation over the most middle and high latitudes of the Northern Hemisphere. The dry days over some areas of the middle and low latitudes are predicted on the increase during the 21st century. These results should attract attentions from a number of sectors, such as hydrology, agriculture, forestry, transportation and health.