长江流域降水的季节变化对流域水资源的影响研究

The Seasonal Precipitation and Floods/Droughts in the Yangtze River Basin

通过分析1961—2005年长江流域降水的季节变化与旱涝分布,发现45年来长江流域春季、秋季降水下降,而夏季、冬季降水增加,其中上游秋季和中下游夏季、冬季降水变化都通过了95%显著性检验.近年来,长江流域降水的季节分配不均,长江流域洪涝较多的时期,夏季降水一般显著增加;而干旱发生时,秋季降水一般下降显著.20世纪80年代中期以来,长江上游干旱化趋势加重,而中下游洪涝增多,这种旱涝并存的格局加剧了长江流域的旱涝灾害.

In this paper, we explored the change of seasonal precipitation and floods/droughts during 1961 to 2005 in the Yangtze River basin, China. The results indicate that the precipitation decreases in spring and autumn while increases in summer and winter in the Yangtze River basin and the trend of precipitation is 95% significant in autumn in the upper Yangtze River basin, while 95% significant trends can be identified in precipitation in summer and winter in the middle and lower Yangtze River basin. The distribution of seasonal precipitation has become more uneven in the Yangtze River basin in recent years, which has caused more floods and droughts. More summer precipitation always leads to more floods and less autumn precipitation always results in more droughts. There are more droughts in the upper Yangtze River basin and more floods in the middle and lower Yangtze River basin since 1985, which have caused a lot of loss. The results of research will be of great significance for flood and drought control in the Yangtze River basin under a changeable climate.