长江流域1961-2012年间极端强降水变化分析

Based on the observed precipitation data at 136 meteorological stations, changes in major characteristics of extreme heavy precipitation events in the Yangtze River Basin during the period of 1961-2012 is analyzed using the Mann-Kendall method. The results shows that, the intensity of extreme heavy precipitation and the fractions of extreme heavy precipitation to the annual precipitation show increasing trend in most areas except in the Tibet Plateau at the upper reach in the past 50 years. Changes in the days of extreme heavy precipitation shows large spatial variations. It shows decreasing trend in the upper Yangtze River Basin and increasing trend in the middle and lower Yangtze River Basin. The total amount of extreme heavy precipitation shows no significant change in the upper Yangtze River Basin and significant increasing trend in the middle and lower Yangtze River Basin. These changes may increase probabilities of flood occurrence in the Yangtze River Basin.