关键词: 极端强降水, 时空分布, 气候变化, 长江流域

Abstract: Recent trends of amount, intensity and frequency of extreme precipitation for the Yangtze River basin are analyzed in this paper. Since mid-1980s, extreme precipitation amount in the Yangtze River basin has significantly increased. The most significant increase occurred in the middle and lower reaches of the Yangtze River. Summer witnessed the most remarkable increase in extreme precipitation amount. Both intensity and frequency of extreme precipitation events have contributed to the rising of the extreme precipitation amount, but the increase of frequency contributes more to the positive trend of precipitation amount than the intensity. The average intervals between two extreme precipitation events have been shortened. It is also interesting to note that the intra-annual distribution of extreme precipitation events in the upper reaches has changed, and the maximum frequency is more likely to occur in June rather than in July. This makes the intra-annual distribution of extreme precipitation events in the upper reaches more like that in the middle and lower reaches, and it might have also increased the risk of larger floods in the middle and lower reaches of the Yangtze River.

Key words: extreme precipitation events, spatial and temporal distribution, climate change, the Yangtze River basin