Trends in frequency of precipitation extremes in the Yangtze River basin, China: 1960–2003 / Tendances d'évolution de la fréquence des précipitations extrêmes entre 1960 et 2003 dans le bassin versant du Fleuve Yangtze (Chine)
Trends in frequency of precipitation extremes in the Yangtze River basin, China: 1960–2003 / Tendances d'évolution de la fréquence des précipitations extrêmes entre 1960 et 2003 dans le bassin versant du Fleuve Yangtze (Chine)
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DOI：
10.1623/hysj.50.3.479.65022
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发表时间：
2005-06
影响因子：
3.5
通讯作者：
Buda Su;B. Xiao;D. Zhu;Tong Jiang
中科院分区：
文献类型：
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作者：
Buda Su;B. Xiao;D. Zhu;Tong Jiang
利用长江流域147个测站的逐日降水资料，分析了近44年（1960-2003年），特别是1990年以来长江流域极端降水发生频率的空间分布和变化趋势。研究结果表明：（1）15 mm降水等雨量线大致划分了长江中下游（高）和长江上游（低）站点的降水极值（对应于第95百分位数）。长江中下游地区极端降水发生的时间也早于长江上游地区。极端降水主要集中在长江中下游的6月和长江上游的7月。(2)在1960-2003年期间，前20年的极端降水量少于后20年。长江中下游地区年降水量极值和1-5天间隔的降水量极值频数呈明显的递增趋势和阶跃变化。极端降水发生的时间较短，相隔几天。长江中下游地区极端降水发生频率最高的月份（6月）也越来越集中。长江上游6月极端事件有上升趋势。如果过去40年观测到的趋势持续到未来，那么长江中下游和长江上游6月份极端降水的增加将增加洪水的可能性。
Abstract The spatial distribution and trends in the frequency of precipitation extremes over the last 44 years (1960–2003), especially since 1990, have been analysed using daily precipitation data from 147 stations in the Yangtze River basin. The research results are as follows: (1) The 15 mm precipitation isohyet approximately divides the precipitation extremes (corresponding to the 95th percentile) of the stations in the middle and lower Yangtze reaches (higher) from those of the upper Yangtze reaches (lower). Also the starting time of the precipitation extremes in the middle and lower Yangtze reaches is earlier than of those in the upper Yangtze reaches. Precipitation extremes are concentrated mostly in June in the middle and lower Yangtze reaches, and July in the upper Yangtze reaches. (2) During the period 1960–2003, the first two decades had fewer precipitation extremes than the last two decades. There have been significant increasing trends and step changes in frequency of annual total precipitation extremes and precipitation extremes with a 1–5 day gap in the middle and lower Yangtze reaches. Precipitation extremes occur more frequently in shorter periods, separated by a few days. Precipitation extremes are also becoming more concentrated in the month with the highest frequency of extremes (June) in the middle and lower Yangtze reaches. In the upper Yangtze reaches, there is an upward tendency of extreme events in June. Increasing precipitation extremes in June for both the middle and lower, and the upper Yangtze reaches will increase the probability of flooding if the observed trends of the last 40 years continue into the future.