中国极端降水事件的频数和强度特征  

Frequency and intensity of extreme precipitation events in China

作　　者：王志福[1,2] 钱永甫[1] 

机构地区：[1]南京大学大气科学系,江苏南京210093 [2]南京信息工程大学江苏省气象灾害重点实验室,江苏南京210044

出　　处：《水科学进展》2009年第1期1-9,共9页Advances in Water Science

基　　金：国家重点基础研究发展计划(973)资助项目(2004CB418300);国家自然科学基金资助项目(40675052)~~

摘　　要：使用1951-2004年中国738个测站逐日降水资料,采用百分位的方法定义极端降水事件的阈值,分析了不同持续时间的极端降水事件的时空分布及变化趋势特征。结果表明,极端降水事件多发于35°N以南,特别是在长江中下游和江南地区以及高原东南部,且在这些地区极端降水事件持续时间也较长。季节分布上,主要出现在夏季,以低持续性事件为主。在中国东部地区,持续时间越长的极端降水其强度往往越强。趋势分析表明,全国持续1d极端事件的相对频数具有上升趋势而平均强度具有下降趋势,其空间上均表现为全国大部分上升、华北和西南等地下降的趋势。持续2d以上极端事件在长江中下游流域、江南地区和高原东部等地区有显著增多和增强的趋势,而在华北和西南地区有减少和减弱趋势,但全国平均的趋势不显著。Using daily rainfall data at 738 stations in China from 1951 to 2004, and defining the 95th percentile as the threshold of extreme precipitation for each station, the characteristics of the spatio-temporal distribution and the linear trend of extreme precipitation events with different durations are analyzed. Results show that the frequency of extreme precipitation events is higher in the regions south of 35°N than in other parts of China, especially in the mid-lower reaches and the southern parts of the Yangtze River and in the southeastern part of the Tibetan Plateau with longer duration. And it happens more in summer than in other seasons. It is found that the frequency decreases rapidly whereas the mean intensity increases with the increase of duration of extreme precipitation events, ing trend for regionally averaged relative especially in eastern part of China. The trend frequency but a decreasing trend for the mean analysis shows that there is an increasintensity of 1-day extreme precipitation events. They both increase significantly in the mid-lower reaches of the Yangtze River, in South China and in eastern Plateau and decrease significantly in some parts of North and Southwest China. The frequency and intensity of the extreme events lasting more than 2 days show a similar spatial distribution with that of 1-day events, but show no significant trends for their regionally averaged values.

关 键 词：极端降水 频数 强度 中国 

分 类 号：P426.614[天文地球—大气科学及气象学]