摘要
选取长江流域沿线及三峡库区12个代表站,根据中国500年旱涝图集等级和各站建站以来5—9月降水量资料,按照旱涝等级标准,分别得到长江全流域、上游流域、中游流域、下游流域及其三峡库区1470—2011年旱涝等级序列。结果表明:长江各流域及其三峡库区均呈现较为明显的旱涝交替阶段,20世纪偏旱频率强烈增加,19世纪和20世纪偏涝频率明显增加。长江流域和三峡库区偏旱以上等级具有准160年周期震荡,全流域偏涝以上存在准140年的周期震荡,但20世纪后有所减弱,三峡库区偏涝以上等级存在准百年的周期震荡。三峡建坝蓄水前后库区降水EOF时空分布呈一致减少趋势,与此同时长江上游降水呈下降趋势,反映了长江上游流域及三峡库区气候趋旱;M-K突变检验显示水库蓄水前后流域上游和库区降水均未发生显著变化。在全球气候变化的背景下,三峡库区旱涝演变并不是孤立事件,而是与长江上游乃至整个长江流域旱涝背景密不可分。
Based on the data from 12 representative stations on the Yangtze River Basin and Three Gorges River Basin,according to the 500-year sequence of drought/flood grades and the precipitation data from May to September since the establishment of the stations,on the basis of drought/flood grade standards,the sequence of drought/flood grades is obtained for the Yangtze River Basin,the upper reaches,the middle reaches,the lower reaches of the Basin,and the Three Gorges Reservoir Area from 1470 to 2011.The results show that the reaches of Yangtze River and the Three Gorges reservoir area displayed the more significant alternating of droughts and floods,but the drought frequency accelerated in the 20 th century and flood frequency increased from the 19 th century.The frequencies of drought over years in the Yangtze River Basin and Three Gorges reservoir area had 160-year periodic oscillation.The frequencies of flood and over in the Yangtze River Basin showed 140 years periodic oscillation,but after the 20 th century the trend weakened,and that in three Gorges reservoir area had 100-years periodic oscillation.The spatial and temporal distribution characteristics of precipitation were consistent with the decreasing trend,by using EOF.At the same time,the precipitation of the upper reaches of the Yangtze River had a downward trend,reflecting the drought trend of the upper reaches of the Yangtze River basin and three Gorges reservoir area.By using M-K mutation test,there was no significant change in precipitation before and after the reservoir water storage in the upper reaches of the Yangtze River Basin and the Three Gorges reservoir area.In the context of global climate change,the drought evolution of the Three Gorges reservoir area is not an isolated event.It is inseparable with the background of the upper reaches of the Yangtze River and the whole basin.
出处
《气象科技》
北大核心
2016年第4期622-630,共9页
Meteorological Science and Technology
基金
公益性(气象)行业科研行业专项"三峡水库气候效应分析评价关键技术及系统研制"(GYHY201306053)
中国长江三峡集团公司项目"三峡工程气候效应分析和评估"资助
关键词
旱涝等级序列
演变特征
长江流域
drought/flood grade sequence
evolution characteristic
Yangtze River basin
