【摘 要】
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With the increasing climate change,extreme droughts happened frequently and caused serious impacts on environmental and economical system in recent years.In 2011,a rare drought happened at middle lowe
【机 构】
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College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875,China
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With the increasing climate change,extreme droughts happened frequently and caused serious impacts on environmental and economical system in recent years.In 2011,a rare drought happened at middle lower reaches of Yangtze River,however its characteristics and influences are still unclear.In this study,a popular drought index Standard Precipitation Index (SPI) were calculated based on nearly 40-year meteorological data of 175 stations at middle lower reaches of Yangtze River,and the characters of history and 2011 drought were analyzed.Furthermore,the impact of 2011 drought was also evaluated.The results suggest that: (1) the drought severity,frequency and influence area increased notably during the past 40 years at middle lower reaches of Yangtze River.Most area at south of Yangtze River is getting drier.On the contrast,most area of Anhui and Jiangsu province,which located at north of Yangtze River,is getting wetter.(2) 2011’s severe drought lasted about 10 months,which started in December 2011 and ended in October 2011.In March 2011,the drought was getting severer,and reached its severest situation in April,when the impact area of classes of severe drought and extreme drought covered 80％ middle lower reaches of Yangtze River.The severity of the drought started to reduce in June 2011.(3) Compared with the droughts happened in the history,2011’s drought is the most serious one.(4) 2011’s drought caused direct economic losses of 14.94 billion yuan and a heavy damage to the wetland ecosystem.The water area of Poyang Lake shrank to 1,326 km2,the least water area in its record.
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