九十年代以来江淮流域夏季典型旱涝成因分析

The Cause Analysis of the Typical Drought and Flood Years in the Area between the Yangtze River and Huaihe River in Summer Since 1990

１９９１年和１９９４年的夏季，江淮地区分别出现了罕见的洪涝灾害和少雨干旱，究其成因是夏季北半球大气环流的异常即５００ｈＰａ极涡、西风带系统和西太平洋副热带高压的强弱、配置不同以及１００ｈＰａ南亚高压的强弱。

Abnormal drought and flood disasters in the area between the Yangtze River and Huaihe River in the summer in 1991 and 1994 were observed respectively.They are caused by anomalous changes of the main general circulation systems in the Northern Hemisphere,such as the intensity and position of the polar vortex,long wave trough and ridge in the westerlies,the west Pacific subtropical high at 500hPa,and South Asia high at 100hPa,as well as that of SST in the tropical ocean.