中文摘要：

利用区域气候模式PRECIS（providing regional climates for impacts studies）输出的SRES A1B情景的日平均气温及降水资料,通过计算相对湿润度指数,分析2011—2100年东北地区作物生长季（5—9月）的干旱趋势。结果表明：A1B情景下,2011—2100年东北地区农作物生长季将呈现明显干旱化趋势,相对气候基准时段（1971—2000年）,未来吉林中南部及辽宁省将变湿润,其余地区将变干燥;就干旱发生范围而言,2011—2100年东北地区农作物生长季的干旱发生范围将呈显著增大趋势,2011—2040年、2041—2070年和2071—2100年的30 a平均值较气候基准时段依次变化了-1.3%、17.4%及38.4%;就干旱频率而言,未来干旱发生频率较高的区域主要集中在黑龙江的齐齐哈尔与大庆、吉林的白城以及辽宁的朝阳地区,而低频率区主要位于吉林东部及辽宁丹东地区,相对气候基准时段,未来干旱频率预计在辽东湾地区降低2%,黑龙江西南部与吉林西部增加8%～10%,其余地区增加2%～6%。

英文摘要：

The values of relative humidity index were calculated using the data of mean daily temperature and precipitation from regional climate model system PRECIS （Providing Regional Climate for Impacts Studies） under SRES A1B scenario so as to analyze the drought trend in northeast China in crop growing season （from May to September）. The results showed that, under A1B scenario, an obvious drought trend would increase in northeast China in crop growing season during the period of 2011 -2100, compared with baseline （1971 -2000） , the central and southern regions in Jilin Province and whole Liaoning Province would become moist, and the other places would be arid. Drought area in northeast China would significantly enlarge in crop growing season in the future, and the 30- year averaged values of drought area during the periods of 2011 -2040,2041 -2070,2071 -2100 would be changed by - 1.3% , 17.4% and 38.4% respectively compared with the baseline. The high drought occurring frequency might occur in the Qiqihar and Daqing regions in Heilongjiang Province, Baicheng in Jilin and Chaoyang in Liaoning, while the low drought occurring frequency in the Dandong region in Liaoning and the eastern region in Jilin. Compared with the baseline,it is estimated that the drought frequency in the future would decrease by 2% in the Liaodong Bay area,but increase by 8% -10% in southwest Heilongjiang and west Jilin and 2% -6% in other regions.