中文摘要：

利用水平分辨率为50 km×50 km的区域气候模式RegCM4,单向嵌套BCC_CSM1.1全球气候系统模式输出结果,以中国西北东部到华北地区为研究区域,对该区域的气候特征以及干旱趋势进行了预估。结果表明：（1）RegCM4模式对研究区域气温和降水的模拟能力可信度较高,能较好地模拟它们的空间分布特征及时间变化趋势,但由于模式存在一些系统性误差,因此部分区域模拟结果比实际略偏高。（2）2041—2050年相较于2006—2010年来讲,RCP4.5情景下研究区域气温将增加1.0℃左右,RCP8.5情景下增加约1.4℃;两种情景下研究区域降水表现为波动变化,一致性趋势不明显,但2041年以后均进入降水减少期。（3）总体来讲,两种情景下2041-2050年研究区域均可能出现较明显的干旱;RCP4.5情景下,夏、秋季2041—2050年干旱情况比前期严重,其中秋季从2042年开始,SPI值普遍偏低,有可能出现连旱现象;RCP8.5情景下,夏季干旱总体呈增加趋势,秋季则呈波动减少趋势,但2045年以后秋季又转为较干期。

英文摘要：

By using a horizontal resolution of 50 km x 50 km regional climate model RegCM4,single nested BCC CSM1.1 global climate system model results.With the eastern Northwest China to North China as the study area,estimated the characterization of temperature and precipitation and drought trends.The results showed that;RegCM4 had a certain ability to simulate temperature and precipitation in the study area,and it can simulate their spatial distribution and time trends,but because the model had some systematic error,so some regional simulation results were slightly higher than the actual number;2041 —2050 compared to 2006 —2010,in study area of temperature would rise 1.0 ℃ in RCP4.5 scenario,and temperature would rise 1.4 ℃ in RCP8.5 scenarios.Under the two scenarios,in study area of precipitation showed fluctuations and they were not obviously consistent trend,but they were involved in the precipitation decreased channel from 2014;Generally speaking,Under the two scenarios,they might be more obvious drought with the study area in 2041 —2050.In RCP4.5 scenario,the study area＇s drought trend would be aggravated in summer and autumn with the 2041 —2050,and the SPI values were generally low and might be appear to drought in autumn from 2042.In RCP8.5 scenario,the study area＇s drought had an overall increasing trend in summer,and the study area＇s drought showed the decreasing trend in autumn,but then turned into drier period from 2045.