中文摘要：

全球气候模型（GCM）提供了有效的方法来评估全球气候变化的过程，并可预估包括人类活动因素驱动在内的未来气候变化情景。然而其较低的分辨率并不能捕捉到那些地表特性复杂区域的气候变化特性。因此，使用包括区域气候模型（RcM）、偏差校正法和统计方法等方法在内的降尺度方法来处理GCM的原始数据以达到评估区域的气候变化的目的。本研究应用使用偏差校正法中的delta方法将24个GCM在IPCC三种气候变化情景下的月尺度数据水平分辨率降尺度到0．5℃，进而用于分析新疆未来气候变化格局。基于降尺度后的计算结果与GCM模型原始数据比较表明：降尺度方法可以改善复杂地表和地形的区域气候变化预估特征，并降低GCM生成的气候数据在新疆地区的不确定性。结果表明：AIB、A2和B1三种情景模式下年均气温和年降水量在21世纪早期具有相似的空间格局与变化趋势，到21世纪中期会产生波动变化。年平均气温在A1B，A2和B1三种情景下到21世纪末将分别达到10℃，11．1℃和8．5℃；与此同时，年降水量将会有波动性的增加趋势。在2020—2070年间，AIB情景下区域年平均气温大于其他两个情景。A1B情景下的年降水量在2020-2040年间也大于其他两个情景。然而，在不同的情境下年平均气温与年降水存在很大的不确定性。不同情景下年平均气温的差异达6℃，而年平均降水差异大约200mm。在区域气候变化格局方面，到21世纪末，在天山中部、伊犁河流域、天山南部和塔里木河下游的年平均气温的增长要比准噶尔盆地、帕米尔高原和昆仑上北坡的小。年降水量在南疆西部呈现出轻微的下降趋势，但是在昌吉，吐鲁番，哈密和阿尔金山北部呈现出增长趋势。

英文摘要：

Accompanied by global climate change, the annual mean air temperature has experienced a strongly increasing trend in the western China, especially in Xinjiang. The Global Climate Model （GCM） provides an efficient and direct method to assess the process of global climate change and project future climate driven by various factors, especially human activity. Since GCMs＇ low spatial resolution cannot capture the characteristics of local climate change due to the land surface＇s complexity, downscaling methods, including Regional Climate Model （RCM）, Bias Correction method and Statistical Method, are proposed to process raw data from GCMs for local climate change assessment. This study applied the delta method, one of Bias Correction methods, to make horizonta! resolution of 24 GCMs models＇ monthly outputs into 0.5~C for analyzing Xinjiang＇s future climate pattern under three IPCC SRES. A comparison between the results from downscaled dada and raw data from GCMs shows that downscaling methods can improve local climate changing feature in complex land surface and topography and to reduce the uncertainty of climate data generated from GCMs in Xinjiang. The results showed that scenarios A1B, A2 and B1 generated similar patterns and trends in annual mean air temperature and annual precipitation in the early 21st century with fluctuations in the middle of the 21st century. The annual mean air temperature will reach 10℃ 11.1℃ and 8.5℃ in A1B, A2 and B1 by the end of the 2Pt century, respectively, while the annual precipitation during the projection period will experience an increasing trend with a little fluctuation. During 2020 and 2070, the annual temperature in A1B scenario is greater than the other scenarios on regional average. The annual precipitation in the A1B scenario is also greater than other scenarios during 2020 and 2040 on regional average. However, there exists a large uncertainty within different SRES with an range of 6℃ in annual temperature and about 200 mm in annual precipitation.