中文摘要：

利用ECHAM5/MPI-OM全球海气耦合模式模拟的当代（1986-2000年）和IPCC A1B情景下未来（2011-2025年）2×15a的模拟输出格点场资料,驱动20 km高水平分辨率区域气候模式RegCM3进行西南地区气候变化的数值模拟,主要分析未来地面温度和降水的可能变化。结果表明：①通过与32个地面气象站观测资料和CRU资料对比分析,RegCM3能够很好的模拟研究区基准时段地面温度和降水的局地分布特征。②A1B情景下未来西南地区年、四季平均温度均明显增加,北部温度变化幅度大于南部。③最高/最低温度一致升高,冬季最高/最低温度变化幅度大于夏季;年、秋冬季降水有所增加,冬季降水增加明显,而春夏季降水略有减少。④研究区未来春夏季温度升高、降水减少的趋势可能导致局部地区高温、干旱等极端天气的可能性增大;同时冬季降水增加,可能加重局部地区洪涝灾害的风险。

英文摘要：

Climate change over southwestern China is simulated by a regional climate model（RegCM3）,using the output from a global coupled atmosphere-ocean model（ECHAM5/MPI-OM） as lateral and surface boundary conditions.Two sets of 15 years of simulations at 20-km gird resolution for present days（1986-2000） and future（2011-2025,under IPCC_A1B scenario） are conducted to analyze the effects of surface air temperature and precipitation on the drought as a focal area.Results show that RegCM3 can reproduce well the spatial distribution of surface air temperature and precipitation in southwestern China compared with the observed data of 32 meteorological stations and grid data of CRU,and simulated annual and summer precipitation is much higher than winter precipitation.The simulated precipitation in winter is higher than observed values.During 2011-2025,there might be a remarkably warming either annually or in other seasons.The temperature change in the northern region is bigger than that in the southern region.The maximum and minimum temperature changes in winter are bigger than those in summer.Annually,precipitation increase is consistent with that in autumn and winter,while precipitation increase is significant in winter.Precipitation decrease in spring and summer is not significant.Temperature increase and precipitation decrease in spring and summer might induce high temperature and droughts to parts of the region,while precipitation increase in winter might increase the risk of local flood disasters.