中文摘要：

基于21个CMIP5全球气候模式集合数据，耦合VIC模型，预估了未来30年（2011—2040年）RCP2．6、RCP4．5和RCP8．5三个情景下长江上游区域积雪的时空变化。结果表明：与基准期1970—1999年相比，长江上游区域未来30年的多年平均气温和各月平均气温都将升高1～2℃，其中冬季和春季升温较大；平均年降水量将增加3％～4％，但秋、冬季降水有所减小。未来30年平均积雪深相对于基准期将减小37．8％左右，在积雪过程中达到最大积雪深的时间与基准期基本相同，而融雪开始的时间略有延后；从空间变化来看，冬季（1月份）长江上游区域大部分地区的积雪深都呈现减小趋势，部分地区积雪深减小超过了50％。

英文摘要：

Based on multi-model ensemble projections for the period 2011--2040 under climate change scenarios, the temporal and spatial variations of snow depth in regions of the upper reaches of the Yangtze River are investigated in this study. The ensemble projections of future snow conditions are obtained using a coupled modeling approach involving 21 global climate models in the phase 5 of the Coupled Model Intercomparison Project （CMIPS） and the VIC （Variable Infiltration Capacity） model. The climate change scenarios considered include the Representative Concentration Pathways （RCPs） 2. 6, 4. 5 and 8.5. Results show that both multi-annual and monthly mean temperatures for the next three decades are projected to rise by 1 to 2℃ relative to the base period （from 1970 to 1999）, with obvious increase in winter and spring seasons. The average annual precipitation would increase by 3% to 4%, while a slight decrease in autumns and winters. The multi-annual mean snow depth for the next three decades is projected to decrease by about 37.8% relative to the base period. The time of maximum snow accumulation should be similar to that in the base period, while the starting time of snow melting would be slightly lagged behind. For the spatial extent of snow cover, the snow depth in most regions of the upper reaches of the Yangtze River would be reduced, and the reduction could be more than 50% in some areas.