未来气候情景下长江源区气温时空分布研究

In the past 50 years, the temperature in the source region of the Yangtze River has risen remarkably, and the ecological and environmental problems have been increasingly prominent. Future temperature changes in the region are expected to contribute to ecosystem conservation and reconstruction. The ASD was used to downscal the daily mean temperature of CanESM2 model. Based on the daily mean temperature data from 1961 to 2014 at three meteorological stations in the study area, the historical data and NCEP downscaling results were used to validate the simulation results. Finally, temporal and spatial variation of temperature in the periods of 2020~2100 under the RCP4.5 were generated on the basis of ASD downscaling model. The results indicate that the CanESM2 model data can effectively simulate the spatial and temporal variations of daily mean temperature at the site scale after ASD downscaling. During the historical observation period, the temperature has increased significantly(P = 0.05) since 1991 in the Yangtze River source region. In the RCP4.5, the temperature will be still showing a significant upward trend in 2020s(2020 ~ 2040), but the trend will slow down in 2040s(2041 ~ 2070). There will be no obvious change during 2070s(2070~2100). Compared with the base period (1961 ~ 1990), the temperature will increase by 1.66 ℃, 2.34 ℃ and 2.76 ℃, respectively. As for the seasonal variation, the temperature increase in the spring and autumn will be most significant, while the temperature increase in the winter will be smaller. The study can be a reference for the rational use of water resources and ecological environment protection in the source region of the Yangtze River, and for the scientific management of water systems in the Yangtze River Basin.