长江源区冰川对全球气候变化的响应

Response of Glaciers in the Source Region of Yangtze River to Global Climate Change

长江源区是青藏高原内部山地冰川集中分布的地区之一 ,其冰川储量都占长江流域冰川总量的一半以上。近几十年以来由于受全球气候变化的影响 ,长江源区气候呈暖干化的倾向 ,大多数冰川呈退缩状态 ,这对长江源区的生态环境产生深刻的影响 ,进而危及整个长江流域的生态安全。用英国Hadley气候预测与研究中心的GCM模型HADCM2预测长江源区未来的气候情景 ,结果显示在不同的实验条件下 ,气候都将由现在的暖干化趋势向暖湿化方向转变。通过建立长江源区对气候变化的响应模型 ,用来预测在未来气候情景下冰川变化的趋势 ,预计在本世纪的不同时期冰川零平衡线 (雪线 )将上升 16～ 5 0m。

The Source Region of Yangtze River is one of the areas in Qinghai-Xizang Plateau where the glaciers are concentrated. The volume of glaciers in this region makes up more than half of that in the whole Yangtze Valley. During the past decades, the temperature in this region has been rising and the precipitation has been dropping due to the global climate change. As a result, the glaciers in this region have been retreating, which will have a great impact on the eco-environment of this region and the ecology security of the Yangtze Valley. The authors use the HADCM2 model to predict the future climate scenarios. The results show that the climate will turn warm and humid in the future. The model for the response of glaciers to the climate change has been established to forecast the glacier change. Under the different climate scenarios the ELA will rise 16-50m in the different periods of the 21th century.