摘要
The Tibetan Plateau (TP) holds ten thousands of alpine glaciers in mid-latitude. They have shrunk with an accelerating retreat rate recently. We applied a distributed temperature-index massbalance model developed by Regine Hock, and coupled with a volume-area scaling method to Xiao Dongkemadi Glacier (XDG) in the central TP, to assess its response to climate change. The result shows the simulated mass balance is in a good agreement with observations (R2=0.75, p〈0.001) during the period of 1989-2012. The simulated mean annual mass balance (-213 mm w.e.) is close to the observation (-233 mm w.e.), indicating the model can be used to estimate the glacier variation in the future. Then the model was forced under the climate scenarios by the output of RegCM4 RCP4.5 and RCP8.5 from 2013 to 2050. The simulated terminus elevation of the glacier will rise from 5454 m a.s.1, in 2o13 to 5533 m a.s.1. (RCP4.5) and 5543 m a.s.1. (RCP8.5) in 2050. XDG will lose its volume with an increasing rate of 600-700 m3 a-1 during the period of 1989-2o5o, indicating the melting water will enhance the river runoff. But for the long term, the contribution to the river runoff will decrease for the shrinkage of glacier scale.
基金
The National Natural Science Foundation of China (Grant No.41401226,41190080 and 41571062)
the China Postdoctoral Science Foundation (Grant No.2015M570865)