Abstract: Change of glaciers in the central Qilian Mountain in recent 50 years, including the Heihe River Basin and the Beidahe River Basin, was analyzed based on the remote sensing data and field survey. Results indicated that the total area of 910 glaciers investigated was reduced by 21.7% with a reduction rate of 0.002 km2•a^-1 during the period from 1956 to 2003, in which the total area of glaciers was reduced by 29.6% in the Heihe River Basin and 18.7% in the Beidahe River Basin. Reduction rate of the small glaciers was generally higher than that of the large ones, indicating that the small glaciers were more sensitive to climate change than the large ones. There was a regional difference in area change of glaciers due to the different geographical locations of the glaciers, local climate conditions and topographic factors in the central Qilian Mountain. Recent field survey revealed that the total area of glaciers in the Hulugou River Basin located in upper reaches of the Heihe River was reduced by 30.1% during the period from 1956 to 2010, and the reduction of glacier area in recent 7 years was 5 times of that in previous years. Shiyi Glacier located in this region was separated into two independent glaciers due to the serious ablation. Glacier melt runoff is the vital water source and plays an important role in stabilizing stream flow and regulating annual variation and distribution.

Key words: remote sensing, field survey, glacier area, Hulugou River Basin, central Qilian Mountain