Abstract:

Using the two-phase remote sensing images based on ETM in 1999 and mainly GF-1 in 2014/2015, two phases of glacier inventory are completed by manual/automatic interpretation methods, and the glacial change in the past 15 years in the Nyainqentanglha Mountain is summarized. The results show that the glaciers were retreating in the mountain from 1999 to 2015, some of which retreated in the east, and the subcontinent was relatively stable in the west. The area covered by the glacier reduced for a total amount of 56.32 km², representing a reduction rate of 0.67%. Ten glaciers have disappeared, representing a reduction rate of 0.16%. The ice volume loss is 5.315 km³, representing a reduction rate of 0.78%. On one hand, the glaciers are retreating in every directions, and the number and size of the glaciers decrease more in the south and east than in the north and west. The number and size of the glaciers decrease mostly in the average slope of 20° to 35°. On the other hand, the size decrease is most significant at the elevations of 4,500 to 5,500 m. Analogously, the glacial size decreased is obvious in the Ganges Basin, followed by the Salween River Basin, where the glaciers are most concentrated. The recession of the glaciers with sizes of ≤5.0 km² are most obvious among the glaciers of other sizes. There is a close relation between the glacial retreat and climate change. The annual average temperature and precipitation changes from three meteorological stations near the mountain over the past 50 years show that the annual average temperature has increased significantly, while the precipitation has fluctuated since 1961. The temperature rise and precipitation drop in the east may have been one of the reasons behind the more severe glacial retreat in the east(than in the west) during this period.

Key words: glacier variation, glacier inventory, remote sensing, Nyainqentanglha Mountain