Recent glacier and glacial lake changes and their interactions in the Bugyai Kangri, southeast Tibet

Abstract

Glaciers in the Bugyai Kangri are located in a transition zone from southeast Tibet, where monsoonal temperate glaciers dominate, to inner Tibet, where continental glaciers dominate. Here we analyze glacier and glacial lake changes in this region using multi-year inventories based on Landsat images from 1981–2013. Results show that the total area of 141 glaciers in the region decreased by 30.44 ±0.89 km2 from 198.35 ±9.54 km2 (1980s) to 167.93 ±4.52 km2 (2010s). The annual area shrinkage rate (–0.48% a–1) is lower than that reported for southeastern Tibet but higher than that of inner Tibet. Both the number and total area of glacial lakes increased between 1981 and 2013. Among all lakes, proglacial lakes contribute most (~81 %) to the expansion. The total area of ten proglacial lakes increased by 150.3 ± 13.17% and of these ten lakes the four that expanded most sharply showed increased calving at their upper margins, resulting in more rapid retreat of lake-terminating glaciers than land-terminating glaciers. Owing to rapid calving, several lakes may undergo further growth in the near future, increasing the potential risk of glacial lake outburst floods.

Keywords

• climate change
• glacier calving
• glacier fluctuations
• jökulhlaups (GLOFs)
• remote sensing