To obtain information on changes in glacier mass balance in the central Nyainqentanglha Range, a comprehensive study was carried out based on digital-elevation models derived from the 1968 topographic maps, the Shuttle Radar Topography Mission DEM (2000) and TerraSAR-X/TanDEM-X (2013). Glacier area changes between 1968 and 2016 were derived from topographic maps and Landsat OLI images. This showed the area contained 715 glaciers, with an area of 1713.42 ± 51.82 km², in 2016. Ice cover has been shrinking by 0.68 ± 0.05% a⁻¹since 1968. The glacier area covered by debris accounted for 11.9% of the total and decreased in the SE–NW directions. Using digital elevation model differencing and differential synthetic aperture radar interferometry, a significant mass loss of 0.46 ± 0.10 m w.e. a⁻¹has been recorded since 1968; mass losses accelerated from 0.42 ± 0.20 m w.e. a⁻¹to 0.60 ± 0.20 m w.e. a⁻¹between 1968–2000 and 2000–2013, with thinning noticeably greater on the debris-covered ice than the clean ice. Surface-elevation changes can be influenced by ice cliffs, as well as debris cover and land- or lake-terminating glaciers. Changes showed spatial and temporal heterogeneity and a substantial correlation with climate warming and decreased precipitation.

The Ili River originates in the Tian Shan Mountains of Northwest China before flowing into Kazakhstan and Lake Balkash. Melting snow and ice are its major contributors. We analyzed glacial changes in the upper Ili River basin between the 1960s and 2007/2009 using topographic maps and satellite imagery from a Landsat TM. The relationships between glacial changes and glacial size, topographic factors, and debris cover were examined. Our results found that total glacial area decreased by 485 ± 177.3 km²(24.2% ± 8.8%) during the study period, and there were no advancing glaciers. Additionally, 331 glaciers disappeared and 18 disintegrated into two or three smaller glaciers. This study demonstrated a linear relationship between glacial area change and elevation. Changes in glaciers smaller than 1 km²were affected by both glacial size and topographic factors, while larger ones were affected by size only. Area losses in debris-covered glaciers were smaller by 2.5% to 7.5% compared to clean ice of the same size in this basin. As in other glaciated regions, glacial retreat in the Ili River basin is attributed to global warming. The slightly increasing precipitation over the study period could not offset the ice melting.