Glacier mass balance over the central Nyaincientanglha Range during recent decades derived from remote-sensing data

To obtain information on changes in glacier mass balance in the central Nyaincientanglha 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 km(2), in 2016. Ice cover has been shrinking by 0.68 +/- 0.05% a(-1) since 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(-1) has been recorded since 1968; mass losses accelerated from 0.42 +/- 0.20 m w.e. a(-1) to 0.60 +/- 0.20 m w.e. a(-1) between 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.