An inventory of glacier changes between 1973 and 2011 for the Geladandong Mountain area, China

Abstract

The snow and ice of the Geladangong Mountain area supply the headwaters of the Yangtze River, and long-term changes to glaciers and ice masses in this region due to a warming climate are of great concern. An inventory of glacier boundaries and changes over decades for the Geladandong Mountain area in China has been conducted using remote sensing imagery from Landsat (MSS, TM, ETM+), CERBES CCD, and GIS techniques. Variations in glacier extent has been measured using a~series of digital images since 1973, including Landsat MSS in 1973, Landsat TM in 1992, Landsat ETM+ in 2004, and CBERS CCD in 2011. All Landsat data are snow-free outside the glacier boundaries, allowing an unsupervised classification method to be used to extract glacier area. For the CBERS CCD data, some areas were covered by clouds and snow, requiring an initial unsupervised classification method to divide glacier, clouds and snow from other land types, followed by a supervised visual interpretation to extract glacier area. The results show a decrease in glacier ice cover in the study area during the past 38 yr. From 1973 to 2011, glacier area decreased from 107 105 hectares to 94 220 hectares, or a change of −12%. The speed at which ice cover is being lost has been decreasing during the past 38 yr. The rate of glacier area loss was 0.47% yr<sup>−1</sup> from 1973–1992, 0.19% yr<sup>−1</sup> from 1992–2004, and 0.14% yr<sup>−1</sup> from 2004–2011. While most of the glaciers are shrinking, some are expanding. For the 1973 to 2004 period, retreating glaciers exposed 14 447 hectares of land, and advancing glaciers spread over 2682 hectares that were not covered by ice in 1973. The net glacier area decrease is 11 765 hectares from 1973–2004. For the 1973 to 2011 period, glaciers expanded over 3791 hectares, and retreated from 16 504 hectares

Accelerated glacier mass loss in the largest river and lake source regions of the Tibetan Plateau and its links with local water balance over 1976–2017

“…Due to the TP's extreme environment, almost no glaciological field measurements have been carried out, but several studies using Landsat images have suggested an accelerated shrinkage of glaciers in this region from 1969 to 2011 (Ye and others, 2006; Zhang and others, 2013b, 2013a). Geodetic glacier mass balances have also been monitored, as shown in Table 1.…”

Quantifying Freshwater Mass Balance in the Central Tibetan Plateau by Integrating Satellite Remote Sensing, Altimetry, and Gravimetry

“…The belt is no longer active according to recent GPS measurements [14]. Tanggula Mountains also served as geographical boundary between the continental climate and the summer Indian monsoon over the plateau [15]. The northern part of the range is subject to continental air masses and the southern part is affected by Indian summer monsoon.…”

Annual Glacier-Wide Mass Balance (2000–2016) of the Interior Tibetan Plateau Reconstructed from MODIS Albedo Products

“…Meanwhile, annual surface thinning ranged from 0.049 m/a [8] In recent years, continuously increasing summer air temperature has been the major reason for the shrinkage of the GLDD glaciers [35,41]. From 1973 to 2009, these glaciers experienced a shrinkage in area cover, with an average rate of decrease of about 2.65 km 2 /a [42], and glacier shrinkage is still on-going [35]. Besides, glacier variation appeared to have heterogeneous spatial characteristics, meaning some glaciers advanced but others retreated [41], and the glacier tongues on the eastern side of the mountain tended to melt more seriously than those on the western side [35].…”