Recent Accelerating Glacier Mass Loss of the Geladandong Mountain, Inner Tibetan Plateau, Estimated from ZiYuan-3 and TanDEM-X Measurements

Lin Liu,Liming Jiang,Xiaoli Ding,Hansheng Wang,Zhimin Zhang

doi:10.3390/rs12030472

Abstract

The headwaters of many Asian rivers are at mountain glaciers of the Tibetan Plateau. Glacier melt-water is a non-negligible contributor of river runoff, especially for a drought year. However, the observation of mass glacier changes was scarce in recent years. Here, we estimated the recent glacier mass change of the Geladandong mountain, by differencing the digital elevation models (DEMs) produced from ZiYuan-3 images and TanDEM-X data. Moreover, we compared the SRTM-C DEM with TanDEM-X DEMs to retrieve glacier mass balances since 2000. The annual mass loss rates of −0.11 ± 0.03 and −0.47 ± 0.09 m w.e. yr−1 were derived in 2000–2012 and 2012−2018, respectively. This result revealed an accelerating rate of negative glacier mass changes during recent years, which is mainly caused by the significant increase of mass loss over non-surge glaciers, rather than surge-type glaciers, which held a slight increase of mass loss. In addition, we found a pronounced discrepancy of glacier mass change between non-surge and surge-type glaciers during 2012−2018, and suggested that this difference may be caused by the heterogeneous responses of surge-type glaciers to climate variations, because of the different timing and type of surge events.

Highlights

The Tibetan Plateau (TP), which is one of the most glacierized areas outside the Arctic and Antarctic, is the water tower of Asia [1]
This paper aims to derive the glacier mass balances of the Geladandong mountain (GLDDM) in recent years, by employing the digital elevation models (DEMs) produced from TanDEM-X InSAR images and ZiYuan-3 (ZY3) tri-stereo optical scenes
An apparent glacier surface lowering was basically detected over the terminus zones of the GLDDM, whereas the upper zones experienced a slight glacier surface thinning or even surface thickening

Summary

Introduction

The Tibetan Plateau (TP), which is one of the most glacierized areas outside the Arctic and Antarctic, is the water tower of Asia [1]. The headwaters of many great Asian rivers (e.g., Yangtze River) are located over mountain glaciers in the TP [2,3]. In a drought year, runoff is mainly originated from glacier melt-water, rather than precipitation, over some river basins [9]. The observation of glacier mass balances is necessary in the TP for investigating the variations of regional water resources. The measurements of glacier mass balances have been conducted in the TP for many years [10,11,12,13]. Similar to other glacierized regions in the ITP, a slight decrease of ice thickness (approximately −0.15 m yr−1) was measured in the first decade of the 21st century [31,32]. Glacier mass balances in recent years remain poorly known for the GLDDM

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