Recent Glacier Mass Balance and Area Changes from DEMs and Landsat Images in Upper Reach of Shule River Basin, Northeastern Edge of Tibetan Plateau during 2000 to 2015

Shiqiang Zhang,Zhihua Zhang,Haojie Li,Qianxin Wu,Xiaowen Zhang

doi:10.3390/w10060796

Abstract

Glacier changes in the Upper Reach of the Shule River Basin (URSRB) serve as a good indicator of climate change in the western part of the Qilian Mountains, located on the northeastern edge of the Tibetan Plateau. However, information on recent glacier changes in the URSRB is limited. In this study, the changes in ice surface elevation were determined using geodetic methods based on digital elevation models (DEMs) derived from the Shuttle Radar Topography Mission (SRTM) (2000), and from pairs of Third Resources Satellite (ZY-3) of China (taken around 2013). In addition, glacier area changes from 2000–2015, were derived from Landsat TM/ETM+/OLI images. The results suggest that 478 glaciers with an area of 375.1 ± 2.68 km2 remained in the URSRB in 2015. Ice cover diminished by 57.5 ± 2.68 km2 (11.9 ± 0.60%), or 0.79 ± 0.04% a−1 and 35 small glaciers disappeared from 2000 to 2015 in the URSRB. The most pronounced glacier shrinkage occurred during 2004 to 2009. The average ice surface elevation of the URSRB from 1999 to 2013 reduced by about 4.98 ± 0.6 m, which is equal to a mass loss of 0.383 ± 0.046 m·a−1. This reduction indicates that the ice storage loss has accelerated since 1999, compared to a mass loss of 0.21 ± 0.04 m·a−1 around Tuanjiefeng from 1966 to 1999, as reported by Xu et al. (2013).

Highlights

Mountain glaciers are a critical freshwater resource for populations inhabiting the downstream region or valleys at the base of mountains [1,2]
Since ZiYuan-3 surveying satellite (ZY-3) has a very high resolution, we could not achieve a higher accuracy of the ground control point, so we used the residual error of the off-glacier region to estimate the error
Reported that the total glacier area in the Shule River Basin decreased by about 24.5 km2 per decade, from the 1970s to 2010, according to the Chinese Glacier Inventory (CGI) (1970s) and SCGI (2006 to 2010)

Summary

Introduction

Mountain glaciers are a critical freshwater resource for populations inhabiting the downstream region or valleys at the base of mountains [1,2]. Worldwide glacier changes and the associated change in future runoff raise major concerns for the sustainability of global water resources [3]. The meltwater from glaciers on the Tibetan Plateau (TP), which is called “Asia’s Water Tower”, is extremely important to the vitality of large rivers, such as the Indus and Brahmaputra Rivers [1]. Reduction in meltwater can be a major threat to the food security of an estimated 60 million people who live in the downstream regions [1,4]. The glacier mass balance is a very useful indicator of climate variability [5], as it provides information about glacier changes in high Asia as an important issue in cryospheric and climate change studies [6].

Methods

Results

Discussion

Conclusion