Determining the Events in a Glacial Disaster Chain at Badswat Glacier in the Karakoram Range Using Remote Sensing

Donghui Shangguan,Jun Liu,Yaojun Li,Wanqin Guo,Da Li,Yongjian Ding,Muhammad Naveed Anjum

doi:10.3390/rs13061165

Abstract

The Karakoram mountain range is prone to natural disasters such as glacial surging and glacial lake outburst flood (GLOF) events. In this study, we aimed to document and reconstruct the sequence of events caused by glacial debris flows that dammed the Immit River in the Hindu Kush Karakoram Range on 17 July 2018. We used satellite remote sensing and field data to conduct the analyses. The order of the events in the disaster chain were determined as follows: glacial meltwater from the G2 glacier (ID: G074052E36491N) transported ice and debris that dammed the meltwater at the snout of the G1 glacier (ID: G074103E36480N), then the debris flow dammed the Immit River and caused Lake Badswat to expand. We surveyed the extent of these events using remote sensing imagery. We analyzed the glaciers’ responses to this event chain and found that the glacial debris flow induced G1 to exhibit accelerating ice flow in parts of the region from 25 July 2018 to 4 August 2018. According to the records from reanalysis data and data from the automatic weather station located 75 km from Lake Badswat, the occurrence of this disaster chain was related to high temperatures recorded after 15 July 2018. The chains of events caused by glacially related disasters makes such hazards more complex and dangerous. Therefore, this study is useful not only for understanding the formation of glacial disaster chains, but also for framing mitigation plans to reduce the risks for vulnerable downstream/upstream residents.

Highlights

Huge stores of ice and snow are located on the Tibetan Plateau (TP) and in the surrounding mountains, which is why this region has been designated as the “Third Pole”
This study focused on glacier behavior in and adjacent to the Immit River, where this glacial debris flow impacted Lake Badswat
The ice collapse in the glacial area caused a small ice-blockage in the river, strengthened the debris flow, and dammed the Immit River, which caused the expansion of Lake Badswat

Summary

Introduction

Consistent warming of the TP is well documented; despite the protection of debris cover, 13–20% of the glacial mass in the Karakoram mountain range will be lost by the end of the 21st century if the background global temperature increases by 1.5 ◦ C [4]. Glaciers in the TP have been shrinking since the 1960s in response to global warming. Unlike those in other parts of the Himalayas, the glaciers in the Karakoram are affected by complex dynamics. Several glaciers in the Karakoram exhibit surge-type behavior, meaning that they speed up and advance rapidly [6,9,10], which demonstrates the unique behavior of glaciers in this region [11].

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Conclusion