Glacial Lake Changes and Identification of Potentially Dangerous Glacial Lakes in the Yi’ong Zangbo River Basin

Miaomiao Qi,Xiaojun Yao,Juan Liu,Dahong Zhang,Hongyu Duan

doi:10.3390/w12020538

Abstract

The southeastern Tibetan Plateau, where monsoonal temperate glaciers are most developed, has a huge number of glacial lakes. Based on Landsat Operational Land Imager (OLI) images, 192 glacial lakes with a total area of 45.73 ± 6.18 km2 in 2016 were delineated in the Yi’ong Zangbo River Basin. Glacial lakes with areas of less than 0.1 km2 accounted for 81.77% of the total number, and glacial lakes located above 4500 m elevation comprised 83.33%. Dramatic glacier melting caused by climate warming has occurred, resulting in the formation and expansion of glacial lakes and the increase of potential glacial lake outburst floods (GLOFs) risk. From 1970 to 2016, the total area of glaciers in the basin has decreased by 35.39%, whereas the number and total area of glacial lakes have, respectively, increased by 86 and 1.59 km2. In that time, 110 new glacial lakes emerged, whereas 24 of the original lakes disappeared. The newly formed lakes have a smaller mean area but higher mean elevation than the lakes that disappeared. Based on five indicators, a first-order method was used to identify glacial lakes that pose potential threats. We identified 10 lakes with very high, 7 with high, 31 with medium, and 19 with low GLOF susceptibility, out of 67 moraine-dammed glacial lakes with areas larger than 0.02 km2. Understanding the behavior of glaciers and glacial lakes is a vital aspect of GLOFs disaster management, and the monitoring of glacial lakes should be strengthened.

Highlights

Glacial lakes are a significant component of the cryosphere, and their formation and development have indirect connections with long-term climatic changes [1,2,3]
The massive topographic landforms together with the Indian monsoons led to the development of distinct temperate valley glaciers, and the region has become a major center of distribution of modern glaciers on the Tibetan Plateau (TP)
Glacial lakes are mainly fed by glacier meltwater, and lake area variation is closely tied to the dynamics of the mother glacier [35,36]

Summary

Introduction

Glacial lakes are a significant component of the cryosphere, and their formation and development have indirect connections with long-term climatic changes [1,2,3]. Global warming has become an indisputable fact. In the context of global warming, glaciers are melting rapidly [4], providing conditions for the formation of glacial lakes. Glacial lakes have the potential to evolve into catastrophic outburst floods (i.e., glacial lake outburst floods, GLOFs) [5,6,7], which are considered to be highly destructive glacial hazards because of their potential size, the extent to which they threaten downstream communities, and their capacity to destroy valuable infrastructure and agricultural land [8,9]. The Tibetan Plateau (TP), known as “the Roof of the World” and “the Third Pole” of the Earth, has numerous glaciers and glacial lakes.

Methods

Discussion

Conclusion