Glacial Lake Outburst Flood Hazard, Downstream Impact, and Risk Over the Indian Himalayas

Abstract

Indian Himalayas are home to numerous glacial lakes, which can pose serious threat to downstream communities and lead to catastrophic socioeconomic disasters in case of a glacial lake outburst flood (GLOF). This study first identified 329 glacial lakes of size greater than 0.05 km 2 in the Indian Himalayas, and then a remote sensing-based hazard and risk assessment was performed on these lakes. Different factors such as avalanche, rockfall, upstream GLOF, lake expansion, identification of the presence of ice cores, and assessment of the stability of moraine were considered for the hazard modeling. Further, a stochastic inundation model was applied to quantify the potential number of buildings, bridges, and hydropower systems that could be inundated by GLOF in each lake. Finally, the hazard parameters and downstream impact were collectively considered to determine the risk linked with each lake. A total of 23 lakes were identified as very high risk lakes and 50 as high-risk lakes. The potential flood volumes associated with various triggering mechanisms were also measured and were used to identify the lakes with the most considerable risk, such as Shakho Cho and Khangchung Tso. This study is anticipated to support stakeholders and decision-makers in identifying critical glacial lakes and make well-informed decisions related to future modeling efforts, field studies, and risk mitigation measures.

Toward Numerical Modeling of Interactions Between Ice-Marginal Proglacial Lakes and Glaciers

“…Proglacial lakes are increasing in number and areal extent globally (Carrivick and Tweed, 2013;Shugar et al, 2020). Many recent regional studies have concentrated on the Himalaya (e.g., Komori, 2008;King et al, 2018King et al, , 2019Brun et al, 2019;Falaschi et al, 2019;Maurer et al, 2019;Tsutaki et al, 2019;Zhang et al, 2019;Kumar et al, 2020;Luo et al, 2020) partly due to the importance of glaciers there for water resources and partly due to the threat posed to downstream communities and infrastructure by glacial outburst floods (GLOFS) or "jökulhlaups" (Carrivick and Rushmer, 2006;Carrivick and Tweed, 2016;Dubey and Goyal, 2020;Thompson et al, 2020;Veh et al, 2020). Examples of studies documenting increasing number and area of proglacial lakes from other regions of the world include southern Iceland (Schomacker, 2010;Guðmundsson et al, 2019), western Greenland (Carrivick and Quincey, 2014), central Tibet (Wang et al, 2013), Austria (Buckel et al, 2018) and south America (Wilson et al, 2018;Emmer et al, 2020).…”

Upward Expansion of Supra-Glacial Debris Cover in the Hunza Valley, Karakoram, During 1990 ∼ 2019

“…Also, the differential ablation caused by an uneven distribution of debris thickness makes it easy for glaciers to form cliffs (Kindermann et al, 2008;Herreid and Pellicciotti, 2018) and ponds (Miles et al, 2016;Chand and Watanabe, 2019) in the ablation zone. Notably, these cliffs and ponds are not only factors that affect the hydrological process but also home to numerous glacial lakes, which can pose a serious threat to downstream communities and lead to catastrophic socioeconomic disasters in cases of glacial lake outburst flood (Benn et al, 2012;Dubey and Goyal, 2020). Therefore, obtaining information about the spatial distribution and temporal variation of supra-glacial debris cover would enhance the understanding of debris-covered glaciers and the glacial hydrological model.…”

Future glacial lakes in High Mountain Asia: an inventory and assessment of hazard potential from surrounding slopes

“…For the assessment of the GLOF potential for already existing lakes, parameters such as permafrost conditions (Bolch and others, 2011), lake expansion (Dubey and Goyal, 2020), moraine dam morphology (Wang and others, 2012), vegetation cover (Veh, 2019) and the likelihood of extreme meteorological conditions (Singh and others, 2014) can be included in addition to a slope hazard classification. When investigating future lakes, however, most of these parameters are unsatisfactory due to enormous uncertainties or a general lack of data.…”