Hazard from Himalayan glacier lake outburst floods

Sustained glacier melt in the Himalayas has gradually spawned more than 5,000 glacier lakes that are dammed by potentially unstable moraines. When such dams break, glacier lake outburst floods (GLOFs) can cause catastrophic societal and geomorphic impacts. We present a robust probabilistic estimate of average GLOFs return periods in the Himalayan region, drawing on 5.4 billion simulations. We find that the 100-y outburst flood has an average volume of 33.5+3.7/−3.7 × 106 m3 (posterior mean and 95% highest density interval [HDI]) with a peak discharge of 15,600+2,000/−1,800 m3⋅s−1. Our estimated GLOF hazard is tied to the rate of historic lake outbursts and the number of present lakes, which both are highest in the Eastern Himalayas. There, the estimated 100-y GLOF discharge (∼14,500 m3⋅s−1) is more than 3 times that of the adjacent Nyainqentanglha Mountains, and at least an order of magnitude higher than in the Hindu Kush, Karakoram, and Western Himalayas. The GLOF hazard may increase in these regions that currently have large glaciers, but few lakes, if future projected ice loss generates more unstable moraine-dammed lakes than we recognize today. Flood peaks from GLOFs mostly attenuate within Himalayan headwaters, but can rival monsoon-fed discharges in major rivers hundreds to thousands of kilometers downstream. Projections of future hazard from meteorological floods need to account for the extreme runoffs during lake outbursts, given the increasing trends in population, infrastructure, and hydropower projects in Himalayan headwaters.

Download Full-text

On the magnitude and frequency of Karakoram Glacier surges

The Cryosphere Discussions ◽

10.5194/tcd-7-5177-2013 ◽

2013 ◽

Vol 7 (5) ◽

pp. 5177-5187

Author(s):

D. J. Quincey ◽

A. Luckman

Keyword(s):

Mass Balance ◽

Return Period ◽

Accurate Mass ◽

Return Periods ◽

Present Evidence ◽

Surface Displacements ◽

Hindu Kush ◽

Glacier Surges

Abstract. The return periods of Karakoram glacier surges are almost entirely unknown. Here, we present evidence of an historic surge of the Khurdopin Glacier that began in the mid-1970s and peaked in 1979. Measured surface displacements reached > 5 km yr–1, two orders of magnitude faster than during quiescence and twice as large as any previously recorded velocity in the region. The Khurdopin Glacier next surged in the late-1990s, equating to a return period of 20 yr. Surge activity in the region needs to be better understood if accurate mass balance assessments of Hindu-Kush–Karakoram–Himalaya glaciers are to be made.

Download Full-text

Distribution pattern of orchids in Uttarakhand, Western Himalayas, India

International Journal of Plant Biology ◽

10.4081/pb.2012.e5 ◽

2012 ◽

Vol 3 (1) ◽

pp. 5 ◽

Cited By ~ 1

Author(s):

Jeewan Singh Jalal

Keyword(s):

Western Ghats ◽

Suitable Habitat ◽

Western Himalayas ◽

Tropical Zone ◽

Orchid Species ◽

Eastern Himalayas ◽

Terrestrial Orchids ◽

Growth Development ◽

Low Altitude ◽

The Tropics

Orchids are widely distributed in tropics, subtropics and temperate regions. Within the tropics, orchids form an important feature of the vegetation, chiefly as epiphytes. India’s epiphytic orchid is to be found primarily in the Eastern Himalayas and Western Ghats, while the terrestrial species flourishes in the Western Himalayas. In the state of Uttarakhand, India, orchid distribution is not homogeneous. Orchids are typically concentrated along the riverine areas and in pockets of moist forests where there is suitable habitat for their growth, development and regeneration. The purpose of this study was to provide a general review of the distribution of orchid species (epiphytic and terrestrial) in Uttarakhand. A total of 240 species (of which 10 are endemic) belonging to 73 <em>genera</em> were recorded. The largest number of orchid species (terrestrial and epiphytic) were encountered in the sub-tropical zone (<1500 m). Terrestrial orchids were distributed throughout the altitudinal gradient, but the largest number of species occurred in two ecotones between high and low altitude forests (1500-2000 m and 3000-3500 m). Twenty-one species were restricted to a particular habitat.

Download Full-text

Long-period variability in ice-dammed glacier outburst floods due to evolving catchment geometry

10.5194/tc-2021-141 ◽

2021 ◽

Author(s):

Amy J. Jenson ◽

Jason M. Amundson ◽

Jonathan Kingslake ◽

Eran Hood

Keyword(s):

Peak Discharge ◽

Water Volume ◽

Flood Hazards ◽

Outburst Flood ◽

Ice Shelf ◽

Outburst Floods ◽

Flood Magnitude ◽

Hydrological System ◽

Basin Geometry ◽

Glacier Flow

Abstract. We combine a glacier outburst flood model with a glacier flow model to investigate decadal to centennial variations in outburst floods originating from ice-dammed marginal basins. Marginal basins form due to retreat and detachment of tributary glaciers, a process that often results in remnant ice being left behind. The remnant ice, which can act like an ice shelf or break apart into a pack of icebergs, limits the basin storage capacity but also exerts pressure on the underlying water and promotes drainage. We find that during glacier retreat there is a strong, nearly linear relationship between flood water volume and peak discharge for individual basins, despite large changes in glacier and remnant ice volumes that are expected to impact flood hydrographs. Consequently, peak discharge increases over time as long as there is remnant ice remaining in a basin, the peak discharge begins to decrease once a basin becomes ice free, and similar size outburst floods can occur for very different glacier volumes. We also find that the temporal variability in outburst flood magnitude depends on how the floods initiate. Basins that connect to the subglacial hydrological system only after reaching flotation yield greater long-term variability in outburst floods than basins that are continuously connected to the subglacial hydrological system (and therefore release floods that initiate before reaching flotation). Our results highlight the importance of improving our understanding of both changes in basin geometry and outburst flood initiation mechanisms in order to better assess outburst flood hazards and impacts on landscape and ecosystem evolution.

Download Full-text

Susceptibility of glacial lakes to avalanche and rockfall in the Hindu-Kush-Himalaya

10.5194/egusphere-egu21-12475 ◽

2021 ◽

Author(s):

Saket Dubey ◽

Manish Goyal ◽

Ashim Sattar ◽

Umesh Haritashya

Keyword(s):

Mass Movement ◽

Major Axis ◽

Glacial Lakes ◽

Hazard Management ◽

Runout Distance ◽

Outburst Floods ◽

Hindu Kush ◽

Run Up ◽

The Stability ◽

Critical Regions

<p>The Hindu-Kush-Himalayan region is home to numerous glacial lakes. Some of these lakes could fail and produce hazardous Glacial Lake Outburst Floods (GLOF). GLOFs are primarily triggered by an avalanche or a rockfall entering the lake that generates an overtopping displacement waves. In the present study, we investigate the susceptibility of all lakes present in the Hindu-Kush-Karakorum (HKH) region (Randolph Glacier inventory region 14 and 15) to the dynamic mass movement (avalanche and rockfall). Avalanche and rockfall trajectories are developed considering various depths and &#8220;Minimum Look-Up Angle&#8221; (MLUA: a term used to define the avalanche runout distance). These trajectories are also validated against the results obtained from the Rapid Mass Movement Simulation (RAMMS) model. The mass movement of avalanche or rockfall along the major axis may enhance the wave run-up leading to a higher impact on the damming structure. Therefore, each susceptible lake is critically assessed for the angle of intrusion of a mass movement. The stability of the glacial lakes was also evaluated using the steep lake front area method to understand the associated hazard. Obtained results suggest that out of 3725 glacial lakes, 239 are susceptible to an avalanche when the mean avalanche depth is considered 50 m, and only 43 if the assumed mean avalanche depth is reduced to 10 m. Furthermore, the rockfall trajectories suggest that 343 lakes are susceptible to rockfall while considering MLUA of 17&#730;, which falls to 217 when MLUA is increased to 23&#730;. Overall, glacial lakes in the Central Himalayas were more susceptible to mass movement than the Karakoram, Western and Eastern Himalayas. We hope that our work will enable stakeholders to make a well-informed decision for hazard management in the Hindu-Kush-Himalayas. In addition to this, developed avalanche and rockfall trajectories will also help identify critical regions and hazard susceptibility structures.</p>

Download Full-text

Glacial Lake Outburst Flood in Nepal: A Challenging Environmental Hazard and Disaster

Academic Voices A Multidisciplinary Journal ◽

10.3126/av.v4i0.12360 ◽

2015 ◽

Vol 4 ◽

pp. 56-67

Author(s):

Shiva Kant Dube

Keyword(s):

Flash Flood ◽

Global Climate ◽

Glacial Lake ◽

Central Himalayas ◽

Outburst Floods ◽

Glacial Lake Outburst Floods ◽

Hindu Kush ◽

Glacial Lake Outburst Flood ◽

Basic Infrastructure ◽

Percent Area

Geographically, Nepal is situated on the lap of the Himalayas occupying 0.3 percent area of Asia and 0.03 percent of the world. Recently, global climate change has invited enormous environmental hazards and disasters in the Hindu-Kush Himalayan region. Catastrophic floods originating from the outburst of glacial lakes have been recognized as one of the primary natural hazards in Nepal, making downstream areas vulnerable. Frequent severe floodscaused by glacier outburst in the Nepal Himalayas, occur once every three years. Nine potentially dangerous glaciers were identified in the Eastern and Central Himalayas during pre- and post-monsoon seasons. At national and international level, Glacial Lake Outburst Floods (GLOF) in Nepal, are receiving considerable attention. Such floods endanger thousands of people, hundreds of villages and basic infrastructure causing disasters. This paper incorporates a case of flash-flood caused by GLOF and torrential rain in India which can be taken as a lesson to mitigate/minimize massive loss of lives and property in the Nepalese context.DOI: http://dx.doi.org/10.3126/av.v4i0.12360Academic Voices Vol.4 2014: 56-67

Download Full-text

Professor Mathews, outburst floods, and other glaciological disasters

Canadian Journal of Earth Sciences ◽

10.1139/e86-088 ◽

1986 ◽

Vol 23 (6) ◽

pp. 859-868 ◽

Cited By ~ 7

Author(s):

Garry K. C. Clarke

Keyword(s):

British Columbia ◽

Physical Model ◽

Mining Operation ◽

Glacial Lake ◽

Outburst Flood ◽

Transportation Corridor ◽

Outburst Floods ◽

Flood Magnitude ◽

Unusual Problem

Misfortunes befalling the Granduc mining operation near Stewart, British Columbia, stimulated Professor Mathews' influential scientific contributions on subglacial hydrology. A series of violent floods from glacier-dammed Summit Lake menaced the transportation corridor between the Granduc ore concentrator and a tidewater dock at Hyder, Alaska. This unusual problem motivated the research of Mathews and later of Gilbert, who together laid the foundation for a greater understanding of the physics of outburst floods. The physical model that evolved from their research can be used to predict outburst flood magnitude and to cast light on the hydrology of ancient floods such as those from glacial Lake Missoula.

Download Full-text

Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

Quaternary Research ◽

10.1016/j.yqres.2005.09.006 ◽

2006 ◽

Vol 65 (02) ◽

pp. 324-335 ◽

Cited By ~ 25

Author(s):

Cassandra R. Fenton ◽

Robert H. Webb ◽

Thure E. Cerling

Keyword(s):

Colorado River ◽

Grand Canyon ◽

Peak Discharge ◽

Dam Failure ◽

Flow Modeling ◽

Hydraulic Characteristics ◽

Outburst Flood ◽

The Usa ◽

Order Of Magnitude ◽

Flood Deposits

AbstractThe failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of the Hyaloclastite Dam released a maximum 11 × 109 m3 of water in 31 h. Peak discharges, estimated from uncertainty in channel geometry, dam height, and hydraulic characteristics, ranged from 2.3 to 5.3 × 105 m3 s−1 for the Hyaloclastite outburst flood. This discharge is an order of magnitude greater than the largest known discharge on the Colorado River (1.4 × 104 m3 s−1) and the largest peak discharge resulting from failure of a constructed dam in the USA (6.5 × 104 m3 s−1). Moreover, the Hyaloclastite outburst flood is the oldest documented Quaternary flood and one of the largest to have occurred in the continental USA. The peak discharge for this flood ranks in the top 30 floods (>105 m3 s−1) known worldwide and in the top ten largest floods in North America.

Download Full-text

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

Remote Sensing ◽

10.3390/rs13061165 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1165

Author(s):

Donghui Shangguan ◽

Da Li ◽

Yongjian Ding ◽

Jun Liu ◽

Muhammad Naveed Anjum ◽

...

Keyword(s):

Remote Sensing ◽

Debris Flow ◽

Reanalysis Data ◽

Mountain Range ◽

Outburst Flood ◽

Ice Flow ◽

Sequence Of Events ◽

Hindu Kush ◽

Disaster Chain ◽

Glacial Lake Outburst Flood

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.

Download Full-text