scholarly journals Glacial Lakes and Glacial Lake Outburst Floods in Nepal

2011 ◽  
Author(s):  
Keyword(s):  
Glacial Lake ◽  
Glacial Lakes ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods

scholarly journals Simulation and Assessment of Future Glacial Lake Outburst Floods in the Poiqu River Basin, Central Himalayas

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1376
Author(s):  
Taigang Zhang ◽  
Weicai Wang ◽  
Tanguang Gao ◽  
Baosheng An
Keyword(s):  
River Basin ◽  
Hazard Assessment ◽  
Glacial Lake ◽  
High Mountain ◽  
Glacial Lakes ◽  
Central Himalayas ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Social And Economic Development ◽  
Glacial Lake Outburst Flood

A glacial lake outburst flood (GLOF) is a typical glacier-related hazard in high mountain regions. In recent decades, glacial lakes in the Himalayas have expanded rapidly due to climate warming and glacial retreat. Some of these lakes are unstable, and may suddenly burst under different triggering factors, thus draining large amounts of water and impacting downstream social and economic development. Glacial lakes in the Poiqu River basin, Central Himalayas, have attracted great attention since GLOFs originating there could have a transboundary impact on both China and Nepal, as occurred during the Cirenmaco GLOF in 1981 and the Gongbatongshaco GLOF in 2016. Based on previous studies of this basin, we selected seven very high-risk moraine-dammed lakes (Gangxico, Galongco, Jialongco, Cirenmaco, Taraco, Beihu, and Cawuqudenco) to simulate GLOF propagation at different drainage percentage scenarios (i.e., 25%, 50%, 75%, and 100%), and to conduct hazard assessment. The results show that, when any glacial lake is drained completely or partly, most of the floods will enter Nepal after raging in China, and will continue to cause damage. In summary, 57.5 km of roads, 754 buildings, 3.3 km2 of farmland, and 25 bridges are at risk of damage due to GLOFs. The potentially inundated area within the Chinese part of the Poiqu River basin exceeds 45 km2. Due to the destructive impacts of GLOFs on downstream areas, appropriate and effective measures should be implemented to adapt to GLOF risk. We finally present a paradigm for conducting hazard assessment and risk management. It uses only freely available data and thus is easy to apply.

scholarly journals New method for assessing the potential hazardousness of glacial lakes in the Cordillera Blanca, Peru

2014 ◽  
Vol 11 (2) ◽  
pp. 2391-2439 ◽  
Author(s):  
A. Emmer ◽  
V. Vilímek
Keyword(s):  
Slope Movement ◽  
Dam Failure ◽  
Glacial Lake ◽  
Flood Wave ◽  
Glacial Lakes ◽  
Cordillera Blanca ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Glacial Lake Outburst Flood ◽  
Dam Overtopping

Abstract. This paper presents a new and easily repeatable objective method for assessing the potential hazardousness of glacial lakes within the Peruvian region of Cordillera Blanca (excluding ice-dammed lakes, which do not reach significant volumes in this region). The presented method was designed to meet four basic principles, which we considered as being crucial. These are: (a) principle of regional focus; (b) principle of objectivity; (c) principle of repeatability; and (d) principle of multiple results. Potential hazardousness is assessed based on a combination of decision trees for clarity and numerical calculation for objectivity. A total of seventeen assessed characteristics are used, of which seven have yet to be used in this context before. Also, several ratios and calculations are defined for the first time. We assume that it is not relevant to represent the overall potential hazardousness of a particular lake by one result (number), thus the potential hazardousness is described in the presented method by five separate results (representing five different glacial lake outburst flood scenarios). These are potentials for: (a) dam overtopping resulting from a dynamic slope movement into the lake; (b) dam overtopping following the flood wave originating in a lake situated upstream; (c) dam failure resulting from a dynamic slope movement into the lake; (d) dam failure following the flood wave originating in a lake situated upstream; and (e) dam failure following a heavy earthquake. All of these potentials theoretically range from 0 to 1. The presented method was verified on the basis of assessing the pre-flood conditions of seven lakes which have produced ten glacial lake outburst floods in the past and ten lakes which have not. A comparison of these results showed that the presented method successfully identifies the potentially hazardous lakes.

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

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 538
Author(s):  
Hongyu Duan ◽  
Xiaojun Yao ◽  
Dahong Zhang ◽  
Miaomiao Qi ◽  
Juan Liu
Keyword(s):  
River Basin ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Huge Number ◽  
First Order ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Glacier Melting ◽  
First Order Method ◽  
Very High

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.

Glacial Lake Outburst Floods Early Warning System to save lives and livelihood of the Nepal Himalaya communities: A case Study of Imja Glacial Lake, Nepal 

2021 ◽  
Author(s):  
Deepak Kc ◽  
Top Khatri ◽  
Rishiram Sharma
Keyword(s):  
Climate Change ◽  
Risk Reduction ◽  
Early Warning ◽  
Early Warning System ◽  
Warning System ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Community Based ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods

<p>Nepal, a mountainous country, is experiencing multiple disasters, majority of which are induced by Climate Change. Erratic rainfall, extremely high temperature during summer, cold waves are some of them. Nepal will experience the impacts of climate change through an increase in temperature, more frequent heat waves and shorter frost durations in the future (5AR IPCC). Nepal is witnessing the increased maximum temperature of 0.56<sup>o</sup>C per decade and the increment of the temperature is even higher in the mountain region (ICIMOD 2019). One of the major impacts of Climate Change among others, is glacier retreat and Glacial Lake Outburst Floods (GLOFS). Nepal has already experienced more than 26 GLOFS (UNDP and ICIMOD 2020), originated both from Nepal and China, Tibet.</p><p>The Imja Glacial Lake is located at 27° 53′ 55“ N latitude, 86° 55’ 20” E longitude and at an altitude of 5010 m in Everest Region of Nepal Himalayas.  Imja was identified during 1960s as a small supra lake, was later expanded to an area of <strong>1.28 Km<sup>2</sup></strong>, <strong>148.9 meter deep</strong>, holding <strong>75.2 million cubic meters </strong>of water in 2014.   Lake lowering by 3.4 metres and establishment of early warning system was done in 2016 by the Government of Nepal and UNDP with the support of Global Environment Facility.  Hydro-met stations & GLOF Sensors in the periphery and downstream  of Imja Lake and automated early warning sirens in six prime settlements in the  downstream of Imja  watershed  linking with  dynamic SMS Alert system along 50 km downstream of Imja Dudh Koshi River have been have been linked with community-based DRM institutions at local government level. This initiative is important for preparedness and response of GLOF Risk Reduction in the Imja Valley, benefitting 71,752 vulnerable people, both local and the tourists visiting the Everest Region of Nepal.</p><p>Early Warning System of Tsho Rolpa Glacial Lake, the biggest Glacial Lake of Nepal is another example in the such system. New inventory of Glacial Lakes has identified 47 critical lakes as priority lakes for GLOF Risk Reduction in Koshi, Gandaki and Karnali basins. In the new context of federal  governance system, the role of federal, province and local government and communities is crucial  for achieving the targets of  Sendai Framework for Disaster Risk Reduction , particularly target “g” and SDGs 11 and 13  through integrating  the targets in the regular planning and   its’ implementation for resilient and Sustainable Development of  Nepal.</p><p><strong>References:</strong></p><p>Glacial lakes and glacial lake outburst floods in Nepal. Kathmandu, ICIMOD 2011,  Nepal Disaster Report, Ministry of Home affairs (MoHA) , 2015, 2018 Annual Reports UNDP 2016, 2017 and 2018,  Imja Hydro-Meteorological and Early Warning System User Manual, Government of Nepal and UNDP, 2017 Project Completion Report: Community Based Flood and Glacial Lake Outburst Risk Reduction Project, Government of Nepal and UNDP, 2017,  Inventory of glacial lakes and identification of potentially dangerous glacial lakes in the Koshi, Gandaki, and Karnali River Basins of Nepal, the Tibet Autonomous Region of China, and India. Research Report, ICIMOD and UNDP, 2020</p><p> </p>

scholarly journals Glaciers, glacial lakes and glacial lake outburst floods in the Mount Everest region, Nepal

2009 ◽  
Vol 50 (53) ◽  
pp. 81-86 ◽  
Author(s):  
Samjwal Ratna Bajracharya ◽  
Pradeep Mool
Keyword(s):  
Average Rate ◽  
Glacial Lake ◽  
High Mountain ◽  
Glacial Lakes ◽  
Mount Everest ◽  
The Past ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Himalayan Glaciers ◽  
Recent Climate

AbstractRecent climate changes have had a significant impact on the high-mountain glacial environment. Rapid melting of glaciers has resulted in the formation and expansion of moraine-dammed lakes, creating a potential danger from glacial lake outburst floods (GLOFs). Most lakes have formed during the second half of the 20th century. Glaciers in the Mount Everest (Sagamartha) region, Nepal, are retreating at an average rate of 10–59 ma–1. From 1976 to 2000, Lumding and Imja Glaciers retreated 42 and 34 ma–1, respectively, a rate that increased to 74 ma–1 for both glaciers from 2000 to 2007. During the past decade, Himalayan glaciers have generally been shrinking and retreating faster while moraine-dammed lakes have been proliferating. Although the number of lakes above 3500 m a.s.l. has decreased, the overall area of moraine-dammed lakes is increasing. Understanding the behaviour of glaciers and glacial lakes is a vital aspect of GLOF disaster management.

scholarly journals Changes in Glaciers and Glacial Lakes and the Identification of Dangerous Glacial Lakes in the Pumqu River Basin, Xizang (Tibet)

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Tao Che ◽  
Lin Xiao ◽  
Yuei-An Liou
Keyword(s):  
River Basin ◽  
Glacial Lake ◽  
Analysis Method ◽  
Glacial Lakes ◽  
Field Surveys ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Increased Risk ◽  
Increase Rate ◽  
Increasing Temperature

Latest satellite images have been utilized to update the inventories of glaciers and glacial lakes in the Pumqu river basin, Xizang (Tibet), in the study. Compared to the inventories in 1970s, the areas of glaciers are reduced by 19.05% while the areas of glacial lakes are increased by 26.76%. The magnitudes of glacier retreat rate and glacial lake increase rate during the period of 2001–2013 are more significant than those for the period of the 1970s–2001. The accelerated changes in areas of the glaciers and glacial lakes, as well as the increasing temperature and rising variability of precipitation, have resulted in an increased risk of glacial lake outburst floods (GLOFs) in the Pumqu river basin. Integrated criteria were established to identify potentially dangerous glacial lakes based on a bibliometric analysis method. It is found, in total, 19 glacial lakes were identified as dangerous. Such finding suggests that there is an immediate need to conduct field surveys not only to validate the findings, but also to acquire information for further use in order to assure the welfare of the humans.

scholarly journals Glacial Lakes in the Nepal Himalaya: Inventory and Decadal Dynamics (1977–2017)

2018 ◽  
Vol 10 (12) ◽  
pp. 1913 ◽  
Author(s):  
Nitesh Khadka ◽  
Guoqing Zhang ◽  
Sudeep Thakuri
Keyword(s):  
Glacial Lake ◽  
Central Himalaya ◽  
Glacial Lakes ◽  
Nepal Himalaya ◽  
Surface Areas ◽  
Proglacial Lakes ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Himalayan Glaciers ◽  
Lake Dynamics

Himalayan glaciers, in general, are shrinking and glacial lakes are evolving and growing rapidly in number and size as a result of climate change. This study presents the latest remote sensing-based inventory (2017) of glacial lakes (size ≥0.0036 km2) across the Nepal Himalaya using optical satellite data. Furthermore, this study traces the decadal glacial lake dynamics from 1977 to 2017 in the Nepal Himalaya. The decadal mapping of glacial lakes (both glacial-fed and nonglacial-fed) across the Nepal Himalaya reveals an increase in the number and area of lakes from 1977 to 2017, with 606 (55.53 ± 16.52 km2), 1137 (64.56 ± 11.64 km2), 1228 (68.87 ± 12.18 km2), 1489 (74.2 ± 14.22 km2), and 1541 (80.95 ± 15.25 km2) glacial lakes being mapped in 1977, 1987, 1997, 2007, and 2017, respectively. Glacial lakes show heterogeneous rates of expansion in different river basins and elevation zones of Nepal, with apparent decadal emergences and disappearances. Overall, the glacial lakes exhibited ~25% expansion of surface areas from 1987 to 2017. For the period from 1987 to 2017, proglacial lakes with ice contact, among others, exhibited the highest incremental changes in terms of number (181%) and surface area (82%). The continuous amplified mass loss of glaciers, as reported in Central Himalaya, is expected to accompany glacial lake expansion in the future, increasing the risk of glacial lake outburst floods (GLOFs). We emphasize that the rapidly increasing glacial lakes in the Nepal Himalaya can pose potential GLOF threats to downstream population and infrastructure.

scholarly journals Glacial Lake Outburst Floods Simulation in the Yi’ong Zangbo River Basin Based on One-Dimensional Hydrodynamic Model

2021 ◽  
Author(s):  
Qi Wang ◽  
Hongyu Duan ◽  
Na Liu ◽  
Zhishui Du ◽  
Pan Wang ◽  
...  
Keyword(s):  
River Basin ◽  
Hydrodynamic Model ◽  
Peak Discharge ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Potential Threat ◽  
One Dimensional ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
The One

Abstract Glacial lake outburst floods (GLOFs) are a serious potential threat to the safety of life and property in downstream areas. In this study, moraine-dammed glacial lakes in the Yi’ong Zangbo River basin were recognized based on Landsat ETM+/TM/OLI images in 2000 and 2019. And the GLOFs for the Jionglaco, the largest glacial lake in this basin, was simulated using the one-dimensional hydrodynamic model. The results show that the total number and area of moraine-dammed glacial lakes in this basin increased by 10 (10.52%) and 5.49 km2 (48.24%) from 2000 to 2019, in which the area of the Jionglaco increased by 3.22 km2. The peak discharge at the breach outlet for five scenarios with different combinations of breach width (80 m and 120 m), depth (2.5 m and 5 m) and flood time (1.5 h and 3 h) are 489 m3/s, 1327.43 m3/s, 444.32 m3/s, 617.47 m3/s and 1570.61 m3/s. With the addition of baseflow in river, the peak discharge at bridge site 15 138.93 km from Jionglaco are 1040.89 m3/s, 1724.00 m3/s, 1024.85 m3/s, 1162.25 m3/s and 1990.52 m3/s. The combination of baseflow in river and the GLOFs discharge results in the increasing peak discharge in the further downstream region. However, the arrival of peak discharge in downstream areas is delayed, which increases the chances of people escaping. This study aims to provide some references for the prevention of GLOFs in this region.

Debris Flows Resulting From Glacial-Lake Outburst Floods in Tibet, China

2010 ◽  
Vol 31 (6) ◽  
pp. 508-527 ◽  
Author(s):  
Peng Cui ◽  
Chao Dang ◽  
Zunlan Cheng ◽  
Kevin M. Scott
Keyword(s):  
Debris Flows ◽  
Glacial Lake ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods
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