scholarly journals Assessing downstream flood impacts due to a potential GLOF from Imja Lake in Nepal

2014 ◽  
Vol 11 (11) ◽  
pp. 13019-13053 ◽  
Author(s):  
M. A. Somos-Valenzuela ◽  
D. C. McKinney ◽  
A. C. Byers ◽  
D. R. Rounce ◽  
C. Portocarrero ◽  
...  
Keyword(s):  
Global Climate ◽  
Glacial Lake ◽  
Flood Impacts ◽  
Impact Reduction ◽  
Outburst Floods ◽  
Increase Risk ◽  
Flood Impact ◽  
Social Environmental ◽  
Downstream Communities ◽  
The Impact

Abstract. Glacial-dominated areas pose unique challenges to downstream communities in adapting to recent and continuing global climate change, including increased threats of glacial lake outburst floods (GLOFs) that can increase risk due to flooding of downstream communities and cause substantial impacts on regional social, environmental and economic systems. The Imja glacial lake in Nepal, with potential to generate a GLOF, was studied using a two-dimensional debris flow inundation model in order to evaluate the effectiveness of proposed measures to reduce possible flooding impacts to downstream communities by lowering the lake level. The results indicate that only minor flood impact reduction is achieved in the downstream community of Dingboche with modest (~3 m) lake lowering. Lowering the lake by 10 m shows a significant reduction in inundated area. However, lowering the lake by 20 m almost eliminates all flood impact at Dingboche. Further downstream at Phakding, the impact of the GLOF is significant and similar reductions in inundation are likely as a result of lake lowering.

scholarly journals Assessing downstream flood impacts due to a potential GLOF from Imja Tsho in Nepal

2015 ◽  
Vol 19 (3) ◽  
pp. 1401-1412 ◽  
Author(s):  
M. A. Somos-Valenzuela ◽  
D. C. McKinney ◽  
A. C. Byers ◽  
D. R. Rounce ◽  
C. Portocarrero ◽  
...  
Keyword(s):  
Global Climate ◽  
Glacial Lake ◽  
Flood Impacts ◽  
Impact Reduction ◽  
Outburst Floods ◽  
Increase Risk ◽  
Flood Impact ◽  
Social Environmental ◽  
Downstream Communities ◽  
The Impact

Abstract. Glacial-dominated areas pose unique challenges to downstream communities in adapting to recent and continuing global climate change, including increased threats of glacial lake outburst floods (GLOFs) that can increase risk due to flooding of downstream communities and cause substantial impacts on regional social, environmental and economic systems. The Imja glacial lake (or Imja Tsho) in Nepal, which has the potential to generate a GLOF, was studied using a two-dimensional debris-flow inundation model in order to evaluate the effectiveness of proposed measures to reduce possible flooding impacts to downstream communities by lowering the lake level. The results indicate that only minor flood impact reduction is achieved in the downstream community of Dingboche with modest (~3 m) lake lowering. Lowering the lake by 10 m shows a significant reduction in inundated area. However, lowering the lake by 20 m almost eliminates all flood impact at Dingboche. Further downstream at Phakding, the impact of the GLOF is significant and similar reductions in inundation are likely as a result of lake lowering.

scholarly journals Evaluation of Glacial Lake Outburst Flood Susceptibility Using Multi-Criteria Assessment Framework in Mahalangur Himalaya

2021 ◽  
Vol 8 ◽  
Author(s):  
Nitesh Khadka ◽  
Xiaoqing Chen ◽  
Yong Nie ◽  
Sudeep Thakuri ◽  
Guoxiong Zheng ◽  
...  
Keyword(s):  
Global Climate ◽  
Rapid Expansion ◽  
Glacial Lake ◽  
Assessment Framework ◽  
Glacial Lakes ◽  
Flood Susceptibility ◽  
Outburst Floods ◽  
Glacial Lake Outburst Flood ◽  
Downstream Communities ◽  
Very High

Ongoing recession of glaciers in the Himalaya in response to global climate change has far-reaching impacts on the formation and expansion of glacial lakes. The subsequent glacial lake outburst floods (GLOFs) are a significant threat to lives and livelihoods as they can cause catastrophic damage up to hundreds of kilometres downstream. Previous studies have reported the rapid expansion of glacial lakes and several notable destructive past GLOF events in the Mahalangur Himalaya, suggesting a necessity of timely and updated GLOF susceptibility assessment. Here, an updated inventory of glacial lakes across the Mahalangur Himalaya is developed based on 10-m Sentinel-2 satellite data from 2018. Additionally, the GLOF susceptibilities of glacial lakes (≥0.045 km2) are evaluated using a multi-criteria-based assessment framework where six key factors are selected and analyzed. Weight for each factor was assigned from the analytical hierarchy process. Glacial lakes are classified into very low, low, medium, high, and very high GLOF susceptibility classes depending upon their susceptibility index based on analysis of three historical GLOF events in the study area. The result shows the existence of 345 glacial lakes (>0.001 km2) with a total area of 18.80 ± 1.35 km2 across the region in 2018. Furthermore, out of the 64 glacial lakes (≥0.045 km2) assessed, seven were identified with very high GLOF susceptibility. We underline that pronounced glacier-lake interaction will likely increase the GLOF susceptibility. Regular monitoring and more detailed fieldworks for these highly susceptible glacial lakes are necessary. This will benefit in early warning and disaster risk reduction of downstream communities.

scholarly journals Flash Flood Impact Assessment in Jeddah City: An Analytic Hierarchy Process Approach

Hydrology ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 10 ◽  
Author(s):  
Umar Lawal Dano
Keyword(s):  
Analytic Hierarchy Process ◽  
Flash Flood ◽  
Productivity Loss ◽  
Flood Hazards ◽  
Analytic Hierarchy ◽  
Flood Impacts ◽  
Impact Reduction ◽  
Flood Impact ◽  
The Government ◽  
Hierarchy Process

Floods are among the most destructive natural hazards that cost lives and disrupt the socioeconomic activities of residents, especially in the rapidly growing cities of developing countries. Jeddah, a coastal city situated in Saudi Arabia, has experienced severe flash flood events in recent years. With intense rainfall, extensive coastal developments, and sensitive ecosystems, the city is susceptible to severe flash flood risks. The objective of this article is to apply an Analytic Hierarchy Process (AHP) model to explore the impacts of flash flood hazards and identify the most effective approaches to reducing the flash flood impacts in Jeddah using expert’s opinions. The study utilizes experts’ judgments and employs the AHP for data analyses and modeling. The results indicated that property loss has the highest probability of occurrence in the events of a flash flood with a priority level of 42%, followed by productivity loss (28%). Injuries and death were rated the least priority of 18% and 12%, respectively. Concerning flood impact reduction alternatives, river management (41%) and early warning system (38%) are the most favorable options. The findings could assist the government to design appropriate measures to safeguard the lives and properties of the residents. The study concludes by underscoring the significance of incorporating experts’ judgments in assessing flash flood impacts.

Reconstruction of Early Holocene jokulhlaups along the Hvita River and Gullfoss waterfall, Iceland

2020 ◽  
Author(s):  
Greta Wells ◽  
Þorsteinn Sæmundsson ◽  
Sheryl Luzzadder-Beach ◽  
Timothy Beach ◽  
Andrew Dugmore
Keyword(s):  
Ice Sheet ◽  
Hydraulic Modeling ◽  
Early Holocene ◽  
Glacial Lake ◽  
Exposure Dating ◽  
Alpine Regions ◽  
Outburst Floods ◽  
Lake Formation ◽  
Geothermal Activity ◽  
Downstream Communities

<p>Glacial lake outburst floods (GLOFs) have occurred across the planet throughout the Quaternary and are a significant geohazard in Arctic and alpine regions today. Iceland experiences more frequent GLOFs—known in Icelandic as jökulhlaups—than nearly anywhere on Earth, yet most research focuses on floods triggered by subglacial volcanic and geothermal activity. However, floods from proglacial lakes may be a better analogue to most global GLOFs.</p><p>As the Icelandic Ice Sheet retreated across Iceland in the Late Pleistocene-Early Holocene, meltwater pooled at ice margins and periodically drained in jökulhlaups. Some of the most catastrophic floods drained from ice-dammed Glacial Lake Kjölur, surging across southwestern Iceland from the interior highlands to the Atlantic Ocean. These floods left extensive geomorphologic evidence along the modern-day course of the Hvítá River, including canyons, scoured bedrock, boulder deposits, and Gullfoss—Iceland’s most famous waterfall. The largest events reached an estimated maximum peak discharge of 300,000 m<sup>3</sup> s<sup>-1</sup>, ranking them among the largest known floods in Iceland and on Earth.</p><p>Yet, all our evidence for the Kjölur jökulhlaups comes from only one publication to date (Tómasson, 1993). My research employs new methods to better constrain flood timing, routing, magnitude, and recurrence interval at this underexplored site. This talk presents new and synthesized jökulhlaup geomorphologic evidence; HEC-RAS hydraulic modeling results of flow magnitude and routing; and ongoing geochronological analyses using cosmogenic nuclide exposure dating and tephrochronology. It also situates these events within Icelandic Ice Sheet deglaciation chronology and environmental change at the Pleistocene-Holocene transition. Finally, it examines the Kjölur floods as an analogue to contemporary ice sheet response, proglacial lake formation, and jökulhlaup processes and landscape evolution in Arctic and alpine regions worldwide, where GLOFs pose an increasing risk to downstream communities due to climate-driven meltwater lake expansion.  </p><p>Citation: Tómasson, H., 1993. Jökulstífluð vötn á Kili og hamfarahlaup í Hvítá í Árnessýslu. Náttúrufræðingurinn 62, 77-98.</p>

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

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

scholarly journals Glacier-Related Hazards Along the International Karakoram Highway: Status and Future Perspectives

2021 ◽  
Vol 9 ◽  
Author(s):  
Yongpeng Gao ◽  
Shiyin Liu ◽  
Miaomiao Qi ◽  
Fuming Xie ◽  
Kunpeng Wu ◽  
...  
Keyword(s):  
River Basin ◽  
Thermal State ◽  
Global Climate ◽  
Glacial Lake ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Drainage Channels ◽  
Karakoram Highway ◽  
Remote Sensing Techniques ◽  
Hunza River

The China–Pakistan international Karakoram Highway passes through the core area of the “Karakoram Anomaly,” whose glaciers have maintained or increased their mass during a period when most glaciers worldwide have receded. We synthesized the literature and used remote-sensing techniques to review the types, distribution, characteristics, causes and frequency of major glacial hazards along the Karakoram Highway. We found that the glacier-related hazards could be divided into direct and indirect hazards, including glacier surges, glacial lake outburst floods, and glacial floods, which are concentrated in East Pamir and the Hunza River Basin. In the past 100 years, hazards from glaciers surges and glacial floods only occurred once and twice, respectively, which appear suddenly, with the hazard-causing process being short-lived and occurring mainly in the summer. Glacial lake outburst floods mainly occur in the spring and summer in the Hunza River Basin. Among these, ice-dammed lakes have the highest frequency of flooding, their formation and outbursts being closely related to the sudden advancement of surge-type glaciers. Under the background of global climate warming, we speculate that the glacier surge cycle may shorten and the frequency of the formation and outbursts in the glacial lakes may increase. In the future, we should combine models and new field observations to simulate, and deepen our understanding of the physical mechanisms of different glacier-related hazards. In particular, on-site monitoring should be carried out, to include the evolution of glaciers subglacial hydrological systems, the thermal state at the base of the glaciers, and the opening and closing of drainage channels at the base of the ice dams.

Impact of LULC Changes on LST in Rajshahi District of Bangladesh: A Remote Sensing Approach

2020 ◽  
Vol 3 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Abdulla Al Kafy ◽  
Abdullah Al-Faisal ◽  
Mohammad Mahmudul Hasan ◽  
Md. Soumik Sikdar ◽  
Mohammad Hasib Hasan Khan ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Temperature ◽  
Land Surface ◽  
Agricultural Land ◽  
Global Climate ◽  
Urban Expansion ◽  
Water Bodies ◽  
Landsat 8 ◽  
Lulc Changes ◽  
The Impact

Urbanization has been contributing more in global climate warming, with more than 50% of the population living in cities. Rapid population growth and change in land use / land cover (LULC) are closely linked. The transformation of LULC due to rapid urban expansion significantly affects the functions of biodiversity and ecosystems, as well as local and regional climates. Improper planning and uncontrolled management of LULC changes profoundly contribute to the rise of urban land surface temperature (LST). This study evaluates the impact of LULC changes on LST for 1997, 2007 and 2017 in the Rajshahi district (Bangladesh) using multi-temporal and multi-spectral Landsat 8 OLI and Landsat 5 TM satellite data sets. The analysis of LULC changes exposed a remarkable increase in the built-up areas and a significant decrease in the vegetation and agricultural land. The built-up area was increased almost double in last 20 years in the study area. The distribution of changes in LST shows that built-up areas recorded the highest temperature followed by bare land, vegetation and agricultural land and water bodies. The LULC-LST profiles also revealed the highest temperature in built-up areas and the lowest temperature in water bodies. In the last 20 years, LST was increased about 13ºC. The study demonstrates decrease in vegetation cover and increase in non-evaporating surfaces with significantly increases the surface temperature in the study area. Remote-sensing techniques were found one of the suitable techniques for rapid analysis of urban expansions and to identify the impact of urbanization on LST.

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