Climate change and rising temperatures are accelerating the rate of deglaciation in the Hindu Kush Karakoram Himalaya(HKH)ranges,leading to the formation of new glacial lakes and the expansion of existing ones.These l...Climate change and rising temperatures are accelerating the rate of deglaciation in the Hindu Kush Karakoram Himalaya(HKH)ranges,leading to the formation of new glacial lakes and the expansion of existing ones.These lakes are often vulnerable to failure,posing a significant threat to downstream communities and infrastructure.Therefore,a comprehensive assessment of Glacier-Lake Outburst Flood(GLOF)hazards and risk assessment is crucial to evaluate flood runout characteristics and identify settlements and infrastructure that are exposed and vulnerable to floods,aiding in the development and implementation of risk reduction strategies.This study aims to simulate a GLOF event induced by the Shisper glacier lake in northern Pakistan,using the HEC-RAS,and to assess its impact on settlements,infrastructure,and agricultural land.For the hydrometeorological analysis of the GLOF event,topographic data from unmanned aerial vehicles(UAVs),stream profiles,discharge data,Manning's roughness coefficient(n),and land use/land cover(LULC)were analyzed using HEC-RAS and geographic information system(GIS).During the GLOF event on May 7,2022,a maximum water depth of 6.3 m and a maximum velocity of 9.5 m/s were recorded.Based on the runout characteristics of this event,vulnerability and risk assessments have been calculated.The physical,social,and environmental vulnerabilities of the at-risk elements were evaluated using the analytical hierarchy process(AHP)and integrated with the hazard data to develop a risk map.The study identified the areas,infrastructure and settlements susceptible to GLOF hazard to support the development and implementation of targeted and evidence-based mitigation and adaptation strategies.展开更多
Rapid climate warming is leading to a notable increase in glacier recession and the formation of glacial lakes,which are becoming increasingly characteristic of high mountain regions globally.These severe cryospheric ...Rapid climate warming is leading to a notable increase in glacier recession and the formation of glacial lakes,which are becoming increasingly characteristic of high mountain regions globally.These severe cryospheric changes critically affect regional water supply,increase geohazards,and threaten lives and livelihoods.This study records regional glaciers and glacial lake dynamics for the period 1990 to 2024,considers the implications of these changes for glacial lake outburst floods(GLOFs)and assesses the potential future flood hazard.Several remotely sensed and reanalysis datasets from 1990 to 2024 are employed to investigate changes in glacier and lake areas.The results highlight a significant reduction in the Manaslu(-0.72±0.20 km^(2)/a)and adjoining glaciers,which led to an increase in the Birendra glacial lake(0.23±0.04 km^(2)/a).Additionally,surface elevation and ice movement data reveal significant thinning of glaciers in the region,averaging-1.52±0.26 m/a,often associated with avalanches near the glacier terminus and triggering GLOFs.Using an HEC-RAS(Hydrologic Engineering Center’s River Analysis System)model,a total extension of 19.3 km of flow channels was revealed,coupled with potential increases in depth,discharge,and velocity,potentially causing massive damage downstream.Regional hazard intensity assessment indicates that five bridges,31 houses,and 1.2 km^(2)of agricultural land may be flooded,with the more populated areas near Samagaun and Banjam being the most affected.Regional climate condition,including significant rising air temperature(0.02℃/a,p<0.05)and declining precipitation(-0.24 mm/a,p<0.05),during recent decades play a crucial role in glacier dynamics and exhibit a significant spatial relation with increased temperature(R^(2)=0.62,α<0.05).Understanding regional cryospheric dynamics and associated risks is therefore essential in designing adaptive mitigation strategies.展开更多
冰湖作为冰川融水主要储蓄载体,能在一定程度延缓区域冰川淡水资源流失,但也为冰湖溃决洪水(Glacial Lake Outburst Floods,GLOFs)、滑坡、泥石流等山地灾害发生提供了孕灾场所,是众多山地冰川灾害链的重要环节。升温、极端气候变化扰动...冰湖作为冰川融水主要储蓄载体,能在一定程度延缓区域冰川淡水资源流失,但也为冰湖溃决洪水(Glacial Lake Outburst Floods,GLOFs)、滑坡、泥石流等山地灾害发生提供了孕灾场所,是众多山地冰川灾害链的重要环节。升温、极端气候变化扰动下,冰川物质亏损/减薄速率进一步加剧,冰湖形态变化速率加快、GLOFs发生频次与规模有所提升、灾害影响效应愈发显著,对高海拔山地冰川区下游居民生命财产和基础设施安全带来潜在风险。鉴于此,本文以冰湖与GLOFs研究为主题,首先,通过冰湖研究文献计量分析确定了近些年研究热点专题;其次,围绕山地冰川冰湖与GLOFs研究的3个主要方向:冰湖与GLOFs遥感监测、冰湖时空演化与冰川变化分析及未来潜在冰湖探测、冰湖灾害风险评估与GLOFs案例研究,遴选10项重要专题内容,分门别类、系统梳理总结、剖析了国内外研究进展,阐述了当下研究存在不足;最后,针对所选专题结合技术发展趋势与研究热点问题,围绕冰湖形态信息与GLOFs智能提取、冰川-冰(前/面)湖系统演化及其气候变化响应关系、冰湖监测预警与灾害防治内容,对未来研究做了一定展望,以期为山地冰川冰湖灾害管理与适应性规划提供借鉴与参考。展开更多
This study investigates the glacial lake outburst flood(GLOF)hazards in the Tsambagarav mountain range in Western Mongolia,focusing on the Khukhnuruu Valley and its interconnected proglacial lakes.Over the last 30 yea...This study investigates the glacial lake outburst flood(GLOF)hazards in the Tsambagarav mountain range in Western Mongolia,focusing on the Khukhnuruu Valley and its interconnected proglacial lakes.Over the last 30 years,significant glacier retreats,driven by rising temperatures and changing precipitation patterns,have led to the formation and expansion of several proglacial lakes.Fieldwork combined with satellite data and meteorological analysis was used to assess the dynamics of glacier and lake area changes,with particular focus on the flood events of July 2021.The research reveals a substantial reduction in glacier area,particularly in the Khukhnuruu E complex,where glacier area decreased by 19.3%.The study highlights the influence of increasing temperatures and summer precipitation,which have accelerated ice melt,contributing to the expansion and eventual breaching of lakes.Additionally,lake area changes were influenced by the steepness of the terrain,with steeper slopes exacerbating peak discharge during floods.Of the studied seven lakes(Lake 1 to Lake 7),Lake 1 experienced the most dramatic reduction,with a decrease in area by 73.51%and volume by 84.84%,followed by Lake 7.This study underscores the region's vulnerability to climate-induced hazards and stresses the need for a comprehensive early warning system and disaster preparedness measures to mitigate future risks.展开更多
Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is apparent.As a consequence,numero...Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is apparent.As a consequence,numerous region-and nation-wide GLOF assessment studies have been published recently.These studies cover large areas and consider hundreds to thousands of lakes,prioritizing the hazard posed by them.Clearly,certain simplification is required for executing such studies,often resulting in neglecting qualitative characteristics which would need manual assignment.Different lake dam types(e.g.,bedrock-dammed,moraine-dammed)are often not distinguished,despite they control GLOF mechanism(dam overtopping/dam breach)and thus GLOF magnitude.In this study,we explore the potential of easily measurable quantitative characteristics and four ratios to approximate the lake dam type.Our dataset of 851 lakes of the Cordillera Blanca suggests that while variances and means of these characteristics of individual lake types differ significantly(F-test,t-test),value distribution of different geometrical properties can’t be used for the originally proposed purpose along the spectra.The only promising results are obtained for extreme values(selected bins)of the ratios.For instance,the low width to length ratio indicates likely morainedammed lake while the high value of ratio indicating round-shape of the lake indicates increased likelihood of bedrock-dammed lake.Overall,we report a negative result of our experiment since there are negligible differences of relative frequencies in most of the bins along the spectra.展开更多
Global climate change during the twentieth century had a significant impact on the glaciers that resulted in creation of new lakes and expansion of existing ones, and ultimately an increase in the number of glacial la...Global climate change during the twentieth century had a significant impact on the glaciers that resulted in creation of new lakes and expansion of existing ones, and ultimately an increase in the number of glacial lake outburst floods(GLOFs) in the Himalayan region. This study reports variation of the end-moraine dammed lakes in the high altitude Hindukush-Karakoram-Himalaya(HKH) region of Pakistan to evaluate future floods hazard under changing climate in this region. An integrated temporal remote sensing and Geographic information system(GIS) based approach using satellite images of Landsat-7 and 8 was adopted to detect 482 endmoraine dammed lakes out of which 339 lakes(>0.02 km2) were selected for temporal change analysis during the 2001-2013 period. The findings of the study revealed a net expansion in the end-moraine dammed lakes area in the Karakoram(about 7.7%) and in the Himalayas(4.6%), while there was a net shrinkage of about 1.5% in the lakes area in the Hindukush range during this period. The percentage increase in the lakes' area was highest above 4500 m asl in the Hindukush, within 3500-4000 m asl in the Himalayas and below 3500 m asl in the Karakoram range. The overall positive change in the lakes' area appears to prevail in various altitudinal ranges of the region. The heterogeneous areal changes in the endmoraine dammed lakes might be attributed to different climate regimes and glacial hydrodynamics in the three HKH ranges. A periodic monitoring of the glacial lakes and their associated glaciers is essential for developing effective hazard assessment and risk reduction strategies for this high altitude Himalayan region.展开更多
基金the Higher Education Commission of Pakistan for supporting the study through the CRG-CPEC-130 project。
文摘Climate change and rising temperatures are accelerating the rate of deglaciation in the Hindu Kush Karakoram Himalaya(HKH)ranges,leading to the formation of new glacial lakes and the expansion of existing ones.These lakes are often vulnerable to failure,posing a significant threat to downstream communities and infrastructure.Therefore,a comprehensive assessment of Glacier-Lake Outburst Flood(GLOF)hazards and risk assessment is crucial to evaluate flood runout characteristics and identify settlements and infrastructure that are exposed and vulnerable to floods,aiding in the development and implementation of risk reduction strategies.This study aims to simulate a GLOF event induced by the Shisper glacier lake in northern Pakistan,using the HEC-RAS,and to assess its impact on settlements,infrastructure,and agricultural land.For the hydrometeorological analysis of the GLOF event,topographic data from unmanned aerial vehicles(UAVs),stream profiles,discharge data,Manning's roughness coefficient(n),and land use/land cover(LULC)were analyzed using HEC-RAS and geographic information system(GIS).During the GLOF event on May 7,2022,a maximum water depth of 6.3 m and a maximum velocity of 9.5 m/s were recorded.Based on the runout characteristics of this event,vulnerability and risk assessments have been calculated.The physical,social,and environmental vulnerabilities of the at-risk elements were evaluated using the analytical hierarchy process(AHP)and integrated with the hazard data to develop a risk map.The study identified the areas,infrastructure and settlements susceptible to GLOF hazard to support the development and implementation of targeted and evidence-based mitigation and adaptation strategies.
基金supported by the Gansu Provincial Science and Technology Program(22ZD6FA005)the Gansu Postdoctoral Science Foundation(E339880202).
文摘Rapid climate warming is leading to a notable increase in glacier recession and the formation of glacial lakes,which are becoming increasingly characteristic of high mountain regions globally.These severe cryospheric changes critically affect regional water supply,increase geohazards,and threaten lives and livelihoods.This study records regional glaciers and glacial lake dynamics for the period 1990 to 2024,considers the implications of these changes for glacial lake outburst floods(GLOFs)and assesses the potential future flood hazard.Several remotely sensed and reanalysis datasets from 1990 to 2024 are employed to investigate changes in glacier and lake areas.The results highlight a significant reduction in the Manaslu(-0.72±0.20 km^(2)/a)and adjoining glaciers,which led to an increase in the Birendra glacial lake(0.23±0.04 km^(2)/a).Additionally,surface elevation and ice movement data reveal significant thinning of glaciers in the region,averaging-1.52±0.26 m/a,often associated with avalanches near the glacier terminus and triggering GLOFs.Using an HEC-RAS(Hydrologic Engineering Center’s River Analysis System)model,a total extension of 19.3 km of flow channels was revealed,coupled with potential increases in depth,discharge,and velocity,potentially causing massive damage downstream.Regional hazard intensity assessment indicates that five bridges,31 houses,and 1.2 km^(2)of agricultural land may be flooded,with the more populated areas near Samagaun and Banjam being the most affected.Regional climate condition,including significant rising air temperature(0.02℃/a,p<0.05)and declining precipitation(-0.24 mm/a,p<0.05),during recent decades play a crucial role in glacier dynamics and exhibit a significant spatial relation with increased temperature(R^(2)=0.62,α<0.05).Understanding regional cryospheric dynamics and associated risks is therefore essential in designing adaptive mitigation strategies.
文摘冰湖作为冰川融水主要储蓄载体,能在一定程度延缓区域冰川淡水资源流失,但也为冰湖溃决洪水(Glacial Lake Outburst Floods,GLOFs)、滑坡、泥石流等山地灾害发生提供了孕灾场所,是众多山地冰川灾害链的重要环节。升温、极端气候变化扰动下,冰川物质亏损/减薄速率进一步加剧,冰湖形态变化速率加快、GLOFs发生频次与规模有所提升、灾害影响效应愈发显著,对高海拔山地冰川区下游居民生命财产和基础设施安全带来潜在风险。鉴于此,本文以冰湖与GLOFs研究为主题,首先,通过冰湖研究文献计量分析确定了近些年研究热点专题;其次,围绕山地冰川冰湖与GLOFs研究的3个主要方向:冰湖与GLOFs遥感监测、冰湖时空演化与冰川变化分析及未来潜在冰湖探测、冰湖灾害风险评估与GLOFs案例研究,遴选10项重要专题内容,分门别类、系统梳理总结、剖析了国内外研究进展,阐述了当下研究存在不足;最后,针对所选专题结合技术发展趋势与研究热点问题,围绕冰湖形态信息与GLOFs智能提取、冰川-冰(前/面)湖系统演化及其气候变化响应关系、冰湖监测预警与灾害防治内容,对未来研究做了一定展望,以期为山地冰川冰湖灾害管理与适应性规划提供借鉴与参考。
基金funded by the National University of Mongolia under grant agreement P2023(grant number P2023-4578)。
文摘This study investigates the glacial lake outburst flood(GLOF)hazards in the Tsambagarav mountain range in Western Mongolia,focusing on the Khukhnuruu Valley and its interconnected proglacial lakes.Over the last 30 years,significant glacier retreats,driven by rising temperatures and changing precipitation patterns,have led to the formation and expansion of several proglacial lakes.Fieldwork combined with satellite data and meteorological analysis was used to assess the dynamics of glacier and lake area changes,with particular focus on the flood events of July 2021.The research reveals a substantial reduction in glacier area,particularly in the Khukhnuruu E complex,where glacier area decreased by 19.3%.The study highlights the influence of increasing temperatures and summer precipitation,which have accelerated ice melt,contributing to the expansion and eventual breaching of lakes.Additionally,lake area changes were influenced by the steepness of the terrain,with steeper slopes exacerbating peak discharge during floods.Of the studied seven lakes(Lake 1 to Lake 7),Lake 1 experienced the most dramatic reduction,with a decrease in area by 73.51%and volume by 84.84%,followed by Lake 7.This study underscores the region's vulnerability to climate-induced hazards and stresses the need for a comprehensive early warning system and disaster preparedness measures to mitigate future risks.
基金the financial support by the University of Grazpartly supported by the Ministry of Education,Youth and Sports of the Czech Republic within the National Sustainability Programme I(NPU I),grant number LO1415Supporting perspective human resources Programme of the Czech Academy of Sciences,project"Dynamics and spatiotemporal patterns of glacial lakes evolution and their implications for risk management and adaptation in recently deglaciated areas"awarded to AE。
文摘Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is apparent.As a consequence,numerous region-and nation-wide GLOF assessment studies have been published recently.These studies cover large areas and consider hundreds to thousands of lakes,prioritizing the hazard posed by them.Clearly,certain simplification is required for executing such studies,often resulting in neglecting qualitative characteristics which would need manual assignment.Different lake dam types(e.g.,bedrock-dammed,moraine-dammed)are often not distinguished,despite they control GLOF mechanism(dam overtopping/dam breach)and thus GLOF magnitude.In this study,we explore the potential of easily measurable quantitative characteristics and four ratios to approximate the lake dam type.Our dataset of 851 lakes of the Cordillera Blanca suggests that while variances and means of these characteristics of individual lake types differ significantly(F-test,t-test),value distribution of different geometrical properties can’t be used for the originally proposed purpose along the spectra.The only promising results are obtained for extreme values(selected bins)of the ratios.For instance,the low width to length ratio indicates likely morainedammed lake while the high value of ratio indicating round-shape of the lake indicates increased likelihood of bedrock-dammed lake.Overall,we report a negative result of our experiment since there are negligible differences of relative frequencies in most of the bins along the spectra.
基金support of International Centre for Integrated Mountain Development (ICIMOD) and Pakistan Meteorlogical Department (PMD) for undertaking this study
文摘Global climate change during the twentieth century had a significant impact on the glaciers that resulted in creation of new lakes and expansion of existing ones, and ultimately an increase in the number of glacial lake outburst floods(GLOFs) in the Himalayan region. This study reports variation of the end-moraine dammed lakes in the high altitude Hindukush-Karakoram-Himalaya(HKH) region of Pakistan to evaluate future floods hazard under changing climate in this region. An integrated temporal remote sensing and Geographic information system(GIS) based approach using satellite images of Landsat-7 and 8 was adopted to detect 482 endmoraine dammed lakes out of which 339 lakes(>0.02 km2) were selected for temporal change analysis during the 2001-2013 period. The findings of the study revealed a net expansion in the end-moraine dammed lakes area in the Karakoram(about 7.7%) and in the Himalayas(4.6%), while there was a net shrinkage of about 1.5% in the lakes area in the Hindukush range during this period. The percentage increase in the lakes' area was highest above 4500 m asl in the Hindukush, within 3500-4000 m asl in the Himalayas and below 3500 m asl in the Karakoram range. The overall positive change in the lakes' area appears to prevail in various altitudinal ranges of the region. The heterogeneous areal changes in the endmoraine dammed lakes might be attributed to different climate regimes and glacial hydrodynamics in the three HKH ranges. A periodic monitoring of the glacial lakes and their associated glaciers is essential for developing effective hazard assessment and risk reduction strategies for this high altitude Himalayan region.
