To improve our knowledge of glacier change in the Tanggula Mountains located in the northeast of the Tibetan Plateau,we delineated outlines of the glaciers in 1991 and 2015 using Landsat TM/OLI images and compared the...To improve our knowledge of glacier change in the Tanggula Mountains located in the northeast of the Tibetan Plateau,we delineated outlines of the glaciers in 1991 and 2015 using Landsat TM/OLI images and compared them with the reported glacier data in the First Chinese Glacier Inventory in 1969 and the Second Chinese Glacier Inventory in 2007.These comparisons showed that the glacier area and ice volume decreased by 524.8 km2 and 37 km3,respectively.The majority of the glacier area loss was concentrated in the area class of 1-5 km2,between 5300 m and 5500 m in elevation,on north and east facing slopes and in the Dam Qu River basin.These glacier changes exhibited spatial and temporal differences.The glacier retreat rate gradually increased from 1969 to 2015,and the rate in the east was higher than that in the west.From 1969 to 2015,the warming rate in the Tanggula Mountains was 0.38°C/10a,while the annual precipitation only increased by 0.4%.The slight increase in the amount of precipitation made a limited contribution to glacier change,while the change in temperature led to noticeable shrinkage of the glaciers.Contrary to the retreat or stagnation of most glaciers in the study area,there were 10 glaciers that experienced clear advance in 1986-2015 with noticeable increases in both area and length.Whether or not these 10 glaciers are surge glaciers requires further study.展开更多
Glaciers in the eastern Pamir are important for water resources and the social and economic development of the region.In the last 50 years,these glaciers have shrunk and lost ice mass due to climate change.In order to...Glaciers in the eastern Pamir are important for water resources and the social and economic development of the region.In the last 50 years,these glaciers have shrunk and lost ice mass due to climate change.In order to understand recent glacier dynamics in the region,a new inventory was compiled from Landsat TM/ETM+ images acquired in2009,free of clouds and with minimal snow cover on the glacierized mountains.The first glacier inventory of the area was also updated by digitizing glacier outlines from topographical maps that had been modified and verified using aerial photographs.Total glacier area decreased by 10.8%±1.1%,mainly attributed to an increase in air temperature,although precipitation,glacier size and topographic features also combined to affect the general shrinkage of the glaciers.The 19.3–21.4 km^3 estimated glacier mass loss has contributed to an increase in river runoff and water resources.展开更多
Mass loss of glaciers in the Chinese Altai was detected using geodetic methods based on topographical maps(1959), the Shuttle Radar Topography Mission(SRTM) Digital Elevation Model(DEM)(2000), and the Advanced Space-b...Mass loss of glaciers in the Chinese Altai was detected using geodetic methods based on topographical maps(1959), the Shuttle Radar Topography Mission(SRTM) Digital Elevation Model(DEM)(2000), and the Advanced Space-borne Thermal Emission and Reflection Radiometer(ASTER) stereo images(2008). The results indicate that a continued and accelerating shrinkage has occurred in the Chinese Altai Mountains during the last 50 years, with mass deficits of 0.43 ± 0.02 and0.54 ± 0.13 m a-1 water equivalent(w.e.) during the periods 1959-1999 and 1999-2008, respectively.Overall, the Chinese Altai Mountains have lost 7.06 ±0.44 km3 in ice volume(equivalent to-0.43 ± 0.03 m a-1 w.e.) from 1959-2008. The spatial heterogeneity in mass loss was potentially affected by comprehensive changes in temperature and precipitation, and had a substantial correlation withglacier size and topographic settings. Comparison shows that in the Chinese Altai Mountains glaciers have experienced a more rapid mass loss than those in the Tianshan and northwestern Tibetan Plateau(TP), and the mass balance of glaciers was slightly less negative relative to those in the Russian Altai, Himalaya, and southern TP.展开更多
Recent studies on glaciers in the West Kunlun Shan, northwest Tibetan Plateau, have shown that they may be stable or retreating slightly. Here, we assess changes in the mass of the glaciers in the West Kunlun Shan(WKS...Recent studies on glaciers in the West Kunlun Shan, northwest Tibetan Plateau, have shown that they may be stable or retreating slightly. Here, we assess changes in the mass of the glaciers in the West Kunlun Shan(WKS) in an attempt to understand the processes that control their behavior. Glaciers over the recent 40 years(1970-2010) have shrunk 3.4±3.1%in area, based on a comparison between two Chinese glacier inventories. Variations of surface elevations, derived from ICESat-GLAS(Ice, Cloud, and Land Elevation Satellite-Geoscience Laser Altimeter System) elevation products(GLA14 data) using the robust linear-fit method, indicate that the glaciers have been gaining mass at a rate of 0.23±0.24 m w.e./a since 2003. The annual mass budget for the whole WKS range from 2003 to 2009 is estimated to be 0.71±0.62 Gt/a. This gain trend is confirmed by MOD10A1 albedo for the WKS region which shows a descent of the mean snowline altitude from 2003 to 2009.展开更多
Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 197o 1：5o,ooo ...Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 197o 1：5o,ooo scale Chinese Topographic Maps series and the other from Landsat TM/ETM＋ images acquired in 2009. Analyses also included boundaries from 2000 and 2014 Landsat TM/ETM＋ images. A continuing and accelerating shrinkage of glaciers occurred here from 1970 to 2014, with glacier area decreasing by 244.38±29.48 km^2 （27.4%±3.3%） or 0.62%±0.08% a^-1. While this is consistent with a changing climate, local topographic parameters, such as altitude, slope, aspect and debris cover, are also important influences. Recession is manifested by a rise in the elevation of the glacier terminus. The shrinkage of glaciers with NE, N and NW orientations exceeded that of other aspects, and glaciers with SE and S orientations experienced less shrinkage. Changes in the average positive difference of glaciation （PDG） show that the western Nyainqentanglha Range has unfavorable conditions for glacier maintenance which is being exacerbated by a warming climate since 1970.展开更多
Mountain glaciers in China are an important water source for both China and adjoining countries, and therefore their adaptation to glacier change is crucial in relation to maintaining populations. This study aims to i...Mountain glaciers in China are an important water source for both China and adjoining countries, and therefore their adaptation to glacier change is crucial in relation to maintaining populations. This study aims to improve our understanding of glacial vulnerability to climate change to establish adaptation strategies. A glacial numerical model is developed using spatial principle component analysis （SPCA） supported by remote sensing （RS） and geographical information system （GIS） technologies. The model contains nine factors--slope, aspect, hillshade, elevation a.s.l., air temperature, precipitation, glacial area change percentage, glacial type and glacial area, describing topography, climate, and glacier characteristics. The vulnerability of glaciers to climate change is evaluated during the period of 1961-2007 on a regional scale, and in the 2030s and 2050s based on projections of air temperature and precipitation changes under the IPCC RCP6.0 scenario and of glacier change in the 21st century. Glacial vulnerability is graded into five levels： potential, light, medial, heavy, and very heavy, using natural breaks classification （NBC）. The spatial distribution of glacial vulnerability and its temporal changes in the 21st century for the RCP6.0 scenario are analyzed, and the factors influencing vulnerability are discussed. Results show that mountain glaciers in China are very vulnerable to climate change, and 41.2% of glacial areas fall into the levels of heavy and very heavy vulnerability in the period 1961-2007. This is mainly explained by topographical exposure and the high sensitivity of glaciers to climate change. Trends of glacial vulnerability are projected to decline in the 2030s and 2050s, but a declining trend is still high in some regions. In addition to topographical factors, variation in precipitation in the 2030s and 2050s is found to be crucial.展开更多
By using a degree-day based distributed hydrological model, regimes of glacial runoff from the Koxkar glacier during 2007-2011 are simulated, and variations and characteristics of major hydrological components are dis...By using a degree-day based distributed hydrological model, regimes of glacial runoff from the Koxkar glacier during 2007-2011 are simulated, and variations and characteristics of major hydrological components are discussed. The results show that the meltwater runoff contributes 67.4%, of the proglacial discharge, out of which snowmelt, clean ice melting, buried-ice ablation and ice-cliff backwasting account for 22.4%, 21.9%, 17.9% and 5.3% of the total melt runoff, respectively. Rainfall runoff is significant in mid-latitude glacierized mountain areas like Tianshan and Karakorum. In the Koxkar glacier catchment, about 11.5% of stream water is initiated from liquid precipitation. Spatial distributions for each glacial runoff component reveal the importance of climatic gradients, local topography and morphology on glacial runoff generation, and temporal variations of these components is closely related to the annual cycle of catchment meteorology and glacier storage. Four stages are recognized in the seasonal variations of glacier storage, reflecting changes in meltwater yields, meteorological conditions and drainage systems in the annual hydrological cycle.展开更多
There are a large number of glaciers and lakes developed in the Nyang Qu Basin of China. Recent climate change has significant impacted on the high-mountain glacial environment. Rapid melting of glaciers contributes t...There are a large number of glaciers and lakes developed in the Nyang Qu Basin of China. Recent climate change has significant impacted on the high-mountain glacial environment. Rapid melting of glaciers contributes to the formation and expansion of moraine-dammed lakes which increase the probability of glacial lake outburst floods(GLOFs). We calculated a multi-temporal lake inventory based on(1) topographic maps in the 1970 s,(2) satellite imageries from 1990 to 2016,(3) First Chinese Glacier Inventory(FCGI),(4) Glacier Inventory of Southeastern Tibet(GIST) and(5) meteorological data. A total of 880 lakes(>0.01 km^2) have been mapped in 2016, with 318 being glacial lakes(GLs) and 462 non-glacier lakes(NGLs). Most of the lakes were mainly located at 4500 m a.s.l. and the lakes dominated by small lakes(<0.1 km^2) where the change of their actual sizes are more significant compared to the larger ones. Meanwhile, we found that there were 178 newly formed GLs and 51 of them had disappeared between 1970 and 2016. During the same period, there can be identified 157 newly formed GLs and 226 had disappeared. We additionally performed a hazard and risk assessment for GL in 2016 and exposed 14 potentially dangerous morainedammed lakes(PDMDLs), covering a total area of 5.88 km2 in the Nyang Qu Basin. There can be found 4 GLs with very high risk, 3 GLs with high risk, 4 GLs with medium risk and 4 GLs with low risk of GLOFs susceptibility. The findings of this study can be used for the future policy of risk management and also be adapted for promoting water resources management.展开更多
Glaciers in the northern Pakistan are a distinctive source of freshwater for the irrigation,drinking and industrial water supplies of the people living in those regions and downstream. These glaciers are under a direc...Glaciers in the northern Pakistan are a distinctive source of freshwater for the irrigation,drinking and industrial water supplies of the people living in those regions and downstream. These glaciers are under a direct global warming impact as indicated in many previous studies. In this study, we estimated the glacier dynamics in terms of Equilibrium Line Altitude(ELA), mass balance and the snout position variation using remote sensing data between 2001 and 2018. Six glaciers, having area≥ 20 km2 each, situated in the Chitral region(Hindukush Mountains) were investigated in this study. Digital Elevation Model(DEM) and available cloud-free continuous series of Landsat and Sentinel satellite images from minimum snow cover season were used to monitor the variability in the studied glaciers by keeping the status of glaciers in year 2001 as a reference. The annual climatic trends of mean temperature and total precipitation from Chitral weather station were detected using the nonparametric Mann-Kendall’s test. Results revealed a general increase in the ELA, decrease in the glacier mass balance and the retreat of snout position.Average upward shift in the ELA for the entire study area and data period was ~345 ± 93 m at a rate of^13 m.a-1 from the reference year’s position i.e.~4803 m asl. Estimated mean mass balance for the entire study area indicated a decline of-0.106 ± 0.295 m w.e. a-1. Periods of snout retreat and advance in different glaciers were found but the mean value over the entire study area was a retreat of-231 ± 140 m.No obvious relationship was found between the glacier variation trends and the available gauged climatic data possibly due to the presence of debris cover in ablation zones of all the studied glaciers which provides insulation and reduces the immediate climatic effects.展开更多
Drought is a significant natural hazard in Herat Province, Afghanistan. The objective of this study was to explore farmers' perceptions of the drought's prevalence and characteristics, its socioeconomic and en...Drought is a significant natural hazard in Herat Province, Afghanistan. The objective of this study was to explore farmers' perceptions of the drought's prevalence and characteristics, its socioeconomic and environmental impacts, their strategies for coping with and mitigating it, and types of conflicts and resolution mechanisms. A questionnaire was completed by 147 farming households. The results indicate that farmers' perceptions regarding drought are in line with the results obtained using the precipitation data. Even though the respondents have religious belief in interpreting the weather related issues, they also perceived drought as the climatic and environmental factors such as increased temperature, decreased precipitation, and other factors like war, financial weakness, deforestation, over-exploitation of groundwater, lack of electricity supply etc. The results show that drought has had serious economic impacts, including loss of employment and reduction in crop yield and livestock production, which have reduced farmers' livelihood options and weakened their financial situation. Social impacts have included migration, a sense of hopelessness and loss, conflicts over water, health problems, impacts on the schooling of children, malnutrition, and limits to food options. Significant environmental impacts such as an increase in temperature, pasture and forest degradation, deterioration of water quality, damage to fish and wildlife habitats, and groundwater depletion were also reported. Farmers used local techniques to adapt to drought and lessen its effects. Farmers perceived irrigation water to be a major source of conflict. Local elders, water-user associations, and formal courts were reported to be the most successful conflict resolution methods. It is expected that the results of this study will support policy makers within government and development agencies in Afghanistan to develop future drought adaptation policies.展开更多
The article Spatio-temporal changes in the six major glaciers of the Chitral River basin(Hindukush Region of Pakistan)between 2001 and 2018,written by Jawaria GUL,Sher MUHAMMAD,LIU Shi-yin,Siddique ULLAH,Shakeel AHMAD...The article Spatio-temporal changes in the six major glaciers of the Chitral River basin(Hindukush Region of Pakistan)between 2001 and 2018,written by Jawaria GUL,Sher MUHAMMAD,LIU Shi-yin,Siddique ULLAH,Shakeel AHMAD,Huma HAYAT and Adnan Ahmad TAHIR,was originally published Online First without Open Access.After publication in volume 17,issue 3,page 572-587,the author decided to opt for Open Choice and to make the article an Open Access publication.Therefore,the copyright of the article has been changed to C The Author(s)2020 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License(http://creativecommons.org/licenses/by/4.0/),which permits use,duplication,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons license,and indicate if changes were made.The original version of this article has been revised due to a retrospective Open Access order.展开更多
基金supported by the National Natural Science Foundation of China(No.41861013)Youth Scholar Scientific Capability Promoting Project of Northwest Normal University(No.NWNU-LKQN-14-4)and(No.DD20190515)the Comprehensive Remote Sensing Survey of Glacier Changes and Glacial Lake Outburst Disasters in the Tibetan Plateau Project of China Geological Survey(No.121201203000160012)
文摘To improve our knowledge of glacier change in the Tanggula Mountains located in the northeast of the Tibetan Plateau,we delineated outlines of the glaciers in 1991 and 2015 using Landsat TM/OLI images and compared them with the reported glacier data in the First Chinese Glacier Inventory in 1969 and the Second Chinese Glacier Inventory in 2007.These comparisons showed that the glacier area and ice volume decreased by 524.8 km2 and 37 km3,respectively.The majority of the glacier area loss was concentrated in the area class of 1-5 km2,between 5300 m and 5500 m in elevation,on north and east facing slopes and in the Dam Qu River basin.These glacier changes exhibited spatial and temporal differences.The glacier retreat rate gradually increased from 1969 to 2015,and the rate in the east was higher than that in the west.From 1969 to 2015,the warming rate in the Tanggula Mountains was 0.38°C/10a,while the annual precipitation only increased by 0.4%.The slight increase in the amount of precipitation made a limited contribution to glacier change,while the change in temperature led to noticeable shrinkage of the glaciers.Contrary to the retreat or stagnation of most glaciers in the study area,there were 10 glaciers that experienced clear advance in 1986-2015 with noticeable increases in both area and length.Whether or not these 10 glaciers are surge glaciers requires further study.
基金supported by the Chinese Academy of Sciences (Grant No.KZZD-EW-12-1)the National Natural Science Foundation (Grant No.41190084)+3 种基金the Ministry of Science and Technology of China (MOST) (Grant Nos.2013FY111400,2010DFA92720-23)an immediate past project from the MOST (Grant No.2006FY110200)provided by "Investigation on glacier resources and their change in China" (Grant No.2006FY110200)"Glacier change monitoring and its impact assessment research in west China" (Grant No.kzcx2-yw-301)
文摘Glaciers in the eastern Pamir are important for water resources and the social and economic development of the region.In the last 50 years,these glaciers have shrunk and lost ice mass due to climate change.In order to understand recent glacier dynamics in the region,a new inventory was compiled from Landsat TM/ETM+ images acquired in2009,free of clouds and with minimal snow cover on the glacierized mountains.The first glacier inventory of the area was also updated by digitizing glacier outlines from topographical maps that had been modified and verified using aerial photographs.Total glacier area decreased by 10.8%±1.1%,mainly attributed to an increase in air temperature,although precipitation,glacier size and topographic features also combined to affect the general shrinkage of the glaciers.The 19.3–21.4 km^3 estimated glacier mass loss has contributed to an increase in river runoff and water resources.
基金supported by the Ministry of Science and Technology of China (MOST) (Grant No. 2013FY111400)the National Natural ScienceFoundation of China (NSFC) (Grant No. 41190084)+4 种基金the Chinese Academy of Sciences (CAS) (Grant No. XDA05090302)the State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute (SKLCS, CAREERI), CAS (Grant No. SKLCS2012-09)the NSFC (Grant No.41471067)provided by "Investigation on glacier resources and their change in China" (Grant No. 2006FY110200)"Glacier change monitoring and its impact assessment research in west China" (Grant No. kzcx2-yw-301)
文摘Mass loss of glaciers in the Chinese Altai was detected using geodetic methods based on topographical maps(1959), the Shuttle Radar Topography Mission(SRTM) Digital Elevation Model(DEM)(2000), and the Advanced Space-borne Thermal Emission and Reflection Radiometer(ASTER) stereo images(2008). The results indicate that a continued and accelerating shrinkage has occurred in the Chinese Altai Mountains during the last 50 years, with mass deficits of 0.43 ± 0.02 and0.54 ± 0.13 m a-1 water equivalent(w.e.) during the periods 1959-1999 and 1999-2008, respectively.Overall, the Chinese Altai Mountains have lost 7.06 ±0.44 km3 in ice volume(equivalent to-0.43 ± 0.03 m a-1 w.e.) from 1959-2008. The spatial heterogeneity in mass loss was potentially affected by comprehensive changes in temperature and precipitation, and had a substantial correlation withglacier size and topographic settings. Comparison shows that in the Chinese Altai Mountains glaciers have experienced a more rapid mass loss than those in the Tianshan and northwestern Tibetan Plateau(TP), and the mass balance of glaciers was slightly less negative relative to those in the Russian Altai, Himalaya, and southern TP.
基金supported by a National Science Foundation of China major project (Grant No. 41190084) funded by the National Natural Science Foundation of Chinathe National Key Technology R&D Program (Grant No. 2012BAC19B07)+2 种基金the International S&T Cooperation Program of the Ministry of Science and Technology of China (Grant No. 2010DFA92720-23)provided by the MOST (Grant No. 2006FY110200)CAS projects (Grant No. KZCX2-YW-301)
文摘Recent studies on glaciers in the West Kunlun Shan, northwest Tibetan Plateau, have shown that they may be stable or retreating slightly. Here, we assess changes in the mass of the glaciers in the West Kunlun Shan(WKS) in an attempt to understand the processes that control their behavior. Glaciers over the recent 40 years(1970-2010) have shrunk 3.4±3.1%in area, based on a comparison between two Chinese glacier inventories. Variations of surface elevations, derived from ICESat-GLAS(Ice, Cloud, and Land Elevation Satellite-Geoscience Laser Altimeter System) elevation products(GLA14 data) using the robust linear-fit method, indicate that the glaciers have been gaining mass at a rate of 0.23±0.24 m w.e./a since 2003. The annual mass budget for the whole WKS range from 2003 to 2009 is estimated to be 0.71±0.62 Gt/a. This gain trend is confirmed by MOD10A1 albedo for the WKS region which shows a descent of the mean snowline altitude from 2003 to 2009.
基金supported by the fundamental program from the Ministry of Science and Technology of China(MOST)(Grant No.2013FY111400)the National Natural Science Foundation of China(Grant No.41190084)+1 种基金the MOST Technology Oriented Project(Grant No.2012BAC19B07)The second Chinese Glacier Inventory was a product of the previous MOST Project(Grant No.2006FY110200)
文摘Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 197o 1：5o,ooo scale Chinese Topographic Maps series and the other from Landsat TM/ETM＋ images acquired in 2009. Analyses also included boundaries from 2000 and 2014 Landsat TM/ETM＋ images. A continuing and accelerating shrinkage of glaciers occurred here from 1970 to 2014, with glacier area decreasing by 244.38±29.48 km^2 （27.4%±3.3%） or 0.62%±0.08% a^-1. While this is consistent with a changing climate, local topographic parameters, such as altitude, slope, aspect and debris cover, are also important influences. Recession is manifested by a rise in the elevation of the glacier terminus. The shrinkage of glaciers with NE, N and NW orientations exceeded that of other aspects, and glaciers with SE and S orientations experienced less shrinkage. Changes in the average positive difference of glaciation （PDG） show that the western Nyainqentanglha Range has unfavorable conditions for glacier maintenance which is being exacerbated by a warming climate since 1970.
基金supported by grants from the National Basic Research Program of China (2013CBA01808)the National Natural Science Foundation of China (41271088)
文摘Mountain glaciers in China are an important water source for both China and adjoining countries, and therefore their adaptation to glacier change is crucial in relation to maintaining populations. This study aims to improve our understanding of glacial vulnerability to climate change to establish adaptation strategies. A glacial numerical model is developed using spatial principle component analysis （SPCA） supported by remote sensing （RS） and geographical information system （GIS） technologies. The model contains nine factors--slope, aspect, hillshade, elevation a.s.l., air temperature, precipitation, glacial area change percentage, glacial type and glacial area, describing topography, climate, and glacier characteristics. The vulnerability of glaciers to climate change is evaluated during the period of 1961-2007 on a regional scale, and in the 2030s and 2050s based on projections of air temperature and precipitation changes under the IPCC RCP6.0 scenario and of glacier change in the 21st century. Glacial vulnerability is graded into five levels： potential, light, medial, heavy, and very heavy, using natural breaks classification （NBC）. The spatial distribution of glacial vulnerability and its temporal changes in the 21st century for the RCP6.0 scenario are analyzed, and the factors influencing vulnerability are discussed. Results show that mountain glaciers in China are very vulnerable to climate change, and 41.2% of glacial areas fall into the levels of heavy and very heavy vulnerability in the period 1961-2007. This is mainly explained by topographical exposure and the high sensitivity of glaciers to climate change. Trends of glacial vulnerability are projected to decline in the 2030s and 2050s, but a declining trend is still high in some regions. In addition to topographical factors, variation in precipitation in the 2030s and 2050s is found to be crucial.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences under Grant No. KZCX2-YW-GJ04National Nature Science Foundation of China (NSFC) under Grant Nos. 41130641 and 41271078
文摘By using a degree-day based distributed hydrological model, regimes of glacial runoff from the Koxkar glacier during 2007-2011 are simulated, and variations and characteristics of major hydrological components are discussed. The results show that the meltwater runoff contributes 67.4%, of the proglacial discharge, out of which snowmelt, clean ice melting, buried-ice ablation and ice-cliff backwasting account for 22.4%, 21.9%, 17.9% and 5.3% of the total melt runoff, respectively. Rainfall runoff is significant in mid-latitude glacierized mountain areas like Tianshan and Karakorum. In the Koxkar glacier catchment, about 11.5% of stream water is initiated from liquid precipitation. Spatial distributions for each glacial runoff component reveal the importance of climatic gradients, local topography and morphology on glacial runoff generation, and temporal variations of these components is closely related to the annual cycle of catchment meteorology and glacier storage. Four stages are recognized in the seasonal variations of glacier storage, reflecting changes in meltwater yields, meteorological conditions and drainage systems in the annual hydrological cycle.
基金the National Natural Science Foundation of China(No.41761144075,No.41861013)Yunnan University(YJRC3201702)National Natural Science Foundation of China Youth Fund Project(No.41801052)。
文摘There are a large number of glaciers and lakes developed in the Nyang Qu Basin of China. Recent climate change has significant impacted on the high-mountain glacial environment. Rapid melting of glaciers contributes to the formation and expansion of moraine-dammed lakes which increase the probability of glacial lake outburst floods(GLOFs). We calculated a multi-temporal lake inventory based on(1) topographic maps in the 1970 s,(2) satellite imageries from 1990 to 2016,(3) First Chinese Glacier Inventory(FCGI),(4) Glacier Inventory of Southeastern Tibet(GIST) and(5) meteorological data. A total of 880 lakes(>0.01 km^2) have been mapped in 2016, with 318 being glacial lakes(GLs) and 462 non-glacier lakes(NGLs). Most of the lakes were mainly located at 4500 m a.s.l. and the lakes dominated by small lakes(<0.1 km^2) where the change of their actual sizes are more significant compared to the larger ones. Meanwhile, we found that there were 178 newly formed GLs and 51 of them had disappeared between 1970 and 2016. During the same period, there can be identified 157 newly formed GLs and 226 had disappeared. We additionally performed a hazard and risk assessment for GL in 2016 and exposed 14 potentially dangerous morainedammed lakes(PDMDLs), covering a total area of 5.88 km2 in the Nyang Qu Basin. There can be found 4 GLs with very high risk, 3 GLs with high risk, 4 GLs with medium risk and 4 GLs with low risk of GLOFs susceptibility. The findings of this study can be used for the future policy of risk management and also be adapted for promoting water resources management.
基金Financial support for this research work by the National Natural Science Foundation of China(NSFC)and ICIMOD(Grant no.41761144075)is highly acknowledged。
文摘Glaciers in the northern Pakistan are a distinctive source of freshwater for the irrigation,drinking and industrial water supplies of the people living in those regions and downstream. These glaciers are under a direct global warming impact as indicated in many previous studies. In this study, we estimated the glacier dynamics in terms of Equilibrium Line Altitude(ELA), mass balance and the snout position variation using remote sensing data between 2001 and 2018. Six glaciers, having area≥ 20 km2 each, situated in the Chitral region(Hindukush Mountains) were investigated in this study. Digital Elevation Model(DEM) and available cloud-free continuous series of Landsat and Sentinel satellite images from minimum snow cover season were used to monitor the variability in the studied glaciers by keeping the status of glaciers in year 2001 as a reference. The annual climatic trends of mean temperature and total precipitation from Chitral weather station were detected using the nonparametric Mann-Kendall’s test. Results revealed a general increase in the ELA, decrease in the glacier mass balance and the retreat of snout position.Average upward shift in the ELA for the entire study area and data period was ~345 ± 93 m at a rate of^13 m.a-1 from the reference year’s position i.e.~4803 m asl. Estimated mean mass balance for the entire study area indicated a decline of-0.106 ± 0.295 m w.e. a-1. Periods of snout retreat and advance in different glaciers were found but the mean value over the entire study area was a retreat of-231 ± 140 m.No obvious relationship was found between the glacier variation trends and the available gauged climatic data possibly due to the presence of debris cover in ablation zones of all the studied glaciers which provides insulation and reduces the immediate climatic effects.
基金The financial support provided by the Kasetsart University
文摘Drought is a significant natural hazard in Herat Province, Afghanistan. The objective of this study was to explore farmers' perceptions of the drought's prevalence and characteristics, its socioeconomic and environmental impacts, their strategies for coping with and mitigating it, and types of conflicts and resolution mechanisms. A questionnaire was completed by 147 farming households. The results indicate that farmers' perceptions regarding drought are in line with the results obtained using the precipitation data. Even though the respondents have religious belief in interpreting the weather related issues, they also perceived drought as the climatic and environmental factors such as increased temperature, decreased precipitation, and other factors like war, financial weakness, deforestation, over-exploitation of groundwater, lack of electricity supply etc. The results show that drought has had serious economic impacts, including loss of employment and reduction in crop yield and livestock production, which have reduced farmers' livelihood options and weakened their financial situation. Social impacts have included migration, a sense of hopelessness and loss, conflicts over water, health problems, impacts on the schooling of children, malnutrition, and limits to food options. Significant environmental impacts such as an increase in temperature, pasture and forest degradation, deterioration of water quality, damage to fish and wildlife habitats, and groundwater depletion were also reported. Farmers used local techniques to adapt to drought and lessen its effects. Farmers perceived irrigation water to be a major source of conflict. Local elders, water-user associations, and formal courts were reported to be the most successful conflict resolution methods. It is expected that the results of this study will support policy makers within government and development agencies in Afghanistan to develop future drought adaptation policies.
文摘The article Spatio-temporal changes in the six major glaciers of the Chitral River basin(Hindukush Region of Pakistan)between 2001 and 2018,written by Jawaria GUL,Sher MUHAMMAD,LIU Shi-yin,Siddique ULLAH,Shakeel AHMAD,Huma HAYAT and Adnan Ahmad TAHIR,was originally published Online First without Open Access.After publication in volume 17,issue 3,page 572-587,the author decided to opt for Open Choice and to make the article an Open Access publication.Therefore,the copyright of the article has been changed to C The Author(s)2020 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License(http://creativecommons.org/licenses/by/4.0/),which permits use,duplication,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons license,and indicate if changes were made.The original version of this article has been revised due to a retrospective Open Access order.
