Glaciers are the most important fresh-water resources in arid and semi-arid regions of western China. According to the Second Chinese Glacier Inventory （SCGI）, primarily compiled from Landsat TM/ETM＋ images, the Qi...Glaciers are the most important fresh-water resources in arid and semi-arid regions of western China. According to the Second Chinese Glacier Inventory （SCGI）, primarily compiled from Landsat TM/ETM＋ images, the Qilian Mountains had 2684 glaciers covering an area of 1597.81＋70.30 km2 and an ice volume of -84.48 km3 from 2005 to 2010. While most glaciers are small （85.66% are 〈1.0 km2）, some larger ones （12.74% in the range 1.0-5.0 km2） cover 42.44% of the total glacier area. The Laohugou Glacier No.12 （20.42 km2） located on the north slope of the Daxue Range is the only glacier 〉20 km2 in the Qilian Mountains. Median glacier elevation was 4972.7 m and gradually increased from east to west Glaciers in the Qilian Mountains are distributed in Gansu and Qinghai provinces, which have 1492 glaciers （760.96 km2） and 1192 glaciers （836.85 km2）, respectively. The Shule River basin contains the most glaciers in both area and volume. However, the Heihe River, the second largest inland river in China, has the minimum average glacier area. A comparison of glaciers from the SCGI and revised glacier inventory based on topographic maps and aerial photos taken from 1956 to 1983 indicate that all glaciers have receded, which is consistent with other mountain and plateau areas in western China. In the past half-century, the area and volume of glaciers decreased by 420.81 km2 （-20.88%） and 21.63 km3 （-20.26%）, re- spectively. Glaciers with areas 〈1.0 km2 decreased the most in number and area recession. Due to glacier shrinkage, glaciers below 4000 m completely disappeared. Glacier changes in the Qilian Mountains presented a clear longitudinal zonality, i.e., the glaciers rapidly shrank in the east but slowly in the central-west. The primary cause of glacier recession was warming temperatures, which was slightly mitigated with increased precipitation.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
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
The Heihe River Basin is the second largest inland river basin in the arid regions of Northwest China. Glaciers provide a large proportion of water resources for human production and living. Studies of glacier changes...The Heihe River Basin is the second largest inland river basin in the arid regions of Northwest China. Glaciers provide a large proportion of water resources for human production and living. Studies of glacier changes and their impact on water resources in the arid lands are of vital importance. A joint expedition was carried out in 2010 for investigating glaciers in the Hulugou Basin, which is located in the upper reaches of Heihe River. There- fore, glacier changes in the Hulugou Basin of central Qilian Mountains during the past 50 years were analyzed in this study by comparing topographic maps, satellite images, digital elevation models and field observation data from different periods. Results showed that the total area of the 6 glaciers in the Hulugou Basin decreased by 0.590±0.005 km^2 during the period 1956-2011, corresponding to a loss of 40.7% over the total area in 1956. The average area reduction rate of the 6 glaciers is 0.011 km^2/a. During the past five decades, the glacier shrinkage was accelerated. The changes in glacier ice surface elevation ranged from -15 to 3 m with an average thinning of 10±8 m or an annual decrease of 0.23±0.18 m （0.20±0.15 m/a water equivalent） for the period 1956-2000. The area of Shiyi Glacier in the Hulugou Basin decreased from 0.64 km^2 in 1956 to 0.53 km2 in 2011 with a reduction rate of 17.2%. The Shiyi Glacier had been divided into two separated glaciers because of severe melting. Comparative analysis showed that glacier shrinkage in the Hulugou Basin is more serious than that in the other regions of Qilian Mountains.展开更多
Based on Landsat MSS/TM/OLI remote sensing images,glaciers vector data in the Qaidam Basin were extracted for 1977,2002,and 2018,and their spatial-temporal variations were analyzed.Results show that there were 2,050 g...Based on Landsat MSS/TM/OLI remote sensing images,glaciers vector data in the Qaidam Basin were extracted for 1977,2002,and 2018,and their spatial-temporal variations were analyzed.Results show that there were 2,050 glaciers covering an area of 1,693.54±40.96 km2 and having an ice volume of 108.65±2.43 km^3 in the Qaidam Basin in 2018.Glaciers with areas<1.0 km2 accounted for the largest number,while glaciers with areas of 1.0−5.0 km2 accounted for the most glacierized area.In the past 50 years,the number of glaciers decreased by 177,and the glacier area and volume reduced by 338.08 km2(−8.12 km^2/a)and 19.92 km3(−0.48 km^3/a),respectively.Retreat altitudes of glaciers were concentrated at 4,900−5,600 m,4,700−5,200 m,and 5,000−5,600 m and reduced areas accounted for 95.53%,77.80%,and 69.19%in the Kunlun,Qilian,and Altun mountains,respectively.The area of north-oriented glaciers decreased the most(−125.43 km^2),but the west-and east-oriented glaciers retreated at the fastest rate(i.e.,−27.11%and−27.10%).All glaciers showed a decreasing trend in sub-regions of the Qaidam Basin from 1977 to 2018.The decreasing trend was accelerated gradually from northwest to southeast in the northern part of the basin,while glacier change was the smallest in the middle section and gradually accelerated towards both ends of the basin's southern part.The temperature had continued to rise,and the precipitation had increased slowly in the Qaidam Basin during the past 50 years.The continuous rise in air temperature was the main reason for the retreat of glaciers.展开更多
Maritime-type glaciers in the eastern Nyainqêntanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better under...Maritime-type glaciers in the eastern Nyainqêntanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better understand the variability of glaciers in this region, we used the band ratio threshold（TM3/TM5 for the Landsat TM /ETM＋ and TM4/TM6 for Landsat OLI） to extract glacier outlines in ~1999 and ~2013. After that, we also generated a series of glacier boundaries and monitored glacier variations in the past 40 years with the help of the Chinese Glacier Inventory data（1975） and Landsat TM, ETM＋ and OLI data. The total glacier area decreased by 37.69 ± 2.84% from 1975 to 2013. The annual percentage area change（APAC） was ~1.32% a-1 and ~1.29% a-1 in the periods 1975-1999 and 1999-2013, respectively. According to the lag theory, the reaction time is probably about 10 years and we discuss the variations of temperature and precipitation between 1965 and 2011. Temperature and precipitation increased between 1965 and 2011 at a rate of 0.34°C /10 a and 15.4 mm/10 a, respectively. Extensive meteorological data show that the glacier shrinkage rate over the period may be mainly due to increasing air temperature, while the increasing precipitation partly made up for the mass loss of glacier ice resulting from increasing temperature may also lead to the low APAC between 1999 and 2013. The lag theory suggests that glacier shrinkage may accelerate in the next 10 years. Small glaciers were more sensitive to climate change, and there was a normal distribution between glacier area and elevation. Glaciers shrank in all aspects, and south aspects diminished faster than others.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
Topography plays an important role in determining the glacier changes.However,topography has often been oversimplified in the studies of the glacier changes.No systematic studies have been conducted to evaluate the re...Topography plays an important role in determining the glacier changes.However,topography has often been oversimplified in the studies of the glacier changes.No systematic studies have been conducted to evaluate the relationship between the glacier changes and topographic features.The present study provided a detailed insight into the changes in the two branches(east branch and west branch)of Urumqi Glacier No.1 in the Chinese Tianshan Mountains since 1993 and systematically discussed the effect of topography on the glacier parameters.This study analyzed comprehensive recently observed data(from 1992/1993 to 2018/2019),including mass balance,ice thickness,surface elevation,ice velocity,terminus,and area,and then determined the differences in the changes of the two branches and explored the effect of topography on the glacier changes.We also applied a topographic solar radiation model to analyze the influence of topography on the incoming shortwave radiation(SW_(in))across the entire glacier,focusing on the difference in the SW_(in) between the two branches.The glacier mass balance of the east branch was more negative than that of the west branch from 1992/1993 to 2018/2019,and this was mainly attributed to the lower average altitude of the east branch.Compared with the west branch,the decrease rate of the ice velocity was lower in the east branch owing to its relatively increased slope.The narrow shape of the west branch and its southeast aspect in the earlier period resulted in a larger glacier terminus retreat of the west branch.The spatial variability of the SW_(in) across the glacier surface became much larger as altitude increased.The SW_(in) received by the east branch was slightly larger than that received by the west branch,and the northern aspect could receive more SW_(in),leading to glacier melting.In the future,the difference of the glacier changes between the two branches will continue to exist due to their topographic differences.This work is fundamental to understanding how topographic features affect the glacier changes,and provides information for building different types of relationship between the glacier area and ice volume to promote further studies on the basin-scale glacier classification.展开更多
Glacier area changes in the Qangtang Plateau are analyzed during 1970-2000 using air photos,relevant photogrammetric maps and satellite images based on the multi-temporal grid method.The results indicate that the melt...Glacier area changes in the Qangtang Plateau are analyzed during 1970-2000 using air photos,relevant photogrammetric maps and satellite images based on the multi-temporal grid method.The results indicate that the melting of glaciers accelerated,only a few of glaciers in an advancing state during 1970-2000 in the whole Qangtang Plateau.However,the glaciers seemed still more stable in the study area than in most areas of western China.We estimate that glacier retreat was likely due to air temperature warming during 1970-2000 in the Qangtang Plateau.Furthermore,the functional model of glacier system is applied to study climate sensitivity of glacier area changes,which indicates that glacier lifespan mainly depends on the heating rate,secondly the precipitation,and precipitation increasing can slow down glacier retreat and make glacier lifespan prolonged.展开更多
Automated image classification and visual interpretation of Landsat imagery were used to extract the glacier boundary in the Nujiang-Salween River Basin(NSRB)around the years 1975,2000,and 2020.The spatiotemporal char...Automated image classification and visual interpretation of Landsat imagery were used to extract the glacier boundary in the Nujiang-Salween River Basin(NSRB)around the years 1975,2000,and 2020.The spatiotemporal characteristics of glacier area changes in the NSRB were determined and the reasons for the spatial heterogeneity in glacier area changes were discussed,based on comparative analyses of temperature and precipitation data from meteorological stations around the NSRB.The results indicate that 1)the total glacier area in the NSRB decreased by 477.78 km^(2)(28.17%)at a rate of-0.62%/a in 1975-2020.Most shrinkage occurred at low and mid altitudes,with the most severe occurring at 5290-5540 m,accounting for 40%of the total shrinkage.Considering other river basins in China,the relative glacier area change rate in the NSRB was similar to that for typical inland river basins in northwest China but lower than that for other transboundary river basins in the southeastern Tibetan Plateau.2)These areal changes in the NSRB presented obvious regional differences.The glaciers in the Hengduan Mountains retreated significantly,followed by those in the Nyainqentanglha Mountains,with relatively low shrinkage observed in the Tanggula Mountains.The number of cold and hot spots indicating areal changes increased after 2000,along with their spatial heterogeneity.3)The glacier shrinkage rate over different time intervals was positively correlated with temperature.Thus,spatial heterogeneity of climate change effects could elucidate differences in the glacier area change rate in different regions of the NSRB.The temperature rise was determined as the primary reason for the significant glacial retreat over the past 45 years.As the significant warming trend continues,the glacier area in the NSRB is likely to shrink further.展开更多
Worldwide examination of glacier change is based on detailed observations from only a small number of glaciers.The ground-based detailed individual glacier monitoring is of strong need and extremely important in both ...Worldwide examination of glacier change is based on detailed observations from only a small number of glaciers.The ground-based detailed individual glacier monitoring is of strong need and extremely important in both regional and global scales.A long-term integrated multi-level monitoring has been carried out on Urumqi Glacier No.1(UG1)at the headwaters of the Urumqi River in the eastern Tianshan Mountains of Central Asia since 1959 by the Tianshan Glaciological Station,Chinese Acamedey of Sciences(CAS),and the glaciological datasets promise to be the best in China.The boundaries of all glacier zones moved up,resulting in a shrunk accumulation area.The stratigraphy features of the snowpack on the glacier were found to be significantly altered by climate warming.Mass balances of UG1 show accelerated mass loss since 1960,which were attributed to three mechanisms.The glacier has been contracting at an accelerated rate since 1962,resulting in a total reduction of 0.37 km2 or 19.3%from 1962 to 2018.Glacier runoff measured at the UG1 hydrometeorological station demonstrates a significant increase from 1959 to 2018 with a large interannual fluctuation,which is inversely correlated with the glacier's mass balance.This study analyzes on the changes in glacier zones,mass balance,area and length,and streamflow in the nival glacial catchment over the past 60 years.It provides critical insight into the processes and mechanisms of glacier recession in response to climate change.The results are not only representative of those glaciers in the Tianshan mountains,but also for the continental-type throughout the world.The direct observation data form an essential basis for evaluating mountain glacier changes and the impact of glacier shrinkage on water resources in the interior drainage rivers within the vast arid and semi-arid land in northwestern China as well as Central Asia.展开更多
Under the background of significant climate warming since the 1980s, the glaciers in China＇s monsoonal temperate glacier region respond to the warming intensely. Based on the glaciohydrological observations at some t...Under the background of significant climate warming since the 1980s, the glaciers in China＇s monsoonal temperate glacier region respond to the warming intensely. Based on the glaciohydrological observations at some typical glaciers from Mts. Yulong （玉龙） and Gongga （贡嘎） of Hengduan （横断） Mountains Range in the southeastern Tibetan plateau, the glaciohydrological changes in the temperate glacier region since the 1980s were investigated. First, the glacier terminus exhibited an accelerating retreat. Second, as the glacier area subject to melting has increased and the ablation season has become longer due to the warming, the ablation of glacier enhanced, leading to increasing contribution of meltwater to annual river discharge. Third, surface topography of small temperate glacier may be changed significantly by crevasses and ruptures developed in the accumulation zone and ice collapse events in the ablation zone. The observed results may indicate a signal that the survival of glaciers in China＇s monsoonal temperate glacier region is being threatened by today＇s climate warming.展开更多
The Puruogangri Ice Field(PIF),classified as an ultra-continental glacier,is considered extremely stable.However,several glaciers in this area have recently experienced surge events with significant instability and in...The Puruogangri Ice Field(PIF),classified as an ultra-continental glacier,is considered extremely stable.However,several glaciers in this area have recently experienced surge events with significant instability and information on surge-type glaciers(STGs)in this region remains scarce.In this study,we identified six STGs and reported the observed characteristics of their surging behavior in the region by mapping glacier boundaries,surface flow velocity information,and glacier surface elevation changes using recent Landsat satellite imagery and shuttle radar topography mission(SRTM),TanDEM,and ASTER digital elevation model(AST14DEM)data.These data provide valuable insights into recent glacial processes,flow instability,and rapid glacial movement.During the active phase of the glaciers,all exhibited frontal advances and changes in surface elevation.Owing to limitations in the satellite imagery,flow velocity profiles were only available for glaciers N1(G089071E33998N),NE1(G089128E33943N),and SE3(G089278E33913N)during the active phase.However,these results effectively reflect the velocity variations in both glaciers before,during,and after the surge.Based on the characteristics of the STG,scientific expeditions,and meteorological data,we believe that the surge in PIF was largely influenced by glacier meltwater and changes in subglacial drainage systems.展开更多
Glaciers are highly sensitive to climate change and are undergoing significant changes in mid-latitudes.In this study,we analyzed the spatiotemporal changes of typical glaciers and their responses to climate change in...Glaciers are highly sensitive to climate change and are undergoing significant changes in mid-latitudes.In this study,we analyzed the spatiotemporal changes of typical glaciers and their responses to climate change in the period of 1990-2015 in 4 different mountainous sub-regions in Xinjiang Uygur Autonomous Region of Northwest China:the Bogda Peak and Karlik Mountain sub-regions in the Tianshan Mountains;the Yinsugaiti Glacier sub-region in the Karakorum Mountains;and the Youyi Peak sub-region in the Altay Mountains.The standardized snow cover index(NDSI)and correlation analysis were used to reveal the glacier area changes in the 4 sub-regions from 1990 to 2015.Glacial areas in the Bogda Peak,Karlik Mountain,Yinsugaiti Glacier,and Youyi Peak sub-regions in the period of 1990-2015 decreased by 57.7,369.1,369.1,and 170.4 km^(2),respectively.Analysis of glacier area center of gravity showed that quadrant changes of glacier areas in the 4 sub-regions moved towards the origin.Glacier area on the south aspect of the Karlik Mountain sub-region was larger than that on the north aspect,while glacier areas on the north aspect of the other 3 sub-regions were larger than those on the south aspect.Increased precipitation in the Karlik Mountain sub-region inhibited the retreat of glaciers to a certain extent.However,glacier area changes in the Bogda Peak and Youyi Peak sub-regions were not sensitive to the increased precipitation.On a seasonal time scale,glacier area changes in the Bogda Peak,Karlik Mountain,Yinsugaiti Glacier,and Youyi Peak sub-regions were mainly caused by accumulated temperature in the wet season;on an annual time scale,the correlation coefficient between glacier area and annual average temperature was-0.72 and passed the significance test at P<0.05 level in the Karlik Mountain sub-region.The findings of this study can provide a scientific basis for water resources management in the arid and semi-arid regions of Northwest China in the context of global warming.展开更多
Glaciers were solid reservoirs and important water resources in western China,but they were retreating significantly in context of global warming.Laohugou Glacier No.12 was the largest valley glacier in Qilian Mountai...Glaciers were solid reservoirs and important water resources in western China,but they were retreating significantly in context of global warming.Laohugou Glacier No.12 was the largest valley glacier in Qilian Mountains.In this study,realtime kinematic(RTK)data,topographic map and World View-2 satellite imagery were used to measure changes in terminus,extent and volume of Laohugou Glacier No.12.Results showed that Laohugou Glacier No.12 was shrinking significantly since 1957.From1960 to 2015,the terminus reduction of Laohugou Glacier No.12 was 402.96 m(3.99%)in total,and glacier length decreased to 9.7 km from 10.1 km.Reduction of glacier area and volume were the most obvious.From 1957 to 2015,glacier area and volume decreased by 1.54 km^2(7.03%)and 0.1816 km^3,respectively.Reduction trend of terminus and area was slowing in 1950-1980s,even stable for a period in the mid-1980s,and then accelerated.Ice core analysis result and nearly meteorological station data shown an increasing trend of temperature in 1957-2015,it was a main reason of continuous retreating of Laohugou Glacier No.12.展开更多
Mountain glacier-related hazards occur worldwide in response to increasing glacier instability and human activity intensity in modern glacierized regions.These hazards are characterized by their spatial aggregation an...Mountain glacier-related hazards occur worldwide in response to increasing glacier instability and human activity intensity in modern glacierized regions.These hazards are characterized by their spatial aggregation and temporal repeatability.Comprehensive knowledge about mountain glacier-related hazards is critical for hazard assessment,mitigation,and prevention in the mountain cryosphere and downstream regions.This article systematically schematizes various mountain glacier-related hazards and analyzes their inherent associations with glacier changes.Besides,the processes,manifestations,and mechanisms of each of the glacier-related hazards are summarized.In the future,more extensive and detailed systematic surveys,for example,considering integrated ground−air−space patterns,should be undertaken for typical glacierized regions to enhance existing knowledge of such hazards.The use of coupled numerical models based on multisource data is challenging but will be essential to improve our understanding of the complex chain of processes involved in thermal−hydrogeomorphic glacier-related hazards in the mountain cryosphere.展开更多
Annual mass balance is an important factor that reflects glacier change and glacier meltwater resources.In this study,we analyzed the changes in glacier area,snow line altitude(SLA)and surface elevation in theány...Annual mass balance is an important factor that reflects glacier change and glacier meltwater resources.In this study,we analyzed the changes in glacier area,snow line altitude(SLA)and surface elevation in theányêmaqên Mountain region using multisource remote sensing data.Then,the annual mass balance of two glaciers was reconstructed by using SLA-mass-balance gradient method.The results showed that the glacier area in theányêmaqên Mountains decreased by 29.4 km2from 1985 to 2017.The average SLAs of the Halong Glacier and Yehelong Glacier were approximately 5290 m and 5188 m,respectively.The glacier mass balance for the two glaciers from 1990 to 2020 was-0.71 m w.e.a^(-1) and-0.63 m w.e.a^(-1),respectively.Our results indicate that SLA is an important indicator of glacier changes,and a long sequence of SLAs can more accurately reconstruct the glacier mass balance of the glacier.The mean annual glacial meltwater-fed streamflow is 1.45×10^(7)m^(3) and 1.12×10^(7)m^(3),respectively.Sensitivity analysis indicates that summer air temperature plays a leading role in regard to the influential climatic factors of glacial retreat in theányêmaqên Mountains.This highlights the potential of the methodology for application on reconstructing annual glacier surface mass balance at larger scales without direct measurements.展开更多
In July, 2009, we investigated the Ningchan River Glacier No. 3. A control network was established around the glacier and the expedition used a GPS-RTK to measure glacial area, terminal and surface altitude, and used ...In July, 2009, we investigated the Ningchan River Glacier No. 3. A control network was established around the glacier and the expedition used a GPS-RTK to measure glacial area, terminal and surface altitude, and used an EKKO GPR to measure glacier thickness. We used a topographic map based on 1972 aerial photo, two TM images in 1995, 2009, and GPS-RTK data in 2009, to analyze the change of the Ningchan River Glacier No. 3 since 1972. Through analysis we found this glacier has been seriously shrinking over the past 37 years. The glacier terminal retreated about 6%, the area was reduced about 13.1%, the volume was reduced about 35.3%, and glacier shrinkage is mainly in the form of thinning. Glacier average thickness reduced from 36.8 m in 1972, to 27.4 m in 2009. Meteorological data around the study area shows that this region in recent decades has undergone differential warming which is the main reason for rapid glacier shrinkage.展开更多
The Ili River is a typical transboundary river between China and Kazakhstan,with glaciers within its basin serving as a crucial solid water resource.Recently,we compiled the Chinese Glacier Inventory of Xinjiang in 20...The Ili River is a typical transboundary river between China and Kazakhstan,with glaciers within its basin serving as a crucial solid water resource.Recently,we compiled the Chinese Glacier Inventory of Xinjiang in 2020(CGI-XJ2020)using high-resolution satellite imagery(<2 m),based on visual interpretation.This study presented the state of glaciers in the Ili River Basin in 2020 by utilizing the data from CGI-XJ2020.It quantified glacier changes in 1960s–2020 based on CGI-XJ2020 and revised datasets from the First and Second Chinese Glacier Inventories.The results indicated that in 2020,the Ili River Basin contained 2,177 glaciers,totaling 1,433.19 km^(2)in area.Among them,213 glaciers were covered by 57.43 km^(2)of debris.The total uncertainty in glacier area was 46.43 km^(2),accounting for approximately 3.2%of the total area.Mapped glacier areas varied from 0.003 to 74.67 km^(2),with an average area of 0.66 km^(2)and a median area of 0.15 km^(2).Glaciers<0.5 km^(2)in size dominated in numbers,accounting for 75.1%of the total.Glaciers in the basin have undergone significant retreat during 1960s–2020,with their total area decreasing by 589.38 km^(2)(29.15%).A total of 495 glaciers(with an area of 49.67 km^(2))disappeared.The average annual glacier area retreat rates for 1960s-2007 and 2007–2020 were 10.86 km^(2)/a(0.54%/a)and 9.41 km^(2)/a(0.61%/a),respectively,showing a continued acceleration in glacier shrinkage,despite a slight decrease in absolute retreat rates.展开更多
The Turpan−Hami Basin in Xinjiang is a resource−scarce area where glaciers are important water resources.Based on the data of the Chinese Glacier Inventory of Xinjiang in 2020(CGI-XJ2020),this study analyzed andexplai...The Turpan−Hami Basin in Xinjiang is a resource−scarce area where glaciers are important water resources.Based on the data of the Chinese Glacier Inventory of Xinjiang in 2020(CGI-XJ2020),this study analyzed andexplained the distribution characteristics of glaciers in the Turpan−Hami Basin in 2020.Additionally,by inte-grating the updated First and Second Chinese Glacier Inventories,the study examined changes within the basinfrom 1962 to 2020.It also assessed the specific impact of glacier changes in the Hami region on the runoff of fourtypical basins.The results indicated that in 2020,the Turpan−Hami Basin contained 354 glaciers,covering anarea of 155.82 km^(2)and an estimated ice volume of 5.81 km3.Small glaciers(<0.5 km^(2))were the most numerous,accounting for 78%of the total,while glaciers ranging from 2.0 to 5.0 km^(2)were the largest area,covering39.37 km^(2),which represents 25.3%of the total glacier area.From 1962 to 2020,the glacier area decreased by85.06 km^(2)(35.3%).Between 1962 and 2009,the area decreased by 72.53 km^(2)(30.11%),with an average annualretreat of 1.54 km^(2)/a(0.64%/a).From 2009 to 2020,the area decreased by 12.53 km^(2)(7.44%),and the averageannual retreat slowed to 1.14 km^(2)/a(0.68%/a).These results suggested that while the total glacier area con-tinues to decline,the rate of decrease in absolute terms has slowed,whereas the relative rate of change hasincreased,indicating an accelerating trend in glacier melt.Climate-driven glacier changes have significantly impacted river hydrology and water resources in Hami.In basins without glaciers,runoff has shown a decreasingtrend,suggesting that the positive effect of increased precipitation on runoff may not be sufficient to offset thenegative impact of rising temperatures.In basins with smaller glaciers,the'peak water'for glacier runoff likelyoccurred in the 1980s and 1990s,and water resources are expected to continue deteriorating.In contrast,basinswith larger glaciers have not yet reached a'peak water'and high flow is projected to persist for decades.展开更多
基金National Natural Science Foundation of China,No.41261016,No.41561016National Basic Work Program of MST,No.2013FY111400+2 种基金Postdoctoral Science Foundation of China,No.2015M572619Opening Foundation Projection of State Key Laboratory of Cryosphere Sciences,CAS,No.SKLCS-OP-2016-10Youth Scholar Scientific Capability Promoting Project of Northwest Normal University,No.NWNU-LKQN-14-4
文摘Glaciers are the most important fresh-water resources in arid and semi-arid regions of western China. According to the Second Chinese Glacier Inventory （SCGI）, primarily compiled from Landsat TM/ETM＋ images, the Qilian Mountains had 2684 glaciers covering an area of 1597.81＋70.30 km2 and an ice volume of -84.48 km3 from 2005 to 2010. While most glaciers are small （85.66% are 〈1.0 km2）, some larger ones （12.74% in the range 1.0-5.0 km2） cover 42.44% of the total glacier area. The Laohugou Glacier No.12 （20.42 km2） located on the north slope of the Daxue Range is the only glacier 〉20 km2 in the Qilian Mountains. Median glacier elevation was 4972.7 m and gradually increased from east to west Glaciers in the Qilian Mountains are distributed in Gansu and Qinghai provinces, which have 1492 glaciers （760.96 km2） and 1192 glaciers （836.85 km2）, respectively. The Shule River basin contains the most glaciers in both area and volume. However, the Heihe River, the second largest inland river in China, has the minimum average glacier area. A comparison of glaciers from the SCGI and revised glacier inventory based on topographic maps and aerial photos taken from 1956 to 1983 indicate that all glaciers have receded, which is consistent with other mountain and plateau areas in western China. In the past half-century, the area and volume of glaciers decreased by 420.81 km2 （-20.88%） and 21.63 km3 （-20.26%）, re- spectively. Glaciers with areas 〈1.0 km2 decreased the most in number and area recession. Due to glacier shrinkage, glaciers below 4000 m completely disappeared. Glacier changes in the Qilian Mountains presented a clear longitudinal zonality, i.e., the glaciers rapidly shrank in the east but slowly in the central-west. The primary cause of glacier recession was warming temperatures, which was slightly mitigated with increased precipitation.
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 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funded by the National Basic Research Program of China (2013CBA01801)the National Natural Science Foundation of China (41301069, 41471058)+1 种基金the Funds for Creative Research Groups of China (41121001)the Special Financial Grant from the China Postdoctoral Science Foundation (2014T70948)
文摘The Heihe River Basin is the second largest inland river basin in the arid regions of Northwest China. Glaciers provide a large proportion of water resources for human production and living. Studies of glacier changes and their impact on water resources in the arid lands are of vital importance. A joint expedition was carried out in 2010 for investigating glaciers in the Hulugou Basin, which is located in the upper reaches of Heihe River. There- fore, glacier changes in the Hulugou Basin of central Qilian Mountains during the past 50 years were analyzed in this study by comparing topographic maps, satellite images, digital elevation models and field observation data from different periods. Results showed that the total area of the 6 glaciers in the Hulugou Basin decreased by 0.590±0.005 km^2 during the period 1956-2011, corresponding to a loss of 40.7% over the total area in 1956. The average area reduction rate of the 6 glaciers is 0.011 km^2/a. During the past five decades, the glacier shrinkage was accelerated. The changes in glacier ice surface elevation ranged from -15 to 3 m with an average thinning of 10±8 m or an annual decrease of 0.23±0.18 m （0.20±0.15 m/a water equivalent） for the period 1956-2000. The area of Shiyi Glacier in the Hulugou Basin decreased from 0.64 km^2 in 1956 to 0.53 km2 in 2011 with a reduction rate of 17.2%. The Shiyi Glacier had been divided into two separated glaciers because of severe melting. Comparative analysis showed that glacier shrinkage in the Hulugou Basin is more serious than that in the other regions of Qilian Mountains.
文摘Based on Landsat MSS/TM/OLI remote sensing images,glaciers vector data in the Qaidam Basin were extracted for 1977,2002,and 2018,and their spatial-temporal variations were analyzed.Results show that there were 2,050 glaciers covering an area of 1,693.54±40.96 km2 and having an ice volume of 108.65±2.43 km^3 in the Qaidam Basin in 2018.Glaciers with areas<1.0 km2 accounted for the largest number,while glaciers with areas of 1.0−5.0 km2 accounted for the most glacierized area.In the past 50 years,the number of glaciers decreased by 177,and the glacier area and volume reduced by 338.08 km2(−8.12 km^2/a)and 19.92 km3(−0.48 km^3/a),respectively.Retreat altitudes of glaciers were concentrated at 4,900−5,600 m,4,700−5,200 m,and 5,000−5,600 m and reduced areas accounted for 95.53%,77.80%,and 69.19%in the Kunlun,Qilian,and Altun mountains,respectively.The area of north-oriented glaciers decreased the most(−125.43 km^2),but the west-and east-oriented glaciers retreated at the fastest rate(i.e.,−27.11%and−27.10%).All glaciers showed a decreasing trend in sub-regions of the Qaidam Basin from 1977 to 2018.The decreasing trend was accelerated gradually from northwest to southeast in the northern part of the basin,while glacier change was the smallest in the middle section and gradually accelerated towards both ends of the basin's southern part.The temperature had continued to rise,and the precipitation had increased slowly in the Qaidam Basin during the past 50 years.The continuous rise in air temperature was the main reason for the retreat of glaciers.
基金supported by the National Science Foundation of China (Grant Nos. 41271024, 41411130204)
文摘Maritime-type glaciers in the eastern Nyainqêntanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better understand the variability of glaciers in this region, we used the band ratio threshold（TM3/TM5 for the Landsat TM /ETM＋ and TM4/TM6 for Landsat OLI） to extract glacier outlines in ~1999 and ~2013. After that, we also generated a series of glacier boundaries and monitored glacier variations in the past 40 years with the help of the Chinese Glacier Inventory data（1975） and Landsat TM, ETM＋ and OLI data. The total glacier area decreased by 37.69 ± 2.84% from 1975 to 2013. The annual percentage area change（APAC） was ~1.32% a-1 and ~1.29% a-1 in the periods 1975-1999 and 1999-2013, respectively. According to the lag theory, the reaction time is probably about 10 years and we discuss the variations of temperature and precipitation between 1965 and 2011. Temperature and precipitation increased between 1965 and 2011 at a rate of 0.34°C /10 a and 15.4 mm/10 a, respectively. Extensive meteorological data show that the glacier shrinkage rate over the period may be mainly due to increasing air temperature, while the increasing precipitation partly made up for the mass loss of glacier ice resulting from increasing temperature may also lead to the low APAC between 1999 and 2013. The lag theory suggests that glacier shrinkage may accelerate in the next 10 years. Small glaciers were more sensitive to climate change, and there was a normal distribution between glacier area and elevation. Glaciers shrank in all aspects, and south aspects diminished faster than others.
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.
基金jointly funded by the Third Xinjiang Scientific Expedition Program (2021xjkk0801)the Youth Innovation Promotion Association of Chinese Academy of Sciences (Y2021110)the State Key Laboratory of Cryospheric Science (SKLCS-ZZ-2022)
文摘Topography plays an important role in determining the glacier changes.However,topography has often been oversimplified in the studies of the glacier changes.No systematic studies have been conducted to evaluate the relationship between the glacier changes and topographic features.The present study provided a detailed insight into the changes in the two branches(east branch and west branch)of Urumqi Glacier No.1 in the Chinese Tianshan Mountains since 1993 and systematically discussed the effect of topography on the glacier parameters.This study analyzed comprehensive recently observed data(from 1992/1993 to 2018/2019),including mass balance,ice thickness,surface elevation,ice velocity,terminus,and area,and then determined the differences in the changes of the two branches and explored the effect of topography on the glacier changes.We also applied a topographic solar radiation model to analyze the influence of topography on the incoming shortwave radiation(SW_(in))across the entire glacier,focusing on the difference in the SW_(in) between the two branches.The glacier mass balance of the east branch was more negative than that of the west branch from 1992/1993 to 2018/2019,and this was mainly attributed to the lower average altitude of the east branch.Compared with the west branch,the decrease rate of the ice velocity was lower in the east branch owing to its relatively increased slope.The narrow shape of the west branch and its southeast aspect in the earlier period resulted in a larger glacier terminus retreat of the west branch.The spatial variability of the SW_(in) across the glacier surface became much larger as altitude increased.The SW_(in) received by the east branch was slightly larger than that received by the west branch,and the northern aspect could receive more SW_(in),leading to glacier melting.In the future,the difference of the glacier changes between the two branches will continue to exist due to their topographic differences.This work is fundamental to understanding how topographic features affect the glacier changes,and provides information for building different types of relationship between the glacier area and ice volume to promote further studies on the basin-scale glacier classification.
基金supported by the National Natural Science Foundation of China (Nos.40871043,40801025)the Project of National Scientific Basic Special Fund on the Ministry of Science and Technology of China (No.2006FY110200)the Key Construction Disciplines of Hunan Province (No.40652001)
文摘Glacier area changes in the Qangtang Plateau are analyzed during 1970-2000 using air photos,relevant photogrammetric maps and satellite images based on the multi-temporal grid method.The results indicate that the melting of glaciers accelerated,only a few of glaciers in an advancing state during 1970-2000 in the whole Qangtang Plateau.However,the glaciers seemed still more stable in the study area than in most areas of western China.We estimate that glacier retreat was likely due to air temperature warming during 1970-2000 in the Qangtang Plateau.Furthermore,the functional model of glacier system is applied to study climate sensitivity of glacier area changes,which indicates that glacier lifespan mainly depends on the heating rate,secondly the precipitation,and precipitation increasing can slow down glacier retreat and make glacier lifespan prolonged.
基金National Natural Science Foundation of China,No.42061005,No.41561003Science and Technology Projects of Yunnan Province,No.202101AT070110。
文摘Automated image classification and visual interpretation of Landsat imagery were used to extract the glacier boundary in the Nujiang-Salween River Basin(NSRB)around the years 1975,2000,and 2020.The spatiotemporal characteristics of glacier area changes in the NSRB were determined and the reasons for the spatial heterogeneity in glacier area changes were discussed,based on comparative analyses of temperature and precipitation data from meteorological stations around the NSRB.The results indicate that 1)the total glacier area in the NSRB decreased by 477.78 km^(2)(28.17%)at a rate of-0.62%/a in 1975-2020.Most shrinkage occurred at low and mid altitudes,with the most severe occurring at 5290-5540 m,accounting for 40%of the total shrinkage.Considering other river basins in China,the relative glacier area change rate in the NSRB was similar to that for typical inland river basins in northwest China but lower than that for other transboundary river basins in the southeastern Tibetan Plateau.2)These areal changes in the NSRB presented obvious regional differences.The glaciers in the Hengduan Mountains retreated significantly,followed by those in the Nyainqentanglha Mountains,with relatively low shrinkage observed in the Tanggula Mountains.The number of cold and hot spots indicating areal changes increased after 2000,along with their spatial heterogeneity.3)The glacier shrinkage rate over different time intervals was positively correlated with temperature.Thus,spatial heterogeneity of climate change effects could elucidate differences in the glacier area change rate in different regions of the NSRB.The temperature rise was determined as the primary reason for the significant glacial retreat over the past 45 years.As the significant warming trend continues,the glacier area in the NSRB is likely to shrink further.
基金This research was funded by the National Natural Science Foundation of China(Grant No.41761134093)the Second Tibetan Plateau Scientific Expedition and Research(Grant No.2019QZKK0201)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Class A)(Grant Nos.XDA20060201 and XDA20020102)and the State Key Laboratory of Cryospheric Sciences Open Research Fund(Grant No.SKLCS-ZZ-2020).
文摘Worldwide examination of glacier change is based on detailed observations from only a small number of glaciers.The ground-based detailed individual glacier monitoring is of strong need and extremely important in both regional and global scales.A long-term integrated multi-level monitoring has been carried out on Urumqi Glacier No.1(UG1)at the headwaters of the Urumqi River in the eastern Tianshan Mountains of Central Asia since 1959 by the Tianshan Glaciological Station,Chinese Acamedey of Sciences(CAS),and the glaciological datasets promise to be the best in China.The boundaries of all glacier zones moved up,resulting in a shrunk accumulation area.The stratigraphy features of the snowpack on the glacier were found to be significantly altered by climate warming.Mass balances of UG1 show accelerated mass loss since 1960,which were attributed to three mechanisms.The glacier has been contracting at an accelerated rate since 1962,resulting in a total reduction of 0.37 km2 or 19.3%from 1962 to 2018.Glacier runoff measured at the UG1 hydrometeorological station demonstrates a significant increase from 1959 to 2018 with a large interannual fluctuation,which is inversely correlated with the glacier's mass balance.This study analyzes on the changes in glacier zones,mass balance,area and length,and streamflow in the nival glacial catchment over the past 60 years.It provides critical insight into the processes and mechanisms of glacier recession in response to climate change.The results are not only representative of those glaciers in the Tianshan mountains,but also for the continental-type throughout the world.The direct observation data form an essential basis for evaluating mountain glacier changes and the impact of glacier shrinkage on water resources in the interior drainage rivers within the vast arid and semi-arid land in northwestern China as well as Central Asia.
基金supported by the West Light Foundation of Chinese Academy of Sciences (No.O828A11001)the Orientation Project of Chinese Academy of Sciences (No.KZCXZ-YW-317)China Postdoctoral Science Foundation (Nos.08R214147,20080440641)
文摘Under the background of significant climate warming since the 1980s, the glaciers in China＇s monsoonal temperate glacier region respond to the warming intensely. Based on the glaciohydrological observations at some typical glaciers from Mts. Yulong （玉龙） and Gongga （贡嘎） of Hengduan （横断） Mountains Range in the southeastern Tibetan plateau, the glaciohydrological changes in the temperate glacier region since the 1980s were investigated. First, the glacier terminus exhibited an accelerating retreat. Second, as the glacier area subject to melting has increased and the ablation season has become longer due to the warming, the ablation of glacier enhanced, leading to increasing contribution of meltwater to annual river discharge. Third, surface topography of small temperate glacier may be changed significantly by crevasses and ruptures developed in the accumulation zone and ice collapse events in the ablation zone. The observed results may indicate a signal that the survival of glaciers in China＇s monsoonal temperate glacier region is being threatened by today＇s climate warming.
基金The Second Tibetan Plateau Scientific Expedition and Research Program,No.2019QZKK020102National Natural Science Foundation of China,No.42130516。
文摘The Puruogangri Ice Field(PIF),classified as an ultra-continental glacier,is considered extremely stable.However,several glaciers in this area have recently experienced surge events with significant instability and information on surge-type glaciers(STGs)in this region remains scarce.In this study,we identified six STGs and reported the observed characteristics of their surging behavior in the region by mapping glacier boundaries,surface flow velocity information,and glacier surface elevation changes using recent Landsat satellite imagery and shuttle radar topography mission(SRTM),TanDEM,and ASTER digital elevation model(AST14DEM)data.These data provide valuable insights into recent glacial processes,flow instability,and rapid glacial movement.During the active phase of the glaciers,all exhibited frontal advances and changes in surface elevation.Owing to limitations in the satellite imagery,flow velocity profiles were only available for glaciers N1(G089071E33998N),NE1(G089128E33943N),and SE3(G089278E33913N)during the active phase.However,these results effectively reflect the velocity variations in both glaciers before,during,and after the surge.Based on the characteristics of the STG,scientific expeditions,and meteorological data,we believe that the surge in PIF was largely influenced by glacier meltwater and changes in subglacial drainage systems.
基金sponsored by the National Key Research&Development Program of China(2017YFB0504204)the K.C.Wong Education Foundation(GJTD-2020-14)+1 种基金the International Collaboration Project of the Chinese Academy of Sciences(131965KYSB20200029)the New Water Resources Strategic Research Project in Southern Xinjiang Uygur Autonomous Region,China(403-1005-YBN-FT6I-8)。
文摘Glaciers are highly sensitive to climate change and are undergoing significant changes in mid-latitudes.In this study,we analyzed the spatiotemporal changes of typical glaciers and their responses to climate change in the period of 1990-2015 in 4 different mountainous sub-regions in Xinjiang Uygur Autonomous Region of Northwest China:the Bogda Peak and Karlik Mountain sub-regions in the Tianshan Mountains;the Yinsugaiti Glacier sub-region in the Karakorum Mountains;and the Youyi Peak sub-region in the Altay Mountains.The standardized snow cover index(NDSI)and correlation analysis were used to reveal the glacier area changes in the 4 sub-regions from 1990 to 2015.Glacial areas in the Bogda Peak,Karlik Mountain,Yinsugaiti Glacier,and Youyi Peak sub-regions in the period of 1990-2015 decreased by 57.7,369.1,369.1,and 170.4 km^(2),respectively.Analysis of glacier area center of gravity showed that quadrant changes of glacier areas in the 4 sub-regions moved towards the origin.Glacier area on the south aspect of the Karlik Mountain sub-region was larger than that on the north aspect,while glacier areas on the north aspect of the other 3 sub-regions were larger than those on the south aspect.Increased precipitation in the Karlik Mountain sub-region inhibited the retreat of glaciers to a certain extent.However,glacier area changes in the Bogda Peak and Youyi Peak sub-regions were not sensitive to the increased precipitation.On a seasonal time scale,glacier area changes in the Bogda Peak,Karlik Mountain,Yinsugaiti Glacier,and Youyi Peak sub-regions were mainly caused by accumulated temperature in the wet season;on an annual time scale,the correlation coefficient between glacier area and annual average temperature was-0.72 and passed the significance test at P<0.05 level in the Karlik Mountain sub-region.The findings of this study can provide a scientific basis for water resources management in the arid and semi-arid regions of Northwest China in the context of global warming.
基金supported by the National Foundational Scientific and Technological Work Programs of the Ministry of Science and Technology of China (grant No. 2013FY111400)the Project from the State Key Laboratory of Cryospheric Sciences (grant No. SKLCS-ZZ-2017)the National Key Geographic Conditions Monitoring: The Project of Basic National Geographical Conditions Monitoring in 2015
文摘Glaciers were solid reservoirs and important water resources in western China,but they were retreating significantly in context of global warming.Laohugou Glacier No.12 was the largest valley glacier in Qilian Mountains.In this study,realtime kinematic(RTK)data,topographic map and World View-2 satellite imagery were used to measure changes in terminus,extent and volume of Laohugou Glacier No.12.Results showed that Laohugou Glacier No.12 was shrinking significantly since 1957.From1960 to 2015,the terminus reduction of Laohugou Glacier No.12 was 402.96 m(3.99%)in total,and glacier length decreased to 9.7 km from 10.1 km.Reduction of glacier area and volume were the most obvious.From 1957 to 2015,glacier area and volume decreased by 1.54 km^2(7.03%)and 0.1816 km^3,respectively.Reduction trend of terminus and area was slowing in 1950-1980s,even stable for a period in the mid-1980s,and then accelerated.Ice core analysis result and nearly meteorological station data shown an increasing trend of temperature in 1957-2015,it was a main reason of continuous retreating of Laohugou Glacier No.12.
基金The study was funded by the Ministry of Science and Technology(2018YFE010010002)the National Natural Science Foundation of China(No.41771075 and No.41701061).
文摘Mountain glacier-related hazards occur worldwide in response to increasing glacier instability and human activity intensity in modern glacierized regions.These hazards are characterized by their spatial aggregation and temporal repeatability.Comprehensive knowledge about mountain glacier-related hazards is critical for hazard assessment,mitigation,and prevention in the mountain cryosphere and downstream regions.This article systematically schematizes various mountain glacier-related hazards and analyzes their inherent associations with glacier changes.Besides,the processes,manifestations,and mechanisms of each of the glacier-related hazards are summarized.In the future,more extensive and detailed systematic surveys,for example,considering integrated ground−air−space patterns,should be undertaken for typical glacierized regions to enhance existing knowledge of such hazards.The use of coupled numerical models based on multisource data is challenging but will be essential to improve our understanding of the complex chain of processes involved in thermal−hydrogeomorphic glacier-related hazards in the mountain cryosphere.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,Grant No.2019QZKK0205)the National Natural Science Foundation of China(grant No.42071077,42171148)the Fundamental Research Funds for the Central Universities(lzujbky-2021-sp11)。
文摘Annual mass balance is an important factor that reflects glacier change and glacier meltwater resources.In this study,we analyzed the changes in glacier area,snow line altitude(SLA)and surface elevation in theányêmaqên Mountain region using multisource remote sensing data.Then,the annual mass balance of two glaciers was reconstructed by using SLA-mass-balance gradient method.The results showed that the glacier area in theányêmaqên Mountains decreased by 29.4 km2from 1985 to 2017.The average SLAs of the Halong Glacier and Yehelong Glacier were approximately 5290 m and 5188 m,respectively.The glacier mass balance for the two glaciers from 1990 to 2020 was-0.71 m w.e.a^(-1) and-0.63 m w.e.a^(-1),respectively.Our results indicate that SLA is an important indicator of glacier changes,and a long sequence of SLAs can more accurately reconstruct the glacier mass balance of the glacier.The mean annual glacial meltwater-fed streamflow is 1.45×10^(7)m^(3) and 1.12×10^(7)m^(3),respectively.Sensitivity analysis indicates that summer air temperature plays a leading role in regard to the influential climatic factors of glacial retreat in theányêmaqên Mountains.This highlights the potential of the methodology for application on reconstructing annual glacier surface mass balance at larger scales without direct measurements.
基金supported by the State Natural Science Fund projects(41071046 and 41201067)the project from the State Key Laboratory of Cryospheric Sciences(SKLCS-ZZ-2012-01-05)the Project for Incubation of Specialists in Glaciology and Geocryology of Nation-al Natural Science Foundation of China(J0930003/J0109)
文摘In July, 2009, we investigated the Ningchan River Glacier No. 3. A control network was established around the glacier and the expedition used a GPS-RTK to measure glacial area, terminal and surface altitude, and used an EKKO GPR to measure glacier thickness. We used a topographic map based on 1972 aerial photo, two TM images in 1995, 2009, and GPS-RTK data in 2009, to analyze the change of the Ningchan River Glacier No. 3 since 1972. Through analysis we found this glacier has been seriously shrinking over the past 37 years. The glacier terminal retreated about 6%, the area was reduced about 13.1%, the volume was reduced about 35.3%, and glacier shrinkage is mainly in the form of thinning. Glacier average thickness reduced from 36.8 m in 1972, to 27.4 m in 2009. Meteorological data around the study area shows that this region in recent decades has undergone differential warming which is the main reason for rapid glacier shrinkage.
基金supported by Third Xinjiang Scientific Expedition Program(Grant No.2022xjkk0101)Second Qinghai-Tibet Scientific Expedition Program(Grant No.2019 QZKK0201)+2 种基金Third Xinjiang Sci-entific Expedition Program(Grant No.2021xjkk0401)National Natural Science Foundation of China(Grant No.42301166)National Natural Science Foundation of China(Grant No.42371148)。
文摘The Ili River is a typical transboundary river between China and Kazakhstan,with glaciers within its basin serving as a crucial solid water resource.Recently,we compiled the Chinese Glacier Inventory of Xinjiang in 2020(CGI-XJ2020)using high-resolution satellite imagery(<2 m),based on visual interpretation.This study presented the state of glaciers in the Ili River Basin in 2020 by utilizing the data from CGI-XJ2020.It quantified glacier changes in 1960s–2020 based on CGI-XJ2020 and revised datasets from the First and Second Chinese Glacier Inventories.The results indicated that in 2020,the Ili River Basin contained 2,177 glaciers,totaling 1,433.19 km^(2)in area.Among them,213 glaciers were covered by 57.43 km^(2)of debris.The total uncertainty in glacier area was 46.43 km^(2),accounting for approximately 3.2%of the total area.Mapped glacier areas varied from 0.003 to 74.67 km^(2),with an average area of 0.66 km^(2)and a median area of 0.15 km^(2).Glaciers<0.5 km^(2)in size dominated in numbers,accounting for 75.1%of the total.Glaciers in the basin have undergone significant retreat during 1960s–2020,with their total area decreasing by 589.38 km^(2)(29.15%).A total of 495 glaciers(with an area of 49.67 km^(2))disappeared.The average annual glacier area retreat rates for 1960s-2007 and 2007–2020 were 10.86 km^(2)/a(0.54%/a)and 9.41 km^(2)/a(0.61%/a),respectively,showing a continued acceleration in glacier shrinkage,despite a slight decrease in absolute retreat rates.
基金supported by the Third Xinjiang Scientific Expedition Program(Grant No.2022xjkk0101)Second Qinghai-Tibet Scientific Expedition Program(Grant No.2019QZKK0201)+2 种基金National Natural Science Foundation of China(Grant No.42301166)National Science Foundation of Gansu Province(Grant No.23JRRA658)Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone(XJYS0907-2024-yb-11)
文摘The Turpan−Hami Basin in Xinjiang is a resource−scarce area where glaciers are important water resources.Based on the data of the Chinese Glacier Inventory of Xinjiang in 2020(CGI-XJ2020),this study analyzed andexplained the distribution characteristics of glaciers in the Turpan−Hami Basin in 2020.Additionally,by inte-grating the updated First and Second Chinese Glacier Inventories,the study examined changes within the basinfrom 1962 to 2020.It also assessed the specific impact of glacier changes in the Hami region on the runoff of fourtypical basins.The results indicated that in 2020,the Turpan−Hami Basin contained 354 glaciers,covering anarea of 155.82 km^(2)and an estimated ice volume of 5.81 km3.Small glaciers(<0.5 km^(2))were the most numerous,accounting for 78%of the total,while glaciers ranging from 2.0 to 5.0 km^(2)were the largest area,covering39.37 km^(2),which represents 25.3%of the total glacier area.From 1962 to 2020,the glacier area decreased by85.06 km^(2)(35.3%).Between 1962 and 2009,the area decreased by 72.53 km^(2)(30.11%),with an average annualretreat of 1.54 km^(2)/a(0.64%/a).From 2009 to 2020,the area decreased by 12.53 km^(2)(7.44%),and the averageannual retreat slowed to 1.14 km^(2)/a(0.68%/a).These results suggested that while the total glacier area con-tinues to decline,the rate of decrease in absolute terms has slowed,whereas the relative rate of change hasincreased,indicating an accelerating trend in glacier melt.Climate-driven glacier changes have significantly impacted river hydrology and water resources in Hami.In basins without glaciers,runoff has shown a decreasingtrend,suggesting that the positive effect of increased precipitation on runoff may not be sufficient to offset thenegative impact of rising temperatures.In basins with smaller glaciers,the'peak water'for glacier runoff likelyoccurred in the 1980s and 1990s,and water resources are expected to continue deteriorating.In contrast,basinswith larger glaciers have not yet reached a'peak water'and high flow is projected to persist for decades.
