The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its impor...The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its importance,there has been a relative paucity of research focusing on the spatiotemporal variations of snow cover,key controlling factors,and variability within HMA sub-basins.This study aims to address this gap by extracting snow cover percentage(SCP)and snow cover days(SCD)data from MOD10A2 snow products,integrating these with precipitation(P)and temperature(T)data from ERA5.Our objective is to analyze the spatiotemporal distribution characteristics of snow cover and to use path analysis to elucidate the key climatic factors and spatial differences influencing snow cover changes.The findings indicate that,on a temporal scale,the overall SCP in HMA exhibited a declining trend from 2001 to 2021.Interannual variations in SCP across HMA sub-basins revealed a decreasing trend in the Pamir(PAM),Western Tibetan Plateau(WTS),Eastern Tibetan Plateau(ETS),Western Kunlun(WKL),Qilian Shan(QLS),and Himalaya(HDS)regions,while an increasing trend was observed in other areas.Spatially,22.97%of the HMA regions experienced an increase in SCD,primarily in the Western Himalaya(WHL),Central Himalaya(CHL),and Southeastern Xizang(SET)regions.Conversely,28.08%of the HMA regions showed a decrease in SCD,predominantly in the Eastern Himalaya(EHL),HDS,and WTS regions.Temperature(T)emerged as the primary influencing factor of SCD change in most HMA sub-basins.However,in the Eastern Kunlun(EKL)and WHL sub-basins,precipitation(P)was identified as the main driver of SCD change,affecting all elevation zones in these regions.Additionally,other climatic conditions can also impact snow cover beyond the primary controlling factor.展开更多
Climate change in High Mountain Asia(HMA)is characterized by elevation dependence,which results in vertical zoning of vegetation distribution.However,few studies have been conducted on the distribution patterns of veg...Climate change in High Mountain Asia(HMA)is characterized by elevation dependence,which results in vertical zoning of vegetation distribution.However,few studies have been conducted on the distribution patterns of vegetation,the response of vegetation to climate change,and the key climatic control factors of vegetation along the elevation gradient in this region.In this study,based on the Normalized Difference Vegetation index(NDVI),we investigated the evolution pattern of vegetation in HMA during 2001-2020 using linear trend and Bayesian Estimator of Abrupt change,Seasonality,and Trend(BEAST)methods.Pearson correlation analysis and partial correlation analysis were used to explore the response relationship between vegetation and climatic factors along the elevation gradient.Path analysis was employed to quantitatively reveal the dominant climatic factors affecting vegetation distribution along the elevation gradient.The results showed that NDVI in HMA increased at a rate of 0.011/10a from 2001 to 2020,and the rate of increase abruptly slowed down after 2017.NDVI showed a fluctuating increase at elevation zones 1-2(<2500 m)and then decreased at elevation zones 3-9(2500-6000 m)with the increase of elevation.NDVI was most sensitive to precipitation and temperature at a 1-month lag.With the increase of elevation,the positive response relationship of NDVI with precipitation gradually weakened,while that of NDVI with temperature was the opposite.The total effect coefficient of precipitation(0.95)on vegetation was larger than that of temperature(0.87),indicating that precipitation is the dominant control factor affecting vegetation growth.Spacially,vegetation growth is jointly influenced by precipitation and temperature,but the influence of precipitation on vegetation growth is dominant at each elevation zone.The results of this study contribute to understanding how the elevation gradient effect influences the response of vegetation to climate change in alpine ecosystems.展开更多
Mountains are important suppliers of freshwater to downstream areas,affecting large populations in particular in High Mountain Asia(HMA).Yet,the propagation of water from HMA headwaters to downstream areas is not full...Mountains are important suppliers of freshwater to downstream areas,affecting large populations in particular in High Mountain Asia(HMA).Yet,the propagation of water from HMA headwaters to downstream areas is not fully understood,as interactions in the mountain water cycle between the cryo-,hydro-and biosphere remain elusive.We review the definition of blue and green water fluxes as liquid water that contributes to runoff at the outlet of the selected domain(blue)and water lost to the atmosphere through vapor fluxes,that is evaporation from water,ground,and interception plus transpiration(green)and propose to add the term white water to account for the(often neglected)evaporation and sublimation from snow and ice.We provide an assessment of models that can simulate the cryo-hydro-biosphere continuum and the interactions between spheres in high mountain catchments,going beyond disciplinary separations.Land surface models are uniquely able to account for such complexity,since they solve the coupled fluxes of water,energy,and carbon between the land surface and atmosphere.Due to the mechanistic nature of such models,specific variables can be compared systematically to independent remote sensing observations-providing vital insights into model accuracy and enabling the understanding of the complex watersheds of HMA.We discuss recent developments in spaceborne earth observation products that have the potential to support catchment modeling in high mountain regions.We then present a pilot study application of the mechanistic land surface model Tethys&Chloris to a glacierized watershed in the Nepalese Himalayas and discuss the use of high-resolution earth observation data to constrain the meteorological forcing uncertainty and validate model results.We use these insights to highlight the remaining challenges and future opportunities that remote sensing data presents for land surface modeling in HMA.展开更多
We provide estimates of glacier mass changes in the High Mountain Asia (HMA) area from April2002 to August 2016 by employing a new version of gravity solutions of the Gravity Recovery and ClimateExperiment (GRACE) twi...We provide estimates of glacier mass changes in the High Mountain Asia (HMA) area from April2002 to August 2016 by employing a new version of gravity solutions of the Gravity Recovery and ClimateExperiment (GRACE) twin-satellite mission. We find a total mass loss trend of the HMA glaciers at a rateof –22.17 (±1.96) Gt/a. The largest mass loss rates of –7.02 (±0.94) and –6.73 (±0.78) Gt/a are found forthe glaciers in Nyainqentanglha Mountains and Eastern Himalayas, respectively. Although most glaciers inthe HMA area show a mass loss, we find a small glacier mass gain of 1.19 (±0.55) and 0.77 (±0.37) Gt/a inKarakoram Mountains and Western Kunlun Mountains, respectively. There is also a nearly zero massbalance in Pamirs. Our estimates of glacier mass change trends confirm previous results from the analysisof altimetry data of the ICESat (ICE, Cloud and Land Elevation Satellite) and ASTER (AdvancedSpaceborne Thermal Emission and Reflection Radiometer) DEM (Digital Elevation Model) satellites inmost of the selected glacier areas. However, they largely differ to previous GRACE-based studies which weattribute to our different post-processing techniques of the newer GRACE data. In addition, we explicitlyshow regional mass change features for both the interannual glacier mass changes and the 14-a averagedseasonal glacier mass changes. These changes can be explained in parts by total net precipitation (netsnowfall and net rainfall) and net snowfall, but mostly by total net radiation energy when compared to datafrom the ERA5-Land meteorological reanalysis. Moreover, nearly all the non-trend interannual masschanges and most seasonal mass changes can be explained by the total net radiation energy data. The massloss trends could be partly related to a heat effect due to increased net rainfall in Tianshan Mountains, QilianMountains, Nyainqentanglha Mountains and Eastern Himalayas. Our new results for the glacier mass changein this study could help improve the understanding of glacier variation in the HMA area and contribute tothe study of global change. They could also serve the utilization of water resources there and in neighboringareas.展开更多
High Mountain Asia(HMA) region contains the world’s highest peaks and the largest concentration of glaciers except for the polar regions, making it sensitive to global climate change. In the context of global warming...High Mountain Asia(HMA) region contains the world’s highest peaks and the largest concentration of glaciers except for the polar regions, making it sensitive to global climate change. In the context of global warming, most glaciers in the HMA show various degrees of negative mass balance,while some show positive or near-neutral balance. Many studies have reported that spatial heterogeneity in glacier mass balance is strongly related to a combination of climate parameters. However, this spatial heterogeneity may vary according to the dynamic patterns of climate change at regional or continental scale. The reasons for this may be related to non-climatic factors. To understand the mechanisms by which spatial heterogeneity forms, it is necessary to establish the relationships between glacier mass balance and environmental factors related to topography and morphology. In this study, climate, topography,morphology, and other environmental factors are investigated. Geodetector and linear regression analysis were used to explore the driving factors of spatial variability of glacier mass balance in the HMA by using elevation change data during 2000–2016. The results show that the coverage of supraglacial debris is an essential factor affecting the spatial heterogeneity of glacier mass balance, followed by climatic factors and topographic factors, especially the median elevation and slope in the HMA. There are some differences among mountain regions and the explanatory power of climatic factors on the spatial differentiation of glacier mass balance in each mountain region is weak, indicating that climatic background of each mountain region is similar. Therefore, under similar climatic backgrounds, the median elevation and slope are most correlated with glacier mass balance. The interaction of various factors is enhanced, but no unified interaction factor plays a primary role. Topographic and morphological factors also control the spatial heterogeneity of glacier mass balance by influencing its sensitivity to climate change. In conclusion,geodetector method provides an objective framework for revealing the factors controlling glacier mass balance.展开更多
The model performance in simulating soil water content(SWC) is crucial for successfully modeling earth’s system,especially in high mountainous areas.In this study,the performance of Community Land Model 5.0(CLM5.0) i...The model performance in simulating soil water content(SWC) is crucial for successfully modeling earth’s system,especially in high mountainous areas.In this study,the performance of Community Land Model 5.0(CLM5.0) in simulating liquid SWC was evaluated against observations from nine in-situ sites in the upper reach of the Heihe River Watershed(HRW),Northwest China.The CLM5.0 shows reliable performance in the study area with correlation coefficients(R) ranging between 0.79–0.93,root mean standard errors(RMSE)ranging between 0.044–0.097 m^(3)/m^(3),and the mean bias(BIAS) ranging between-0.084–0.061 m^(3)/m^(3).The slightly worse performance of CLM5.0 than CLM4.5 on alpine meadow and grassland is mainly caused by the revised canopy interception parameterization.The CLM5.0 overestimates interception and underestimates evapotranspiration(ET) on both alpine meadow and grassland during the growth period.The systematical overestimations at all the grassland sites indicate that the underestimation of ET is much larger than the overestimation of interception on grassland during growth period,while the errors of simulated interception and ET are partially canceled out on alpine meadow.Moreover,the underestimation of ET is more responsible for the overestimation of SWC than the overestimation of interception in the high mountainous area.It is necessary to estimate reasonable empirical parameter α(proportion of leaf water collection area) in interception parameterization scheme and further improve the dry surface layerbased soil evaporation resistance parameterization introduced in CLM5.0 in future researches.The performance of CLM5.0 is better under completely frozen stage than thawing stage and freezing stage,because of low variations of liquid SWC caused by extremely low hydraulic conductivity of soils.The underestimation of liquid SWC under frozen state is caused by underestimation of soil temperature,which leads to more ice mass and less liquid water in total water content.展开更多
Velocity is an important component of glacier dynamics and directly reflects the response of glaciers to climate change.As a result,an accurate determination of seasonal variation in glacier velocity is very important...Velocity is an important component of glacier dynamics and directly reflects the response of glaciers to climate change.As a result,an accurate determination of seasonal variation in glacier velocity is very important in understanding the annual variation in glacier dynamics.However,few studies of glacier velocity in the High Mountain Asia(HMA)region were done.Along these lines,in this work,based on Sentinel-1 glacier velocity data,the distribution of glacier velocity in the HMA region was plotted and their seasonal variations during 2015-2020 were systematically analysed.The average glacier velocity in the HMA region was 0.053 m/d,and was positively correlated with the glacier area and slope.Glaciers in the Karakoram Mountains had the fastest average flow velocity(0.060 m/d),where the glaciers exhibited the largest average area and average slope.Moreover,glaciers in the GangdisêMountains had the slowest velocity(0.022 m/d)and the smallest average glacier area.The glacier flows were the fastest in spring(0.058 m/d),followed by summer(0.050 m/d),autumn(0.041 m/d),and winter(0.040 m/d).In addition,the glacier flows were the maximum in May,being 1.4 times of the annual average velocity.In some areas,such as the Qilian,Altun,Tibetan Interior,Eastern Kunlun,and Western Kunlun mountains,the peak glacier velocities appeared in June and July.The glacier velocity in the HMA region decreased in midsummer and reached the minimum in December when it was 75%of the annual average.These results highlight the role of meltwater in the seasonal variation in glacier flows in late spring and early summer.The seasonal velocity variation of lake-terminating glaciers was similar to that of land-terminating ones,but the former flowed faster.The velocity difference close to the mass balance line between the lake-and land-terminating glaciers was obviously greater in spring than in other seasons.In summer,the difference between the lake-and land-terminating glaciers at a normalized distance of 0.05-0.40 from the terminus was significantly greater than those of other seasons.The velocity difference between the lake-and land-terminating glaciers is closely related to the variable of ice thickness,and also to the frictional force of the terminal base reduced by proglacial lakes.Thus,it can be concluded that in addition to the variation of the glacier thickness and viscosity,the variation of glacier water input also plays a key role in the seasonal variation of glacier velocity.展开更多
Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars,1863 dominates among crustaceans.In July,its abundance comprised 64%-98%of the total plankton...Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars,1863 dominates among crustaceans.In July,its abundance comprised 64%-98%of the total plankton fauna in the pelagial of these lakes,approximately 30%in the littoral zone and10%in small northern thermokarst lakes.Biometric measurements and morphological descriptions based on scanning microscope images are supplemented by the data on its geographic distribution and phenology.展开更多
The high alpine and subalpine vegetation of Dinaric Alps is very diverse. These are conditional on genuine patterns of development of the geological substrate, climate, soil and terrain on the mountain world, which ar...The high alpine and subalpine vegetation of Dinaric Alps is very diverse. These are conditional on genuine patterns of development of the geological substrate, climate, soil and terrain on the mountain world, which are interconnected and spatially, and ecologically away. Also, today high mountain vegetation is extremely important indicator of global changes. In this area are many refugia of glacial biodiversity. Very illustrative example for understanding the specific forms of ecological diversity is high alpine vegetation in the area of the Balkan Peninsula. Vegetation of alpine belt of Western Balkans and Bosnia and Herzegovina is differed by extremely high level of biological and ecological diversity. Climatogenous vegetation are alpine and sub-alpine pastures above of timberline, then extra zonal forms of vegetation - glaciers, rock creeps, breaches of rocks, alpine springs, marsh, and tall greenery. This vegetation is dominant determinant of alpine ecosystems that creates their unique physiognomy and also enables prime production of biomass. It is different with extraordinary floral richness, especially in a number of endemic species and glacier relicts that are included in a large number of phytocoenoses, many of which are of endemic. In syntaxonomic sense, alpine vegetation is differentiated into lo classes： Elyno- Seslerietea, Juncetea trifidi, Salicetea herbaceae,Thalspietea rotundifolii, Asplenietea trichomanis, and Scheuchzerio-Caricetea fuscae, Montio- Cardaminetea, Loiseleurio-Vaccinietea, Mulgedio- Aconitetea and Molinio-Arrhenatheretea. These classes are differentiated into ao vegetation orders, 38 alliances and 19o associations and sub-associations. In total, that is 6o % of communities of total vegetation diversity of Bosnia and Herzegovina, and 12.5% of classes of highest syntaxonomic categories in vegetation diversity of Europe.展开更多
High montain lakes are regarded as sensitive indicators of environmental changes in local and global scales.In recent years,climate change has considerablely influenced the timing of ice phenomena in these lakes.The o...High montain lakes are regarded as sensitive indicators of environmental changes in local and global scales.In recent years,climate change has considerablely influenced the timing of ice phenomena in these lakes.The objective of the paper is an investigation of long-term changes and periodicity of ice phenomena in high mountain Lake Morskie Oko(1392.8 m a.s.l.)located in the Tatra Mts.in the period 1971-2020.The study employed the Lomb-Scargle periodogram,linear regression modelling for temporal trends,correlation analysis,parameters of variability,and flashiness index.Periodicity of the duration of ice phenomena(~5.4 y)and ice cover on the lake(~13.5 y)was observed,although both are statistically insignificant.Ice cover duration has been interrupted several times by winter thaws after 1996 whereas no such events had been reported earlier.The trend towards a delayed appearance of ice phenomena reaches 4.0 d·decade^(-1)(p<0.001).The observed trend towards an earlier ice phenomena disappearance reaches 5.1 d·decade^(-1)(p<0.001).It results in a decline of the number of days with ice phenomena on Lake Morskie Oko at a rate of 9.0 d·decade^(-1)(p<0.001).The duration of ice cover on Lake Morskie Oko has been decreasing at a rate of 10.4 d·decade^(-1).It is attributed to later freezeup(3.9 d·decade^(-1),p<0.001)and earlier ice break-up(5.6 d·decade^(-1),p<0.001).An increasing trend of average annual air temperature(0.4°C·decade^(-1),p<0.001)in the period 1971-2020 is observed.A statistically significant correlation is recorded between ice phenomena and ice cover(beginning,end,duration),average annual air temperature,average air temperature of three summer months(June,July,August),and average air temperature of the six months period from June to November.Higher air temperature induces growing heat resources accumulated in the lake water in the summer and autumn seasons,potentially causing later initiation of ice phenomena in the lake.There is no statistically significant relationship between maximum ice thickness and any air temperature parameters.Variability of maximum ice thickness appears to have been significantly increasing in the second part of the investigated period(1996-2020).展开更多
High Mountain Asia(HMA),recognized as a third pole,needs regular and intense studies as it is susceptible to climate change.An accurate and high-resolution Digital Elevation Model(DEM)for this region enables us to ana...High Mountain Asia(HMA),recognized as a third pole,needs regular and intense studies as it is susceptible to climate change.An accurate and high-resolution Digital Elevation Model(DEM)for this region enables us to analyze it in a 3D environment and understand its intricate role as the Water Tower of Asia.The science teams of NASA realized an 8-m DEM using satellite stereo imagery for HMA,termed HMA 8-m DEM.In this research,we assessed the vertical accuracy of HMA 8-m DEM using reference elevations from ICESat-2 geolocated photons at three test sites of varied topography and land covers.Inferences were made from statistical quantifiers and elevation profiles.For the world’s highest mountain,Mount Everest,and its surroundings,Root Mean Squared Error(RMSE)and Mean Absolute Error(MAE)resulted in 1.94 m and 1.66 m,respectively;however,a uniform positive bias observed in the elevation profiles indicates the seasonal snow cover change will dent the accurate estimation of the elevation in this sort of test sites.The second test site containing gentle slopes with forest patches has exhibited the Digital Surface Model(DSM)features with RMSE and MAE of 0.58 m and 0.52 m,respectively.The third test site,situated in the Zanda County of the Qinghai-Xizang,is a relatively flat terrain bed,mostly bare earth with sudden river cuts,and has minimal errors with RMSE and MAE of 0.32 m and 0.29 m,respectively,and with a negligible bias.Additionally,in one more test site,the feasibility of detecting the glacial lakes was tested,which resulted in exhibiting a flat surface over the surface of the lakes,indicating the potential of HMA 8-m DEM for deriving the hydrological parameters.The results accrued in this investigation confirm that the HMA 8-m DEM has the best vertical accuracy and should be of high use for analyzing natural hazards and monitoring glacier surfaces.展开更多
Data material of a long-term high mountain ecosystem research project was used to interpret thegrazing impact of reindeers. In central Norwayinvestigations were conducted to both, areas wherereindeer grazing is exclud...Data material of a long-term high mountain ecosystem research project was used to interpret thegrazing impact of reindeers. In central Norwayinvestigations were conducted to both, areas wherereindeer grazing is excluded, and areas whereintensive pasturing is present for a long period oftime. The comparative analysis of grazing impact was based on similar environmental conditions. Theresults were transposed to northern Norway wheredramatic overgrazing had been exceeding thecarrying capacity. Using landscape ecologicalmappings, especially of vegetation and soils, theimpact of reindeer grazing in different areas becameobvious. Non-grazed lichen-dominated ecosystems of the snow-free locations functioned sensitively nearthe limit of organism survival. These localities weremost influenced by grazing as they offer the winterforage to the reindeers. So, intensive grazing incentral Norway led to landscape degradation bydestruction of the vegetation and superinduced bysoil erosion. Those features were comparable to thesituation in northern Norway, where a broad-scale destruction of the environment combined with adepression of the altitudinal belts had occurred dueto overgrazing. Functioning principles of intact high mountain systems were explained and used to interpret theenvironmental background for the understanding ofdegradation phenomena. Finally, the use of a newmodel calculating the carrying capacity of high mountain landscape was discussed.展开更多
In lowlands climate-specific processes due to weathering and erosion are dominant, whilst the geomorphology of mountains is dependent on the geologic-tectonic structure, i.e., the energy of erosion that increases acco...In lowlands climate-specific processes due to weathering and erosion are dominant, whilst the geomorphology of mountains is dependent on the geologic-tectonic structure, i.e., the energy of erosion that increases according to the vertical. The expression ＂extremely high mountains＂ has been established as the extreme of a continuous mountain classification. It has to be understood in terms of geomorphology, glaciology and vegetation. Correspondence of the planetary and hypsometric change of forms is of great value as synthetic explanation. It is confirmed with regard to vegetation, periglacial geomorphology and glaciology. Due to the world-wide reconstruction of the snowline its paleoclimatie importance increases, too. Apart from lower limits the periglacial and glacial altitudinal levels also show zones of optimum development and climatic upper limits in the highest mountains of the earth. According to the proportion of the altitudinal levels a classification as to arid, temperate and humid high mountains has been carried out.展开更多
With the rapid development of science and technology, radio and television are becoming more and more popular. In addition, the continuous improvement of people's spiritual and cultural enthusiasm puts forward hig...With the rapid development of science and technology, radio and television are becoming more and more popular. In addition, the continuous improvement of people's spiritual and cultural enthusiasm puts forward higher requirements for radio and television. In order to ensure signal coverage, most radio and television stations choose high mountains. There are some problems and shortcomings when starting the mountain station. The integrity, integrity and reliability of radio station facilities and equipment depend on the security of transmissions and broadcasts. In order to ensure the safety and high-quality transmission of broadcast signals, the daily safety management of equipment in the computer room is very important.展开更多
The tea tree [Camellia sinensis (L) Kuntze] is one of the world’s economic crops. It is an especially important crop for southern China. Environmental factors related to the tea yield and quality in some high mountai...The tea tree [Camellia sinensis (L) Kuntze] is one of the world’s economic crops. It is an especially important crop for southern China. Environmental factors related to the tea yield and quality in some high mountain areas of China are identified in this paper. These factors are: geology, topography, climate, hydrology, soil and vegetation. Climatological factors are the most important. Using data collected from meteorological stations which are situated at the summit and the base of high mountains, this paper discusses ecological climatic problems in growing tea in China. The ecological climatic characteristics of the famous tea areas mainly included are as follows: more . amounts of clouds and fog, less percentage of sunshine, abundant rainfall and high relative humidity in the air, temperatures that rise and fall slowly, daily and annual temperature ranges that are smaller, more days that are suitable for tea growing and low wind speeds in the lee-sides and valleys of mountains. All of these展开更多
The High Mountain Asia(HMA) hosts the largest and most extensive mid-to low-latitude mountain glaciers,forming a crucial part of the “Asian Water Tower”.The temporal span of remote sensing data in previous regional ...The High Mountain Asia(HMA) hosts the largest and most extensive mid-to low-latitude mountain glaciers,forming a crucial part of the “Asian Water Tower”.The temporal span of remote sensing data in previous regional glacier inventories impacts quantitative estimates in glaciological studies.Remote sensing big data,including cloud-free Sentinel-2 and Landsat-8 optical imagery,along with Sentinel-1 SAR data during the ablation period from July to September 2020,were utilized to generate a new time-stamped glacier inventory for the HMA(HMAGI-2020).Glacier outlines were automatically delineated using a VGG16-UNET deep learning model,leveraging unique spectral,polarization,and topographic characteristics as inputs,achieving an accuracy of up to 92.8%.The automated results were segmented based on existing glacier inventories,followed by manual corrections conducted primarily using Sentinel-2,supplemented by Landsat-8 in areas covered by optical imagery.A total of 93043 glaciers were manually corrected,and 15 attributes,including area,perimeter,and terrain parameters derived from the Copernicus DEM,were calculated for each glacier.The HMAGI-2020 includes 97934 glaciers whose area is larger than 0.01 km^(2),covering an area of 91837.77±2527.70 km^(2).The mean uncertainty of glacier delineation was calculated to be ±6.67% using a buffer-zone method combined with the VGG16-UNET.Across the HMA,the average glacier surface elevation is approximately 5094 m,with an average slope of 25.66°.Over 75% of glaciers are oriented toward the south,southwest,or southeast.Comparison with previous glacier inventories revealed a retreat of HMA glaciers over the past two decades,with glacier area reductions exceeding 20% in the southeastern HMA.In contrast,the Karakoram-West Kunlun region remains relatively stable,with only a slight area increase of less than 1%.Due to its advantages in data source consistency and temporal precision,the HMAGI-2020 is regarded as providing accurate glacier boundaries and attributes in 2020.This inventory is expected to provide essential data support for research on glaciology,climate change,and water resource management of the HMA in the context of global change.展开更多
High-Mountain Asia(HMA)is an important source of freshwater since it holds the largest reservoir of frozen water outside the polar regions.HMA feeds ten great rivers,ultimately supporting more than 2 billion people.Ho...High-Mountain Asia(HMA)is an important source of freshwater since it holds the largest reservoir of frozen water outside the polar regions.HMA feeds ten great rivers,ultimately supporting more than 2 billion people.However,the threat of accelerated glacier melt,which is a consequence of unprecedented global warming since the early 1950s,threatens water resources in the surrounding countries.Accurate predictions of the near-term temperature change and synergistic mass loss of glaciers are essential but challenging to implement because of the impacts of internal climate variability.Here,based on large ensembles of state-of-the-art decadal climate prediction experiments,we provide evidence that the internally generated surface air temperature variations in HMA can be predicted multiple years in advance,and the model initialization has robust added value to the decadal prediction skill.Real-time decadal forecasts suggest that the HMA will experience accelerated warming in 2025-2032,where the surface warming will increase by 0.98°C(0.67 to 1.33°C;5%to 95%range)relative to the reference period 1991-2020,which is equivalent to 1.75 times the observed warming during 2016-2023.The decadal predictability originates from extratropical Pacific decadal variability modes,which modulate the convective heating in the tropical Pacific and influence HMA via the eastward-propagating atmospheric Kelvin waves.Accelerated warming in the coming decade will likely increase the shrinkage of the glacier volume over the HMA by 1.4%.This change poses unprecedented challenges,including potential water scarcity,ecosystem disruption,and increased risk of natural disasters,to HMA and surrounding regions.展开更多
High Mountain Asia(HMA),known as the"Asian Water Tower",is the Earth’s critical water source and provides important ecosystem services for millions of people in the downstream[1].Due to its high altitude an...High Mountain Asia(HMA),known as the"Asian Water Tower",is the Earth’s critical water source and provides important ecosystem services for millions of people in the downstream[1].Due to its high altitude and extensive cryosphere,HMA is sensitive and vulnerable to climate change[1-3].Currently,HMA has been experiencing a notable temperature increase at a rate twice that of the global average,accompanied by complex changes in precipitation patterns[1,4,5].展开更多
Mountain communities in Nepal are increasingly exposed to climate-induced shifts in water availability,driven by glacial retreat,altered precipitation/snowmelt regimes,and declining groundwater sources.This study pres...Mountain communities in Nepal are increasingly exposed to climate-induced shifts in water availability,driven by glacial retreat,altered precipitation/snowmelt regimes,and declining groundwater sources.This study presents an integrated framework combining hydrological source analysis with socio-demographic survey data to evaluate seasonal water contributions and communitylevel water use patterns in the Upper Marsyangdi catchment,Manang District,Nepal.Isotopic(δ^(18)O)and geochemical(silica)tracers were used in a Bayesian mixing model to quantify the seasonal contributions of glacial melt,snow,rain,and groundwater to river flow.Findings indicate that groundwater dominates pre-monsoon flow(60%-70%)while post-monsoon discharge reflects more balanced inputs from all sources.In parallel,120 household surveys were analysed using Latent Class Analysis to characterise water use across domestic,agricultural,energy,and tourism sectors.Results reveal spatial and demographic gradients in water source dependency,including gender and occupation as important predictors of water use.Respondents reported perceived increases in spring flow,alongside reductions in the availability of snow for household and tourism use and deteriorating river water quality and quantity,particularly affecting hydropower operations.Adaptation strategies include increased reliance on water storage infrastructure and source switching.The study highlights the value of applying probabilistic methods to hydrological and sociocultural data to identify vulnerable populations and inform targeted,context-sensitive adaptation strategies.The proposed framework is transferable to other high-altitude regions,offering a robust approach for assessing climate resilience through the synthesis of scientific and local knowledge systems.展开更多
In the context of global warming,glaciers in the Asian High Mountains(AHMs)are shrinking at an accelerating rate.Projecting their future change is helpful for understanding the hydrological and climatic effects relate...In the context of global warming,glaciers in the Asian High Mountains(AHMs)are shrinking at an accelerating rate.Projecting their future change is helpful for understanding the hydrological and climatic effects related to glacier retreat.Here,we projected glacier change in the AHMs from 1979 to 2100 under shared socioeconomic pathway(SSP)scenarios from the perspective of temperature,equilibrium-line altitude(ELA),and accumulation area.The annual mean temperature in the AHMs increased by 1.26℃ from 1979 to 2014,corresponding to an increase of 210 m in the mean ELA and a decrease of 1.7×10^(4)km^(2) in the glacier accumulation area.Under the SSP2-4.5(SSP5-8.5)scenario,the annual mean temperature in the AHMs would increase by 2.84℃(3.38℃)in 2040–2060 relative to that in 1850–1900,leading to the mean ELA reaching an elevation of5661 m(5777 m).The accumulation area in the AHMs decreased by 46.3%from 1995 to 2014 and was projected to decrease by60.1%in 2040–2060.Moreover,the annual mean temperature in the AHMs was projected to increase by 3.76℃(6.44℃)in2080–2100 relative to that in 1850–1900,corresponding to the ELA reaching an elevation of 5821 m(6245 m)and the accumulation area decreasing to 1.8×10^(4)km^(2)(0.5×10^(4)km^(2)).These data suggest that the conditions for glacier development will disappear in most of the AHMs,except for extreme high-altitude regions in the Tianshan,Pamir,and Himalaya Mountains.Under the SSP2-4.5(SSP5-8.5)scenario,when the global mean temperature increases 1.5℃(2℃)above pre-industrial levels,the annual mean temperature will increase by 2.12℃(2.86℃)and the accumulation area will decrease by 15%(48%)in the AHMs compared with that in 1995–2015.Therefore,a 1.5℃ increase in global warming would keep 40%more of the glacial accumulation area(1.5×10^(4)km^(2))in the AHMs compared to a 2℃ increase in global warming.展开更多
基金supported by Tianchi talent project(Granted No.51052401507)。
文摘The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its importance,there has been a relative paucity of research focusing on the spatiotemporal variations of snow cover,key controlling factors,and variability within HMA sub-basins.This study aims to address this gap by extracting snow cover percentage(SCP)and snow cover days(SCD)data from MOD10A2 snow products,integrating these with precipitation(P)and temperature(T)data from ERA5.Our objective is to analyze the spatiotemporal distribution characteristics of snow cover and to use path analysis to elucidate the key climatic factors and spatial differences influencing snow cover changes.The findings indicate that,on a temporal scale,the overall SCP in HMA exhibited a declining trend from 2001 to 2021.Interannual variations in SCP across HMA sub-basins revealed a decreasing trend in the Pamir(PAM),Western Tibetan Plateau(WTS),Eastern Tibetan Plateau(ETS),Western Kunlun(WKL),Qilian Shan(QLS),and Himalaya(HDS)regions,while an increasing trend was observed in other areas.Spatially,22.97%of the HMA regions experienced an increase in SCD,primarily in the Western Himalaya(WHL),Central Himalaya(CHL),and Southeastern Xizang(SET)regions.Conversely,28.08%of the HMA regions showed a decrease in SCD,predominantly in the Eastern Himalaya(EHL),HDS,and WTS regions.Temperature(T)emerged as the primary influencing factor of SCD change in most HMA sub-basins.However,in the Eastern Kunlun(EKL)and WHL sub-basins,precipitation(P)was identified as the main driver of SCD change,affecting all elevation zones in these regions.Additionally,other climatic conditions can also impact snow cover beyond the primary controlling factor.
基金supported by the Xinjiang Uygur Autonomous Region Major Scientific and Technological Special Project Research and Demonstration on the Development Model of Ecological Agriculture and Efficient Utilization of Soil and Water Resources in Modern Irrigation Areas(2023A02002-1).
文摘Climate change in High Mountain Asia(HMA)is characterized by elevation dependence,which results in vertical zoning of vegetation distribution.However,few studies have been conducted on the distribution patterns of vegetation,the response of vegetation to climate change,and the key climatic control factors of vegetation along the elevation gradient in this region.In this study,based on the Normalized Difference Vegetation index(NDVI),we investigated the evolution pattern of vegetation in HMA during 2001-2020 using linear trend and Bayesian Estimator of Abrupt change,Seasonality,and Trend(BEAST)methods.Pearson correlation analysis and partial correlation analysis were used to explore the response relationship between vegetation and climatic factors along the elevation gradient.Path analysis was employed to quantitatively reveal the dominant climatic factors affecting vegetation distribution along the elevation gradient.The results showed that NDVI in HMA increased at a rate of 0.011/10a from 2001 to 2020,and the rate of increase abruptly slowed down after 2017.NDVI showed a fluctuating increase at elevation zones 1-2(<2500 m)and then decreased at elevation zones 3-9(2500-6000 m)with the increase of elevation.NDVI was most sensitive to precipitation and temperature at a 1-month lag.With the increase of elevation,the positive response relationship of NDVI with precipitation gradually weakened,while that of NDVI with temperature was the opposite.The total effect coefficient of precipitation(0.95)on vegetation was larger than that of temperature(0.87),indicating that precipitation is the dominant control factor affecting vegetation growth.Spacially,vegetation growth is jointly influenced by precipitation and temperature,but the influence of precipitation on vegetation growth is dominant at each elevation zone.The results of this study contribute to understanding how the elevation gradient effect influences the response of vegetation to climate change in alpine ecosystems.
基金supported by the ESA and NRSCC Dragon 5 cooperation project“Cryosphere-hydrosphere interactions of the Asian water towers:using remote sensing to drive hyper-resolution ecohydrological modelling”[Grant no.59199]PB and FP acknowledge funding from the SNSF(High-elevation precipitation in High Mountain Asia,HOPE)[Grant no.183633]+4 种基金ESM,MK,SFu and FP acknowledge funding from the ERC under the European Union’s Horizon 2020 research and innovation program(Rapid mass losses of debris-covered glaciers in High Mountain Asia,RAVEN)[Grant no.772751]LJ,CZ and MMe acknowledge the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)[grant no.2019QZKK010308,no.2019QZKK0206]the National Natural Science Foundation of China projects(Grant no.42171039,no.91737205)the Chinese Academy of Sciences President’s International Fellowship Initiative[Grant no.2020VTA0001]the MOST High-Level Foreign Expert Program[Grant no.G2022055010L].
文摘Mountains are important suppliers of freshwater to downstream areas,affecting large populations in particular in High Mountain Asia(HMA).Yet,the propagation of water from HMA headwaters to downstream areas is not fully understood,as interactions in the mountain water cycle between the cryo-,hydro-and biosphere remain elusive.We review the definition of blue and green water fluxes as liquid water that contributes to runoff at the outlet of the selected domain(blue)and water lost to the atmosphere through vapor fluxes,that is evaporation from water,ground,and interception plus transpiration(green)and propose to add the term white water to account for the(often neglected)evaporation and sublimation from snow and ice.We provide an assessment of models that can simulate the cryo-hydro-biosphere continuum and the interactions between spheres in high mountain catchments,going beyond disciplinary separations.Land surface models are uniquely able to account for such complexity,since they solve the coupled fluxes of water,energy,and carbon between the land surface and atmosphere.Due to the mechanistic nature of such models,specific variables can be compared systematically to independent remote sensing observations-providing vital insights into model accuracy and enabling the understanding of the complex watersheds of HMA.We discuss recent developments in spaceborne earth observation products that have the potential to support catchment modeling in high mountain regions.We then present a pilot study application of the mechanistic land surface model Tethys&Chloris to a glacierized watershed in the Nepalese Himalayas and discuss the use of high-resolution earth observation data to constrain the meteorological forcing uncertainty and validate model results.We use these insights to highlight the remaining challenges and future opportunities that remote sensing data presents for land surface modeling in HMA.
基金This work is funded by the National Key R&D Program of China(2017YFA0603103)the National Natural Science Foundation of China(41974009,42004007)+1 种基金the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDB-SSW-DQC027,QYZDJ-SSW-DQC042)the open fund of State Key Laboratory of Geodesy and Earth's Dynamics(SKLGED2021-2-6)。
文摘We provide estimates of glacier mass changes in the High Mountain Asia (HMA) area from April2002 to August 2016 by employing a new version of gravity solutions of the Gravity Recovery and ClimateExperiment (GRACE) twin-satellite mission. We find a total mass loss trend of the HMA glaciers at a rateof –22.17 (±1.96) Gt/a. The largest mass loss rates of –7.02 (±0.94) and –6.73 (±0.78) Gt/a are found forthe glaciers in Nyainqentanglha Mountains and Eastern Himalayas, respectively. Although most glaciers inthe HMA area show a mass loss, we find a small glacier mass gain of 1.19 (±0.55) and 0.77 (±0.37) Gt/a inKarakoram Mountains and Western Kunlun Mountains, respectively. There is also a nearly zero massbalance in Pamirs. Our estimates of glacier mass change trends confirm previous results from the analysisof altimetry data of the ICESat (ICE, Cloud and Land Elevation Satellite) and ASTER (AdvancedSpaceborne Thermal Emission and Reflection Radiometer) DEM (Digital Elevation Model) satellites inmost of the selected glacier areas. However, they largely differ to previous GRACE-based studies which weattribute to our different post-processing techniques of the newer GRACE data. In addition, we explicitlyshow regional mass change features for both the interannual glacier mass changes and the 14-a averagedseasonal glacier mass changes. These changes can be explained in parts by total net precipitation (netsnowfall and net rainfall) and net snowfall, but mostly by total net radiation energy when compared to datafrom the ERA5-Land meteorological reanalysis. Moreover, nearly all the non-trend interannual masschanges and most seasonal mass changes can be explained by the total net radiation energy data. The massloss trends could be partly related to a heat effect due to increased net rainfall in Tianshan Mountains, QilianMountains, Nyainqentanglha Mountains and Eastern Himalayas. Our new results for the glacier mass changein this study could help improve the understanding of glacier variation in the HMA area and contribute tothe study of global change. They could also serve the utilization of water resources there and in neighboringareas.
基金supported by the National Natural Science Foundation of China(42071085,41701087)the Open Project of the State Key Laboratory of Cryospheric Science(SKLCS 2020-10)。
文摘High Mountain Asia(HMA) region contains the world’s highest peaks and the largest concentration of glaciers except for the polar regions, making it sensitive to global climate change. In the context of global warming, most glaciers in the HMA show various degrees of negative mass balance,while some show positive or near-neutral balance. Many studies have reported that spatial heterogeneity in glacier mass balance is strongly related to a combination of climate parameters. However, this spatial heterogeneity may vary according to the dynamic patterns of climate change at regional or continental scale. The reasons for this may be related to non-climatic factors. To understand the mechanisms by which spatial heterogeneity forms, it is necessary to establish the relationships between glacier mass balance and environmental factors related to topography and morphology. In this study, climate, topography,morphology, and other environmental factors are investigated. Geodetector and linear regression analysis were used to explore the driving factors of spatial variability of glacier mass balance in the HMA by using elevation change data during 2000–2016. The results show that the coverage of supraglacial debris is an essential factor affecting the spatial heterogeneity of glacier mass balance, followed by climatic factors and topographic factors, especially the median elevation and slope in the HMA. There are some differences among mountain regions and the explanatory power of climatic factors on the spatial differentiation of glacier mass balance in each mountain region is weak, indicating that climatic background of each mountain region is similar. Therefore, under similar climatic backgrounds, the median elevation and slope are most correlated with glacier mass balance. The interaction of various factors is enhanced, but no unified interaction factor plays a primary role. Topographic and morphological factors also control the spatial heterogeneity of glacier mass balance by influencing its sensitivity to climate change. In conclusion,geodetector method provides an objective framework for revealing the factors controlling glacier mass balance.
基金partially funded by the National Natural Science Foundation of China (41877148 and 42030501)Key Laboratory of Ecohydrology of Inland River Basin,Chinese Academy of Sciences。
文摘The model performance in simulating soil water content(SWC) is crucial for successfully modeling earth’s system,especially in high mountainous areas.In this study,the performance of Community Land Model 5.0(CLM5.0) in simulating liquid SWC was evaluated against observations from nine in-situ sites in the upper reach of the Heihe River Watershed(HRW),Northwest China.The CLM5.0 shows reliable performance in the study area with correlation coefficients(R) ranging between 0.79–0.93,root mean standard errors(RMSE)ranging between 0.044–0.097 m^(3)/m^(3),and the mean bias(BIAS) ranging between-0.084–0.061 m^(3)/m^(3).The slightly worse performance of CLM5.0 than CLM4.5 on alpine meadow and grassland is mainly caused by the revised canopy interception parameterization.The CLM5.0 overestimates interception and underestimates evapotranspiration(ET) on both alpine meadow and grassland during the growth period.The systematical overestimations at all the grassland sites indicate that the underestimation of ET is much larger than the overestimation of interception on grassland during growth period,while the errors of simulated interception and ET are partially canceled out on alpine meadow.Moreover,the underestimation of ET is more responsible for the overestimation of SWC than the overestimation of interception in the high mountainous area.It is necessary to estimate reasonable empirical parameter α(proportion of leaf water collection area) in interception parameterization scheme and further improve the dry surface layerbased soil evaporation resistance parameterization introduced in CLM5.0 in future researches.The performance of CLM5.0 is better under completely frozen stage than thawing stage and freezing stage,because of low variations of liquid SWC caused by extremely low hydraulic conductivity of soils.The underestimation of liquid SWC under frozen state is caused by underestimation of soil temperature,which leads to more ice mass and less liquid water in total water content.
基金supported by the Major Project on Natural Science Foundation of Universities in Anhui Province(2022AH040111)the National Natural Science Foundation of China(42071085,41701087)。
文摘Velocity is an important component of glacier dynamics and directly reflects the response of glaciers to climate change.As a result,an accurate determination of seasonal variation in glacier velocity is very important in understanding the annual variation in glacier dynamics.However,few studies of glacier velocity in the High Mountain Asia(HMA)region were done.Along these lines,in this work,based on Sentinel-1 glacier velocity data,the distribution of glacier velocity in the HMA region was plotted and their seasonal variations during 2015-2020 were systematically analysed.The average glacier velocity in the HMA region was 0.053 m/d,and was positively correlated with the glacier area and slope.Glaciers in the Karakoram Mountains had the fastest average flow velocity(0.060 m/d),where the glaciers exhibited the largest average area and average slope.Moreover,glaciers in the GangdisêMountains had the slowest velocity(0.022 m/d)and the smallest average glacier area.The glacier flows were the fastest in spring(0.058 m/d),followed by summer(0.050 m/d),autumn(0.041 m/d),and winter(0.040 m/d).In addition,the glacier flows were the maximum in May,being 1.4 times of the annual average velocity.In some areas,such as the Qilian,Altun,Tibetan Interior,Eastern Kunlun,and Western Kunlun mountains,the peak glacier velocities appeared in June and July.The glacier velocity in the HMA region decreased in midsummer and reached the minimum in December when it was 75%of the annual average.These results highlight the role of meltwater in the seasonal variation in glacier flows in late spring and early summer.The seasonal velocity variation of lake-terminating glaciers was similar to that of land-terminating ones,but the former flowed faster.The velocity difference close to the mass balance line between the lake-and land-terminating glaciers was obviously greater in spring than in other seasons.In summer,the difference between the lake-and land-terminating glaciers at a normalized distance of 0.05-0.40 from the terminus was significantly greater than those of other seasons.The velocity difference between the lake-and land-terminating glaciers is closely related to the variable of ice thickness,and also to the frictional force of the terminal base reduced by proglacial lakes.Thus,it can be concluded that in addition to the variation of the glacier thickness and viscosity,the variation of glacier water input also plays a key role in the seasonal variation of glacier velocity.
基金Supported by the Projects"Modem state,biodiversity and ecology of the shore zone of Baikal"(VI.51.1.10)(2013-2016)the "Dynamics of natural and natural-human systems to climate change and anthropogenic pressures(for example,Trans-Baikal)"(Ⅷ.79.1.2)(2013-2016)
文摘Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars,1863 dominates among crustaceans.In July,its abundance comprised 64%-98%of the total plankton fauna in the pelagial of these lakes,approximately 30%in the littoral zone and10%in small northern thermokarst lakes.Biometric measurements and morphological descriptions based on scanning microscope images are supplemented by the data on its geographic distribution and phenology.
基金the part of Project Obrasci ekoloko-sintaksonomskog diverziteta u procjeni stanja i nosivog kapaciteta ekosistema zivotne sredine.(The patterns of ecological-syntaxo-nomical diversity in assessment of state and carrying capacity of environment - Kanton Sarajevo,Federacija BiH,Bosna i Hercegovina,2007-09)
文摘The high alpine and subalpine vegetation of Dinaric Alps is very diverse. These are conditional on genuine patterns of development of the geological substrate, climate, soil and terrain on the mountain world, which are interconnected and spatially, and ecologically away. Also, today high mountain vegetation is extremely important indicator of global changes. In this area are many refugia of glacial biodiversity. Very illustrative example for understanding the specific forms of ecological diversity is high alpine vegetation in the area of the Balkan Peninsula. Vegetation of alpine belt of Western Balkans and Bosnia and Herzegovina is differed by extremely high level of biological and ecological diversity. Climatogenous vegetation are alpine and sub-alpine pastures above of timberline, then extra zonal forms of vegetation - glaciers, rock creeps, breaches of rocks, alpine springs, marsh, and tall greenery. This vegetation is dominant determinant of alpine ecosystems that creates their unique physiognomy and also enables prime production of biomass. It is different with extraordinary floral richness, especially in a number of endemic species and glacier relicts that are included in a large number of phytocoenoses, many of which are of endemic. In syntaxonomic sense, alpine vegetation is differentiated into lo classes： Elyno- Seslerietea, Juncetea trifidi, Salicetea herbaceae,Thalspietea rotundifolii, Asplenietea trichomanis, and Scheuchzerio-Caricetea fuscae, Montio- Cardaminetea, Loiseleurio-Vaccinietea, Mulgedio- Aconitetea and Molinio-Arrhenatheretea. These classes are differentiated into ao vegetation orders, 38 alliances and 19o associations and sub-associations. In total, that is 6o % of communities of total vegetation diversity of Bosnia and Herzegovina, and 12.5% of classes of highest syntaxonomic categories in vegetation diversity of Europe.
文摘High montain lakes are regarded as sensitive indicators of environmental changes in local and global scales.In recent years,climate change has considerablely influenced the timing of ice phenomena in these lakes.The objective of the paper is an investigation of long-term changes and periodicity of ice phenomena in high mountain Lake Morskie Oko(1392.8 m a.s.l.)located in the Tatra Mts.in the period 1971-2020.The study employed the Lomb-Scargle periodogram,linear regression modelling for temporal trends,correlation analysis,parameters of variability,and flashiness index.Periodicity of the duration of ice phenomena(~5.4 y)and ice cover on the lake(~13.5 y)was observed,although both are statistically insignificant.Ice cover duration has been interrupted several times by winter thaws after 1996 whereas no such events had been reported earlier.The trend towards a delayed appearance of ice phenomena reaches 4.0 d·decade^(-1)(p<0.001).The observed trend towards an earlier ice phenomena disappearance reaches 5.1 d·decade^(-1)(p<0.001).It results in a decline of the number of days with ice phenomena on Lake Morskie Oko at a rate of 9.0 d·decade^(-1)(p<0.001).The duration of ice cover on Lake Morskie Oko has been decreasing at a rate of 10.4 d·decade^(-1).It is attributed to later freezeup(3.9 d·decade^(-1),p<0.001)and earlier ice break-up(5.6 d·decade^(-1),p<0.001).An increasing trend of average annual air temperature(0.4°C·decade^(-1),p<0.001)in the period 1971-2020 is observed.A statistically significant correlation is recorded between ice phenomena and ice cover(beginning,end,duration),average annual air temperature,average air temperature of three summer months(June,July,August),and average air temperature of the six months period from June to November.Higher air temperature induces growing heat resources accumulated in the lake water in the summer and autumn seasons,potentially causing later initiation of ice phenomena in the lake.There is no statistically significant relationship between maximum ice thickness and any air temperature parameters.Variability of maximum ice thickness appears to have been significantly increasing in the second part of the investigated period(1996-2020).
基金The authors gratefully acknowledge the science teams of NASA High Mountain Asia 8-meter DEM and NASA ICESat-2 for providing access to the data.This work was conducted with the infrastructure provided by the National Remote Sensing Centre(NRSC),for which the authors were indebted to the Director,NRSC,Hyderabad.We acknowledge the continued support and scientific insights from Mr.Rakesh Fararoda,Mr.Sagar S Salunkhe,Mr.Hansraj Meena,Mr.Ashish K.Jain and other staff members of Regional Remote Sensing Centre-West,NRSC/ISRO,Jodhpur.The authors want to acknowledge Dr.Kamal Pandey,Scientist,IIRS,Dehradun,for sharing field-level information about the Auli-Joshimath.This research did not receive any specific grant from funding agencies in the public,commercial,or not-for-profit sectors.
文摘High Mountain Asia(HMA),recognized as a third pole,needs regular and intense studies as it is susceptible to climate change.An accurate and high-resolution Digital Elevation Model(DEM)for this region enables us to analyze it in a 3D environment and understand its intricate role as the Water Tower of Asia.The science teams of NASA realized an 8-m DEM using satellite stereo imagery for HMA,termed HMA 8-m DEM.In this research,we assessed the vertical accuracy of HMA 8-m DEM using reference elevations from ICESat-2 geolocated photons at three test sites of varied topography and land covers.Inferences were made from statistical quantifiers and elevation profiles.For the world’s highest mountain,Mount Everest,and its surroundings,Root Mean Squared Error(RMSE)and Mean Absolute Error(MAE)resulted in 1.94 m and 1.66 m,respectively;however,a uniform positive bias observed in the elevation profiles indicates the seasonal snow cover change will dent the accurate estimation of the elevation in this sort of test sites.The second test site containing gentle slopes with forest patches has exhibited the Digital Surface Model(DSM)features with RMSE and MAE of 0.58 m and 0.52 m,respectively.The third test site,situated in the Zanda County of the Qinghai-Xizang,is a relatively flat terrain bed,mostly bare earth with sudden river cuts,and has minimal errors with RMSE and MAE of 0.32 m and 0.29 m,respectively,and with a negligible bias.Additionally,in one more test site,the feasibility of detecting the glacial lakes was tested,which resulted in exhibiting a flat surface over the surface of the lakes,indicating the potential of HMA 8-m DEM for deriving the hydrological parameters.The results accrued in this investigation confirm that the HMA 8-m DEM has the best vertical accuracy and should be of high use for analyzing natural hazards and monitoring glacier surfaces.
文摘Data material of a long-term high mountain ecosystem research project was used to interpret thegrazing impact of reindeers. In central Norwayinvestigations were conducted to both, areas wherereindeer grazing is excluded, and areas whereintensive pasturing is present for a long period oftime. The comparative analysis of grazing impact was based on similar environmental conditions. Theresults were transposed to northern Norway wheredramatic overgrazing had been exceeding thecarrying capacity. Using landscape ecologicalmappings, especially of vegetation and soils, theimpact of reindeer grazing in different areas becameobvious. Non-grazed lichen-dominated ecosystems of the snow-free locations functioned sensitively nearthe limit of organism survival. These localities weremost influenced by grazing as they offer the winterforage to the reindeers. So, intensive grazing incentral Norway led to landscape degradation bydestruction of the vegetation and superinduced bysoil erosion. Those features were comparable to thesituation in northern Norway, where a broad-scale destruction of the environment combined with adepression of the altitudinal belts had occurred dueto overgrazing. Functioning principles of intact high mountain systems were explained and used to interpret theenvironmental background for the understanding ofdegradation phenomena. Finally, the use of a newmodel calculating the carrying capacity of high mountain landscape was discussed.
文摘In lowlands climate-specific processes due to weathering and erosion are dominant, whilst the geomorphology of mountains is dependent on the geologic-tectonic structure, i.e., the energy of erosion that increases according to the vertical. The expression ＂extremely high mountains＂ has been established as the extreme of a continuous mountain classification. It has to be understood in terms of geomorphology, glaciology and vegetation. Correspondence of the planetary and hypsometric change of forms is of great value as synthetic explanation. It is confirmed with regard to vegetation, periglacial geomorphology and glaciology. Due to the world-wide reconstruction of the snowline its paleoclimatie importance increases, too. Apart from lower limits the periglacial and glacial altitudinal levels also show zones of optimum development and climatic upper limits in the highest mountains of the earth. According to the proportion of the altitudinal levels a classification as to arid, temperate and humid high mountains has been carried out.
文摘With the rapid development of science and technology, radio and television are becoming more and more popular. In addition, the continuous improvement of people's spiritual and cultural enthusiasm puts forward higher requirements for radio and television. In order to ensure signal coverage, most radio and television stations choose high mountains. There are some problems and shortcomings when starting the mountain station. The integrity, integrity and reliability of radio station facilities and equipment depend on the security of transmissions and broadcasts. In order to ensure the safety and high-quality transmission of broadcast signals, the daily safety management of equipment in the computer room is very important.
文摘The tea tree [Camellia sinensis (L) Kuntze] is one of the world’s economic crops. It is an especially important crop for southern China. Environmental factors related to the tea yield and quality in some high mountain areas of China are identified in this paper. These factors are: geology, topography, climate, hydrology, soil and vegetation. Climatological factors are the most important. Using data collected from meteorological stations which are situated at the summit and the base of high mountains, this paper discusses ecological climatic problems in growing tea in China. The ecological climatic characteristics of the famous tea areas mainly included are as follows: more . amounts of clouds and fog, less percentage of sunshine, abundant rainfall and high relative humidity in the air, temperatures that rise and fall slowly, daily and annual temperature ranges that are smaller, more days that are suitable for tea growing and low wind speeds in the lee-sides and valleys of mountains. All of these
基金supported by the International Cooperation Project of Science and Technology Plan of Jiangsu Province(Grant No.BZ2024032)the National Natural Science Foundation of China(Grant Nos.41830105, 42201135)。
文摘The High Mountain Asia(HMA) hosts the largest and most extensive mid-to low-latitude mountain glaciers,forming a crucial part of the “Asian Water Tower”.The temporal span of remote sensing data in previous regional glacier inventories impacts quantitative estimates in glaciological studies.Remote sensing big data,including cloud-free Sentinel-2 and Landsat-8 optical imagery,along with Sentinel-1 SAR data during the ablation period from July to September 2020,were utilized to generate a new time-stamped glacier inventory for the HMA(HMAGI-2020).Glacier outlines were automatically delineated using a VGG16-UNET deep learning model,leveraging unique spectral,polarization,and topographic characteristics as inputs,achieving an accuracy of up to 92.8%.The automated results were segmented based on existing glacier inventories,followed by manual corrections conducted primarily using Sentinel-2,supplemented by Landsat-8 in areas covered by optical imagery.A total of 93043 glaciers were manually corrected,and 15 attributes,including area,perimeter,and terrain parameters derived from the Copernicus DEM,were calculated for each glacier.The HMAGI-2020 includes 97934 glaciers whose area is larger than 0.01 km^(2),covering an area of 91837.77±2527.70 km^(2).The mean uncertainty of glacier delineation was calculated to be ±6.67% using a buffer-zone method combined with the VGG16-UNET.Across the HMA,the average glacier surface elevation is approximately 5094 m,with an average slope of 25.66°.Over 75% of glaciers are oriented toward the south,southwest,or southeast.Comparison with previous glacier inventories revealed a retreat of HMA glaciers over the past two decades,with glacier area reductions exceeding 20% in the southeastern HMA.In contrast,the Karakoram-West Kunlun region remains relatively stable,with only a slight area increase of less than 1%.Due to its advantages in data source consistency and temporal precision,the HMAGI-2020 is regarded as providing accurate glacier boundaries and attributes in 2020.This inventory is expected to provide essential data support for research on glaciology,climate change,and water resource management of the HMA in the context of global change.
基金supported by the National Natural Science Foundation of China under the project entitled“Basic Science Center Research Program for the Tibetan Plateau Earth System”(41988101)the National Natural Science Foundation of China(42205039)+1 种基金the Chinese Academy of Sciences(XDA20060102)the Youth Innovation Team of China Meteorological Administration(CMA2023QN15).
文摘High-Mountain Asia(HMA)is an important source of freshwater since it holds the largest reservoir of frozen water outside the polar regions.HMA feeds ten great rivers,ultimately supporting more than 2 billion people.However,the threat of accelerated glacier melt,which is a consequence of unprecedented global warming since the early 1950s,threatens water resources in the surrounding countries.Accurate predictions of the near-term temperature change and synergistic mass loss of glaciers are essential but challenging to implement because of the impacts of internal climate variability.Here,based on large ensembles of state-of-the-art decadal climate prediction experiments,we provide evidence that the internally generated surface air temperature variations in HMA can be predicted multiple years in advance,and the model initialization has robust added value to the decadal prediction skill.Real-time decadal forecasts suggest that the HMA will experience accelerated warming in 2025-2032,where the surface warming will increase by 0.98°C(0.67 to 1.33°C;5%to 95%range)relative to the reference period 1991-2020,which is equivalent to 1.75 times the observed warming during 2016-2023.The decadal predictability originates from extratropical Pacific decadal variability modes,which modulate the convective heating in the tropical Pacific and influence HMA via the eastward-propagating atmospheric Kelvin waves.Accelerated warming in the coming decade will likely increase the shrinkage of the glacier volume over the HMA by 1.4%.This change poses unprecedented challenges,including potential water scarcity,ecosystem disruption,and increased risk of natural disasters,to HMA and surrounding regions.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0906)the National Natural Science Foundation of China(52479055)+2 种基金the National Key R&D Program of China(2023YFC3209900)the Fundamental Research Funds for the Central Universities,Peking University(7100604495)the Excellent Young Scientists Fund of the National Natural Science Foundation of China。
文摘High Mountain Asia(HMA),known as the"Asian Water Tower",is the Earth’s critical water source and provides important ecosystem services for millions of people in the downstream[1].Due to its high altitude and extensive cryosphere,HMA is sensitive and vulnerable to climate change[1-3].Currently,HMA has been experiencing a notable temperature increase at a rate twice that of the global average,accompanied by complex changes in precipitation patterns[1,4,5].
基金funded by the Natural Environment Research Council’s Global Challenges Research Fund(NE/P016146/1)。
文摘Mountain communities in Nepal are increasingly exposed to climate-induced shifts in water availability,driven by glacial retreat,altered precipitation/snowmelt regimes,and declining groundwater sources.This study presents an integrated framework combining hydrological source analysis with socio-demographic survey data to evaluate seasonal water contributions and communitylevel water use patterns in the Upper Marsyangdi catchment,Manang District,Nepal.Isotopic(δ^(18)O)and geochemical(silica)tracers were used in a Bayesian mixing model to quantify the seasonal contributions of glacial melt,snow,rain,and groundwater to river flow.Findings indicate that groundwater dominates pre-monsoon flow(60%-70%)while post-monsoon discharge reflects more balanced inputs from all sources.In parallel,120 household surveys were analysed using Latent Class Analysis to characterise water use across domestic,agricultural,energy,and tourism sectors.Results reveal spatial and demographic gradients in water source dependency,including gender and occupation as important predictors of water use.Respondents reported perceived increases in spring flow,alongside reductions in the availability of snow for household and tourism use and deteriorating river water quality and quantity,particularly affecting hydropower operations.Adaptation strategies include increased reliance on water storage infrastructure and source switching.The study highlights the value of applying probabilistic methods to hydrological and sociocultural data to identify vulnerable populations and inform targeted,context-sensitive adaptation strategies.The proposed framework is transferable to other high-altitude regions,offering a robust approach for assessing climate resilience through the synthesis of scientific and local knowledge systems.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0201)the National Natural Science Foundation of China(Grant No.41571062)。
文摘In the context of global warming,glaciers in the Asian High Mountains(AHMs)are shrinking at an accelerating rate.Projecting their future change is helpful for understanding the hydrological and climatic effects related to glacier retreat.Here,we projected glacier change in the AHMs from 1979 to 2100 under shared socioeconomic pathway(SSP)scenarios from the perspective of temperature,equilibrium-line altitude(ELA),and accumulation area.The annual mean temperature in the AHMs increased by 1.26℃ from 1979 to 2014,corresponding to an increase of 210 m in the mean ELA and a decrease of 1.7×10^(4)km^(2) in the glacier accumulation area.Under the SSP2-4.5(SSP5-8.5)scenario,the annual mean temperature in the AHMs would increase by 2.84℃(3.38℃)in 2040–2060 relative to that in 1850–1900,leading to the mean ELA reaching an elevation of5661 m(5777 m).The accumulation area in the AHMs decreased by 46.3%from 1995 to 2014 and was projected to decrease by60.1%in 2040–2060.Moreover,the annual mean temperature in the AHMs was projected to increase by 3.76℃(6.44℃)in2080–2100 relative to that in 1850–1900,corresponding to the ELA reaching an elevation of 5821 m(6245 m)and the accumulation area decreasing to 1.8×10^(4)km^(2)(0.5×10^(4)km^(2)).These data suggest that the conditions for glacier development will disappear in most of the AHMs,except for extreme high-altitude regions in the Tianshan,Pamir,and Himalaya Mountains.Under the SSP2-4.5(SSP5-8.5)scenario,when the global mean temperature increases 1.5℃(2℃)above pre-industrial levels,the annual mean temperature will increase by 2.12℃(2.86℃)and the accumulation area will decrease by 15%(48%)in the AHMs compared with that in 1995–2015.Therefore,a 1.5℃ increase in global warming would keep 40%more of the glacial accumulation area(1.5×10^(4)km^(2))in the AHMs compared to a 2℃ increase in global warming.
