Glacier Mass-Balance Variation in China during the Past Half Century

The aim of this study is to investigate the impact of temperature trend on glacier-mass balance, snow density, snowmelt, snow depth and runoff by using observations of nine glacier stations that covered most of the China over the period of 1979-2013. Trend analysis showed an increasing trend of temperature on all of the selected stations. On an average, temperature was increasing at the rate of 0.46/10a. The increasing trend of temperature showed a negative relationship with annual glacier-mass balance on most of the stations and caused a decrease in annual balance. Results of Pearson’s correlation analysis showed a highly significant negative correlation between temperature and snow density (correlation coefficient (CC = -0.661 at 0.01 significance level). There was a significant positive correlation between temperature and snowmelt (CC = 0.532 at 0.01 significance level). There was a significant negative correlation between temperature and snow depth (correlation coefficient (CC = -0.342 at 0.05 significance level). Moreover, there was a significant positive correlation between temperature and runoff (CC = 0.586 at 0.01 significance level). Increasing trend of temperature caused an increasing trend of annual snowmelt and runoff anomaly% at the rate of 24.82/10a and 9.87/10a, respectively. On the other hand, a declining trend in annual snow density and snow depth anomaly% was found at a rate of -5.32/10a and -1.93/10a, respectively. We concluded that the snow density, snowmelt and runoff are significantly sensitive to temperature in China. This contribution has provided information for further understanding of glacier variation and its influencing factors.

The mass-balance characteristics and sensitivities to climate variables of Laohugou Glacier No.12,western Qilian Mountains,China

Due to global warming, glaciers on the Tibetan Plateau(TP) are experiencing widespread shrinkage; however, the mechanisms controlling glacier variations across the TP are still rather unclear, especially on the northeastern TP. In this study, a physically based, distributed surface-energy and mass-balance model was used to simulate glacier mass balance forced by meteorological data. The model was applied to Laohugou No. 12 Glacier, western Qilian Mountains, China, during2010~2012. The simulated albedo and mass balance were validated and calibrated by in situ measurements. The simulated annual glacier-wide mass balances were-385 mm water equivalent(w.e.) in 2010/2011 and-232 mm w.e. in 2011/2012,respectively. The mean equilibrium-line altitude(ELA) was 5,015 m a.s.l., during 2010~2012, which ascended by 215 m compared to that in the 1970 s. The mean accumulation area ratio(AAR) was 39% during the two years. Climatic-sensitivity experiments indicated that the change of glacier mass balance resulting from a 1.5 °C increase in air temperature could be offset by a 30% increase in annual precipitation. The glacier mass balance varied linearly with precipitation, at a rate of130 mm w.e. per 10% change in total precipitation.

Spatiotemporal deformation analysis of glaciers and surrounding landscapes in the Shishapangma region using InSAR techniques

Glacier dynamics in the Himalayan midlatitudes,particularly in regions like the Shishapangma,are not yet fully understood,especially the localized topographic and climatic impacts on glacier deformation.This study analyzes the spatiotemporal characteristics of glacier surface deformation in the Shishapangma region using the Small Baseline Subset(SBAS)Interferometric Synthetic Aperture Radar(In SAR)technique.The analysis reveals an average deformation rate of-4.02±17.65 mm/yr across the entire study area,with glacier regions exhibiting significantly higher rates of uplift(16.87±13.20 mm/yr)and subsidence(20.11±14.55 mm/yr)compared to non-glacier areas.It identifies significant surface lowering on the mountain flanks and localized uplift in certain catchments,emphasizing the higher deformation rates in glacial areas compared to non-glacial ones.We found a strong positive correlation between temperature and cumulative deformation(correlation coefficient of 0.63),particularly in glacier areas(0.82).The research highlights the role of temperature as the primary driver of glacier wastage,particularly at lower elevations,with strong correlations found between temperature and cumulative deformation.It also indicates the complex interactions between topographic features,notably,slope gradient,which shows a positive correlation with subsidence rates,especially for slopes below 35°.South-,southwest-,and west-facing slopes exhibit significant uplift,while north-,northeast-,and east-facing slopes predominantly subside.Additionally,we identified transition zones between debris-covered glaciers and clean ice as areas of most intense deformation,with average rates exceeding 30 mm/yr,highlighting these as potential high-risk zones for geohazards.This study comprehensively analyzes the deformation characteristics in both glacier and non-glacier areas in the Shishapangma region,revealing the complex interplay of topographic,climatic,and hydrological factors influencing glacier dynamics.

基于VIC_glacier模型的拉萨河水文模拟及冰川径流研究

拉萨河作为青藏高原南部雅鲁藏布江最大的支流,冰川融水是其径流的重要组成部分。本文基于VIC模型和度日模型构建的VIC_glacier模型,模拟了1990—2010年拉萨河流域径流过程。结果表明:(1)与VIC模型相比,VIC_glacier模型在研究区的径流模拟效果更好,日径流模拟值与观测值的相关系数接近0.8,纳什效率系数在0.75以上;(2)从上游到下游,冰川融水对径流的贡献率分别为21.4%(旁多站)、17.7%(唐加站)、14.5%(拉萨站),呈逐渐减少趋势;(3)冰川径流和非冰川径流年内变化均呈现“单峰型”形态,且在8月份达到峰值;(4)1990—2010年间,年冰川径流量整体呈现上升趋势,与同期气温上升的变化规律一致;年冰川融水对径流的贡献率与年降水量呈反比关系。研究成果可为拉萨河流域的水资源管理提供参考。

Quantifying glacier surging and associated lake dynamics in Amu Darya river basin using UAV and remote sensing data

Glaciers in the Pamir region are experiencing rapid melting and receding due to climate change,which has a significant implication for the Amu Darya river basin.Predominantly,surging glaciers,which undergo unpredictable advances,are potentially leading to the obstruction of high-altitude river channels and also glacial lake outburst floods.decrease of-703.5±30.0 m.There is a substantial increase in the number(from 19 to 75)and area(from 4889.7±0.6 m2 to 15345.5±0.6 m2)of RGS lakes along with supra-glacier ponds based on a comparison of ArcGIS base map in 2011 and high-resolution UAV data in 2023.For M glacier,number of lakes increased from 4 to 22 but the lake area declined from 10715.2±0.6 to 365.6±0.6 m2.It was noted that the largest lake in 2011 with an area of 10406.4±0.6 m2 at the southeastern portion of the glacier was not observed in 2023 due to outburst.Both the glaciers have substantially impacted the river flow(Abdukahor river)by obstructing a significant proportion of river channel in recent years and might cause outburst floods.These findings enhance the understanding of glacier dynamics and their impacts on the surrounding areas,emphasizing the urgent need for continued monitoring and appropriate management strategies,with a specific focus on surging glaciers and the associated risks.

A review of physicochemical properties of dissolved organic carbon and its impact over mountain glaciers

Investigating the characteristics and transformation of water-soluble carbonaceous matter in the cryosphere regions is important for understanding biogeochemical process in the earth system.Water-soluble carbonaceous matter is a heterogeneous mixture of organic compounds that is soluble in aquatic environments.Despite its importance,we still lack systematic understanding for dissolved organic carbon(DOC)in several aspects including exact chemical composition and physical interactions with microorganisms,glacier meltwater.This review presents the chemical composition and physical properties of glacier DOC deposited through anthropogenic emission,terrestrial,and biogenic sources.We present the molecular composition of DOC and its effect over snow albedo and associated radiative forcings.Results indicate that DOC in snow/ice is made up of aromatic protein-like species,fulvic acid-like materials,and humic acid-like materials.Light-absorbing impurities in surface snow and glacier ice cause considerable albedo reduction and the associated radiative forcing is definitely positive.Water-soluble carbonaceous matter dominated the carbon transport in the high-altitude glacial area.Owing to prevailing global warming and projected increase in carbon emission,the glacial DOC is expected to release,which will have strong underlying impacts on cryosphere ecosystem.The results of this work have profound implications for better understanding the carbon cycle in high altitude cryosphere regions.A new compilation of globally distributed work is required,including large-scale measurements of glacial DOC over high-altitude cryosphere regions,to overcome and address the scientific challenges to constrain climate impacts of light-absorbing impurities related processes in Earth system and climate models.

Comprehensive analysis of glacier recession(2000-2020)in the Nun-Kun Group of Glaciers,Northwestern Himalaya

Himalayan glaciers are shrinking rapidly,especially after 2000.Glacier shrinkage,however,shows a differential pattern in space and time,emphasizing the need to monitor and assess glacier changes at a larger scale.In this study,changes of 48 glaciers situated around the twin peaks of the Nun and Kun mountains in the northwestern Himalaya,hereafter referred to as Nun-Kun Group of Glaciers(NKGG),were investigated using Landsat satellite data during 2000-2020.Changes in glacier area,snout position,Equilibrium Line Altitude(ELA),surface thickness and glacier velocity were assessed using remote sensing data supplemented by field observations.The study revealed that the NKGG glaciers have experienced a recession of 4.5%±3.4%and their snouts have retreated at the rate of 6.4±1.6 m·a^(-1).Additionally,there was a 41%increase observed in the debris cover area during the observation period.Using the geodetic approach,an average glacier elevation change of-1.4±0.4 m·a^(-1)was observed between 2000 and 2012.The observed mass loss of the NKGG has resulted in the deceleration of glacier velocity from 27.0±3.7 m·a^(-1)in 2000 to 21.2±2.2 m·a^(-1)in 2020.The ELA has shifted upwards by 83.0±22 m during the period.Glacier morphological and topographic factors showed a strong influence on glacier recession.Furthermore,a higher recession of 12.9%±3.2%was observed in small glaciers,compared to 2.7%±3.1%in larger glaciers.The debris-covered glaciers showed lower shrinkage(2.8%±1.1%)compared to the clean glaciers(9.3%±5%).The glacier depletion recorded in the NKGG during the last two decades,if continued,would severely diminish glacial volume and capacity to store water,thus jeopardizing the sustainability of water resources in the basin.

Estimating glacier dynamics and supraglacial lakes together with associated regional hazards using high-resolution datasets in Pamir

Recent climate dynamics denote patterns and variations in climatic conditions and associated cryospheric changes in the Pamir region,affecting downstream ecosystems and communities.The present investigation describes changes in Baralmos glacier and supraglacial lakes,along with related hazards,using meteorological observations,reanalysis products,and high-resolution satellite imagery from 2002 to 2022.Moreover,observations using Unmanned Aerial Vehicles(UAVs)were conducted between 2020 and 2022 to document recent variations.Reanalysis data suggested that there are no obvious trends in annual air temperature and precipitation except for a significant temperature rise in July(the warmest month)of about 1.34°C/decade(p<0.05)and precipitation decrease in December(p<0.05).During the last two decades of investigation,lake areas expanded from 20500 to 62800±21 m2,representing an approximately threefold increase,leading to increased mudflows in the Surkhob river and causing severe damage to property and infrastructures,most prominently during 2020 and 2022.The UAV data reveal an average decrease of-2.7±0.5 m in surface elevation downstream of Baralmos glacier between 2020 and 2022.This study is vital for implementing more intensive measures of the glacial environment and defining suitable mitigation strategies in the Pamir region.

Glacier area change and its impact on runoff in the Manas River Basin,Northwest China from 2000 to 2020

Understanding the distribution and dynamics of glaciers is of great significance to the management and allocation of regional water resources and socio-economic development in arid regions of Northwest China.In this study,based on 36 Landsat images,we extracted the glacier boundaries in the Manas River Basin,Northwest China from 2000 to 2020 using eCognition combined with band operation,GIS(geographic information system)spatial overlay techniques,and manual visual interpretation.We further analyzed the distribution and variation characteristics of glacier area,and simulated glacial runoff using a distributed degree-day model to explore the regulation of runoff recharge.The results showed that glacier area in the Manas River Basin as a whole showed a downward trend over the past 21 a,with a decrease of 10.86%and an average change rate of–0.54%/a.With the increase in glacier scale,the number of smaller glaciers decreased exponentially,and the number and area of larger glaciers were relatively stable.Glacier area showed a normal distribution trend of increasing first and then decreasing with elevation.About 97.92%of glaciers were distributed at 3700–4800 m,and 48.11%of glaciers were observed on the northern and northeastern slopes.The retreat rate of glaciers was the fastest(68.82%)at elevations below 3800 m.There was a clear rise in elevation at the end of glaciers.Glaciers at different slope directions showed a rapid melting trend from the western slope to the southern slope then to the northern slope.Glacial runoff in the basin showed a fluctuating upward trend in the past 21 a,with an increase rate of 0.03×10^(8) m^(3)/a.The average annual glacial runoff was 4.80×10^(8) m^(3),of which 33.31%was distributed in the ablation season(June–September).The average annual contribution rate of glacial meltwater to river runoff was 35.40%,and glacial runoff accounted for 45.37%of the total runoff during the ablation season.In addition,precipitation and glacial runoff had complementary regulation patterns for river runoff.The findings can provide a scientific basis for water resource management in the Manas River Basin and other similar arid inland river basins.

Short communication:Extreme glacier mass loss triggered by high temperature and drought during hydrological year 2022/2023 in Qilian Mountains

In the hydrological year 2022/2023,the glaciers in the Qilian Mountains experienced unprecedented mass loss.The glacier-wide mass balance was-1,188 mm w.e.,in contrast to-350 mm of average mass balance since 1990 over the Bailanghe Glacier No.12 in the middle of Qilian Mountains.The temperature during 2022–2023 reached the highest value ever recorded,second only to 2022,while at the same time the precipitation amount was less compared to other year since 2000,which together led to the strongest glacier mass loss during 2022–2023.The atmospheric circulation analysis shows that the high temperature in the Qilian Mountains in 2023 was jointly caused by the Arctic air mass and East Asian monsoon.

Glacier area change (1993-2019) and its relationship to debris cover, proglacial lakes, and morphological parameters in the Chandra-Bhaga Basin, Western Himalaya, India

Glacier inventories serve as critical baseline data for understanding the impacts of climate change on glaciers.The present study maps the outlines of glaciers in the Chandra-Bhaga Basin(western Himalaya)for the years 1993,2000,2010,and 2019 using Landsat Thematic Mapper(TM),Enhanced Thematic Mapper(ETM),and Operational Land Imager(OLI)datasets.A total of 251 glaciers,each having an area above 0.5 km^(2),were identified,which include 216 clean-ice and 35 debris-covered glaciers.Area changes are estimated for three periods:1993-2000,2000-2010,and 2010-2019.The total glacierized area was 996±62 km^(2) in 1993,which decreased to 973±70 km^(2) in 2019.The mean rate of glacier area loss was higher in the recent decade(2010-2019),at 0.036 km^(2),compared to previous decades(0.029 km^(2) in 2000-2010 and 0.025 km^(2) in 1993-2000).Supraglacial debris cover changes are also mapped over the period of 1993 and 2019.It is found that the supraglacial debris cover increased by 14.12±2.54 km^(2)(15.2%)during 1993-2019.Extensive field surveys on Chhota Shigri,Panchi II,Patsio,Hamtah,Mulkila,and Yoche Lungpa glaciers were carried out to validate the glacier outlines and supraglacial debris cover estimated using satellite datasets.Controls of various morphological parameters on retreat were also analyzed.It is observed that small,clean ice,south oriented glaciers,and glaciers with proglacial lakes are losing area at faster rates than other glaciers in the basin.

Emerging glacier forelands alter carbon dynamics on the Tibetan Plateau

The critical challenge of ongoing climate warming is resulting in glacier melting globally,a process accompanied by the formation of substantial glacier forelands.This phenomenon emerges as a pivotal area of study,especially in the Tibetan Plateau(TP),known as the Third Pole and the Asian Water Tower.In particular,the rapid retreat of temperate glaciers in the southeastern TP has led to the formation of expansive glacier forelands.These forelands are not merely evidence of climate shifts but are also key areas for transformative carbon dynamics.Moreover,the newly exposed land surface actively adjusts the balance of dissolved organic carbon,especially in meltwater,and influences the release of greenhouse gases from a range of sources including glacial lakes,subglacial sediments,and supraglacial/proglacial rivers.These processes play a crucial role in the dynamics of atmospheric carbon dioxide.Drawing from our intensive and detailed observations over several years,this perspective not only emphasizes the importance of the underexplored impact of glacier forelands on carbon cycles but also opens a window into understanding potential future trajectories in a warming world.

Comparison of the precision of glacier flow rates derived from offset-tracking using Sentinel-2 and Landsat-8/9 imagery

Offset-tracking is an essential method for deriving glacier flow rates using optical imagery.Sentinel-2(S2)and Landsat-8/9(L8/9)are popular optical satellites or constellations for polar studies,offering high spatial resolution with relatively short revisit time,wide swath width,and free accessibility.To evaluate and compare the precision of offset-tracking results yielded with these two kinds of data,in this study S2 and L8/9 imagery observed in Petermann Glacier in Greenland,Karakoram in High-Mountains Asia,and Amery Ice Shelf in the Antarctic are analyzed.Outliers and various systematic error sources in the offset-tracking results including orbital and strip errors were analyzed and eliminated at the pre-process stage.Precision at the off-glacier(bare rock)region was evaluated by presuming that no deformation occurred;then for both glacierized and the off-glacier regions,precision of velocity time series was evaluated based on error propagation theory.The least squares method based on connected components was used to solve flow rates time series based on multi-pair images offset-tracking.The results indicated that S2 achieved slightly higher precision than L8/9 in terms of both single-pair derived displacements and least square solved daily flow rates time series.Generally,the RMSE of daily velocity is 26%lower for S2 than L8/9.Moreover,S2 provided higher temporal resolution for monitoring glacier flow rates.

Preserving glacier mass:Cellulosic LENZING^(TM) fibers provide snow and ice protection solution

In field trials on Austrian glaciers,nonwovens made of ce u osic LENZING^(TM) fibers are being used to cover glacier mass.They are showing promising results and offer a sustainable solution for glacier protection.Nonwovens containing fossilbased synthetic fibers might cause negative environmental consequences such as microplastics on glaciers.Geotextiles with ce u osic LENZINGTMfibers won the prestigious Swiss BIO TOP,an award for wood and material innovations.Geotextiles are already widely used to protect snow and ice on glaciers frommelting.

耦合时序InSAR和动力学模型的大雪山石冰川含冰量反演

石冰川是发育于冰缘环境中的一种特殊地貌,其内部冻结冰在气候暖化背景下是高寒山区重要的淡水资源.本文利用时序InSAR提取了川西高原大雪山地区1280个活动石冰川的表面年平均运动速率,然后采用耦合表面运动速率和和动力学模型的反演方法定量估计了这些石冰川的含冰量和储水当量.编目清单显示大雪山石冰川主要分布在海拔4300~4900m之间,面积介于0.004~1.5km^(2)之间,厚度主要分布在6~32m之间.研究区石冰川沿坡向最大年运动速率约为125 cm·a^(-1),所有石冰川年均形变速率平均约27 cm·a^(-1);研究区所有石冰川含冰量位于57%~74%之间(平均值为70.1%),对应的总水储量约为2.884 km3.与传统基于“面积-体积”含冰量经验估计方法相比,发现传统方法仅适宜于小面积石冰川的含冰量估算.此外,研究区内石冰川数目约是冰川的10倍,但石冰川与冰川的水储量比值为1:2.7.本研究为进一步探究大雪山地区石冰川的水文效应提供了关键数据资料,同时为高寒环境广泛发育的石冰川水储量估计提供了可行的方法参考.

Disentangling the contributing components of stream water by using environmental tracers

Identifying the various components contributing to river discharge can be challenging.This study relies on stable isotopes and electrical conductivity(EC)of water as tracers to distinguish the different components contributing to total river discharge.Additionally,we have made an effort to comprehend the processes that may influence glacier ice melt as well as the limits of oxygen-based hydrograph separation.Two distinct geographic domains in terms of climates and topographies were examined.The first study site represents the upper Ganga catchment(central Himalaya),while the second site is located in the Chandra sub-basin in western Himalaya.Errors in estimating the proportion of glacier melt in isotope mixing model are likely if end-member isotopic compositions,are not well defined,particularly for rainfall.Hydrograph separation results indicate that snowmelt is the largest contributor to total river flow in both regions.The contribution of snowmelt to the total runoff of the upper Ganga ranged from~60%to 70%.The estimated contributions of glacier melt varied from 36%to 63%in upper Ganga headwater to 6%to 15%at Devprayag and~8%at Rishikesh.In the Hamtah River,glacier and snowmelt contributions,quantified using a two-component mixing model,ranged from 10%to 14%during the pre-and postmonsoon seasons of 2013.The significant spatial and temporal variability,coupled with overlapping isotopic signatures,suggests complex glacio-fluvial interactions in these catchments.Local slow-moving air masses with whirling motion closer to the study area irrespective of the direction,and air parcels coming through Bay of Bengal branch are characterized by depleted isotopic rainfall compared to air masses originating from the Arabian Sea.

An integrated approach for GLOF hazard,vulnerability and risk assessment in the Karakoram Mountain Range of northern Pakistan

Climate change and rising temperatures are accelerating the rate of deglaciation in the Hindu Kush Karakoram Himalaya(HKH)ranges,leading to the formation of new glacial lakes and the expansion of existing ones.These lakes are often vulnerable to failure,posing a significant threat to downstream communities and infrastructure.Therefore,a comprehensive assessment of Glacier-Lake Outburst Flood(GLOF)hazards and risk assessment is crucial to evaluate flood runout characteristics and identify settlements and infrastructure that are exposed and vulnerable to floods,aiding in the development and implementation of risk reduction strategies.This study aims to simulate a GLOF event induced by the Shisper glacier lake in northern Pakistan,using the HEC-RAS,and to assess its impact on settlements,infrastructure,and agricultural land.For the hydrometeorological analysis of the GLOF event,topographic data from unmanned aerial vehicles(UAVs),stream profiles,discharge data,Manning's roughness coefficient(n),and land use/land cover(LULC)were analyzed using HEC-RAS and geographic information system(GIS).During the GLOF event on May 7,2022,a maximum water depth of 6.3 m and a maximum velocity of 9.5 m/s were recorded.Based on the runout characteristics of this event,vulnerability and risk assessments have been calculated.The physical,social,and environmental vulnerabilities of the at-risk elements were evaluated using the analytical hierarchy process(AHP)and integrated with the hazard data to develop a risk map.The study identified the areas,infrastructure and settlements susceptible to GLOF hazard to support the development and implementation of targeted and evidence-based mitigation and adaptation strategies.

Glacier change in the Tanggula Mountains, Tibetan Plateau,in 1969-2015

To improve our knowledge of glacier change in the Tanggula Mountains located in the northeast of the Tibetan Plateau,we delineated outlines of the glaciers in 1991 and 2015 using Landsat TM/OLI images and compared them with the reported glacier data in the First Chinese Glacier Inventory in 1969 and the Second Chinese Glacier Inventory in 2007.These comparisons showed that the glacier area and ice volume decreased by 524.8 km2 and 37 km3,respectively.The majority of the glacier area loss was concentrated in the area class of 1-5 km2,between 5300 m and 5500 m in elevation,on north and east facing slopes and in the Dam Qu River basin.These glacier changes exhibited spatial and temporal differences.The glacier retreat rate gradually increased from 1969 to 2015,and the rate in the east was higher than that in the west.From 1969 to 2015,the warming rate in the Tanggula Mountains was 0.38°C/10a,while the annual precipitation only increased by 0.4%.The slight increase in the amount of precipitation made a limited contribution to glacier change,while the change in temperature led to noticeable shrinkage of the glaciers.Contrary to the retreat or stagnation of most glaciers in the study area,there were 10 glaciers that experienced clear advance in 1986-2015 with noticeable increases in both area and length.Whether or not these 10 glaciers are surge glaciers requires further study.

The response of lake-glacier variations to climate change in Nam Co Catchment, central Tibetan Plateau, during 1970-2000

Based upon the 1970 aero-photo topographic map, and TM/ETM satellite images taken in 1991 and 2000, the authors artificially interpreted boundaries of lake and glaciers in Nam Co Catchment, and quantified lake-glacier area variations in different stages by ＂integrated method＂ with the support of GIS. Results show that from 1970 to 2000, lake area increased from 1942.34 km^2 to 1979.79 km^2 at a rate of 1.27 km^2/a, while glacier area decreased from 167.62 km^2 to 141.88 km^2 at a rate of 0.86 km^2/a. The increasing rate of lake in 1991-2000 was 1.76 km^2/a that was faster than 1.03 km^2/a in 1970-1991, while in the same period of time, the shrinking rates of glaciers were 0.97 km^2/a and 0.80 km^2/a respectively. Important factors, relevant to lake and glacier response to the climate, such as air temperature, precipitation, potential evapotranspiration and their values in warm and cold seasons, were discussed. The result suggests that temperature increasing is the main reason for the accelerated melting of glaciers. Lake expansion is mainly induced by the increase of the glacier melting water, increase of precipitation and obvious decrease of potential evapotranspiration. Precipitation, evaporation and their linkages with lake enlargement on regional scale need to be thoroughly studied under the background of global warming and glacier retreating.