Flooding(or breaching)of inter-connected proglacial lakes by cascading overflow in the arid region of Western Mongolia(Mt.Tsambagarav,Mongolian Altai)

This study investigates the glacial lake outburst flood(GLOF)hazards in the Tsambagarav mountain range in Western Mongolia,focusing on the Khukhnuruu Valley and its interconnected proglacial lakes.Over the last 30 years,significant glacier retreats,driven by rising temperatures and changing precipitation patterns,have led to the formation and expansion of several proglacial lakes.Fieldwork combined with satellite data and meteorological analysis was used to assess the dynamics of glacier and lake area changes,with particular focus on the flood events of July 2021.The research reveals a substantial reduction in glacier area,particularly in the Khukhnuruu E complex,where glacier area decreased by 19.3%.The study highlights the influence of increasing temperatures and summer precipitation,which have accelerated ice melt,contributing to the expansion and eventual breaching of lakes.Additionally,lake area changes were influenced by the steepness of the terrain,with steeper slopes exacerbating peak discharge during floods.Of the studied seven lakes(Lake 1 to Lake 7),Lake 1 experienced the most dramatic reduction,with a decrease in area by 73.51%and volume by 84.84%,followed by Lake 7.This study underscores the region's vulnerability to climate-induced hazards and stresses the need for a comprehensive early warning system and disaster preparedness measures to mitigate future risks.

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 (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.

Morphology of crater and caldera lakes in the Far Eastern region of Russia and the features of their development

Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data available.The authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric characteristics.It has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal activity.While lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric indicators.It was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their basins.The volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous processes.For the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were calculated.Repeated observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 years.This analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their study.The results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying other volcanic lakes.

Quantifying freeze-melt dynamics of lakes on the Tibetan Plateau using Sentinel-1 synthetic aperture radar imagery

The ice phenology of alpine lakes on the Tibetan Plateau(TP)is a rapid and direct responder to climate changes,and the variations in lake ice exhibit high temporal frequency characteristics.MODIS and passive microwave data are widely used to monitor lake ice changes with high temporal resolution.However,the low spatial resolutions make it difficult to effectively quantify the freeze-melt dynamics of lakes.This work used Sentinel-1 synthetic aperture radar(SAR)data to derive high-resolution ice maps(about 6 days),then with the aid of Sentinel-2 optical images to quantify freeze-melt processes in three typical lakes on the TP(e.g.Selin Co,Ayakekumu Lake,and Nam Co).The results showed that three lakes had an average annual ice period of 125-157 days and a complete ice cover period of 72-115 days,from 2018 to 2022.They exhibit different ice phenology patterns.Nam Co is characterized by repeated episodes of freezing,melting,and refreezing,resulting in a prolonged freeze-up period.Meanwhile,the break-up period of Nam Co lasts for a longer duration(about 19 days),and the break-up exhibits a smooth process.Similarly,Ayakekumu Lake showed more significant inter-annual fluctuations in the freeze-up period,with deviations of up to 28 days observed among different years.Compared to the other two lakes,Selin Co experienced a relatively short freeze-up and break-up period.In short,Sentinel-1 SAR data can effectively monitor the weekly and seasonal variations in lake ice on the TP.Particularly,this data facilitates quantification of the freeze-melt dynamics.

Shallow sub-lakes are essential for sustaining the successful wintering of waterbirds in Poyang Lake,China

For migratory waterbirds,the quality of wintering habitat is related to spring migration and successful breeding in the next year.The availability of food resources in the habitat is critical and varies within water levels.Although the water-level fluctuations in Poyang Lake have been extremely variable interannually in recent years,the wintering waterbird populations have remained relatively stable.Hence,the mechanism of maintaining the stability is worth exploring.This study aimed to compare the distribution of vegetation and herbivorous wa-terbirds in 2015-2016 and 2016-2017,focusing on three shallow sub-lakes and one main lake are.The results showed that the emergence of tubers and the growth of Carex spp.provided a continuous food supply and habitat for wintering waterbirds with a gradual decline in the water level.Shallow sub-lakes supported almost all of the tuber-eating waterbirds(1.42-1.62×10^(5))and most geese(1.34-1.53×10^(6)).However,the main lake area,covered with Persicaria hydropiper,did not provide adequate and accessible food.This resulted in almost no distribution of tuber-eating waterbirds,with only a few geese congregating in early winter.Our results demonstrated that the shallow sub-lakes under human control provided a different environment from the main lake and are key to sustaining the successful wintering of hundreds of thousands of migratory waterbirds in Poyang Lake.Therefore,we recommend refining the anthropogenic management of the shallow sub-lakes to regulate the water level to ensure the carrying capacity of Poyang Lake.

Assessment of rehabilitation strategies for lakes affected by anthropogenic and climatic changes: A case study of the Urmia Lake, Iran

Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a.

Microscopic analysis on eukaryotic algae and cyanobacteria in nine seasonal lakes and ponds in Vestfjella,Dronning Maud Land,Antarctica

Antarctic continental lakes and ponds are among the most impoverished aquatic environments on earth but many of them support flourishing populations of cyanobacteria,eukaryotic algae,protozoans,and some multicellular animals.In this study,we present results of a microscopic analysis of cyanobacteria and eukaryotic algae from nine diverse types of Antarctic continental water bodies during one austral summer.The results supplement and enlarge our previous studies on the limnological characteristics of the epiglacial and supraglacial lakes and ponds in Dronning Maud Land,an area that has received little attention from limnologists.The taxon with highest frequency among the samples(n=79)was Mesotaenium cf.berggrenii,a eukaryotic Zygnematophyceae,which occurred in 82%of the samples with a maximum cell density of 68 cells·mL^(-1).The taxa with second and third highest frequency were the prokaryotes Gloeocapsopsis(60%)and Leptolyngbya(41%),followed by Chlamydomonas(34%)and Cyanothece(29%).The number of taxa varied between 7-21 among the lakes and ponds,being highest in a supraglacial lake,and lowest in an epiglacial lake.The results did not reveal any obvious correlation between the abundance of any taxa and the water chemistry,but water bodies with inorganic sediments had higher cell densities and biomasses than those without sediment.This suggests the importance of sediment in supporting biological diversity in these ultraoligotrophic lakes and ponds.

Glacial lakes under climate change: the imperative for comparative studies of microbial carbon metabolism in the Qinghai-Xizang Plateau and the Arctic

Glacial lakes,intimately linked to glacier termini,are crucial landscape features of the Qinghai-Xizang Plateau(QXP,Qinghai-Tibet Plateau)and the Arctic.Climate warming has accelerated glacier retreat and the rapid expansion of glacial lakes in both regions.Despite being typically considered harsh environments,these lakes serve as vital reservoirs for microbial biodiversity and carbon metabolism.In the face of climate change,glacial lake ecosystems over the QXP and the Arctic are undergoing unprecedentedtransformations.Thisopinioneditorial highlights the significance of conducting research and establishing long-term monitoring programs focused on microbial carbon metabolism in these glacial lakes.

Comparison and Selection of Water Restoration Techniques for Artificial Landscape Lakes in Nantong City

As an important part of urban infrastructure,urban water system is of great and far-reaching significance for ensuring urban flood control and waterlogging safety,protecting ecological environment and building livable homes.Taking the urban water system of Nantong as an example,Nantong Water Resources Bureau issued R evision of Nantong Urban Water System Planning in 2017,and put forward the construction of the"two circles,eight lakes and nine veins"water system layout,giving new vitality to the urban water system.In view of problems existing in newly excavated artificial landscape lakes,such as fragile water ecosystem,strong eutrophication trend,poor environmental sensory effect and unsatisfactory water landscape effect,it is urgent to study the in-situ water ecological restoration technique of"algae-controlling zooplankton+submerged plant community"to build a"grass-type clear water"ecosystem for artificial landscape lakes,so as to improve the water sensory index and self-purification ability and finally realize the double improvement of"sensory effect and water quality"of artificial landscape lakes.

Ecological Restoration Technologies of Urban Artificial Landscape Lakes

Aiming at the problems of water pollution and ecological environment degradation in urban artificial landscape lakes,the ecological restoration technologies of artificial landscape lakes at home and abroad were studied to provide some reference for the ecological restoration of urban artificial landscape lakes in China.

Hydrochemistry of the lakes in the southern Badain Jaran Desert and its paleosalinity reconstruction

The reconstruction of paleohydrology,especially paleosalinity,is an important component of paleoenvironmental research.Researches on the modern characteristics of lake water chemistry and the relationship between lake salinity and hydrochemistry are the basis of paleoenvironment reconstruction.The modern hydrochemical characteristics and the relationship between ion composition and salinity of modern lakes are the basis of paleosalinity reconstruction.In this study,hydrochemical analysis of 21 lakes in the Badain Jaran Desert(BJD)was carried out.The relationships between the Sr/Ca and Mg/Ca ratios and total dissolved solids(TDS)were analyzed.The results show that Na^(+),K^(+),Cl-and SO_(4)^(2-)have high positive correlations with TDS,and Mg^(2+),Sr^(2+),CO_(3)_(2-)and HCO_(3)^(-)have lower correlations with TDS.The Sr/Ca and Mg/Ca ratios do not increase linearly with TDS.Hydrochemical analysis indicates that the studied lakes are in the carbonate precipitation stage and that evaporation is the main factor controlling lake evolution in the BJD.The relationships between the Mg/Ca and Sr/Ca ratios and TDS are mainly influenced by lake evolution stage and the hydrochemical types of the lakes.On the basis of comprehensive previous studies,the factors affecting lake evolution,the Mg and Sr partition coefficients and other hydrochemical parameters that change with lake evolution all affect the relationship between chemical composition and salinity.To reconstruct paleosalinity more accurately,more detailed research on the modern hydrochemical characteristics of lakes and the relationship between the element ratios of carbonates and water salinity should be carried out.

Future Development Direction of the Restoration of Mountains,Rivers,Forests,Farmlands,Lakes,and Grasslands and the Faced Problems

In this paper,the definition,connotation,and internal relationship of mountains,rivers,forests,farmlands,lakes,and grasslands in China are elaborated,and the current situation of ecological restoration projects for mountains,rivers,forests,farmlands,lakes,and grasslands was introduced.Moreover,the problems that have arisen in the specific implementation process of pilot projects were analyzed,such as unclear target positioning,inaccurate analysis of ecological problems,insufficient engineering design systematicness,weak operability of evaluation standards,and weak coordination in engineering management.The development direction and major needs for the protection and restoration of mountains,rivers,forests,farmlands,lakes,and grasslands in the future have been proposed from four aspects:theoretical research,engineering design,effect evaluation,and monitoring and supervision.

青藏铁路沿线湖泊及其与铁路最小距离演变研究

受全球气候变化影响,青藏高原湖泊近年来变化剧烈,充分了解湖泊演变特征及其驱动因素对保护沿湖重大工程设施有重要意义。基于青海湖与错那湖的Landsat遥感影像、面积数据和水位观测数据,本文对两湖演变及其与青藏铁路最小距离变化进行了细致研究,进一步结合中国区域高时空分辨率地面气象要素驱动数据集(CMFD)和气象站的气象数据,揭示了影响两湖水位变化的主要气象因子,结果表明:(1)1956-2004年青海湖呈退缩态势,2004年水位和面积达到最低值后转为逐渐增加,2004-2020年水位年均增长率为0.20 m·a^(-1),2004-2022年面积年均增长率为19.20 km^(2)·a^(-1)。2000-2018年的错那湖水位与从20世纪70年代至2022年的面积均呈轻微波动变化,水位和面积的年际最大变化值分别为0.60 m和9.98 km^(2)。(2)1990-2022年青海湖与青藏铁路最小距离先增加后减小,2004年后二者最小距离以19.6 m·a^(-1)的速率缩短,至2022年最小距离为74.3 m;2004-2022年错那湖与青藏铁路最小距离变化趋势不明显,至2022年二者最小距离为32.3 m。(3)青海湖的水位变化受风速、年降水量、向下短波辐射、向下长波辐射和比湿影响,贡献率分别为38%、24%、20%、14%和4%;错那湖水位变化主要受年降水量影响,其余气象因子与水位变化相关性不显著。

Seasonal dynamics of wintering waterbirds in two shallow lakes along Yangtze River in Anhui Province

The shallow lake wetlands in the middle and lower Yangtze River floodplain are important wintering and stopover habitats for migratory waterbirds on the East Asia-Australia Flyway.With increasing fishery practices in recent years,however,the wetlands have deteriorated significantly and now threaten wintering waterbirds.To gain insight into the influence of deteriorating wetlands on waterbirds,we conducted a survey of wintering waterbird species,population size,and distribution across 11 belt transects in Caizi Lake and Shengjin Lake,two shallow lakes along the Yangtze River in Anhui Province from November 2007-April 2008 and from November 2008-April 2009,respectively.The impacts of different fishery patterns on the distribution of waterbirds were also analyzed.A total of 43 waterbirds species belong to 7 orders of 12 families were counted during the surveys,of which 38 were found in Caizi Lake with a density of 8.2 ind./hm2,and 42 in Shengjin Lake with a density of 3.5 ind./hm2.Geese（Anser cygnoides）,bean geese（Anser fabalis）,tundra swan（Cygnus columbianus）,and dunlin（Calidris alpina） were the dominant species in the two shallow lakes.Species number and individual assemble reached maximum at the end of December and in early January of the following year,without coincidence of the largest flock for different ecological groups.Based on waterbird diversity across the 11 belt transects and the fishery patterns,habitats could be divided into three groups.Gruiformes,Anseriformes and Charadriiformes had relatively higher densities in the natural fishery zones and lower densities in the cage fishery zones;whereas,the density of Ardeidae showed little change across all lake zones.It is important to develop sustainable fishery patterns in shallow lakes along the middle and lower Yangtze River floodplain to better protect resources of wintering waterbirds.

低温下基于Lakes液的皖西白鹅精液稀释液研究

为研究低温（2—5℃）条件下皖西白鹅精液稀释液，以Lakes液为参考，通过更换糖（果糖、葡萄糖、蔗糖）和缓冲物质（柠檬酸钾、Tris、EDTA）来筛选最佳组合。结果表明：①Lakes液（果糖＋柠檬酸钾）中，精子有效保存时间为42h，总保存时间为234h。②与Lakes液相比，“果糖＋Tris”组合最佳，精子有效保存时间为48h（P〈0．01），总保存时间为264h（P〈0．01）；其次为“葡萄糖＋Tris”组合，精子有效保存时间为43h（P〉0．05），总保存时间为240h（P〈0．01）。③其他组合的有效保存时间及总保存时间均低于Lakes液（P〈0．01）。

应用谷歌地球引擎和多维特征集构建的艾比湖流域长时序景观分类模型

以新疆艾比湖流域为研究区域,整合历史遥感影像数据与现场地表特征考察,将艾比湖流域景观类型划分为6类(耕地、林地、草地、水域、建设用地、未利用地);以谷歌地球引擎(GEE)平台提供的艾比湖流域2002—2023年(2002、2008、2013、2018、2023年)的陆地卫星(Landsat)影像为基础数据源,以艾比湖流域长时序景观分类为评价指标,光谱指数(归一化植被指数、增强植被指数、归一化水体指数、归一化建筑指数)、地形特征(海拔、坡度、坡向)、纹理特征(角二阶矩阵、对比度、相关性、熵、协方差、逆方差、总和平均值)为影响因素,从光谱指数、地形特征、纹理特征三个角度构建并筛选最优多维特征模型;分别运用分类回归树(CART)、随机森林(RF)、梯度提升树(GBT)、支持向量机(SVM)机器学习算法,对艾比湖流域长时序景观信息进行自动分类,对比4种机器学习算法的分类精度,遴选最适用于艾比湖流域的景观分类模型。结果表明:(1)应用谷歌地球引擎云计算平台,能够高效处理、分析及可视化研究区近22 a的景观分类结果。(2)3类特征重要性,由大到小依次为光谱指数(31.52%)、地形特征(17.18%)、纹理特征(3.83%)。地形特征在单一特征中分类精度最高;光谱特征联合纹理特征,在双特征配置中对提高研究区景观分类精度呈现出较好效果;而整合光谱指数、地形特征、纹理特征的模型,能够在任一特征组合的基础上有效提高研究区景观分类模型精度。(3)4种分类算法融合光谱、地形、纹理特征,分类精度由高到低依次为随机森林、梯度提升树、分类回归树、支持向量机;随机森林在5期(2002、2008、2013、2018、2023年)影像中的总体分类精度不低于93%,卡帕系数(Kappa)不低于0.92,最适用于艾比湖流域景观分类。

鄱阳湖地区湿地保护现状及其主要影响因素

在鄱阳湖区域,选取鄱阳湖国家级自然保护区、鄱阳湖南矶湿地国家级自然保护区、都昌候鸟省级自然保护区、东鄱阳湖国家湿地公园、都昌北鄱阳湖湿省级地公园5个典型湿地保护地为研究地;采用问卷调查方法,选择研究地的管理人员、技术人员、野外工作人员、其他工作人员,调查研究地的资源保护与破坏现状、湿地保护地存在的问题、保护地存在问题的成因、对现实问题的解决方式及建议,问卷有效率93.64%。依据调查数据,分析鄱阳湖地区湿地保护现状及其主要影响因素。调查结果表明:①鄱阳湖湿地保护现状较为理想,湿地资源得到了合理的保护和利用。在受访者中,83.50%工作人员认为湿地水鸟种类增加或维持不变、74.76%工作人员认为湿地水鸟数量增加或维持不变、73.78%工作人员认为湿地水鸟已经达到或基本达到最适数量、63.11%工作人员认为湿地水鸟繁殖能力增加或不变。②各保护地的湿地保护现状差异明显,在受访者中,62.38%工作人员认为鄱阳湖地区湿地保护过程中存在不利影响,主要集中在生态旅游、水量减少、湿地污染、湿地占用等方面。80.58%工作人员认为湿地生态旅游存在负面影响,其中63.10%工作人员认为生态旅游存在严重影响;33.01%工作人员认为湿地保护地的不利基础设施建设存在严重影响或一般影响;82.52%工作人员认为湿地水量减少是湿地保护面临的问题之一;53.40%工作人员认为湿地污染是湿地保护面临的问题之一。③鄱阳湖地区湿地破坏的成因包括鄱阳湖地区湿地保护法规不完善、湿地保护的政府间联动机制不健全、湿地工作人员构成不合理。④改进措施,完善地方湿地立法、政府间部门联动机制、地区人才培养机制及相关政策。

常温下基于Lakes液的皖西白鹅精液稀释液研究

为研究常温(20～25℃)条件下皖西白鹅精液稀释液,以Lakes液为参考,通过更换糖(果糖、葡萄糖、蔗糖)和缓冲物质(柠檬酸钾、Tris、EDTA)来筛选最佳组合。结果表明:①Lakes液(果糖+柠檬酸钾)中,精子有效保存时间为13h,总保存时间为74h。②与Lakes液相比",果糖+Tris"组合最佳,精子有效保存时间为16h(p<0.01),总保存时间为80h(p<0.01);其次为"葡萄糖+Tris"组合,精子有效保存时间为14h(p﹥0.05),总保存时间为78h(p<0.01)。③其它组合有效保存时间及总保存时间均低于Lakes液(p<0.01)。

Lake inventory and potentially dangerous glacial lakes in the Nyang Qu Basin of China between 1970 and 2016

There are a large number of glaciers and lakes developed in the Nyang Qu Basin of China. Recent climate change has significant impacted on the high-mountain glacial environment. Rapid melting of glaciers contributes to the formation and expansion of moraine-dammed lakes which increase the probability of glacial lake outburst floods(GLOFs). We calculated a multi-temporal lake inventory based on(1) topographic maps in the 1970 s,(2) satellite imageries from 1990 to 2016,(3) First Chinese Glacier Inventory(FCGI),(4) Glacier Inventory of Southeastern Tibet(GIST) and(5) meteorological data. A total of 880 lakes(>0.01 km^2) have been mapped in 2016, with 318 being glacial lakes(GLs) and 462 non-glacier lakes(NGLs). Most of the lakes were mainly located at 4500 m a.s.l. and the lakes dominated by small lakes(<0.1 km^2) where the change of their actual sizes are more significant compared to the larger ones. Meanwhile, we found that there were 178 newly formed GLs and 51 of them had disappeared between 1970 and 2016. During the same period, there can be identified 157 newly formed GLs and 226 had disappeared. We additionally performed a hazard and risk assessment for GL in 2016 and exposed 14 potentially dangerous morainedammed lakes(PDMDLs), covering a total area of 5.88 km2 in the Nyang Qu Basin. There can be found 4 GLs with very high risk, 3 GLs with high risk, 4 GLs with medium risk and 4 GLs with low risk of GLOFs susceptibility. The findings of this study can be used for the future policy of risk management and also be adapted for promoting water resources management.