1976-2010年祁连山中段岗格尔肖合力雪山冰川退缩和气候变化的关系研究

运用最大似然监督分类法和比值阈值法（TM3/TM5）结合目视解译方法,从1976、1990、2001和2010的MSS、TM、ETM影像中提取了岗格尔肖合力雪山四个时段的冰川边界,并结合距其较近的托勒、野牛沟、祁连、德令哈和刚察5个气象站点1960-2010年年总降水量数据和年平均气温数据进行了分析,得到如下结论：1）...     

Region-wide glacier area and mass budgets for the Shaksgam River Basin,Karakoram Mountains,during 2000–2016

The Karakoram Mountains are well known for their widespread surge-type glaciers and slight glacier mass gains.On the one hand,glaciers are one of the sensitive indicators of climate change,their area and thickness will adjust with climate change.On the other hand,glaciers provide freshwater resources for agricultural irrigation and hydroelectric generation in the downstream areas of the Shaksgam River Basin(SRB)in western China.The shrinkage of glaciers caused by climate change can significantly affect the security and sustainable development of regional water resources.In this study,we analyzed the changes in glacier area from 2000 to 2016 in the SRB using Landsat TM(Thematic Mapper)/ETM+(Enhanced Mapper Plus)/OLI(Operational Land Imager)images.It is shown that the SRB contained 472 glaciers,with an area of 1840.3 km2,in 2016.The glacier area decreased by 0.14%/a since 2000,and the shrinkage of glacier in the southeast,east and south directions were the most,while the northeast,north directions were the least.Debris-covered area accounted for 8.0%of the total glacier area.We estimated elevation and mass changes using the 1 arc-second SRTM(Shuttle Radar Topography Mission)DEM(Digital Elevation Model)(2000)and the resolution of 8 m HMA(High Mountain Asia)DEM(2016).An average thickness of 0.08(±0.03)m/a,or a slight mass increase of 0.06(±0.02)m w.e./a has been obtained since 2000.We found thinning was significantly lesser on the clean ice than the debris-covered ice.In addition,the elevation of glacier surface is spatially heterogeneous,showing that the accumulation of mass is dominant in high altitude regions,and the main mass loss is in low altitude regions,excluding the surge-type glacier.For surge-type glaciers,the mass may transfer from the reservoir to the receiving area rapidly when surges,then resulting in an advance of glacier terminus.The main surge mechanism is still unclear,it is worth noting that the surge did not increase the glacier mass in this study.     

Spatiotemporal changes of typical glaciers and their responses to climate change in Xinjiang,Northwest China

Glaciers are highly sensitive to climate change and are undergoing significant changes in mid-latitudes. In this study, we analyzed the spatiotemporal changes of typical glaciers and their responses to climate change in the period of 1990-2015 in 4 different mountainous sub-regions in Xinjiang Uygur Autonomous Region of Northwest China: the Bogda Peak and Karlik Mountain sub-regions in the Tianshan Mountains; the Yinsugaiti Glacier sub-region in the Karakorum Mountains; and the Youyi Peak sub-region in the Altay Mountains. The standardized snow cover index (NDSI) and correlation analysis were used to reveal the glacier area changes in the 4 sub-regions from 1990 to 2015. Glacial areas in the Bogda Peak, Karlik Mountain, Yinsugaiti Glacier, and Youyi Peak sub-regions in the period of 1990-2015 decreased by 57.7, 369.1, 369.1, and 170.4 km², respectively. Analysis of glacier area center of gravity showed that quadrant changes of glacier areas in the 4 sub-regions moved towards the origin. Glacier area on the south aspect of the Karlik Mountain sub-region was larger than that on the north aspect, while glacier areas on the north aspect of the other 3 sub-regions were larger than those on the south aspect. Increased precipitation in the Karlik Mountain sub-region inhibited the retreat of glaciers to a certain extent. However, glacier area changes in the Bogda Peak and Youyi Peak sub-regions were not sensitive to the increased precipitation. On a seasonal time scale, glacier area changes in the Bogda Peak, Karlik Mountain, Yinsugaiti Glacier, and Youyi Peak sub-regions were mainly caused by accumulated temperature in the wet season; on an annual time scale, the correlation coefficient between glacier area and annual average temperature was -0.72 and passed the significance test at P<0.05 level in the Karlik Mountain sub-region. The findings of this study can provide a scientific basis for water resources management in the arid and semi-arid regions of Northwest China in the context of global warming.     

近20 a中国天山东段典型冰川变化及其气候响应

冰川作为重要的淡水资源的存储体,也是气候变化的敏感"指示器"。在干旱半干旱区,冰川变化对人们的生产、生活和生态产生重要的影响。本文基于1990—2015年Landsat TM及ETM+遥感影像数据,利用雪盖指数法(NDSI)和阈值法,分析博格达峰及喀尔力克山的冰川面积变化,结合长时间序列的气温、降水数据分析天山东段典型冰川的气候响应。结果表明:(1)博格达峰与喀尔力克山的冰川均呈现退缩趋势,与气温和降水的变化趋势一致。(2)博格达峰和喀尔力克山冰川面积变化在东南坡向有波动增加趋势,其他坡向则未出现该现象。(3)从两个冰川不同坡向的面积和面积重心分布变化分析,博格达峰冰川面积在东坡方向退缩速率最大,而喀尔力克山的冰川在东北坡方向退缩速率最大。(4)根据栅格气象资料分析,近四五十年博格达地区冰川面积退缩速率大于喀尔力克山地区,并且博格达峰降水量的增加对冰川的退缩起到的作用不大,喀尔力克山的降水量对冰川面积的退缩起到了一定的抑制作用。(5)通过对博格达峰地区和喀尔力克山地区不同坡向的冰川面积与年均气温、年均降水量进行Person相关性分析,博格达峰地区、喀尔力克山地区各个坡向的冰川面积变化与降水相关系数均很小。但博格达峰地区北、东北、东南坡向的冰川面积与区域气温变化相关系数较高,喀尔力克山地区东南、东北坡向的冰川面积与区域气温的相关系数高且显著性明显。分析其原因,在年内尺度上,博格达峰地区、喀尔力克山地区是湿季气温升高所致,干湿两季降水量的增多,并没有使得冰川整体的退缩有所减缓。     

基于面向对象分类的马兰冰帽变化与气候响应

以Landsat遥感影像和数字高程数据为基础数据,利用面向对象分类方法提取了马兰冰帽1990、2000、2015年3期冰川边界,并分析了冰帽变化情况。结果表明:马兰冰帽在近25 a来一直处于退缩状态。由1990年的195.87 km~2减少到2015年的188.60 km~2,退缩了7.27 km~2,占1990年冰帽面积的3.71%,退缩速率为0.15%·a~(-1);不同时段内冰帽变化速率具有差异性,1990—2000、2000—2015年2个时段内冰帽退缩速率分别为0.16%·a~(-1)、0.14%·a~(-1),冰帽退缩速率处于减慢状态;不同朝向的冰川发育特点和变化差异显著,南坡冰川退缩速率较北坡慢。25 a来,研究区域内夏季平均气温升高了2.21℃,升温显著,增温率为0.67℃·(10a)~(-1),年降水量增加了53.52 mm,线性增加率为16.22 mm·(10a)~(-1),增加速度缓慢。由此推断,夏季气温显著升高是引起马兰冰帽持续退缩的主要原因。同时,研究发现地形条件对冰川规模变化也产生重要影响。     

Glacier mass balance and its impacts on streamflow in a typical inland river basin in the Tianshan Mountains,northwestern China

Glaciers are known as natural 'solid reservoirs', and they play a dual role between the composition of water resources and the river runoff regulation in arid and semi-arid areas of China. In this study, we used in situ observation data from Urumqi Glacier No. 1, Xinjiang Uygur Autonomous Region, in combination with meteorological data from stations and a digital elevation model, to develop a distributed degree-day model for glaciers in the Urumqi River Basin to simulate glacier mass balance processes and quantify their effect on streamflow during 1980-2020. The results indicate that the mass loss and the equilibrium line altitude (ELA) of glaciers in the last 41 years had an increasing trend, with the average mass balance and ELA being -0.85 (±0.32) m w.e./a (meter water-equivalent per year) and 4188 m a.s.l., respectively. The glacier mass loss has increased significantly during 1999-2020, mostly due to the increase in temperature and the extension of ablation season. During 1980-2011, the average annual glacier meltwater runoff in the Urumqi River Basin was 0.48×10⁸ m³, accounting for 18.56% of the total streamflow. We found that the annual streamflow in different catchments in the Urumqi River Basin had a strong response to the changes in glacier mass balance, especially from July to August, and the glacier meltwater runoff increased significantly. In summary, it is quite possible that the results of this research can provide a reference for the study of glacier water resources in glacier-recharged basins in arid and semi-arid areas.     

1957-2009年祁连山老虎沟流域冰川变化遥感研究

利用1:50000地形图,4期Landsat TM遥感影像及2009年RTK冰川边界测量结果,获得了1957-2009年间老虎沟冰川流域的面积变化特征,结合气候变化背景资料,探讨了冰川面积变化对气候变化的响应。结果表明:目视解译是老虎沟流域冰川变化遥感研究的最优方法;1957-2009年间老虎沟冰川面积共减少了11.59%,以1994-1999年间的缩减最为显著,1999-2009年间的变化次之,1957-1994年变化最小。冰川缩减率与气温增加值成正比,与冰川规模成反比。该结果为进一步丰富冰川变化及水资源研究奠定了基础,具有重要的科研价值和社会意义。     

Five decades of glacier changes in the Hulugou Basin of central Qilian Mountains,Northwest China

The Heihe River Basin is the second largest inland river basin in the arid regions of Northwest China. Glaciers provide a large proportion of water resources for human production and living. Studies of glacier changes and their impact on water resources in the arid lands are of vital importance. A joint expedition was carried out in 2010 for investigating glaciers in the Hulugou Basin, which is located in the upper reaches of Heihe River. Therefore, glacier changes in the Hulugou Basin of central Qilian Mountains during the past 50 years were analyzed in this study by comparing topographic maps, satellite images, digital elevation models and field observation data from different periods. Results showed that the total area of the 6 glaciers in the Hulugou Basin decreased by 0.590±0.005 km2 during the period 1956–2011, corresponding to a loss of 40.7% over the total area in 1956. The average area reduction rate of the 6 glaciers is 0.011 km2/a. During the past five decades, the glacier shrinkage was accelerated. The changes in glacier ice surface elevation ranged from –15 to 3 m with an average thinning of 10±8 m or an annual decrease of 0.23±0.18 m(0.20±0.15 m/a water equivalent) for the period 1956–2000. The area of Shiyi Glacier in the Hulugou Basin decreased from 0.64 km2 in 1956 to 0.53 km2 in 2011 with a reduction rate of 17.2%. The Shiyi Glacier had been divided into two separated glaciers because of severe melting. Comparative analysis showed that glacier shrinkage in the Hulugou Basin is more serious than that in the other regions of Qilian Mountains.     

Spatial variability between glacier mass balance and environmental factors in the High Mountain Asia

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.     

30 a来长江源区冰川变化遥感监测

根据地形图、航空相片和Landsat ETM+数字影像,采用比值阈值法对青藏高原东北部长江源区1969/1971-1999/2002年间的冰川变化进行了研究;同时,选取覆盖同一区域（格拉丹东峰北坡）的Landsat MSS (1973年)、Landsat TM (1992年)以及2景2005/2006年获取的1B级ASTER数字遥感影像,进一步分析源区冰川的连续变化规律。结果表明：① 研究区的冰川平均退缩了108.3 m,冰川面积减少了5.3%,其中,色的日峰地区的面积变化率最大,冰川面积减少12.9%;唐古拉山北坡冰川相对处于稳定状态,面积仅减少了4.3%。② 格拉丹东峰北坡冰川面积变化速率不均匀,1969-1973年冰川面积变化最快,平均变化量为-1.16 km²·a^-1,1973年后冰川变化有所减缓,1973-1992年和1992-2002年平均变化量均为-0.59 km²·a^-1,而2002年后冰川面积变化又有所加快,平均变化量为-0.95 km²·a^-1。③ 沱沱河、五道梁和治多3个气象站的气温和降水变化显示,暖季气温升高是导致研究区冰川退缩的主要因素,此外,气温升高的快慢可能是引起上述3个区域冰川变化差异的重要原因之一。     

祁连山北大河流域冰川变化遥感监测

基于1956年地形图和2003年ASTER影像数据,在RS和GIS技术支持下,确定了1956年和2003年的冰川边界,对祁连山北大河流域冰川近47 a来的变化进行了研究。结果表明：该流域372条冰川面积在47 a间共减小了33.56 km²,平均每条减小0.09 km²,变化率-15.42%,冰川末端累计退缩51 015 m。分析显示,小冰川比大冰川消融的更快。对研究区附近气象站近年来的年平均气温、夏季平均气温和年降水量进行分析,认为气温升高是北大河流域冰川快速萎缩的主要原因。与中国西部其他冰川进行对比研究发现,北大河流域冰川消融速率比新疆要快,但较黑河流域及其他子流域要慢,初步推测是由冰川所在区域的气候及冰川自身因素共同作用的结果。     

近40a来南阿尔泰山区现代冰川变化及其对气候变化的响应

以1972,1989,2000,2011四个不同时段的遥感影像资料为基础,通过计算机自动提取结合人工解译获得研究区各时段冰川信息。参考世界冰川编目(WGI)分别对分布在中国、俄罗斯和哈萨克斯坦境内的冰川进行编目及属性更新,完成南阿尔泰山蒙古境内冰川编目。对不同时段冰川信息进行对比,并结合气温、降水等气候资料对其变化特征进行分析。结果表明:(1)1972-2011a,南阿尔泰山区冰川总面积从633.91km2减少至329.03km2,退缩面积304.88km2,占1972a冰川总面积的48.1%;(2)不同面积等级冰川数量与面积变化呈反相关关系,小冰川对气候的响应更为敏感;(3)研究区各坡向冰川均在退缩,其中南向、东北向、东向、北向退缩较快,西向、西南向、东南向、西北向相对缓慢;(4)1972-2008a研究区增温显著,降水以1987a为界先增后波动中稳定,二者的水热组合是区内冰川退缩的主要原因。     

近50年来新疆天山南北坡典型流域冰川与冰川水资源的变化

冰川是大自然修筑的"固体水库",在水资源的构成中占有重要地位。新疆地处内陆干旱区,是我国现代冰川面积分布最广的地区之一。冰川和冰川融水为新疆灌溉农业发展提供了可靠的水资源保障。本文根据中国冰川编目及近年来其它冰川研究成果和监测资料,对1960年以来新疆,主要是天山山区的冰川与冰川径流的变化进行了分析。分析表明,受全球气候变暖的影响,上世纪60年代以来至本世纪初,天山冰川的变化整体上以退缩为主,1963-2000年冰川面积平均减少12.5%。但受地理位置和地势条件的影响,不同流域的冰川变化存在着较大的区域性差异。随着冰川的强烈退缩和冰川融水的增加,使得近十余年来新疆天山地区大部分冰川补给河流径流量呈增加的趋势。     

印度河上游流域冰川度日因子变化及其影响因素

当前,基于正积温的度日模型广泛应用于冰川消融研究中,该模型的核心参数是度日因子。根据印度河上游Sachen、Gharko、Barpu冰川2014-2016年的物质平衡和气温实测资料,计算得到消融期内各冰川研究区的度日因子,并分析了度日因子的时空变化特征及影响因素。研究结果显示:Sachen、Gharko、Barpu冰川度日因子均值分别为2. 83 mm·d^-1·℃-1、3. 74 mm·d^-1·℃^-1、3. 91 mm·d^-1·℃^-1;各冰川度日因子皆随着海拔升高而递增,海拔递增率分别为0. 003 7 mm·d^-1·℃^-1·m^-1、0. 007 4 mm·d^-1·℃^-1·m^-1、0. 004 1 mm·d^-1·℃^-1·m^-1;对于同一观测点而言,度日因子不是一个常数,会随着时间的变化而改变,冰川度日因子随着年际变化呈增加的趋势;度日因子受表碛影响显著,度日因子整体上随着表碛厚度的增加而递减。然而表碛厚度低于2 cm时,表碛的覆盖作用促进了冰川的消融,表碛覆盖区冰川度日因子大于裸露区冰川;冰川朝向的变化对度日因子产生了一定的影响,面向阳坡的冰川度日因子随海拔递增率大于阴坡。     

近23年来北天山冰川面积变化对气候的响应

利用1989、1998、2011年的Landsat TM、ETM+遥感影像为数据源,运用比值阈值法(b3/b5)结合目视解译方法,提取了北天山3个时段的冰川边界,并在地理信息系统技术支持下分析了该区域冰川的变化情况。研究表明:北天山整体变化幅度较大,冰川表现为萎缩的趋势,近23年来冰川面积减小了14.93%。分析认为,较大的变化率是由于研究区面积<1km2的冰川数量占总数的比重较大(近80%)造成的。同时分析了北天山冰川空间结构特征,<0.5km2面积的冰川对气候变化最为敏感,消融率最高,1～5km2面积的冰川对消融总量贡献比例最大。依据分形理论对未来冰川变化进行初步预测,分析认为研究区冰川的消融率仍保持比较高的状态。     

近40年东帕米尔高原冰川变化及其对气候的响应

以1972年、2000年和2011年Landsat Mss/TM/ETM+遥感影像处理和目视解译结果为依据,分析了东帕米尔高原1972～2011年冰川变化情况。结果表明:1972～2011年研究区冰川面积、储量减少了103.97km2和8.04km3,分别占1972年冰川总面积、储量的5.79%和6.69%。但冰川退缩具有不等速性,1972～2000年面积、储量年退缩百分比分别为0.182%和0.212%,而2000～2011年仅为0.045%和0.048%。对流域内两个气象站气候资料的分析表明:1972～2000年冰川快速退缩与1970～1980年气温偏高而降水偏少有关,2000～2011年冰川退缩趋缓与80年代以后相对低温和湿润气候相关。     

1973-2010年布喀塔格峰冰川波动对气候变化的响应

通过遥感图像处理技术和目视解译方法提取1973-2010年位于昆仑山中段的布喀塔格峰冰川界限,用GIS分析近37a冰川面积变化,并系统地研究其对气候变化的响应情况。结果表明:1973-2010年布喀塔格峰冰帽表现先扩大(1973-1976年)后退缩(1976-2010年)趋势,总面积缩小了5.42%,每年退缩0.14%。分析1960-2010年研究区的气候变化特征,发现布喀塔格峰冰帽退缩的关键因素是气候变暖,年降水量的增加不能够抵消由夏季温度剧烈上升导致的冰川消融率,并且地形条件、地理位置以及冰川规模都是影响冰川波动的重要因素。     

Multi-decadal variations in glacier flow velocity and the influencing factors of Urumqi Glacier No.1 in Tianshan Mountains,Northwest China

Urumqi Glacier No. 1 is a representative glacier in the inland areas of Central Asia and is the only Chinese reference glacier in the World Glacier Monitoring Service. In this study, we explored multi-decadal variations in the flow velocity of the glacier and the influencing factors based on continuous field observations and path coefficient analysis. Results show that the glacier flow velocity decreased from 5.5 m/a in 1980/1981 to 3.3 m/a in 2010/2011. The annual variation in the direction of glacier flow velocity in the western branch and eastern branch was less than 1°–3°, and the change of glacier flow velocity in the western branch was more dramatic than that in the eastern branch. Glacier flow velocity was influenced by glacier morphology(including glacier area, glacier length, and ice thickness), glacier mass balance and local climate conditions(air temperature and precipitation), the glacier morphology being the leading factor. The long-term flow velocity data set of Urumqi Glacier No. 1 contributes to a better understanding of glacier dynamics within the context of climatic warming.     

Ice thickness distribution and volume estimation of Burqin Glacier No. 18 in the Chinese Altay Mountains

Information on the thickness distribution and volume of glacier ice is highly important for glaciological applications; however, detailed measurements of the ice thickness of many glaciers in the Chinese Altay Mountains remain lacking. Burqin Glacier No. 18 is a northeast-orientated cirque glacier located on the southern side of the Altay Mountains. This study used PulseEKKO^® PRO 100A enhancement ground-penetrating radar (GPR) to survey the ice thickness and volume of Burqin Glacier No. 18 in summer 2018. Together with GPR surveying, spatial distributed profiles of the GPR measurements were concurrently surveyed using the real-time kinematic (RTK) global navigation satellite system (GNSS, Unistrong E650). Besides, we used QuickBird, WorldView-2, and Landsat TM to delineate accurate boundary of the glacier for undertaking estimation of glacier ice volume. GPR measurements revealed that the basal topography of profile B1-B2 was flat, the basal topography of profile C1-C2 presented a V-type form, and the basal topography of profile D1-D2 had a typical U-type topographic feature because the bedrock near the central elevation of the glacier was relatively flat. The longitudinal profile A1-A2 showed a ladder-like distribution. Glacier ice was thin at the terminus and its thickness increased gradually from the elevation of approximately 2620 m a.s.l. along the main axis of the glacier tongue with an average value of 80 (±1) m. The average ice thickness of the glacier was determined as 27 (±2) m and its total ice volume was estimated at 0.031 (±0.002) km³. Interpretation of remote sensing images indicated that during 1989-2016, the glacier area reduced from 1.30 to 1.17 km² (reduction of 0.37%/a) and the glacier terminus retreated at the rate of 8.48 m/a. The mean ice thickness of Burqin Glacier No. 18 was less than that of the majority of other observed glaciers in China, especially those in the Qilian Mountains and Central Chinese Tianshan Mountains; this is probably attributable to differences in glacier type and climatic setting.     

北阿尔泰山近30年冰川变化研究

利用1980年的MSS影像,2000、2010年的Landsat TM影像为数据源,运用监督分类法、比值法,结合目视解译提取了北阿尔泰山30年来的冰川变化信息。结果表明:北阿尔泰山1980-2010年冰川面积减少了12.3%,年平均退缩速率为0.43%.a-1;冰储量减少了13.9%,年平均减少速率为0.46%.a-1,并且发现2000-2010年是冰川快速退缩期,在整个北阿尔泰山范围内又以卡通斯基山和北楚伊斯基山退缩较快。利用NECP/NCAR资料,分析了30年来温度、降水的变化与冰川退缩的关系,发现研究区的冰川的退缩主要受控于夏季温度变化,受降水影响较小。