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1.
A surge of Perseibreen, Svalbard, examined using aerial photography and ASTER high resolution satellite imagery 总被引：1，自引：0，他引：1
The identification of surge activity is important in assessing the duration of the active and quiescent phases of the surge cycle of Svalbard glaciers. Satellite and aerial photographic images are used to identify and describe the form and flow of Perseibreen, a valley glacier of 59 km2 on the east coast of Spitsbergen. Heavy surface crevassing and a steep ice front, indicative of surge activity, were first observed on Perseibreen in April 2002. Examination of high resolution (15 m) Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery confirmed this surge activity. Perseibreen retreated by almost 750 m between 1961 and 1990. Between 1990 and the summer of 2000, Perseibreen switched from retreat and its front began to advance. Rapid advance was underway during the period June 2000 to May 2001, with terminus advance at over 400 m yr−1 . Between May and August 2001 the rate increased to over 750 m yr−1 . The observed crevasse orientation indicates that ice was in longitudinal tension, suggesting the down-glacier transfer of mass. Ice surface velocities, derived from image correlation between ASTER images, were 2-2.5 m d−1 between May and August 2001. The glacier was flowing at a relatively uniform speed with sharp velocity gradients located close to its lateral margins, a velocity structure typical of ice masses in the active phase of the surge cycle. The stress regime is extensional throughout and the surge appears to be initiated low on the glacier. This is similar to the active-phase dynamics of other Svalbard tidewater glaciers. Perseibreen has probably been inactive since at least 1870, a period of about 130 years to the present surge which defines a minimum length for the quiescent phase. 相似文献
2.
北极斯瓦尔巴群岛冰川大多数属于亚极地型(sub-polar)或多热型(polythermal)。Austre Br(?)ggerbreen和Midre Lovénbreen冰川(＜10km~2)长时间系列物质平衡研究显示,自小冰期结束以来几乎所有的观测年中夏季消融比冬季积累更大,导致冰体稳定地减小；而面积更大、海拔高度更高的冰川如Kongsvegen冰川(105km~2)则更加接近稳定态的平衡。斯瓦尔巴群岛冰川流动速率一般较低,但跃动相当频繁,控制跃动型冰川空间分布的因素包括冰川长度、基底岩性和多热场。可通过冰川水文特征、钻孔温度测量和无线电回波探测获取斯瓦尔巴群岛冰川热场的信息。斯瓦尔巴群岛冰川的低流速和多热性结构对冰川上的排水系统相当重要,整个群岛淡水径流的四个主要来源分别是冰川消融、雪融化、夏季降雨和冰崩解,经验回归方法和模式方法用于计算淡水径流量。因夏季融水渗浸作用、采样分辨率低和化学成分分析有限,早期斯瓦尔巴群岛冰芯的准确定年受到严重影响,但最近的研究显示,来自斯瓦尔巴群岛冰帽的冰芯数据仍然能够提供重要的气候和环境信息。通过我国北极黄河站2005年度科学考察,我们已初步建立了Austre Lovénbreen冰川和Pedersenbreen冰川监测系统,并计划在Austre Lovénbreen冰川进行钻孔温度测量、冰川气象要素观测、冰川前缘水文观测以及冰川厚度和内部结构测量,重点开展斯瓦尔巴群岛冰川基本特征和发育条件、冰川表面能量和物质平衡、冰川波动与气候变化关系、淡水径流年际和季节性变化和气/雪/冰界面过程等方面的研究。 相似文献
3.
1990-2011年西昆仑峰区冰川变化的遥感监测 总被引：2，自引：0，他引：2
本文应用Landsat 5、7 TM、ETM+影像分析1990-2011年昆仑山西段昆仑峰区冰川变化特征,结果表明:1990-2011年冰川面积减少16.83 km2,退缩率仅为0.65%,冰川退缩趋势不明显。单条冰川变化有进有退,中峰冰川末端在2002-2004年以661 m/a的速率前进,初步判定为跃动冰川。1991-1998年,崇测冰川面积增加9.47 km2,冰川末端以200 m/a的速率前进,不排除有跃动冰川的可能性。尽管近年来全球气温普遍上升,大量冰川处于退缩状态,但统计已有研究结果发现近50年来青藏高原存在冰川长度、面积增加,冰川物质平衡为正的现象,表现出冰川对气候变化复杂的反馈机制。通过分析气象站点和冰芯资料,研究区周边地区气温上升、降水量缓慢增加可能是冰川微弱退缩的原因之一;增强的西风环流带来更多的降水、研究区以极大陆型大规模冰川为主,也可能是冰川退缩幅度较小的原因。 相似文献
4.
利用Landsat影像，EDM影像等数据资料，使用遥感图像处理及目视解译方法提取了喜马拉雅山东段中国与不丹边境地区冰川从1990—2015年4期边界，研究其与气温降水变化关系，并选取特定冰川，对其表面流速进行估算。研究表明：1990—2015年，该地区冰川退缩速率达0.43%·a-1，并且冰川年退缩率逐渐增大，表明冰川消融速度逐渐加快。该时段内，气温呈现明显上升趋势，导致了冰川的快速消融。通过对冰川表面流速的估算，得出中国与不丹边境地区研究选取的冰前湖对冰川流速具有促进作用，加速冰川消融。 相似文献
5.
JULIAN A. DOWDESWELL 《Polar research》1986,4(1):25-32
Landsat multispectral scanner images and 1:50, 000 scale aerial photographs are used to measure marginal fluctuations in 22 outlet glaciers of the Nordaustlandet ice caps, Svalbard, for all or parts of the period 1969 to 1981. Little was previously known about the behaviour of these glacier termini. Digital analysis of Landsat computer compatible tapes yielded measurement errors of less than ±150m, whereas data extracted from aerial photographs had an accuracy of ±25 m. Of the 22 glacier termini examined using aerial photographs, 15 were retreating, four were static and three were advancing. Retreat was usually in the order of hundreds of metres during the period of observation. For any outlet glacier, retreat was probably a result of either (1) glacier response to climatic wanning since the early part of the 20th century, or (2) stagnation and thinning during the quiescent period between surges. Short term iceberg calving events may also be responsible for retreat in a few cases. All observed outlet glaciers of Austfonna were static or retreating between 1969 and 1981, but analysis of Landsat imagery and aerial photographs showed that five outlet glaciers from Vestfonna and one from Vegafonna were advancing for all or part of that period. Bodleybreen advanced by a mean of 440 and a maximum of 580m a−1 between 1976 and 1981. Bodleybreen, Søre Rijpbreen, and Palanderbreen are identified as surging, based on increases or changes in the pattern of surface crevassing. The ice streams Aldousbreen, Frazerbreen, and Idunbreen also advanced between 1976 and 1981, but surface crevasse patterns remained largely unaltered and surging is not inferred. 相似文献
6.
The drainage pattern of Hansbreen and Werenskioldbreen, two polythermal glaciers in Svalbard 总被引：2，自引：0，他引：2
Anja Pälli John C. Moore Jacek Jania Leszek Kolondra Piotr Glowacki 《Polar research》2003,22(2):355-371
To improve our understanding of Svalbard-type polythermal glacier drainage, hydraulic geometry models of the subglacial hydrology of two contrasting glaciers in Svalbard have been constructed. The models are tested against a uniquely long and rich set of field observations spanning 45 years. Digital elevation models (DEMs) were constructed from bedrock data measured with ground penetrating radar and surface data of two medium-sized polythermal glaciers, Hansbreen and Werenskioldbreen, in south-west Spitsbergen. Hansbreen has a low angle bed with over-deepenings and a calving front, while Werenskioldbreen has steeper bed and terminates on land. Together they are representative of many Svalbard glaciers. The DEMs were used to derive maps of hydraulic potential and subglacial drainage networks. Validation of the models was done using field observations including location mapping and speleological exploration of active moulins, positions of main river outflows, dyetracing and water chemistry studies, and observations of water pressure inside moulins. Results suggest that the water pressure is generally close to ice overburden pressure but varies greatly depending on local conditions such as bed location, the thickness of cold ice layer, the thickness of the glacier and seasonal changes in meltwater input. 相似文献
7.
8.
Both marginal fluctuation and areal change were used to detect the accurate dynamics of glacier change in the study area using Landsat MSS, ETM, SPOT HRV and topographic maps based on GIS. From 1963 to 1977, four of eight glaciers advanced, two of them retreated and another two kept stable, the glacier advanced generally. From 1977 to 1986, four of eight glaciers retreated and the others kept stable, but the retreated glaciers were those which advanced from 1963 to 1977. From 1986 to 2000, seven of eight glaciers retreated and only one glacier kept stable, the retreating velocity was 10-15 m/a. Glacier recession in this period became very fast and universal. From 1963 to 2000, the area of glaciers decreased from 5479.0 ha to 4795.4 ha, up to 12.5%. It is alarming that most of glacier retreats happened from 1986 to 2000. This was very consistent with change process of summer mean temperature in this region and global warming beginning in the 1980s. 相似文献
9.
近40年天山冰川变化的遥感监测 总被引：3，自引：0，他引：3
Both marginal fluctuation and areal change were used to detect the accurate dynamics of glacier change in the study area using Landsat MSS, ETM, SPOT HRV and topographic maps based on GIS. From 1963 to 1977, four of eight glaciers advanced, two of them retreated and another two kept stable, the glacier advanced generally. From 1977 to 1986, four of eight glaciers retreated and the others kept stable, but the retreated glaciers were those which advanced from 1963 to 1977. From 1986 to 2000, seven of eight glaciers retreated and only one glacier kept stable, the retreating velocity was 10-15 m/a. Glacier recession in this period became very fast and universal. From 1963 to 2000, the area of glaciers decreased from 5479.0 ha to 4795.4 ha, up to 12.5%. It is alarming that most of glacier retreats happened from 1986 to 2000. This was very consistent with change process of summer mean temperature in this region and global warming beginning in the 1980s. 相似文献
10.
RS analysis of glaciers change in the Heihe River Basin,Northwest China,during the recent decades 总被引：2，自引：1，他引：1
Baojuan Huai Zhongqin Li Shengjie Wang Meiping Sun Ping Zhou Yan Xiao 《地理学报(英文版)》2014,24(6):993-1008
The Heihe River Basin is the second largest inland river basin in Northwest China and it is also a hotspot in arid hydrology, water resources and other aspects of researches in cold regions. In addition, the Heihe River Basin has complete landscape, moderate watershed size, and typical social ecological environmental problems. So far, there has been no detailed assessment of glaciers change information of the whole river basin. 1：50,000 topographic map data, Landsat TM/ETM＋ remote sensing images and digital elevation model data were used in this research. Through integrated computer automatic interpretation and visual interpretation methods, the object-oriented image feature extraction method was applied to extract glacier outline information. Glaciers change data were derived from analysis, and the glacier variation and its response to climate change in the period 1956/1963–2007/ 2011 were also analyzed. The results show that：（1） In the period 1956/1963–2007/2011, the Heihe River Basin＇s glaciers had an evident retreat trend, the total area of glaciers decreased from 361.69 km2 to 231.17 km~2; shrinking at a rate of 36.08%, with average single glacier area decrease 0.14 km~2; the total number of the glaciers decreased from 967 to 800.（2） Glaciers in this basin are mainly distributed at elevations of 4300–4400 m, 4400–4500 m and 4500–4600 m; and there are significant regional differences in glaciers distribution and glaciers change.（3） Compared with other western mountain glaciers, glaciers retreat in the Heihe River Basin has a higher rate.（4） Analysis of the six meteorological stations＇ annual average temperature and precipitation data from 1960 to 2010 suggests that the mean annual temperature increased significantly and the annual precipitation also showed an increasing trend. It is concluded that glacier shrinkage is closely related with temperature rising, besides, glacier melting caused by rising temperatures greater than glacier mass supply by increased precipitation to 相似文献
11.
通过对天山乌鲁木齐河源 1号冰川的雷达回波探测 ,清晰地揭示出冰川底部冰 /岩界面的位置及其起伏变化特征 ,显示出雷达波对山地冰川良好的穿透能力和对冰下地形的高分辨能力 ,冰川雷达测厚的误差小于 1 .2 %。研究结果显示 ,1号冰川东支冰川平均厚度为 5 8.77m ,西支冰川平均厚度为 44.84m ,冰体厚度最大值发育于冰川中部趋于主流线位置。冰川冰储量计算表明 ,东支冰储量为 0 .0 5 1 868km3,西支冰储量为 0 .0 2 0 2 1 0km3。表面和底部地形有明显差异 ,主要因冰川动力过程对基岩强烈的地貌作用所致 ,意味着冰床的起伏地形对冰川浅层冰体的运动过程影响不显著。 相似文献
12.
1978-2015年喀喇昆仑山克勒青河流域冰川变化的遥感监测 总被引：1，自引：1，他引：0
本文采用1978、1991、2001和2015年的Landsat MSS、TM、ETM+和OLI遥感影像,通过遥感图像计算机辅助分类和目视解译等方法提取冰川边界,分析喀喇昆仑山克勒青河流域冰川在1978-2015年间的进退变化。结果表明：1978-2015年间研究区冰川面积由1821.70 km2减少至1675.92 km2,减少145.78 km2,占1978年冰川总面积的8.00%;冰川消融率较低,在气候变暖的背景下反而呈现出退缩速率由快变慢的趋势。研究区东南向冰川退缩率明显高于西北向,冰川退缩率随冰川规模的增大而减小。研究区内有27处冰川在1978-2015年间发生过特殊的前进现象,面积与长度显著增加。其中,木斯塔冰川西侧冰川末端在1996-1998年间前进速度为904 m/a,乔戈里冰川东侧冰川末端在2007-2009年间前进速度为446 m/a,5Y654D0097冰川末端在1978-1990年间前进速度为238 m/a,初步判定这三条冰川为跃动冰川。以10 a为滞后期分析研究区周边气象站点资料发现：研究区气温持续升高,降水量以1981年为分界点呈现“先减后增”趋势是冰川退缩速率减慢的原因之一;此外,亚大陆型冰川性质、巨大山势条件和高山冷储作用,也可能是冰川退缩幅度较小的原因。 相似文献
13.
Mountain glaciers are sensitive to environment. It is important to acquire ice flow velocities over time for glacier research and hazard forecast. For this paper, cross-correlating of optical images is used to monitor ice flow velocities, and an improvement, which is called ＂moving grid,＂ is made to this method. For this research, two remote-sensing images in a certain glacier area, dur-ing different times are selected. The first image is divided into grids, and we calculated the correlation coefficient of each window in the grid with the window on the second image. The window with the highest correlation coefficient is considered the counter-part one on the first image. The displacement of the two corresponding windows is the movement of the glacier, and it is used to calculate glacier surface velocity. Compared to the traditional way of dividing an image with ascertain grid, this method uses small steps to move the grid from one location to another adjacent location until the whole glacier area is covered in the image, thus in-creasing corresponding point density. We selected a glacier in the Tianshan Mountains for this experiment and used two re-mote-sensing images with a 10-year interval to determine this method. 相似文献
14.
60-year changes and mechanisms of Urumqi Glacier No. 1 in the eastern Tianshan of China,Central Asia
ZhongQin Li HuiLin Li ChunHai Xu YuFeng Jia FeiTeng Wang PuYu Wang XiaoYing Yue 《寒旱区科学》2020,12(6):380-388
Worldwide examination of glacier change is based on detailed observations from only a small number of glaciers. The ground-based detailed individual glacier monitoring is of strong need and extremely important in both regional and global scales. A long-term integrated multi-level monitoring has been carried out on Urumqi Glacier No. 1 (UG1) at the headwaters of the Urumqi River in the eastern Tianshan Mountains of Central Asia since 1959 by the Tianshan Glaciological Station, Chinese Acamedey of Sciences (CAS), and the glaciological datasets promise to be the best in China. The boundaries of all glacier zones moved up, resulting in a shrunk accumulation area. The stratigraphy features of the snowpack on the glacier were found to be significantly altered by climate warming. Mass balances of UG1 show accelerated mass loss since 1960, which were attributed to three mechanisms. The glacier has been contracting at an accelerated rate since 1962, resulting in a total reduction of 0.37 km2 or 19.3% from 1962 to 2018. Glacier runoff measured at the UG1 hydrometeorological station demonstrates a significant increase from 1959 to 2018 with a large interannual fluctuation, which is inversely correlated with the glacier's mass balance. This study analyzes on the changes in glacier zones, mass balance, area and length, and streamflow in the nival glacial catchment over the past 60 years. It provides critical insight into the processes and mechanisms of glacier recession in response to climate change. The results are not only representative of those glaciers in the Tianshan mountains, but also for the continental-type throughout the world. The direct observation data form an essential basis for evaluating mountain glacier changes and the impact of glacier shrinkage on water resources in the interior drainage rivers within the vast arid and semi-arid land in northwestern China as well as Central Asia. 相似文献
15.
纳木错流域近30年来湖泊-冰川变化对气候的响应 总被引：20，自引：1，他引：19
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 "inte-grated method" with the support of GIS. Results show that from 1970 to 2000, lake area in-creased from 1942.34 km2 to 1979.79 km2 at a rate of 1.27 km2/a, while glacier area de-creased from 167.62 km2 to 141.88 km2 at a rate of 0.86 km2/a. The increasing rate of lake in 1991-2000 was 1.76 km2/a that was faster than 1.03 km2/a in 1970-1991, while in the same period of time, the shrinking rates of glaciers were 0.97 km2/a and 0.80 km2/a respectively.Important factors, relevant to lake and glacier response to the climate, such as air tempera-ture, 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 gla-cier melting water, increase of precipitation and obvious decrease of potential evapotranspi-ration. 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. 相似文献
16.
以Landsat MSS/TM/ETM+/OLI 遥感影像和数字高程模型为数据源,在遥感和地理信息技术支持下,分析了阿尔金山地区1973、1999、2010、2015 四期冰川变化特征。研究表明：（1）1973-2015 年,冰川总面积共退缩了58.78 km2,年均退缩率为0.40%·a-1,东段退缩速率最快,其次是西段,中段最慢,且冰川退缩速率呈现出先变快后变慢的变化趋势。（2）各个坡向都出现不同程度的退缩,偏南坡比偏北坡冰川退缩严重。（3）冰川面积退缩速率与规模等级呈现反相关关系,小规模冰川退缩速率快。（4）冰川分布随海拔变化呈正态分布,海拔越低退缩速率越快。统计分析气象数据表明,气候变暖是冰川退缩的主要原因,同时地形与冰川规模也影响冰川变化。 相似文献
17.
近50年新疆天山奎屯河流域冰川变化及其对水资源的影响 总被引：5，自引：0，他引：5
基于地形图、遥感影像、气象与水文资料,对气候变化背景下奎屯河流域近50 a冰川变化及其对水资源的影响进行了研究。结果表明：1964~2015年该流域冰川面积减小了约65.4 km2,冰储量亏损了约4.39 km3,且2000年后冰川消融与退缩加快。消融期内正积温增大带来的冰川物质支出（消融）高于源自年内降水的冰川物质收入（积累）是造成该流域冰川消融与退缩的主要原因。1964~2010年该流域径流年际变化总体呈上升趋势,1993年后径流增加趋势显著,且周期性丰枯变化发生了改变。52 a间该流域冰储量亏损引发的水资源损失量达39.5×108m3,年均亏损量约占多年平均径流量的12%,且20世纪80年代后冰川融水在径流中所占比重增大。 相似文献
18.
纳木错流域近30 年来湖泊 - 冰川变化对气候的响应 总被引：13，自引：0，他引：13
利用1970 航测地形图和1991、2000 年两期卫星影像数据, 人工建立数字高程模型 (DEM), 解译不同时期的湖泊、冰川边界, 在GIS 技术支持下采用图谱的方法, 定量分析了 湖泊、冰川的面积变化情况。结果表明, 自1970~2000 年期间, 纳木错湖面面积从1941.64 km2 增加到1979.79 km2, 增加的速率为1.27 km2/a; 流域内冰川的面积从167.62 km2 减少到141.88 km2, 退缩速率为0.86 km2/a。其中, 湖面面积在1991~2000 年的增加速率为1.76 km2/a, 明显大于其在1970~1991 年的1.03 km2/a; 而冰川面积在1991~2000 年的退缩速率为 0.97 km2/a, 明显大于其在1970~1991 年的0.80 km2/a。对比该流域前后两个时期的气温、降水和蒸发变化, 发现升温幅度的增加是冰川加速退缩的根本原因, 而湖面的加速扩张主要受冰川的加剧退缩及其引起的融水增加影响, 但与区域降水量略微增加和蒸发量显著减少也具有密切联系。区域降水增加和蒸发减少及其与湖面扩张之间的内在联系仍是一个需要深入探讨的问题。 相似文献
19.
念青唐古拉山脉西段雪线高度变化遥感观测 总被引：3，自引：0，他引：3
利用Landsat TM/ETM+/8 OLI和HJ1A遥感影像资料作为数据源,通过目视解译方法,提取念青唐古拉山脉西段雪线高度变化值,同时对研究区周边气温与降水变化趋势进行分析,研究其与冰川变化的关系。结果表明：2004~2013年北坡13条冰川和南坡15条冰川的雪线高度都呈升高的趋势;从整体上来考察,北坡雪线高度升高值为14 m/a,南坡升高值为4.9 m/a,北坡升高速度比南坡快;自1964年以来,研究区气温升高趋势显著,降水增加不明显,气候变暖是冰川退缩的主要原因;北坡冰川比南坡冰川经历更大的物质负平衡,主要是由于气温的升高率北坡比南坡快所致。 相似文献
20.
利用面向对象分类方法,从Landsat影像中提取了1990年、2000年、2010年、2015年4期布喀达坂峰地区冰川空间分布数据,并利用GIS技术分析研究区最近25 a来冰川变化,探讨了冰川对气候变化的响应关系。结果表明：布喀达坂峰冰川总面积退缩了7.28 km2,退缩速率为0.29 km2·a-1,占1990年的1.78%,且1990-2000年、2000-2010年、2010-2015年各个时段内冰川退缩速率呈较快-快-慢的状态,不同朝向的冰川退缩速率略有差异,南坡山谷冰川退缩速率最快,北坡坡面冰川次之,中段平顶冰川退缩速率最慢;冰川表面运动速度沿中流线向冰川侧脊和冰川末端递减,符合冰川运动一般规律,而不同类型的冰川其表面运动速度的时空变化具有差异性。研究发现,夏季均温的显著升高和年降水量的缓慢增加的共同作用是引起布喀达坂峰冰川退缩的主要原因。此外,地势条件和冰川自身结构等因素对冰川变化的作用也不容忽视。 相似文献