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1.
青藏高原冰川变化遥感监测研究综述   总被引：1，自引：0，他引：1  
在全球变暖影响下,青藏高原冰川消融造成的冰川径流增大、冰湖溃决等问题威胁着山区及其周边居民的生命财产安全,对青藏高原冰川变化的研究日益紧迫。本文综述了国内外山地冰川变化遥感监测手段的发展、冰川面积及冰面高程变化的遥感监测研究现状、存在问题与发展趋势,并总结了中国青藏高原冰川变化遥感监测研究的主要成果。此外,本文基于2003-2009年ICESat/GLAS数据,计算了青藏高原各山区冰面高程变化及其冰川消融量。结果显示：青藏高原冰川面积持续减少,青藏高原冰面高程的平均变化为-0.24±0.03 m/a,冰川融水量为-14.86±11.88 km3/a,冰川变化呈现从青藏高原东、南外缘山区往内陆与西、北部山区减慢的时空特征。  相似文献   

2.
Accurate measurements of glacier elevation changes play a crucial role in various glaciological studies related to glacier dynamics and mass balance. In this paper, glacier elevation changes of Urumqi Glacier No.1 between August 2015 and August 2017 were investigated using Sentinel-1 A data and DInSAR technology. Meanwhile, the atmospheric delay error was corrected with the MODIS MOD05_L2 products. The weight selection iteration method was applied to calibrate the glacier elevation changes in the mass balance years 2015-2016 and 2016-2017. Finally, the geodetic method was employed to calculate the elevation change values of individual stakes of Urumqi Glacier No.1. Moreover, the elevation change values corrected by the weight selection iteration method were verified. Results showed as follows:(1) the elevation of Urumqi Glacier No.1 glacier affected by atmospheric delay was 1.270 cm from 2015 to 2016. The glacier elevation affected by atmospheric delay from 2016 to 2017 was 1.071 cm.(2) The elevation change value of Urumqi Glacier No.1 was-1.101 m from 2015 to 2016, and the elevation of Urumqi Glacier No.1 decreased by 1.299 m from 2016 to 2017. The overall thickness of Urumqi Glacier No. 1 was thinning.(3) By comparing the elevation change results of individual stakes with corresponding points corrected by the weight selection iteration method, the mean squared errors of difference were 0.343 m and 0.280 m between the two mass balance years, respectively.(4) The accuracy of elevation change in non-glaciated areas was 0.039 m from 2015 to 2016 and 0.034 m from 2016 to 2017. Therefore, it is reliable to use Sentinel-1 A data and the study method proposed in this paper to calculate the elevation change of mountain glaciers with very low horizontal movement.  相似文献   

3.
This study reports on the clean ice area and surface elevation changes of the Khersan and Merjikesh glaciers in the north of Iran between 1955 and 2010 based on several high to medium spatial resolution remote sensing data.The object-oriented classification technique has been applied to nine remote sensing images to estimate the debris-free areas.The satellite-based analysis revealed that the clean ice areas of Khersan and Merjikesh glaciers shrank since 2010 with an overall area decrease of about 45% and 60% respectively.It means that the dramatic proportions of 1955 glaciers surface area are covered with debris during the last five decades.Although the general trend is a clean ice area decrease,some advancement is observed over the period of 1997-2004.During 1987-1991 the maximum decrease in the clean ice area was observed.However,the clean ice area had steadily increased between 1997 and 2010.To quantify the elevation changes besides the debris-free change analysis,several Digital Elevation Models(DEMs) were extracted from aerial photo(1955),topographic map(1997),ASTER image(2002) and Worldview-2 image(2010) and after it a 3-D Coregistration and a linear relationship adjustments techniques were used to remove the systematic shifts and elevation dependent biases.Unlike the sinusoidal variation of our case studies which was inferred from planimetric analysis,the elevation change results revealed that the glacier surface lowering has occurred during 1955-2010 continuously without any thickening with the mean annual thinning of about 0.4 ± 0.04 m per year and 0.3 ± 0.026 m per year for Khersan and Merjikesh glaciers,respectively.The maximum thinning rate has been observed during 1997-2002(about 1.1 ± 0.09 per year and 0.96 ± 0.01 mper year,respectively),which was compatible partially with debris-free change analysis.The present result demonstrates that although in debris-covered glaciers clean ice area change analysis can illustrate the direction of changes(retreat or advance),due to the high uncertainty in glacier area delineation in such glaciers,it cannot reveal the actual glacier changes.Thus,both planimetric and volumetric change analyses are very critical to obtain accurate glacier variation results.  相似文献   

4.
冰川变化监测对生态灾害预防、区域水资源调控、气候变化研究等意义重大。利用冰川在雷达干涉影像上表现出失相干这一特性,选用1998年ERS 1/2与2018年 Sentinel-1A重轨单视复数SAR数据,通过相干系数取阈值的方法获取东帕米尔高原两个时期的冰川边界,以Landsat TM/OLI影像和全球陆地冰川空间监测计划发布的数据验证本文冰川边界提取的精度,从而分析冰川变化。结果表明：① 拟合研究区相干系数图上相干系数γ与对应像元个数的曲线关系,冰川区像元个数会在低相干区域积累形成一个小的波峰。曲线一阶导数变缓的点（冰川区向非冰川区过渡的转折点）即为所选阈值点,利用SAR相干系数取阈值法提取的冰川边界与光学遥感影像结合RGI6.0数据提取的验证冰川边界具有较好的一致性,SAR干涉相干系数提取冰川边界的方法是可行而有效的,ERS 1/2与Sentinel-1A提取的冰川总面积精度均在90%以上,而且SAR数据能够有效提取光学遥感影像难以识别的冰川表碛覆盖;② 1998年和2018年东帕米尔高原冰川总面积减少了318.59 km2,年平均变化速率为-15.93 km2/a,冰川退缩面积占冰川总面积的23%;③ 对大、中型规模冰川来说,表碛覆盖型冰川退缩较其他冰川明显;从坡向上来看,20年各个坡向冰川均有所退缩,其中东南坡冰川退缩最多,西坡冰川退缩最少;从海拔上来看,1998年冰川集中分布在4519~5421 m海拔区间内,2018年集中分布在4682~5320 m海拔区间内;在3325~5710 m海拔区间内冰川退缩明显,4915 m海拔附近达到退缩极大值。  相似文献   

5.
数字高程模型（Digital Elevation Model, DEM）是地球表层系统科学相关研究的基础数据,DEM数据精度的定量评价对科学选择DEM数据源、量化数据误差的影响等具有重要意义。在目前全球尺度可免费获取的DEM数据中,2018年发布的TanDEM-X 90 m DEM（TanDEM-X 90）数据凭借其较好的现势性得到了广泛关注。然而,目前大区域尺度上开展的针对TanDEM-X 90数据精度的评价工作较为有限,缺乏对其整体精度及误差空间分布特征的系统认知。本文以ICESat/GLAS卫星测高数据为评价数据,并选择SRTM-3 DEM和AW3D30 DEM作为对比数据,以平均绝对误差（MAE）、均方根误差（RMSE）、偏度和峰度等为统计指标,重点研究了TanDEM-X 90在中国主要陆地区域的误差统计特征和空间分布规律,探讨了高程、坡度、地貌类型、土地覆盖等对DEM精度的影响,并进行了适用性分析。结果表明：① 在中国区域,TanDEM-X 90数据的平均绝对误差和均方根误差分别为4.31 m和7.87 m,其高程精度与SRTM-3相近,但明显低于AW3D30;② 当坡度低于4°时,TanDEM-X 90的整体精度为3种数据中最高的;③ 对于平原、丘陵、台地这3类地貌类型,TanDEM-X 90相较SRTM-3而言具有一定精度优势;④ 本研究还以流域为单元绘制了全国尺度的TanDEM-X 90误差空间分布图,为该数据在全国尺度或典型区域的应用提供重要参考。研究也表明TanDEM-X 90在反映地表高程信息方面具有更好的时效性,能更好地反映中国区域近年来受人类活动影响的地表高程变化。  相似文献   

6.
Glacier variations in the Tibetan Plateau and surrounding mountain ranges in China affect the livelihood of over one billion people who depend on water from the Yellow, Yangtze, Brahmaputra, Ganges and Indus rivers originating in these areas. Based on the results of the present study and published literature, we found that the glaciers shrank 15.7% in area from 1963 to 2010 with an annual area change of -0.33%. The shrinkage generally decreased from peripheral mountain ranges to the interior of Tibet.The linear trends of annual air temperature and precipitation at 147 stations were 0.36°C(10a)~(-1) and 8.96 mm(10a)~(-1) respectively from 1961 to 2010. The shrinkage of glaciers was well correlated with the rising temperature and the spatial patterns of the shrinkage were influenced by other factors superimposed on the rising temperature such as glacier size, type, elevation, debris cover and precipitation.  相似文献   

7.
Maritime-type glaciers in the eastern Nyainqêntanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better understand the variability of glaciers in this region, we used the band ratio threshold(TM3/TM5 for the Landsat TM /ETM+ and TM4/TM6 for Landsat OLI) to extract glacier outlines in ~1999 and ~2013. After that, we also generated a series of glacier boundaries and monitored glacier variations in the past 40 years with the help of the Chinese Glacier Inventory data(1975) and Landsat TM, ETM+ and OLI data. The total glacier area decreased by 37.69 ± 2.84% from 1975 to 2013. The annual percentage area change(APAC) was ~1.32% a-1 and ~1.29% a-1 in the periods 1975-1999 and 1999-2013, respectively. According to the lag theory, the reaction time is probably about 10 years and we discuss the variations of temperature and precipitation between 1965 and 2011. Temperature and precipitation increased between 1965 and 2011 at a rate of 0.34°C /10 a and 15.4 mm/10 a, respectively. Extensive meteorological data show that the glacier shrinkage rate over the period may be mainly due to increasing air temperature, while the increasing precipitation partly made up for the mass loss of glacier ice resulting from increasing temperature may also lead to the low APAC between 1999 and 2013. The lag theory suggests that glacier shrinkage may accelerate in the next 10 years. Small glaciers were more sensitive to climate change, and there was a normal distribution between glacier area and elevation. Glaciers shrank in all aspects, and south aspects diminished faster than others.  相似文献   

8.
Recent changes occurred in terminus of the debris-covered Bilafond Glacier in the Karakoram Range in the Himalayas, Northern Pakistan was investigated in this research. Landsat MSS, TM and ETM＋ images were used for this study. Digital elevation models derived from ASTER GDEM and SRTM were also utilized. Visible, infrared and thermal infrared channels were utilized in order to get accurate glacier change maps. Three methods were tried to map this debris-covered glacier in this research. The glacier has been mapped successfully and the changes in the glacier terminus from 1978 to 2011 have been calculated. Manual, semi-automatic and thermal methods were found to give similar results. It was found that the glacier has undergone serious ablation during this period despite of the fact that many of the larger glaciers in the Hindu Kush and Karakoram mountain regions in the Upper Indus Basin were reported to be expanding. The terminus has been moved back about 600 meters during this period and there was an abrupt change in the glacier terminus during 1990-2002. We propose that debris thickness is not the only factor that influences the glacier ablation but the altitude of the debris-covered glacier as well. Many glaciers in the Karakoram region reported to be expanding were having higher altitudes compared to the study area.  相似文献   

9.
Glacier changes since the early 1960s,eastern Pamir,China   总被引：2，自引：0，他引：2  
Glaciers in the eastern Pamir are important for water resources and the social and economic development of the region.In the last 50 years,these glaciers have shrunk and lost ice mass due to climate change.In order to understand recent glacier dynamics in the region,a new inventory was compiled from Landsat TM/ETM+ images acquired in2009,free of clouds and with minimal snow cover on the glacierized mountains.The first glacier inventory of the area was also updated by digitizing glacier outlines from topographical maps that had been modified and verified using aerial photographs.Total glacier area decreased by 10.8%±1.1%,mainly attributed to an increase in air temperature,although precipitation,glacier size and topographic features also combined to affect the general shrinkage of the glaciers.The 19.3–21.4 km~3 estimated glacier mass loss has contributed to an increase in river runoff and water resources.  相似文献   

10.
Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 1970 1:50,000 scale Chinese Topographic Maps series and the other from Landsat TM/ETM+ images acquired in 2009. Analyses also included boundaries from 2000 and 2014 Landsat TM/ETM+ images. A continuing and accelerating shrinkage of glaciers occurred here from 1970 to 2014, with glacier area decreasing by 244.38 ± 29.48 km~2(27.4% ± 3.3%)or 0.62% ± 0.08% a~(–1). While this is consistent with a changing climate, local topographic parameters, such as altitude, slope, aspect and debris cover, are also important influences. Recession is manifested by a rise in the elevation of the glacier terminus. The shrinkage of glaciers with NE, N and NW orientations exceeded that of other aspects, and glaciers with SE and S orientations experienced less shrinkage. Changes in the average positive difference of glaciation(PDG) show that the western Nyainqentanglha Range has unfavorable conditions for glacier maintenance which is being exacerbated by a warming climate since 1970.  相似文献   

11.
GPS measurement,an effective method for surveying glacier surface topography,has been applied in some glaciers for many years.The Shuiguan River No.4 glacier,a small glacier with its area of 1.84 km2 in 1972,located in the east of the Qilian Mountains,China,was selected to study its ice elevation change using GPS measurement in 2007.This study was conducted on the ablation area with GPS-measured area 0.5 km2.The ice elevation change of the glacier was obtained by comparing the DEM obtained by a 1:50 000 topographic map made in 1972 with the DEM by GPS-measured data acquired in 2007.The differences of the two DEMs showed the thinning condition of the glacier was apparent.The mean thinning was 15±8 m with the mean thinning rate of 0.42±0.22 m a-1 for 1972-2007 in the measurement area,which equaled 0.38±0.20 m yr-1 in water equivalent(w.e.).The prominent thinning occurred on the south part of the glacier,which was the area near the glacier terminus with the maximum thinning of 41±8 m.Assuming the thinning value of 15±8 m for the glacier area below 4640 m a.s.l.,the wasting ice mass was calculated to be 6.4±3.2×10-3 km3 for 1972-2007,corresponding to 5.7±2.8×10-3 km3 w.e.,which meant that the montane runoff released by the glacier was at least 5.7±2.8×106 m3 between 1972-2007.  相似文献   

12.
Climate change induces profound changes in mountain territories that affect the activities pursued there. Tourism is one activity that is strongly impacted by these changes. Most research on tourism in mountain regions has focused on winter sports tourism, but glacier tourism, a summer activity, is also severely affected by climate change-induced phenomena, including glacier retreat and other geomorphological processes. Given that Alpine glacier tourism has been pursued since the 18 th century and glaciers have been changing throughout this period, this article aims to examine the adaptations implemented by glacier tourism operators since the activity's beginnings. Through analysis of historical documents, glaciological surveys and semi-structured interviews, this paper reveals how tourism activities around the Mer de Glace(the largest French glacier) have been impacted by glacier fluctuations since the first visit to the area in 1741. The study reveals that these developments have mainly been driven by glacier retreat and associated paraglacial dynamics. More recently, the shortening of the period of snow cover on the glacier has also impacted tourism activities. Most of the adaptation strategies implemented by tourism operators during the period in question are found to be reactive, consisting in the installation of safety equipment, the renovation of access points or the building of new structures to allow tourist activities to continue despite the consequences of glacier retreat. Other strategies, such as the adoption of new activities by workers previously specialised in another, are identified that could be considered transformative strategies, although these were only adopted by workers when their activity was no longer feasible. The analysis of materials from 1741 to the present also reveals that the recent impacts of climate change on glacier tourism are much more significant and diverse than those produced by past fluctuations. Therefore, it is important that stakeholders take suitable measures to ensure the sustainable future of the Mer de Glace and other glacier tourism destinations.  相似文献   

13.
The topographic maps of 1：50, 000 scales, aerial photographs taken in 1966, one Landsat image taken in 1999, and SRTM data from 2000 were used to quantify the losses in area and volume of the glaciers on the Su-lo Mountain, in the northeastern Tibetan Plateau, China in the past 30 years. The total glacier area decreased from 492.9 km^2 in 1966 to 458.2 km^2 in 1999. The volume loss of the studied glaciers reached 1.4 km^3 from 1966 to 2000. This agrees with documented changes in other mountain glaciers of the whole Tibetan Plateau.  相似文献   

14.
Life cycle of glaciers in the Himalayan region has notably changed due to the climatic variability since last few decades. Glaciers across the world and specially the Himalayan glaciers have shown large scale degeneration in the last few decades. Himalayan glaciers serve as an important fresh water resource for the downstream communities, who are dependent on this water for domestic and other purposes. Therefore, glacier shrinkage and the associated hydrological changes pose a significant problem for regional-scale water budgets and resource management. These issues necessitate the regular and rigorous monitoring of the wastage pattern of the Himalayan glaciers in field and using satellite remote sensing data. In this work, we report rapid and enhanced degeneration of the frontal part of the Kangriz glacier, Jammu and Kashmir (J & K), in terms of surface melting, debris cover, snout characteristics and meltwater discharge. Ablation data acquired during 2016–2017 shows the average lowering of the frontal part of the glacier to be ~148 ± 34 cm, one-third of which was found to have occurred within a 13 day time period in September, 2017. Also, the quantum of ice melt was found to be inversely influenced (r = -0.84) by the debris thickness. 15 day meltwater discharge measurement revealed its strong relationship with snout disintegration pattern, evidenced twice during the said time period. Volume of water discharged from the glacier was estimated to be 7.91×106 m3 for the measurement duration. Also, mean daily discharge estimated for the 15 days interval showed good positive correction (r = 0.78) with temperature indicating the direct dependency of the former on land surface temperature conditions of the region. Besides the lowering and discharge observations, the frequent ice-block break-offs at the glacier snout further enhance its overall drastic degeneration. The study suggests that, being the largest glacier in the Suru basin, the Kangriz glacier needs to be continuously monitored in order to understand its glacio-hydrological conditions.  相似文献   

15.
Tropical glaciers are extremely sensitive to a warming climate. In this paper, the evolution of the remaining tropical glaciers in Australasia(Irian Jaya, Indonesia) during the period 1988-2015 was quantified. Landsat series images, a digital elevation model from SRTM, and previously published data were used. Estimated total glacier area in 1988, 1993, 1997 and 2004 was 3.85 km2±0.13 km2, 3.01 km2±0.08 km2, 2.49 km2±0.07 km2 and 1.725 km2 ±0.042 km2, respectively. Only 0.58 km2±0.016 km2 glacierized area remained in 2015 in Puncak Jaya, which is about 84.9% loss in just 27 years. If this rate continued, the remaining tropical glaciers in Australasia would disappear in the 2020 s. Timeseries analysis of climate variables showed significant positive trends in air temperature(0.009°C per year) and relative humidity(0.43% per year) but no considerable tendency was observed for precipitation. Warming climate together with mining activities would accelerate loss of glacier coverage in this region.  相似文献   

16.
This study used Corona KH-4A and Advanced Land Observing Satellite (ALOS) PRISM images to generate digital terrain models (DTMs) of the distal part of Imja Glacier,where a few supraglacial ponds (～0.07 km 2) expanded into the large Imja Glacier Lake (Imja Tsho,～0.91 km 2) between 1964 and 2006.DTMs and subsequently derived topographical maps with contour intervals of 1 m were created from the high-resolution images (Corona in 1964 and ALOS in 2006) in the Leica Photogrammetric Suite (LPS) platform.The DTMs and topographic maps provided excellent representation of the elevation and micro-topography of the glacier surface,such as its supra-glacial ponds/lake,surface depressions,and moraine ridges,with an error of about +/-4 m (maximum).The DTMs produced from the Corona and ALOS PRISM images are suitable for use in studies of the surface change of glaciers.The topographical maps produced from the Corona data (1964) showed that part of the dead ice in the down-glacier area was even higher than the top of the lateral moraine ridges,while the glacier surface in the up-glacier area was noticeably lower than the moraine crests.This suggests more extensive melting of glacier ice in the up-glacier area before 1964.The average lowering of the glacier surface from 1964 to 2006 was 16.9 m for the dead-ice area west of the lake and 47.4 m for the glacier surface east of the lake;between 1964 and 2002,the lake surface lowered by 82.3 m.These figures represent average lowering rates of 0.4,1.1,and 2.2 m/year for the respective areas.  相似文献   

17.
GLACIER MELTWATER RUNOFF IN CHINA AND ITS NOURISHMENT TO RIVER   总被引：3，自引：0，他引：3  
ＧＬＡＣＩＥＲＭＥＬＴＷＡＴＥＲＲＵＮＯＦＦＩＮＣＨＩＮＡＡＮＤＩＴＳＮＯＵＲＩＳＨＭＥＮＴＴＯＲＩＶＥＲ￥ＹａｎｇＺｈｅｎｎｉａｎｇ（杨针娘）（ＬａｎｚｈｏｕＩｎｓｔｉｔｕｔｅｏｆＧｌａｃｉｏｌｏｇｙａｎｄＧｅｏｃｒｙｏｌｏｇｙ，ｔｈｅＣｈｉｎｅｓ...  相似文献   

18.
利用1990-2010年的TM影像和DEM数据,通过面向对象的分类方法提取了玛纳斯河流域南山4个时期的冰雪分布信息,并结合近20 a（1987-2007年）的气温资料对研究区冰雪时空分布特征和变化原因进行了研究。结果表明：（1）1990-2010年间,研究区冰雪面积从1442.32 km2退缩到710.54 km2,面积减少了50.7%。（2）1990-2010年间,冰雪变化主要呈现退缩的态势,尤其在海拔4000 m以下,面积减少更为剧烈,在海拔4000 m以上相对平缓。这种现象在研究区东区表现的更为明显,西区相对较小。（3）自1987年以来,气温的升高是冰雪面积不断退缩的主要原因之一。  相似文献   

19.
The study investigated the streamflow response to the shrinking cryosphere under changing climate in the Lidder valley, Upper Indus Basin(UIB), Kashmir Himalayas. We used a combination of multitemporal satellite data and topographic maps to evaluate the changes in area, length and volume of the glaciers from 1962 to 2013. A total of 37 glaciers from the Lidder valley, with an area of 39.76 km~2 in 1962 were selected for research in this study. It was observed that the glaciers in the valley have lost ~28.89 ±0.1% of the area and ~19.65 ±0.069% of the volume during the last 51 years, with variable interdecadal recession rates. Geomorphic and climatic influences on the shrinking glacier resources were studied. 30-years temperature records(1980-2010) in the study area showed a significant increasing trend in all the seasons. However, the total annual precipitation during the same period showed a nonsignificant decreasing trend except during the late summer months(July, August and September), when the increasing trend is significant. The depletion of glaciers has led to the significant depletion of the streamflows under the changing climate in the valley. Summer streamflows(1971-2012) have increased significantly till mid-nineties but decreased significantly thereafter, suggesting that the tipping point of streamflow peak, due to the enhanced glacier-melt contribution under increasing global temperatures, may have been already reached in the basin. The observed glacier recession and climate change patterns, if continued in future, would further deplete the streamflows with serious implications on water supplies for different uses in the region.  相似文献   

20.
Mass balance is a key indicator of the sensitivity of glaciers to climate change. Field measurement is one of the most important ways to study the mass balance of glaciers. Based on observations of mass balance in the ablation zone of Shuiguan Glacier No.4, Qilian Mountains, China, combined with the balance ratio between accumulation and ablation, we established a linear relation between mass balance and altitude. The results show that the mean annual mass balance of this glacier was ~510 mm w.e. from 2010 to 2013. The uncertainty in the balance ratio value does not lead to a significant difference in the mass balance. The equilibrium-line altitude rose by 180 m from 1972 to 2013, while the accumulation–area ratio decreased from 0.68 to 0.25. These variations may be caused by changes in air temperature. Meanwhile, the glacier is at present not in a steady state, and it may continue to shrink by a further ~900 m, even without further climate warming. In the western Lenglongling Mountains, assuming that the glaciers are in a steady state and the Equilibrium-line altitudes(ELAs)remain similar, there will be only 46 glaciers left, covering a total area of 19.2 km~2, in other words, only 22.3% of the glaciers area in 1972.  相似文献   

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