共查询到16条相似文献，搜索用时 187 毫秒
1.
喀喇昆仑山分布有众多的跃动型冰川,跃动机理存在异质性。使用Landsat、Sentinel-1A、TSX/TDX等多源遥感数据,获取了中喀喇昆仑布拉尔杜冰川在跃动期间冰川表面高程和表面流速变化。结果表明：布拉尔杜冰川从2006年开始,流速逐渐增加;到2013年之后进入快速运动期,最高流速可达4.9 m·d-1;2015年8月底,冰川表面速度急剧下降,随后保持较低的流速至2016年1月,而后流速再次增加,到同年2月初便进入平静期。2000—2014年冰川主干中上游有明显隆起,而冰川接收区明显减薄,最大减薄达89 m;2014—2018年冰川主干中上游以及各支流均有不同程度的减薄,冰川主干的接收区高程显著增加,最大增厚120 m。根据冰川表面高程变化以及流速变化的特征,认为布拉尔杜冰川的支流引发了此次跃动,且本次跃动受水文机制的影响较大;结合现有的数据和文献,推断布拉尔杜冰川的跃动间隔约为40 a;为喀喇昆仑冰川跃动研究提供更多的实例,也可为此区域冰川灾害预警研究提供参考。 相似文献
2.
冰川运动控制着冰量输送变化,为冰川变化和冰川灾害研究提供重要信息。为了探讨东帕米尔高原冰川运动特征及其影响因素,基于ITS_LIVE和GoLIVE分析了不同规模、不同地形条件、表碛/非表碛区域的冰川运动速度状况。研究结果表明:(1)东帕米尔高原冰川平均运动速度为5.31 m·a^-1,冰川运动速度与冰川规模相关,表现为大冰川比小冰川运动快;(2)冰川运动速度与平均坡度相关,表现为随平均坡度增加先增后减,坡度过大不利于冰川积累,表现为厚度(规模)小,则速度慢。(3)西南(8.69 m·a^-1)、东南(11.67 m·a^-1)坡向的冰川运动速度大于其它坡向的冰川运动速度,与各个坡向的冰川规模相关。(4)表碛覆盖型冰川的运动速度小于非表碛覆盖型冰川,表碛对冰川运动速度起到抑制作用。(5)1989-2018年东帕米尔高原冰川运动速度表现稳定,与冰川年际变化稳定相对应。消融期冰川运动速度小于其它季节,与年内冰川厚度变化相关。 相似文献
3.
基于无人机摄影测量的梅里雪山明永冰川末端表面高程动态监测 总被引：1，自引：0，他引：1
位于横断山区的梅里雪山地区,受地形与气候的影响,该地区光学遥感及微波遥感应用较为受限。论文基于大疆精灵4RTK无人机搭配中海达UBase,于2018年11月9日和2019年11月12日对梅里雪山地区明永冰川末端开展了2期摄影测量,估算冰川消融区表面高程变化,监测冰川动态变化。研究结果表明:冰川区表面形态在不同位置有显著差别,航测冰川区中下部大量表碛覆盖,有少量沿冰川主流线方向发育的裂隙;航测冰川区中上部表碛覆盖较少,大量横向裂隙发育。2018年11月至2019年11月,明永冰川末端表面高程平均变化-1.67 m。冰川表面高程变化空间分布差异显著,在航测冰川区上部高程差存在正负交替现象,航测冰川区中部以减薄为主,而航测冰川区下部以增厚为主。与高亚洲地区其他山系冰川变化对比,梅里雪山地区是冰川表面高程变化最显著的地区。 相似文献
4.
中国冰川区表碛厚度估算及其影响研究进展 总被引：5，自引：1，他引：4
表碛覆盖型冰川是中国西部分布较为广泛的冰川类型,其典型特征是冰川消融区部分或全部覆盖了一层厚度不一的表碛。与裸冰或雪相比,表碛覆盖层下冰的融化过程有独特性,表碛厚度空间分布对一条冰川的消融、物质平衡和径流过程的影响有别于无表碛覆盖型冰川。本文回顾了近年来表碛厚度分布及其影响的研究,通过对这些进展进行总结以进一步明晰表碛影响研究的方向;同时着重介绍了近期发展的基于遥感影像热红外波段和可见光近红外波段、大气—表碛层—冰川界面能量平衡过程的表碛厚度估算方法和表碛覆盖综合评估模型,结合地面观测,分析了以遥感反演的表碛层热阻系数表征表碛厚度的精度,介绍了这类模型在表碛覆盖型冰川物质平衡和径流研究中的应用效果,以及在综合评估流域/区域尺度表碛影响的应用情况,并分析了该模型存在的不足及进一步改进的研究方向,为实现中国西部区域表碛影响的系统评估奠定基础,从而提升对区域水资源和冰川灾害的模拟和预测能力。 相似文献
5.
表碛覆盖型冰川是中国西部较为常见的冰川类型。表碛层存在于大气—冰川冰界面,强烈影响大气圈与冰冻圈之间的热交换。表碛厚度的空间异质性可极大地改变冰川的消融率和物质平衡过程,进而影响冰川径流过程和下游水资源。基于Landsat TM/TIRS数据,运用能量平衡方程反演了贡嘎山地区冰川表碛厚度,研究了贡嘎山地区冰川在1990—2019年间表碛覆盖范围及厚度变化情况,同时对比了东西坡差异。结果表明：① 贡嘎山地区冰川表碛扩张总面积达43.824 km2。其中,海螺沟冰川扩张2.606 km2、磨子沟冰川1.959 km2、燕子沟冰川1.243 km2、大贡巴冰川0.896 km2、小贡巴冰川0.509 km2、南门关沟冰川2.264 km2,年均扩张率分别为3.2%、11.1%、1.5%、0.9%、1.0%和6.5%;② 海螺沟冰川、磨子沟冰川、燕子沟冰川、大贡巴冰川、小贡巴冰川、南门关沟冰川表碛平均增厚分别为5.2 cm、3.1 cm、3.7 cm、6.8 cm、7.3 cm和13.1 cm;③ 西坡冰川表碛覆盖度高,表碛覆盖年均扩张率低,冰川末端退缩量小;东坡冰川表碛覆盖年均扩张率高,但表碛覆盖度总体低于西坡,冰川末端退缩量大。 相似文献
6.
《干旱区地理》2021,44(5):1350-1364
利用ITS_LIVE数据、Landsat数据提取了喀喇昆仑山北坡42条冰川的表面流速。将末端运动与表面运动特征结合起来,分析对比了不同运动类型冰川表面流速的时空变化。结果表明:(1)1989—2018年,研究区42条冰川中,存在稳定冰川16条、前进冰川6条、退缩冰川1条、跃动冰川19条。空间上,流速分布符合冰川运动一般原理,可在积累区和冰舌上部发现明显的高值区域,这些区域多出现在跃动冰川主干或支部,流速大小一般在100.00 m·a~(-1)之上,如在音苏盖提冰川南分支,其最大流速可达到358.33 m·a~(-1)。(2)冰川流速分布与地形要素的关系密切。流速在海拔4600～5000 m之间达到最大(54.55 m·a~(-1)),是冰川末端流速的10倍以上;分布在坡度0～5°之间的42条冰川平均流速最大,并且随着坡度的增大,流速逐渐减小;处于东向的冰川流速最大,处于西南向的流速最小。(3)稳定冰川流速年际变化较稳定,不同年份相同位置的流速值较一致;而对于前进冰川和退缩冰川而言,年际流速波动均较大;跃动冰川不同位置年际流速变化不同。末端发生前进的跃动冰川表面流速变化不大,但末端变化速度却可超过100.00 m·a~(-1),甚至可达到500.00 m·a~(-1)。(4)长度更长、面积更大的冰川易发生跃动。气候、雪崩和地形也是影响冰川运动速度变化的主要原因。 相似文献
7.
无人机遥感能够获取高精度、高分辨率的冰川表面三维形态,有助于揭示冰川的运动和消融变化,现已成为冰川变化监测的重要技术支撑。针对无人机高分辨率影像能够有效识别表碛覆盖型冰川表面细节特征点的优势,本文引入金字塔影像集和最小二乘匹配方法联合开展特征点的追踪,用以实现冰川表面特征点三维位移场提取和动态变化分析。以贡嘎山贡巴冰川冰舌区作为典型研究区域,利用高分辨率无人机影像生成消融期前后（2018年6月9日和10月17日）的正射影像数据和数字表面模型,基于2期正射影像提取冰川表面特征点并实施追踪以获得三维位移场,在此基础上初步探明贡巴冰川冰舌段表面位移速率最大为7.51 cm/d,垂向消融速率超过11 cm/d。本文相关研究数据和结果可为冰川及复杂地形山区地质灾害的监测提供参考。 相似文献
8.
基于天山托木尔峰青冰滩72号冰川2008年高精度差分GPS测量资料,2009年末端重复测量数据以及1964年地形图,通过对比研究近45 a来该冰川的变化特征,结果表明:1964~2009年,青冰滩72号冰川末端退缩1 852 m,年均后退41 m,由此造成面积减少约为1.53 km2,年均减少0.03 km2;1964~2008年,冰舌平均减薄9.59±6 m,年均减薄约0.22±0.14 m,冰储量亏损达14.1±8.8×10-3 km3(12.7±7.9×10-3 km3 w.e.)。与天山其它区域典型监测冰川相比,青冰滩72号冰川消融强烈,是区域气候、末端海拔、冰川类型、表碛覆盖等因素综合影响的结果。 相似文献
9.
对位于北极Svalbard群岛新奥尔松(Ny-lesund)的Austre Lovénbreen和Pedersenbreen冰川首个物质平衡年(2005/06年度)的冰川表面物质平衡及其运动特征进行研究,并阐述了Austre Lovénbreen冰川末端位置的变化状况。结果表明:(1)Austre Lovénbreen和Pedersenbreen冰川净物质平衡分别为-0.44和-0.20m w.e.,年消融量分别为0.99和0.94m w.e.,对应冰川零平衡线高度分别为478.10和494.87m。(2)两条冰川符合Svalbard地区跃动冰川运动的特征模式。运动速度矢量的水平分量表现为:向主流线辐合或平行于主流线。下游运动速度较慢,而在中上游运动相对较快。Austre Lovénbreen冰川表面各观测点的运动速度平均值为2.28m·a-1,运动速度最大值和最小值分别为3.91和0.81m·a-1;Pedersenbreen冰川表面观测点运动速度平均值为6.74m·a-1,运动速度最大值和最小值分别为8.13和5.49m·a-1。运动速度矢量的垂直分量表现为:消融区冰川消融量随海拔升高而减弱,Austr... 相似文献
10.
对位于北极Svalbard群岛新奥尔松﹙Ny-(A)lesund﹚的Austre Lovénbreen和Pedersenbreen冰川首个物质平衡年(2005/06年度)的冰川表面物质平衡及其运动特征进行研究,并阐述了Austre Lovénbreen冰川末端位置的变化状况.结果表明: (1) Austre Lovénbreen和Pedersenbreen冰川净物质平衡分别为-0.44和-0.20 m w.e.,年消融量分别为0.99和0.94 m w.e.,对应冰川零平衡线高度分别为478.10和494.87 m.(2) 两条冰川符合Svalbard地区跃动冰川运动的特征模式.运动速度矢量的水平分量表现为:向主流线辐合或平行于主流线.下游运动速度较慢,而在中上游运动相对较快.Austre Lovénbreen冰川表面各观测点的运动速度平均值为2.28 m·a-1,运动速度最大值和最小值分别为3.91和0.81 m·a-1;Pedersenbreen冰川表面观测点运动速度平均值为6.74 m·a-1,运动速度最大值和最小值分别为8.13和5.49 m·a-1.运动速度矢量的垂直分量表现为:消融区冰川消融量随海拔升高而减弱,Austre Lovénbreen冰川至E断面表现出微弱的积累,海拔高度略有升高.实际垂直运动量总体符合冰川运动的一般形式,即积累区向下运动,消融区向上运动.(3) Austre Lovénbreen冰川末端2005/06年度处于退缩状态,平均退缩量达21.83 m·a-1,各观测点中最大、最小退缩量分别为77.30和2.76 m·a-1,差异显著. 相似文献
11.
基于第二次冰川编目的中国冰川现状 总被引：27，自引：6，他引：21
以2004年之后的Landsat TM/ETM+和ASTER遥感影像为基础,参考第一次中国冰川目录及其他文献资料,经过影像校正、自动解译、野外考察、人工修订、交互检查和成果审定等技术环节,完成占全国冰川总面积85.5%的现状冰川编目,确定中国目前共有冰川48571条,总面积约5.18×104βkm2,约占全国国土面积的0.54%,冰川储量约4.3~4.7×103βkm3。中国冰川数量和面积分别以面积<0.5βkm2的冰川和面积介于1.0~50.0βkm2的冰川为主,面积最大的冰川是音苏盖提冰川（359.05βkm2）。中国西部14座山系（高原）均有冰川分布,其中昆仑山冰川数量最多,其次是天山、念青唐古拉山、喜马拉雅山和喀喇昆仑山,这5座山系冰川数量占全国冰川总数量的72.3%;冰川面积和冰储量位列前3位的山系分别为昆仑山、念青唐古拉山和天山,尽管喀喇昆仑山冰川数量和面积均小于喜马拉雅山,但前者冰储量高于后者。从冰川海拔分布来看,海拔4500~6500βm之间是冰川集中发育区域,约占全国冰川总面积的4/5以上。冰川资源在各流域分布差异显著,东亚内流区（5Y）是中国冰川分布数量最多、面积最大的一级流域,约占全国冰川总量的2/5以上;黄河流域（5J）是冰川数量最少、规模最小的一级流域,仅有冰川164条,面积126.72βkm2。新疆和西藏的冰川面积和冰储量约占全国冰川总面积的9/10。 相似文献
12.
High-precision measuring of glacier evolution remains a challenge as the available global and regional remote sensing techniques cannot satisfactorily capture the local-scale processes of most small- and medium-sized mountain glaciers. In this study, we use a high-precision local remote sensing technique, long-range terrestrial laser scanning (TLS), to measure the evolution of Urumqi Glacier No.1 at an annual scale. We found that the dense point clouds derived from the TLS survey can be used to reconstruct glacier surface terrain, with certain details, such as depressions, debris-covered areas, and supra-glacial drainages can be distinguished. The glacier experienced pronounced thickness thinning and continuous retreat over the last four mass-balance years (2015-2019). The mean surface slope of Urumqi Glacier No.1 gradually steepened, which may increase the removal of glacier mass. The glacier was deeply incised by two very prominent primary supra-glacial rivers, and those rivers presented a widening trend. Extensive networks of supra-glacial channels had a significant impact on accelerated glacier mass loss. High-precision measuring is of vital importance to understanding the annual evolution of this type of glacier. 相似文献
13.
The Impact Of Extreme Summer Melt on Net Accumulation of an Avalanche Fed Glacier,as Determined by Ground‐Penetrating Radar 
下载免费PDF全文
下载免费PDF全文 Heather Purdie Wolfgang Rack Brian Anderson Tim Kerr Trevor Chinn Ian Owens Matthew Linton 《Geografiska Annaler: Series A, Physical Geography》2015,97(4):779-791
Glacier mass balance is more sensitive to warming than cooling, but feedbacks related to the exposure of previously buried firn and ice in very warm years is not generally considered in sensitivity studies. A ground‐penetrating radar survey in the accumulation area of Rolleston Glacier, New Zealand shows that five years of previous net accumulation was removed by melt from parts of the glacier above the long‐term equilibrium line altitude during a single negative mass balance year. Rolleston Glacier receives a large amount of accumulation from snow avalanches, which may temporarily buffer it from climate warming by providing additional mass that has accumulated at higher elevations, effectively increasing the elevation range of the glacier. However, glaciers reliant on avalanche input may have high sensitivity to climatic variations because the extra mass is concentrated on a small part of the glacier, and small variations in avalanche input could have a large impact on overall glacier accumulation. Further research is needed to better estimate the amount and spatial distribution of accumulation by avalanche in order to quantify the climate sensitivity of small avalanche‐fed glaciers. 相似文献
14.
Debris-covered glaciers, characterized by the presence of supraglacial debris mantles in their ablation zones, are widespread in the China-Pakistan Economic Corridor (CPEC) and surroundings. For these glaciers, thin debris layers accelerate the melting of underlying ice compared to that of bare ice, while thick debris layers retard ice melting, called debris-cover effect. Knowledge about the thickness and thermal properties of debris cover on CPEC glaciers is still unclear, making it difficult to assess the regional debris-cover effect. In this study, thermal resistance of the debris layer estimated from remotely sensed data reveals that about 54.0% of CPEC glaciers are debris-covered glaciers, on which the total debris-covered area is about 5,072 km2, accounting for 14.0% of the total glacier area of the study region. We find that marked difference in the extent and thickness of debris cover is apparent from region to region, as well as the debris-cover effect. 53.3% of the total debris-covered area of the study region is concentrated in Karakoram, followed by Pamir with 30.2% of the total debris-covered area. As revealed by the thermal resistance, the debris thickness is thick in Hindu Kush on average, with the mean thermal resistance of 7.0×10-2 ((m2?K)/W), followed by Karakoram, while the thickness in western Himalaya is thin with the mean value of 2.0×10-2 ((m2?K)/W). Our findings provide a basis for better assessments of changes in debris-covered glaciers and their associated hydrological impacts in the CPEC and surroundings. 相似文献
15.
Andrew G. Fountain & Aldo Vecchia 《Geografiska Annaler: Series A, Physical Geography》1999,81(4):563-573
Glacier mass balance is estimated for South Cascade Glacier and Maclure Glacier using a one-dimensional regression of mass balance with altitude as an alternative to the traditional approach of contouring mass balance values. One attractive feature of regression is that it can be applied to sparse data sets where contouring is not possible and can provide an objective error of the resulting estimate. Regression methods yielded mass balance values equivalent to contouring methods. The effect of the number of mass balance measurements on the final value for the glacier showed that sample sizes as small as five stakes provided reasonable estimates, although the error estimates were greater than for larger sample sizes. Different spatial patterns of measurement locations showed no appreciable influence on the final value as long as different surface altitudes were intermittently sampled over the altitude range of the glacier. Two different regression equations were examined, a quadratic, and a piecewise linear spline, and comparison of results showed little sensitivity to the type of equation. These results point to the dominant effect of the gradient of mass balance with altitude of alpine glaciers compared to transverse variations. The number of mass balance measurements required to determine the glacier balance appears to be scale invariant for small glaciers and five to ten stakes are sufficient. 相似文献
16.
The precise glacier boundary is a fundamental requirement for glacier inventory, the assessment of climate change and water management in remote mountain areas. However, some glaciers in mountain areas are covered by debris. The high spatial resolution images bring opportunities in mapping debris-covered glaciers. To discuss the capability of Chinese GaoFen-1 satellite lacking the short wave infrared band and thermal infrared band in mapping glaciers, this study distinguished supraglacial terrain from surrounding debris by combining GaoFen-1(GF-1) wide-field-view(WFV) images, the ratio of the thermal infrared imagery and morphometric parameters(DEM and slope) with 30 m resolution. The overall accuracy of 90.94% indicated that this method was effective for mapping supraglacial terrain in mountain areas. Comparing this result with the combination of GF-1 WFV and low-resolution morphometric parameters shows that a high-quality DEM and the thermal infrared band enhanced the accuracy of glacier mapping especially debris-covered ice in steep terrain. The user's and producer's accuracies of glacier area were also improved from 89.67% and 85.95% to 92.83% and 90.34%, respectively. GF data is recommended for mapping heavily debris-covered glaciers and will be combined with SAR data for future studies. 相似文献