叶尔羌河上游冰川阻塞湖库容测量及最大洪水流量的计算分析

冰川阻塞湖的突然排水是叶尔羌河突发性洪水发生的根本原因.借助于对冰川阻塞湖库容的测量及分析,计算出可能的最大库容量,进而给出叶尔羌河今后可能的最大洪水流量为6888.40m~3/s。     

东帕米尔高原昆盖山跃动冰川遥感监测研究

冰川跃动是冰川周期性地快速运动,给下游生命财产安全带来巨大威胁。对已经发现的跃动冰川进行监测不仅有助于提高对冰川跃动机理的认识,而且对冰川跃动灾害预警预报和风险评估都具有重要的意义。在中国第二次冰川编目中发现,1963-2009年东帕米尔高原昆盖山的5Y663L0023冰川末端发生大幅前进。本文利用Landsat影像、ASTER立体像对等数据对该冰川前进过程进行监测研究。结果表明：该冰川于1990-1992年和2007-2013年分别前进81±30 m和811±30 m,其中2007-2013年的前进属于跃动引发的前进。其中跃动最高峰在2007年8月21日-2008年10月26日,期间32.7×10⁶ m³的冰体发生卸载,导致末端前进了704±30 m,面积扩张了0.34 km²。针对东帕米尔地区跃动冰川周期研究的空白,本文认为该冰川跃动周期中跃动期为4 a,平静期最短为15 a左右。该冰川属于多温型冰川,跃动受热力学机制影响的可能性较大,但液态降水、冰雪融水的增加也是影响因素。     

喀喇昆仑山乔戈里峰北坡主要冰川运动特征

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。     

克勒青河的冰川地质与地貌

本文通过实地考察并参考前人资料,对人迹罕至的叶尔羌河上游克勒青河的冰川地质、地貌进行了全面论述.这里新构造运动强烈,形成高山峻岭,现代冰川发育,冰塔林立冰湖分布其间,是我国现代冰川分布范围最大的地区。目前由于雪线上升,冰舌后退,予计50年后对冰川堵塞河道的突发性洪水灾害将消失。     

北极Svalbard地区Austre Lovénbreen和Pedersenbreen冰川表面物质平衡和运动特征分析

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.     

北极Svalbard地区Austre Lovénbreen和Pedersenbreen冰川表面物质平衡和运动特征分析

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...     

近50 年来天山地区典型冰川厚度及储量变化

冰川储量变化与冰川水资源量变化以及冰川对河川径流的贡献量密切相关。在GPR-3S技术支持下, 本研究基于雷达测厚数据、不同时期的高分辨率遥感影像、地形图及实测资料, 分析了天山三个典型地区四条代表性冰川近期厚度及储量变化特征, 并通过对比探讨了造成变化差异的可能原因。结果表明, 1962-2006 年乌鲁木齐河源1 号冰川厚度平均减薄0.15m a^-1, 冰储量亏损26.2×10⁶ m³, 冰川末端平均退缩3.8 m a^-1;博格达峰南坡的黑沟8 号冰川在1986-2009 年间, 冰舌平均减薄0.57 m a^-1, 冰储量损失了25.5×10⁶ m³, 末端平均退缩11.0 m a^-1;位于博格达峰北坡的四工河4 号冰川在1962-2009 年间冰舌平均减薄0.32 m a^-1, 冰储量亏损14.0×10⁶ m³, 末端平均后退8.0 m a^-1;1964-2008 年间, 托木尔峰青冰滩72 号冰川冰舌平均减薄0.22 m a^-1, 由此至少造成冰储量亏损14.1×10⁶ m³, 末端退缩达40.0 m a^-1。对比分析显示, 青冰滩72 号冰川消融退缩最为强烈, 黑沟8 号冰川次之, 与乌鲁木齐河源1 号冰川、科其喀尔冰川相差不大, 稍大于四工河4 号冰川和哈密庙尔沟冰川。这种差异可能与区域气候变化和冰川物理特征有直接关系。     

中喀喇昆仑布拉尔杜冰川近期跃动分析

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。     

叶尔羌河1987年洪水予报与未来洪水趋势予测

叶尔河是南疆最大河流,洪水问题十分突出,以冰雪融水洪水和冰川突发性洪水危害最大。本文分析了不同类型洪水特点,揭示了洪水发生规律,通过资料、航片解译分析结合野外实地考察测量,对叶尔羌河1987年洪水进行了予报,并对叶尔羌河未来洪水发展变化趋势作了初步予测。     

冰川与冻土

冰川P343.62006032188喀喇昆仑山克勒青河谷近年来发现有跃动冰川=Surgingglacier found in Shaksgam river,Karakorum Mountains/上官冬辉,刘时银…∥冰川冻土.—2005,27(5).—641~644根据相关历史资料,利用GIS进行了不同时期的冰川分布图的制作,对比分析了不同时期冰川范围.重点监测了喀喇昆仑山北坡克勒青河的5Y654D48、5Y654D97的不同时段内的冰川运动状况.结果发现:5Y654D48冰川和5Y654D97冰川分别在1990-2000年与1977-1990年间运动速度达272m.a-1,213.1m.a-1,比其它时段运动速度大7~20倍,具备跃动冰川的运动特征.图3表1参13(洪…     

Observations of the Drainage of an Ice-Dammed Lake — Strupvatnet,Troms, Norway

The behaviour of the ice-dammed lake, Strupvatnet, Troms County, Norway, is described. Past observations are noted and related to observations in 1959 and to other ice-dammed lakes. Mechanisms for opening and maintaining water flow during a ‘hlaup’ are discussed. It is considered that Liestol's melt widening process operates after initiation by a pressure gradient across the dam. The lake and the internal drainage system of the glacier are thus linked. There is no evidence of lifting of the ice dam at Strupbreen.     

塔里木河流域60 a来天然径流变化趋势分析

利用塔里木河流域近60 a的地表径流、气温和降水量资料,通过趋势分析、突变检验、年代际分析等方法分析了塔里木河流域地表径流变化的时空差异性,探讨了塔里木河流域天然径流变化对气温、降水量变化的响应。研究表明：近60 a来塔里木河流域三源流径流整体存在增加的趋势,但干流径流存在减少的趋势;塔里木河流域三源流增加强度在1993年前后从强到弱依次为阿克苏河、叶尔羌河、和田河,进入2000年后从强到弱依次为和田河、叶尔羌河、阿克苏河;塔里木河流域三源流径流强度增加主要受降水增加和由气温增加引起的融雪径流增加的双重影响。     

Glacial Lake Musselshell: Late Wisconsin slackwater on the Laurentide ice margin in central Montana, USA

Cosmogenic surface exposure ages of glacial boulders deposited in ice-marginal Lake Musselshell suggest that the lake existed between 20 and 11.5 ka during the Late Wisconsin glacial stage (MIS 2), rather than during the Late Illinoian stage (MIS 6) as traditionally thought. The altitude of the highest ice-rafted boulders and the lowest passes on the modern divide indicate that glacial lake water in the Musselshell River basin reached at least 920–930 m above sea level and generally remained below 940 m. Exposures of rhythmically bedded silt and fine sand indicate that Lake Musselshell is best described as a slackwater system, in which the ice-dammed Missouri and Musselshell Rivers rose and fell progressively throughout the existence of the lake rather than establishing a lake surface with a stable elevation. The absence of varves, deltas and shorelines also implies an unstable lake. The changing volume of the lake implies that the Laurentide ice sheet was not stable at its southernmost position in central Montana. A continuous sequence of alternating slackwater lake sediment and lacustrine sheetflood deposits indicates that at least three advances of the Laurentide ice sheet occurred in central Montana between 20 and 11.5 ka. Between each advance, it appears that Lake Musselshell drained to the north and formed two outlet channels that are now occupied by extremely underfit streams. A third outlet formed when the water in Lake Musselshell fully breached the Larb Hills, resulting in the final drainage of the lake. The channel through the Larb Hills is now occupied by the Missouri River, implying that the present Missouri River channel east of the Musselshell River confluence was not created until the Late Wisconsin, possibly as late as 11.5 ka.     

近50 年气候变化背景下中国冰川面积状况分析

根据近年来中国典型区域冰川面积变化遥感监测数据,结合139 个地面站的气温、降水量与28 个探空站的0 ℃层高度气象资料,分析了近50 年气候变化背景下中国冰川面积状况。结果表明,研究区冰川面积从20 世纪60-70 年代的23982 km²减小到21 世纪初的21893 km²,根据冰川分布进行加权计算后冰川面积退缩了10.1%,对时间插补后得到1960 年以来的冰川面积年均变化率为0.3 % a^-1。就冰川面积变化的空间分布特征而言,天山的伊犁河流域、准噶尔内流水系、阿尔泰山的鄂毕河流域、祁连山的河西内流水系等都是冰川退缩程度较高的区域。近50 年中国冰川区夏季地面气温与大气0 ℃层高度均呈上升趋势,而降水量的增幅却相对轻微,增长的降水量不足以抵消升温对冰川的影响,气候变暖是影响冰川面积变化的主要因素。     

Glacier area shrinkage in China and its climatic background during the past half century

Based on the glacier area variation records in the typical regions of China monitored by remote sensing, as well as the meteorological data of air temperature and precipitation from 139 stations and the 0℃ isotherm height from 28 stations, the glacier area shrinkage in China and its climatic background in the past half century was discussed. The initial glacier area calculated in this study was 23,982 km2 in the 1960s/1970s, but the present area was only 21,893 km2 in the 2000s. The area-weighted shrinking rate of glacier was 10.1%, and the interpolated annual percentage of area changes (APAC) of glacier was 0.3% a-1 since 1960. The high APAC was found at the Ili River Basin and the Junggar Interior Basin around the Tianshan Mountains, the Ob River Basin around the Altay Mountains, the Hexi Interior Basin around the Qilian Mountains, etc. The retreat of glacier was affected by the climatic background, and the influence on glacier of the slight-increased precipitation was counteracted by the significant warming in summer.     

EVIDENCE FOR LATE-GLACIAL ICE DAMMED LAKES IN THE CENTRAL STRAIT OF MAGELLAN AND BAHÍA INÚTIL, SOUTHERNMOST SOUTH AMERICA

ABSTRACT. This paper critically appraises the evidence for a succession of ice-dammed lakes in the central Strait of Magellan ( c. 53°S) c. 17 000–12 250 cal. yr BP. The topographic configuration of islands and channels in the southern Strait of Magellan means that the presence of lakes provides compelling constraints on the position of former ice margins. Lake shorelines and glacio-lacustrine sediments have been dated by their association with a key tephra layer from Volcan Reclús (c. 15 510–14 350 cal. years bp ) and by ¹⁴C-dated peats. The timing of glacial lake formation and associated glacier readvances is at odds with the rapid and widespread glacier retreat of the Patagonian ice fields further north after c. 17 000 cal. yr bp , suggesting rather that the lakes were coeval with the Antarctic Cold Reversal and persisted to the Late-glacial/Holocene transition. This apparent asymmetrical latitudinal response in glacier behaviour may reflect overlapping spheres of northern hemisphere and Antarctic climatic influence in the Magellan region.     

近50年气候变化背景下中国西部冰川面积状况分析(英文)

Based on the glacier area variation records in the typical regions of China moni-tored by remote sensing, as well as the meteorological data of air temperature and precipitation from 139 stations and the 0℃ isotherm height from 28 stations, the glacier area shrinkage in China and its climatic background in the past half century was discussed. The initial glacier area calculated in this study was 23,982 km2 in the 1960s/1970s, but the present area was only 21,893 km2 in the 2000s. The area-weighted shrinking rate of glacier was 10.1%, and the interpolated annual percentage of area changes (APAC) of glacier was 0.3% a-1 since 1960. The high APAC was found at the Ili River Basin and the Junggar Interior Basin around the Tianshan Mountains, the Ob River Basin around the Altay Mountains, the Hexi Interior Basin around the Qilian Mountains, etc. The retreat of glacier was affected by the climatic background, and the influence on glacier of the slight-increased precipitation was counteracted by the significant warming in summer.     

The Glaciolacustrine Landform–Sediment Assemblage at Heinabergsjökull, Iceland

Landform–sediment assemblages associated with two ice-dammed lakes, one active and one fossil, at Heinabergsjökull in southeast Iceland are described. The current ice-dammed lake (Vatnsdalur) is dominated by a large aggradational terrace, as well as an excellent suite of shorelines. The second fossil ice-dammed lake dates from the Neoglacial maximum of Heinabergsjökull ( c . 1887) and drained during the late 1920s. This lake is associated with a suite of shorelines and ice-marginal glaciolacustrine fans. The sedimentology of one of these fans is described. Between 50 and 70% of the sediment succession is dominated by ice-rafted sediment, although rhythmites, matrix-rich gravels, sands and graded sand–silt couplets are also present. A range of intra-formational, soft-sediment deformation structures are present, consistent with liquefaction and deformation associated with loading, current shear, and iceberg calving. The landform–sediment assemblages described from Heinabergsjökull provide important data for the interpretation of Pleistocene ice-dammed lakes.     

DEGLACIATION OF THE EASTERN FLANK OF THE NORTH PATAGONIAN ICEFIELD AND ASSOCIATED CONTINENTAL-SCALE LAKE DIVERSIONS

ABSTRACT. We examine the deglaciation of the eastern flank of the North Patagonian Icefield between latitudes 46° and 48°S in an attempt to link the chronology of the Last Glacial Maximum moraines and those close to present-day outlet glaciers. The main features of the area are three shorelines created by ice-dammed lakes that drained eastwards to the Atlantic. On the basis of 16 ¹⁴C and exposure age dates we conclude that there was rapid glacier retreat at 15–16 ka (calendar ages) that saw glaciers retreat 90–125 km to within 20 km of their present margins. There followed a phase of glacier and lake stability at 13.6–12.8 ka. The final stage of deglaciation occurred at c. 12.8 ka, a time when the lake suddenly drained, discharging nearly 2000 km³ to the Pacific Ocean. This latter event marks the final separation of the North and South Patagonian Icefields. The timing of the onset of deglaciation and its stepped nature are similar to elsewhere in Patagonia and the northern hemisphere. However, the phase of lake stability, coinciding with the Antarctic Cold Reversal and ending during the Younger Dryas interval, mirrors climatic trends as recorded in Antarctic ice cores. The implication is that late-glacial changes in southern Patagonia were under the influence of the Antarctic realm and out of phase with those of the northern hemisphere.     

西藏山南地区沉错湖泊与径流水化学特征及主控因素初探

选取枪勇冰川径流-卡鲁雄曲（河）-沉错（湖）为研究区域,开展高原湖泊及其补给河流与冰川径流的水化学特征研究,并探讨影响主离子组成的主控因素。结果表明：夏季湖水主要离子呈均匀混合状态,pH值、电导率、TDS及优势阴阳离子在整个湖泊空间上变化不显著;总体上,从上游冰川融水径流、河水至下游湖泊,离子浓度呈现上升趋势;融水径流及河水的水化学类型主要受岩石风化作用控制,表现为SO₄^2--Ca²⁺-Mg²⁺类型;沉错湖水的水化学类型主要受蒸发结晶作用控制,表现为SO₄^2--Na⁺-Ca²⁺类型,在蒸发作用下Ca²⁺逐渐沉淀析出,Na⁺浓度不断升高而成为绝对优势阳离子。