喀喇昆仑山乔戈里峰北坡主要冰川运动特征  

Characteristics of major glacial movements on the northern slope of K2,Karakoram

作　　者：李海娟 刘时银 吴坤鹏 LI Haijuan;LIU Shiyin;WU Kunpeng(Institute of International Rivers and Eco-security,Yunnan University,Kunming 650500,Yunnan,China)

机构地区：[1]云南大学国际河流与生态安全研究院,云南昆明650500

出　　处：《干旱区地理》2021年第5期1350-1364,共15页Arid Land Geography

基　　金：第二次青藏科考项目(2019QZKK0208);云南大学人才项目(YJRC3201702)。

摘　　要：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。The surface velocity of 42 glaciers on the northern slope of K2(Mount Qogir),Karakoram was extracted from ITS_LIVE and Landsat data.Combined with data regarding the characteristics of end and surface movements,the spatial and temporal variations of the surface velocity of glaciers with different movement types were analyzed and compared.The results show that(1)from 1989 to 2018,among the 42 glaciers in the study area,we observed 16 stable,6 advancing,1 retreating,and 19 surging glaciers.The velocity distribution in space is consistent with the general principle of glacier movement,and obvious high-value areas can be found in the accumulation area and upper region of the glacier tongue;these areas are mostly in the trunk or branch of the active glacier,and the velocity is generally>100.00 m·a^(-1).For example,in the southern branch of the Yengisogat glacier,the maximum velocity can reach 358.33 m·a^(-1).(2)The glacier velocity distribution is closely related to topographical factors.The maximum flow velocity(54.55 m·a^(-1))is between 4600 m and 5000 m,which is>10 times that of the end of the glacier.The average velocity of the 42 glaciers in the slope angle range of 0°to 5°is the highest,and the velocity decreases with the increase of the slope angle.Glaciers flowing toward the east have the greatest flow rate,and those that flow toward the southwest have the smallest.(3)The interannual variation of the velocity of the stable glacier is small,and the velocity values at the same location are consistent across different years.For advancing and retreating glaciers,the fluctuation in interannual velocity is large.The annual velocity variation of the surging glacier is found to be location dependent.The surface velocity of the glacier with a moving tip shows little change,but the change velocity of the glacier tip can be>100.00 m·a^(-1) and even up to 500.00 m·a^(-1).(4)Glaciers with longer lengths and larger areas are prone to surge.Climate,avalanches,and topography also play a major role in determining glacier

关 键 词：冰川 喀喇昆仑山北坡 ITS_LIVE数据 Landsat数据 表面流速 时空变化 

分 类 号：P343.6[天文地球—水文科学]