基于多源遥感数据的希夏邦马峰地区冰前湖演化与冰川动力学响应分析

Proglacial Lake Evolution and Glacial Dynamic Response in Shishapangma Area Using Multi-Source Remote Sensing Data

  • 摘要: 希夏邦马峰地区位于喜马拉雅山中段,冰川与冰前湖广泛发育,近年来受气候变暖影响发生显著变化。基于2007至2020年高分辨率Planet光学遥感与ALOS-1/2 SAR数据,重点分析典型冰前湖面积与容积时序演变特征,反演母冰川的流速及时序形变。结果表明,2010年至2020年冰前湖面积持续扩张,其中岗西错与嘎隆错年均面积增长率分别为0.05 km2/a与0.09 km2/a。冰前湖能够改变冰川末端动力学条件,入湖型冰川运动速率显著高于陆地终止型冰川,2014至2019年入湖型与陆地终止型冰川平均流速分别为33.2 m/a与22.4m/a,累积形变均超过200 m。研究区域冰前湖扩张与母冰川运动存在相互作用,母冰川形变与冰湖面积呈显著相关关系,气候变暖则是冰川运动与冰前湖扩张的外部影响因子。研究明确了冰前湖扩张、母冰川动态变化及外部气温间的关联,为气候变暖背景下冰冻圈研究及冰前湖溃决灾害风险评估提供科学依据。

     

    Abstract: Objectives: The Shishapangma region is in the central Himalayas, where glaciers and proglacial lakes are widely distributed. Under global climate warming, the cryospheric environment in this area has undergone remarkable changes. Clarifying the coupling relationship between proglacial lake evolution and the dynamic response of parent glaciers is essential for mountain cryosphere research and glacial lake outburst disaster risk assessment. This study quantitatively analyzes the spatiotemporal variations of typical proglacial lakes and the kinematic characteristics of their parent glaciers to reveal their interaction mechanism. Methods: Based on high-resolution Planet optical remote sensing and ALOS-1/2 SAR datasets from 2007 to 2020, we extracted the boundary and calculated the area and volume changes of Gangxi Co and Galong Co. The PO-SBAS (Pixel Offset Tracking Small Baseline Subsets) method was adopted to invert the flow velocity and time-series cumulative deformation of glaciers. We further compared the dynamic differences between lake-terminating glaciers and land-terminating glaciers, and analyzed the correlation between lake expansion and glacier deformation, as well as the driving effect of climate warming. Results: The two proglacial lakes showed a continuous expansion trend from 2010 to 2020, with annual area growth rates of 0.05 km2/a for Gangxi Co and 0.09 km2/a for Galong Co. The water body at the glacier terminus changes the mechanical conditions of glacier movement: laketerminating glaciers move much faster than land-terminating ones. During 2014-2019, the average velocity of laketerminating glaciers reached 33.2 m/a, while that of land-terminating glaciers was 22.4 m/a, and both types accumulated deformation over 200 m. There was a significant correlation between proglacial lake expansion and parent glacier deformation, and rising temperature acted as the primary external driving factor. Conclusions: This study systematically expounds the linkage among proglacial lake expansion, glacier dynamic evolution and climatic factors in the Shishapangma area of central Himalayas. The results can provide scientific support for cryospheric process research and the risk prevention of proglacial lake outburst floods under climate warming.

     

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