ISSN 1003-8035 CN 11-2852/P

    雅鲁藏布江林芝至山南段石冰川识别与驱动因素分析

    Identification and Driving-Factor Analysis of Rock Glaciers along the Linzhi-Shannan Section of the Yarlung Tsangpo River

    • 摘要: 雅鲁藏布江位于中国西南部,该流域地形复杂包括高山、峡谷,地势落差大,是地质灾害频繁发生的区域。
      目的 为研究河流上游林芝至山南段石冰川的分布特征和对外界环境变化的响应机制,
      方法 选取Sentinel-1升降轨数据,结合光学遥感影像,采用Stacking-InSAR和SBAS-InSAR技术对石冰川进行识别,并运用交叉小波变换与小波相干分析方法,分析石冰川形变与气温、降水的关系。
      结果 共识别石冰川164条,空间分布分析表明其主要分布在高程45005500 m,坡度10°~40°与雅鲁藏布江间隔为4~10 km的区域内,且尤以北向和西北向的石冰川最为发育;交叉小波变换与小波相干分析表明,研究区石冰川形变周期项与降水、气温在340天周期上存在显著时频耦合特征。
      结论 气温通过冻融循环影响石冰川形变过程,降水则以短期扰动形式影响形变动态,二者协同调控石冰川形变过程。

       

      Abstract: The Yarlung Tsangpo River basin in southwestern China is characterized by complex topography, high mountains, deep gorges, and large elevation gradients, making it prone to frequent geohazards.
      Objective This study investigates the distribution characteristics of rock glaciers along the Linzhi-Shannan section of the upper Yarlung Tsangpo River and their response mechanisms to environmental change.
      Methods Sentinel-1 ascending- and descending-track data were combined with optical remote-sensing imagery. Stacking-InSAR and SBAS-InSAR techniques were used to identify rock glaciers, and cross-wavelet transform and wavelet coherence analyses were applied to examine relationships between rock-glacier deformation, air temperature, and precipitation.
      Results A total of 164 rock glaciers were identified. Spatial distribution analysis shows that they are mainly distributed at elevations of 4,500-5,500 m, slopes of 10°-40°, and distances of 4-10 km from the Yarlung Tsangpo River, with north- and northwest-facing rock glaciers being the most developed. Cross-wavelet transform and wavelet coherence analyses indicate that periodic components of rock-glacier deformation in the study area show significant time-frequency coupling with precipitation and air temperature on an approximately 340-day cycle.
      Conclusion Air temperature affects rock-glacier deformation through freeze-thaw processes, whereas precipitation affects deformation dynamics through short-term disturbances; together, these factors regulate rock-glacier deformation.

       

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