In reaction to a warming climate in the Southeastern Tibetan Plateau (SETP), the direction and intensity of surface flow in maritime glaciers undergo adjustments, causing glacial debris flow and ice avalanches. The safe operation of mega transportation projects across the region has been seriously threatened, e.g., the Sichuan-Tibet transportation corridor. Consequently, the measurement in three dimensions (3-D) consistently merits attention in the surface flow evolution for this glaciated region. In this study, we first mapped the 3-D and long-term surface flow of the glacier ensemble in the Namcha Barwa during 2019–2022 using the space-borne Synthetic Aperture Radar (SAR) technique, specifically applying the pixel offset tracking (POT) method to obtain deformation estimation of SAR-derived data. Subsequently, 3-D glacier velocities were acquired from the Multidimensional Small Baseline Subset (MSBAS) method conducted with the above datasets. Results show that two fast-moving glaciers were detected in the glacier ensemble, namely Dem Glacier and Namjagbrawa Glacier. Dem Glacier mainly flows eastward horizontally with a velocity of approximately 120 m/yr. And the inconspicuous vertical changes reveals that the glacier has sufficient winter supply. Although the detectable proportion of Namjagbrawa Glacier is relatively small, SAR results can perform well in limited pixels verified through optical results. It flows swifter over roughly −150 m/yr in the east, north, and vertical directions due to the vast elevation differences. However, other glaciers in the ensemble generally maintained slow flow, with multidimensional velocities below 20 m/yr. All glaciers’ flow velocities and the local climate in temporal are parallelism in the variations, which exhibit summer-accelerated and winter-slowed seasonal patterns. There were no surge signs during the study phase, which does not preclude the possibility of future emergence. The maritime glaciers in the SETP should be therefore multidimensional and continuous monitored to implement early warning and forecasting for mega transportation projects.

中文翻译：

---

对青藏高原东南部南迦巴瓦海冰川的 SAR 数据集进行 3D 流速时间序列分析

青藏高原东南部气候变暖导致海洋冰川表面流的方向和强度发生调整，导致冰川泥石流和冰崩。川藏交通走廊等区域特大型交通工程的安全运营受到严重威胁。因此，三维 (3-D) 测量在该冰川区域的表面流演化中始终值得关注。在本研究中，我们首先使用星载合成孔径雷达（SAR）技术绘制了2019-2022年南迦巴瓦冰川群的3D和长期表面流动图，特别是应用像素偏移跟踪（POT ) 方法来获得 SAR 导出数据的变形估计。随后，通过使用上述数据集进行的多维小基线子集（MSBAS）方法获得了 3D 冰川速度。结果表明，在冰川群中检测到了两个快速移动的冰川，即德姆冰川和南迦布拉瓦冰川。德姆冰川主要水平向东流动，流速约为 120 m/年。而不明显的垂直变化则揭示了冰川冬季补给充足。虽然南迦布拉瓦冰川的可探测比例较小，但通过光学结果验证，SAR结果在有限像素内表现良好。由于巨大的高差，它在东、北和垂直方向的流速更快，大约为-150 m/年。然而，冰川群中的其他冰川通常保持缓慢流动，多维速度低于 20 m/年。所有冰川的流速与当地气候在时间上都是平行变化的，呈现夏季加速、冬季减缓的季节模式。研究阶段没有出现激增迹象，这并不排除未来出现的可能性。因此，应对SETP的海洋冰川进行多维度、持续的监测，以对大型交通项目实施预警和预报。