Glacier surface velocities in the Jankar Chhu Watershed, western Himalaya, India: Study using Landsat time series data (1992–2020)

This datasets presents a spatial and temporal surface velocity analysis of 33 glaciers in the Jankar Chhu Watershed (JCW), western Himalaya. The surface velocity was computed using the Co-registration of Optically Sensed Images and Correlation (COSI-Corr) tool on the Landsat images spanning nearly three decades (1992–2020).

Glaciers in the JCW exhibit three distinct spatial velocity patterns. The type-I glaciers show nearly stagnant (<5 m yrˉ1) debris-covered tongues but a maximum velocity of >60 m yrˉ1 in the debris-free accumulation area. The type-II glaciers exhibit active tongues (>50 m yrˉ1) yet have slow movement in the accumulation zone. The type-III glaciers show prolonged (<10 m yrˉ1) yet consistent movement throughout the flow line. Results show that the average surface velocity of studied glaciers was 11.10 ± 4.1 m yrˉ1 in 1992/93, which increased (by ∼43%) to 15.87 ± 2.4 m yrˉ1 in 2000/02 and further increased (by ∼59%) to 25.25 ± 1.5 m yrˉ1 in 2017/18. Glaciers show seasonal fluctuations in surface velocities with an apparent “summer speedup” of ∼19%–200% compared to the winter velocities. Inter-annual velocities show an increasing trend during the observation periods.

本数据集呈现了位于喜马拉雅山脉西部江卡楚流域（JCW）的33个冰川的时空表面速度分析。通过在跨越近三十年（1992-2020）的Landsat图像上应用光学图像配准与相关性（COSI-Corr）工具，计算了表面速度。JCW的冰川呈现出三种独特的空间速度模式。I型冰川表现出近乎停滞（<5 m/yr）的覆盖碎屑舌，但在无碎屑的积累区达到最大速度>60 m/yr。II型冰川展现出活跃的舌部（>50 m/yr），但在积累区移动缓慢。III型冰川则显示出沿流动线持续（<10 m/yr）的运动。结果表明，所研究冰川的平均表面速度在1992/93年为11.10 ± 4.1 m/yr，到2000/02年增加了（约43%）至15.87 ± 2.4 m/yr，并在2017/18年进一步增加了（约59%）至25.25 ± 1.5 m/yr。冰川的表面速度表现出季节性波动，与冬季速度相比，夏季速度明显加快，增幅约为19%-200%。在观测期间，年际速度显示出上升趋势。