Feature tracking analysis of Bechung Glacier dynamics using Landsat imagery: Surface displacement and velocity assessment in Bhutan

Abstract

Glaciers are critical indicators of climate change, and their dynamics significantly influence water resources and ecosystems. In Bhutan, the state of glaciers directly impacts water availability, human livelihoods, food security, and hydropower generation. However, detailed studies on glacier dynamics in this region remain limited. This study investigates the dynamics of the Bechung Glacier using feature tracking methods applied to Landsat 7, 8, and 9 imageries spanning 2000–2022. We analysed glacier surface displacement, velocity patterns, ice thickness distribution, and potential sites for glacier lake formation. Results indicate mean surface velocities of 6.9 ± 0.5 m/yr, with maximum displacement rates of 13.8 m/yr observed in the upper ablation zone. Ice thickness, estimated using a laminar flow model incorporating surface slope and velocity data, ranges from 0 to 225 ± 15 m, with the thickest ice concentrated in the central flow line. Analysis of bed topography revealed three over-deepened sections with potential for future lake formation, the largest having a maximum depth of 112 m. Surface velocity measurements from 2000 to 2022 provide crucial baseline data for monitoring glacier response to regional climate change. These findings enhance our understanding of Himalayan glacier dynamics and provide crucial baseline data for hydrological modelling. The results will support evidence-based decision-making for water resource management and natural hazard mitigation strategies in Bhutan’s changing climate. This study uses feature tracking to examine Bechung Glacier dynamics, a previously unstudied glacier in Bhutan, using Landsat data from 2000-2022. The glacier flows at a mean surface velocity of 6.9 m/year, with displacement rates reaching 13.8 m/year in its upper ablation zone. Ice thickness reaches up to 225 m, and the glacier bed contains three deep depressions, the largest measuring 112 m. The findings support better decisions on water resource planning and natural hazard preparedness in Bhutan as its climate changes. This study uses feature tracking to examine Bechung Glacier dynamics, a previously unstudied glacier in Bhutan, using Landsat data from 2000-2022. The glacier flows at a mean surface velocity of 6.9 m/year, with displacement rates reaching 13.8 m/year in its upper ablation zone. Ice thickness reaches up to 225 m, and the glacier bed contains three deep depressions, the largest measuring 112 m. The findings support better decisions on water resource planning and natural hazard preparedness in Bhutan as its climate changes.