2:45 PM - 3:00 PM
[ACC26-05] Debris thickness estimation by thermal infrared imagery on Batal Glacier in Chandra basin, Indian Himalaya
★Invited Papers
Keywords:Glacier, debris, thermal imagery
In debris-covered glaciers, which are abundant in the Himalayas, it is known that the debris layer on the glacier surface has a significant effect on glacier variation through an insulating effect and an increase in solar radiation absorption due to albedo lowering. It has become important to estimate the fluctuation trend of glaciers over a wide area from the viewpoint of water resources and disaster glaciers, and in recent years, many studies have been performed by remote sensing.
The purpose of this study is to improve the accuracy of glacier variation evaluation by time series of the surface temperature of the glacier and the spatial distribution of the debris layer thickness by estimating the debris layer thickness from the thermal characteristics. Two types of surface temperatures data were used: fixed-point observation data from a thermal infrared camera during field observations conducted in the autumn in 2023, and remote sensing data (Landsat 8 Level 2 products surface temperatures).
As a result of unsupervised classification of the time-series pattern of each grid of the obtained surface temperature images, it was found that the time-series pattern classification of the ground surface temperature by remote sensing can clearly distinguish between the thick terminal area and thin middle area of the debris glacier in the basin, and a clear relationship between the debris layer thickness and the temperature time-series change pattern can be seen. In addition, the boundary between the debris covered glacier area, which is generally difficult to distinguish from optical satellite images, and the off-glacier area was clearly separated. In addition, from the time-series pattern in the surface temperature in the field, a clear change in the pattern of changes in the surface temperature was observed at the thick and thin points of the debris layer. In the presentation, we will also report on the results of the study on the surface change pattern and the thickness of the debris layer.
The purpose of this study is to improve the accuracy of glacier variation evaluation by time series of the surface temperature of the glacier and the spatial distribution of the debris layer thickness by estimating the debris layer thickness from the thermal characteristics. Two types of surface temperatures data were used: fixed-point observation data from a thermal infrared camera during field observations conducted in the autumn in 2023, and remote sensing data (Landsat 8 Level 2 products surface temperatures).
As a result of unsupervised classification of the time-series pattern of each grid of the obtained surface temperature images, it was found that the time-series pattern classification of the ground surface temperature by remote sensing can clearly distinguish between the thick terminal area and thin middle area of the debris glacier in the basin, and a clear relationship between the debris layer thickness and the temperature time-series change pattern can be seen. In addition, the boundary between the debris covered glacier area, which is generally difficult to distinguish from optical satellite images, and the off-glacier area was clearly separated. In addition, from the time-series pattern in the surface temperature in the field, a clear change in the pattern of changes in the surface temperature was observed at the thick and thin points of the debris layer. In the presentation, we will also report on the results of the study on the surface change pattern and the thickness of the debris layer.