High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment
Girona‐Mata M, Miles ES, Ragettli S, Pellicciotti F. 2019. High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment. Water Resources Research. 55(8), 6754–6772.
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https://doi.org/10.1029/2019WR024935
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Journal Article
| Published
| English
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Author
Girona‐Mata, Marc;
Miles, Evan S.;
Ragettli, Silvan;
Pellicciotti, FrancescaISTA
Abstract
The snow cover dynamics of High Mountain Asia are usually assessed at spatial resolutions of 250 m or greater, but this scale is too coarse to clearly represent the rugged topography common to the region. Higher-resolution measurement of snow-covered area often results in biased sampling due to cloud cover and deep shadows. We therefore develop a Normalized Difference Snow Index-based workflow to delineate snow lines from Landsat Thematic Mapper/Enhanced Thematic Mapper+ imagery and apply it to the upper Langtang Valley in Nepal, processing 194 scenes spanning 1999 to 2013. For each scene, we determine the spatial distribution of snow line altitudes (SLAs) with respect to aspect and across six subcatchments. Our results show that the mean SLA exhibits distinct seasonal behavior based on aspect and subcatchment position. We find that SLA dynamics respond to spatial and seasonal trade-offs in precipitation, temperature, and solar radiation, which act as primary controls. We identify two SLA spatial gradients, which we attribute to the effect of spatially variable precipitation. Our results also reveal that aspect-related SLA differences vary seasonally and are influenced by solar radiation. In terms of seasonal dominant controls, we demonstrate that the snow line is controlled by snow precipitation in winter, melt in premonsoon, a combination of both in postmonsoon, and temperature in monsoon, explaining to a large extent the spatial and seasonal variability of the SLA in the upper Langtang Valley. We conclude that while SLA and snow-covered area are complementary metrics, the SLA has a strong potential for understanding local-scale snow cover dynamics and their controlling mechanisms.
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Publishing Year
Date Published
2019-08-01
Journal Title
Water Resources Research
Volume
55
Issue
8
Page
6754-6772
ISSN
eISSN
IST-REx-ID
Cite this
Girona‐Mata M, Miles ES, Ragettli S, Pellicciotti F. High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment. Water Resources Research. 2019;55(8):6754-6772. doi:10.1029/2019wr024935
Girona‐Mata, M., Miles, E. S., Ragettli, S., & Pellicciotti, F. (2019). High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment. Water Resources Research. American Geophysical Union. https://doi.org/10.1029/2019wr024935
Girona‐Mata, Marc, Evan S. Miles, Silvan Ragettli, and Francesca Pellicciotti. “High‐resolution Snowline Delineation from Landsat Imagery to Infer Snow Cover Controls in a Himalayan Catchment.” Water Resources Research. American Geophysical Union, 2019. https://doi.org/10.1029/2019wr024935.
M. Girona‐Mata, E. S. Miles, S. Ragettli, and F. Pellicciotti, “High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment,” Water Resources Research, vol. 55, no. 8. American Geophysical Union, pp. 6754–6772, 2019.
Girona‐Mata M, Miles ES, Ragettli S, Pellicciotti F. 2019. High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment. Water Resources Research. 55(8), 6754–6772.
Girona‐Mata, Marc, et al. “High‐resolution Snowline Delineation from Landsat Imagery to Infer Snow Cover Controls in a Himalayan Catchment.” Water Resources Research, vol. 55, no. 8, American Geophysical Union, 2019, pp. 6754–72, doi:10.1029/2019wr024935.
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