Climatic drivers of the 2024 Thyanbo Glacial Lake Outburst in Nepal deciphered using Sentinel-2 NDWI/MNDWI analysis
DOI:
https://doi.org/10.64866/j.ijdscr.2025.10017Keywords:
Remote Sensing Analysis, Spectral Water Indices, Glacier–Lake Monitoring, Climate Change Impacts, Glacial Lake Outburst Floods (GLOFs)Abstract
Thyanbo Glacial Lake in the Thame region of Nepal experienced a destructive outburst flood on 16 August 2024, displacing more than one hundred people and damaging homes, hotels, a school, and a health post. This study examines the climatic and hydrological conditions that contributed to the event using multi-temporal satellite imagery from 2017 to December 2024. Lake area, perimeter, and volume were estimated using the Normalized Difference Water Index (NDWI) and Modified NDWI (MNDWI), while temperature and precipitation records were analysed to assess their influence on meltwater input and lake expansion. From 2017 to 2023, the lake remained relatively stable, with areas ranging from 32,881 to 41,758 m² and volumes from 118×10³ to 159×10³ m³. A pronounced shift occurred in 2024, when rising temperatures and intensified monsoon rainfall drove rapid lake growth. By 30 July 2024, the lake reached its maximum extent (43,902 m²) and volume (169×10³ m³), coinciding with summer temperatures exceeding 5°C and a marked increase in rainfall. Following the 16 August outburst, lake area declined by more than 70% and volume by nearly 80%, indicating extensive drainage and geomorphic reconfiguration. Overall, the findings show that short‐term climatic extremes, superimposed on long‐term warming, contributed to moraine failure and the resulting Glacial Lake Outburst Floods (GLOFs). The study underscores the value of combining spectral water indices with climatic trends to detect early warning signals. These results highlight the need for improved real-time lake monitoring, integration of local weather observations, and targeted hazard preparedness for downstream communities. Continuous satellite-based surveillance is essential for anticipating future GLOFs risks in rapidly changing Himalayan environments.
Downloads
References
Aawaaj News, 2024-08-16. Lake outburst triggers massive flooding and landslides in Solukhumbu. https://awaajnews.com/visualstories/lake-outburst-triggers-massive-flooding-and-landslides-in-solukhumbu/
Bajracharya, S.R., Shrestha, B., 2011. The Status of Glaciers in the Hindu Kush Himalayan Region. International Centre for Integrated Mountain Development (ICIMOD). https://doi.org/10.53055/ICIMOD.551
Congalton, R.G., 1991. A review of assessing the accuracy of classifications of remotely sensed data. Remote Sensing of Environment 37, 35–46. https://doi.org/10.1016/0034-4257(91)90048-B
Cook, S.J., Quincey, D.J., 2015. Estimating the volume of Alpine glacial lakes. Earth Surface Dynamics 3, 559–575. https://doi.org/10.5194/esurf-3-559-2015
Du, Y., Zhang, Y., Ling, F., Wang, Q., Li, W., Li, X., 2016. Water bodies’ mapping from Sentinel-2 imagery with modified normalized difference water index at 10-m spatial resolution produced by sharpening the SWIR band. Remote Sensing 8, 354. https://doi.org/10.3390/rs8040354
Du, Z., Li, W., Zhou, D., Tian, L., Ling, F., Wang, H., Sun, B., 2014. Analysis of Landsat-8 OLI imagery for land surface water mapping. Remote Sensing Letters 5, 672–681. https://doi.org/10.1080/2150704X.2014.960606
Farsight Nepal, 2024-08-17. Thame GLOF displaces residents in Solukhumbu. https://farsightnepal.com/news/363
Florath, J., Keller, S., Abarca-del Rio, R., Hinz, S., Staub, G., Weinmann, M., 2022. Glacier monitoring based on multi-spectral and multi-temporal satellite data: A case study for classification with respect to different snow and ice types. Remote Sensing 14, 845. https://doi.org/10.3390/rs14040845
Gautam, V.K., Gaurav, P.K., Murugan, P., Annadurai, M., 2015. Assessment of surface water dynamics in Bangalore using WRI, NDWI, MNDWI, supervised classification and k–t transformation. Aquatic Procedia 4, 739–746. https://doi.org/10.1016/j.aqpro.2015.02.095
International Centre for Integrated Mountain Development (ICIMOD), 2024-08-17. GLOF from Thyanbo glacial lake sweeps away Thame village. https://www.icimod.org/press-release/glof-from-thyanbo-glacial-lake-sweeps-away-thame-village/
Kargel, J.S., Abrams, M.J., Bishop, M.P., Bush, A., Hamilton, G., Jiskoot, H., Raup, B., 2010. Aster imaging and analysis of glacier hazards, in: Ramachandran, B., Justice, C., Abrams, M. (Eds.), Land Remote Sensing and Global Environmental Change (Remote Sensing and Digital Image Processing). Springer, volume 11, p. 113–150. https://doi.org/10.1007/978-1-4419-6749-7_15
Richardson, S.D., Reynolds, J.M., 2000. An overview of glacial hazards in the Himalayas. Quaternary International 65–66, 31–47. https://doi.org/10.1016/S1040-6182(99)00035-X
Shugar, D.H., Burr, A., Haritashya, U.K., Kargel, J.S., Watson, C.S., Kennedy, M.C., Clague, J.J., 2020. Rapid worldwide growth of glacial lakes since 1990. Nature Climate Change 10, 939–945. https://doi.org/10.1038/s41558-020-0855-4
The Kathmandu Post, 2024-08-16. Flood in Solukhumbu destroys 12 houses. https://kathmandupost.com/national/2024/08/16/flood-in-solukhumbu-destroys-12-houses
Wigmore, O., Mark, B., 2017. Monitoring tropical debris-covered glacier dynamics from high-resolution unmanned aerial vehicle photogrammetry, Cordillera Blanca, Peru. The Cryosphere 11, 2463–2480. https://doi.org/10.5194/tc-11-2463-2017
Woolway, R.I., Kraemer, B.M., Lenters, J.D., Merchant, C.J., O’Reilly, C.M., Sharma, S., 2020. Global lake responses to climate change. Nature Reviews Earth & Environment 1, 388–403. https://doi.org/10.1038/s43017-020-0067-5
Xu, H., 2006. Modification of normalised difference water index (NDWI) to enhance open water features in remotely sensed imagery. International Journal of Remote Sensing 27, 3025–3033. https://doi.org/10.1080/01431160600589179
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Bhuwan Singh Bisht, Bimal Joshi, Soniya Koirala, Sabita Sapkota, Harish Bhatt (Author)
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
How to Cite
