Based on glacier inventory and 85 Gaofen-1/6 PMS images, 21 Sentinel 2A/2B MSI images and 16 Landsat OLI images, the boundary of glacial lakes in 2020 in Nepal were derived by using manual visual interpretation. The result shows that there were 2420 glacial lakes in Nepal, with an area range of 0.00015-4.79760 km2 and a total area of 87.57±5.28 km2. This dataset provides basic data for water resources evaluation, glacial lake outburst floods and glacier hydrology study in Nepal.
1.Name of Data
Nepal_glacial_lake_2020.shp
2.Data description of attribute items
GLAKE_ID: The coding of glacial Lake
GL_Image: Information of source image
GL_Elev: The average elevation of glacial lake (m)
GL_Area: The area of glacial lake (km2)
GL_Peri: The perimeter of glacial lake (m)
GL_Long: The longitude of centroid of the glacial lakes (°)
GL_Lati: The latitude of centroid of the glacial lakes (°)
1.Landsat Images
Download from the websites of the United States Geological Survey (https://www.usgs.gov/).
2.Glacier Inventory
RGI 6.0 (https://www.glims.org/RGI/rgi60_dl.html).
3.SRTM
Shuttle Radar Topography Mission digital elevation model V3 with spatial resolution of 30 m (https://earthexplorer.usgs.gov/).
1. Pre-processing of Remote Sensing Data：
False Colour Compositing Image and Geometric correction
2. Extracting the preliminary lake extent：
Determining the approximate extent of a glacial lake using an existing glacial lake dataset as a reference.
Reference：Wang X., Guo X., Yang C., Liu Q., Wei J., Zhang Y., Liu S., Zhang Y., Jiang Z., and Tang Z. Glacial lake inventory of High Mountain Asia (1990–2018) derived from Landsat images. Earth Syst. Sci. Data Discuss., doi：https://doi.org/10.5194/essd-2019-212
3. Manual Vectorization and Entering of Attribute Data
Vectorisation of glacial lake boundaries for the Nepal region. After vectorization of a glacial lake, it was required that manual attribute items (e.g., data source and lake area) be input concurrently.
4. Interactive Checking and Accuracy Control
(1) Glacial lakes were discerned via dataset interaction;
(2) Glacial lake boundary vectorization results were checked interactively by another vectorization results;The Arcgis Earth imagery was used as an important auxiliary reference data source for error examination.
Accuracy of Data：
(1) The percentage difference of the absolute area encircled by the manually delineated lake boundary and that derived by the GPS survey varied from 5.5–25.5 %.
(2) The average accuracy of the delineation of glacial lake boundaries was within ±0.5 pixels .
(3) The total absolute area error and average relative error of glacial lakes in Nepal in 2020 was approximately ±5.28 km2 and ±6.25 %, respectively.
| # | number | name | type |
| 1 | 2019YFE0127700 | Integrated Application of Earth Observations for Sendai Framework for Disaster RiskReduction | National key R & D plan |
| 2 | 42071089 | Research on Ice Phenology of Lakes on the Tibetan Plateau | National Natural Science Foundation of China |
| 3 | 41861013 | Research on monitoring and modelling of ice-cover thickness of the Qinghai Lake based on airborne ice-penetrating radar | National Natural Science Foundation of China |
This work is licensed under a
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CSTR:11738.11.ncdc.nieer.db2544.2022
10.12072/ncdc.NIEER.db2544.2022