There are many lakes on the Tibetan Plateau. The phenology and duration of lake ice age in this area is very sensitive to regional and global climate change, so it is used as a key indicator of climate change research, especially the comparative study of environmental changes in the Earth's three poles. However, due to its harsh natural environment and sparse population, it lacked routine field measurements of lake ice phenology. Using the Moderate-resolution Imaging Spectroradiometer (MODIS) to normalize the Different Snow Index (NDSI) data, the lake ice was monitored at a resolution of 500 meters to fill the observation gap. The traditional snow map algorithm was used to detect the daily ice volume and coverage extent of lakes under sunny condition. The spatial and temporal continuity of lake surface conditions was applied to re-determine the daily ice volume and coverage extent of lakes under cloud cover condition through a series of steps. Time series analysis was performed on 308 lakes larger than 3 k㎡ to determine effective record of lake ice extent and coverage, then to form a daily lake ice extent and coverage data set. And furthermore, four lake ice phenological parameters: freeze-up start ( FUS), freeze-up end (FUE), break-up start (BUS), and break-up end (BUE) can be obtained from 216 lakes of the data set, and two parameters: FUS and BUE can be obtained from the other 92 lakes.

File naming and required software

The data set contains 5,834 raster files, 1 vector file, and 308 Excel files. The raster files were named "Daily Lake Ice Extent." The vector file contains information such as the number, names, location, surface area, and classification codes of the processed lakes. The names of the excel files were corresponded to the lake numbers. Each excel file contains 6 columns and information on the daily ice coverage of the corresponding lakes from July 2002 to June 2018. The attributes of each column are: succession, date, lake coverage, lake ice coverage, cloud coverage, lake coverage, and lake ice coverage after cloud processing. Users can use vector files to determine the quantity, location and classification of a given lake first, and then get the corresponding Excel file of daily lake ice coverage data of a given year to monitor the lake ice freeze-thaw and study climate change.

Data Citations Data citation guideline What's data citation?

Cite as:

Qiu, Y. (2019). Daily lake ice extent and cover proportion dataset of the Tibetan Plateau based on MODIS (2002-2018). A Big Earth Data Platform for Three Poles, DOI: 10.11922/sciencedb.744. (Download the reference： RIS | Bibtex )

Using this data, the data citation is required to be referenced and the related literatures are suggested to be cited.

Support Program

CASEarth:Big Earth Data for Three Poles（grant No. XDA19070000） (No:XDA19000000)

Pan-Third Pole Environment Study for a Green Silk Road-A CAS Strategic Priority A Program (No:XDA20000000)

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