Global maps derived from Collection 2 Landsat 5, 7, 8, and 9 scenes 1999-2025 highlight the changes in surface water extent during this period. Maps include the interannual dynamics 1999-2025, discrete dynamics classes, annual water percent, mean monthly water percent, and the water percent for individual months. Water percent is calculated from only the land and water observations. For additional information about these results, please see the associated journal article (Pickens et al., Remote Sensing of Environment 2020).
Web-based visualizations of these results are also available:
https://glad.earthengine.app/view/surface-water-dynamics-v2
Please use that URL when linking to this dataset.
The Intergovernmental Panel on Climate Change (IPCC) provides guidance on reporting areal extent and change of land cover and land use, requiring the use of estimators that neither over or underestimate dynamics to the degree possible, and that have known uncertainties. The maps provided by GLAD do not have these properties. However, the maps can be leveraged to facilitate appropriate probability-based statistical methods in deriving statistically valid areas of forest extent and change. Specifically, the maps may be used as a stratifier in targeting forest extent and/or change by a probability sample. The team at GLAD has demonstrated such approaches using the GLAD surface water dynamics in sample-based area estimation (Pickens et al., RSE, 2020).
This update of global surface water dynamics uses Collection 2 Landsat 5, 7, 8, and 9 data and improved filtering and composite rules.
This work is licensed under a Creative Commons Attribution 4.0 International License. You are free to copy and redistribute the material in any medium or format, and to transform and build upon the material for any purpose, even commercially. You must give appropriate credit, provide a link to the license, and indicate if changes were made.
Use the following credit when these data are displayed:
Source: Hansen/UMD/Google/USGS/NASA
Use the following credit when these data are cited:
Pickens, A.H., Hansen, M.C., Hancher, M., Stehman, S.V., Tyukavina, A., Potapov, P., Marroquin, B., Sherani, Z., 2020. Mapping and sampling to characterize global inland water dynamics from 1999 to 2018 with full Landsat time-series. Remote Sensing of Environment 243, 111792. https://doi.org/10.1016/j.rse.2020.111792
This global dataset is divided into 10x10 degree tiles. All files contain unsigned 8-bit values and have a spatial resolution of 0.00025° per pixel, or approximately 30 meters per pixel at the equator.
To download individual 10x10 degree granules, click on a region on the map below and then click on the URLs underneath it.
You can also analyze these results directly in Google Earth Engine using the asset IDs displayed in the Earth Engine App. If you are not yet an Earth Engine user, you may sign up here.