AI-generated Key Takeaways
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These Landsat Collection 2 Tier 1 Level 2 composites provide annual Normalized Difference Water Index (NDWI) data from 1984 to present, derived from orthorectified scenes.
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The NDWI measures the liquid water content of vegetation canopies, with values ranging from -1.0 to 1.0, and is calculated using Near-IR and a second IR band.
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These annual composites include all scenes from the year, with the most recent pixel being used for the composite value, excluding certain images based on time and location criteria for Landsat 7 and 8.
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Landsat datasets are in the public domain and can be used freely, with acknowledgement to the U.S. Geological Survey (USGS) as the data source being appreciated.
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The dataset is available on the Google Earth Engine platform for analysis and visualization, with free access for research, education, and nonprofit use.
- Dataset Availability
- 1984-01-01T00:00:00Z–2025-01-01T00:00:00Z
- Dataset Provider
- USGS
- Cadence
- 1 Year
- Tags
Description
These Landsat Collection 2 Tier 1 Level 2 composites are made from Tier 1 Level 2 orthorectified scenes.
The Normalized Difference Water Index (NDWI) is sensitive to changes in liquid water content of vegetation canopies. It is derived from the Near-IR band and a second IR band, ≈1.24μm when available and the nearest available IR band otherwise. It ranges in value from -1.0 to 1.0. See Gao (1996) for details.
These composites are created from all the scenes in each annual period beginning from the first day of the year and continuing to the last day of the year. All the images from each year are included in the composite, with the most recent pixel as the composite value.
Notes:
The code used to create the composites can be seen here.
Only daytime images with WRS_ROW < 122 are included.
For Landsat 7 , images after 2017-01-01 are excluded due to orbital drift.
For Landsat 8, images before 2013-05-01 are excluded due to pointing issues.
Bands
Bands
| Name | Pixel Size | Description |
|---|---|---|
NDWI |
30 meters | Normalized Difference Water Index |
Terms of Use
Terms of Use
Landsat datasets are federally created data and therefore reside in the public domain and may be used, transferred, or reproduced without copyright restriction.
Acknowledgement or credit of the USGS as data source should be provided by including a line of text citation such as the example shown below.
(Product, Image, Photograph, or Dataset Name) courtesy of the U.S. Geological Survey
Example: Landsat-7 image courtesy of the U.S. Geological Survey
See the USGS Visual Identity System Guidance for further details on proper citation and acknowledgement of USGS products.
Explore with Earth Engine
Code Editor (JavaScript)
var dataset = ee.ImageCollection('LANDSAT/COMPOSITES/C02/T1_L2_ANNUAL_NDWI') .filterDate('2017-01-01', '2017-12-31'); var colorized = dataset.select('NDWI'); var colorizedVis = { min: 0.0, max: 1.0, palette: ['0000ff', '00ffff', 'ffff00', 'ff0000', 'ffffff'], }; Map.setCenter(6.746, 46.529, 6); Map.addLayer(colorized, colorizedVis, 'Colorized');