Dataset
Global Mangrove Watch
1. Updates
| Aug. 03, 2026 |
Global Mangrove Watch, version 4.1 (v4.1.12) raster dataset was released.
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| Aug. 05, 2022 |
Global Mangrove Watch (version 3.0) raster dataset was released. |
| Nov. 05, 2021 |
Global Mangrove Watch (version 2.0) raster dataset was released. |
2. Overview
The Global Mangrove Watch (GMW) was established in 2011 under JAXA's Kyoto & Carbon Initiative. It is an international collaboration led by Aberystwyth University, solo Earth Observation, Wetlands International, The Nature Conservancy and JAXA.
The Global Mangrove Watch (GMW) dataset (version 4.1) provides maps of estimated global extent and changes of mangrove forests derived from for 41 annual epochs between 1985 and 2025.
See the K&C Global Mangrove Watch and
Global Mangrove Watch Platform for further information, and the Mangrove expedition at Kagoshima & Okinawa (Management:Specified Nonprofit Corporation "ManGlobal®") for detailed distribution of mangrove information in Japan.
3. Dataset description
| Dataset name: | Global Mangrove Watch, version 4.1 (v4.1.12) |
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| Content: | Mangrove geographical extent for the years 1985 through 2025 |
| Pixel spacing: | 30 m (0.000269469 degrees) |
| Data type: | Raster (BYTE) |
| Number of bands: | 41 (band 1: 1985, band 2: 1986, ..., band 41: 2025) |
| Pixel values: | DN=1: mangroves; DN=0: non-mangrove |
| Format: | GeoTIFF |
| Projection: | Geographic coordinates (WGS 84, EPSG=4326) |
4. Methodology
The GMW mangrove maps were derived from a combination of optical (Landsat and Sentinel 2) and L-band SAR (JERS-1 SAR, ALOS PALSAR and ALOS-2 PALSAR-2) satellite data. The accuracy assessment for the mangrove extent estimated a global F1-Score of 0.9276 (0.9220 - 0.9330), with an omission of 6.357% (5.648 - 7.133) and a commission of 8.093% (7.093 - 9.128). The methodology used to derive the maps is described in:
Bunting, P., Hilarides, L., Rosenqvist, A., Oakes, G., Castro Brandão Vaz dos Santos, P., Worthington, T., Rosenqvist, J., Zanaga, D., Van De Kerchove, R., Kobayashi, K. and Tadono, T. (2026). Global Mangrove Watch: Timeseries of Mangrove Extent (Version 4.1.12) [Dataset]. Zenodo.
5. Download
Please register your information from following URL to download the dataset. It is required your email address.
This is temporally registration (especially please check your email address again) and will send email you to accept your registration request. After the confirmation of your request, the download information will send by email.
The dataset download site is
6. Note for data use
The dataset is available for free public use under the "Terms of Use of Research Data" except for the "2.1. Credit".
To publish images using the dataset as it is, please display "©Global Mangrove Watch" or "©Aberystwyth University, solo Earth Observation, Wetlands International, The Nature Conservancy and JAXA."
Users should keep in mind that the GMW dataset is a global-scale dataset, generated with a single methodology applied over all regions. As such, the accuracy of the map may vary between locations and with scale. In particular, the timeseries is dependent on the availability of satellite imagery, and in the 1990s and 1980s, the availability of imagery can be significantly reduced over certain regions.
7. Contacts
The ALOS-2/ALOS Science Project
Earth Observation Research Center (EORC)
Japan Aerospace Exploration Agency (JAXA)
E-mail: aprojectjaxa.jp
Dr. Ake Rosenqvist, GMW and K&C Science Coordinator
solo Earth Observation (soloEO)
Tokyo, Japan
E-mail: ake.rosenqvistsoloEO.com