2023-05-04T13:11:58.897307

2024-10-04T16:27:34.392469

1 hectare

Global

global

Global Mangrove Watch, 2022. "Global Mangrove Extent (v3.0)." https://www.globalmangrovewatch.org. Accessed through Global Forest Watch on [Date]. www.globalforestwatch.org.

Global Mangrove Extent

Global Mangrove Watch, v3.0 Bunting, P.; Rosenqvist, A.; Hilarides, L.; Lucas, R.M.; Thomas, N.; Tadono, T.; Worthington, T.A.; Spalding, M.; Murray, N.J.; Rebelo, L.-M. Global Mangrove Extent Change 1996–2020: Global Mangrove Watch Version 3.0. Remote Sens. 2022, 14, 3657. [https://doi.org/10.3390/rs14153657](https://doi.org/10.3390/rs14153657)

[Creative Commons Attribution 4.0 International License](https://creativecommons.org/licenses/by/4.0/)

English

This dataset was generated within the framework of the [Global Mangrove Watch (GMW)](https://www.globalmangrovewatch.org/), an initiative convened by [Aberystwyth University](https://www.aber.ac.uk/en/dges/), [soloEO](https://www.soloeo.com/), [The Nature Conservancy](https://www.nature.org/) and [Wetlands International](https://www.wetlands.org/).<br><br>The dataset (v3.0) depicts the global extent of mangrove forests for the years 1996, 2007-2010, and 2015-2020, derived by L-band Synthetic Aperture Radar (SAR) global mosaic datasets from the Japan Aerospace Exploration Agency (JAXA), thus developing a long-term time-series of global mangrove extent and change. The study used a map-to-image approach to change detection where the baseline map (GMW v2.5) was updated using thresholding and a contextual mangrove change mask.<br><br>The classification was confined using a mangrove habitat mask, which defined regions where mangrove ecosystems can be expected to exist. The mangrove habitat definition was based on geographical parameters such as latitude, elevation and distance from ocean water. The habitat mask was initially developed in GMW v2.0 and has been revised in subsequent versions.

Global coverage of mangroves for select years from 1996 to 2020

Mangrove extent maps in v3.0 have an estimated accuracy of 87.4% (95th CI: 86.2 - 88.6%). Noted confusion exists in fragmented areas of mangroves, including around aquaculture ponds. Additional cautions should be exercised if accessing net change, or individual gain and loss data from the v3.0 dataset. A source of error in v3.0 included a misregistration in the SAR mosaic datasets, resulting in the omission of known change events and commissions where change was known not to have occurred. This was partially corrected for using tie points automatically generated via the method of [Bunting et al. 2010](https://doi.org/10.1016/j.imavis.2009.12.005). The changes associated with misregistration errors are considered to be similar in terms of gain and loss due to the random nature of the input data, so it is recommended that the observed net change statistics are used for analysis rather than individual gain and loss statistics. [Country statistics](https://zenodo.org/record/6894273/files/gmw_v3_country_statistics_ha.xlsx?download=1) have been provided directly by GMW and include corrections for commission and omission errors.  

Most robust global mangrove layer available

www.globalmangrovewatch.org.

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