Global Mangrove Watch
This study used the Japan Aerospace Exploration Agency (JAXA) 11-duration L-band Synthetic Aperture Radar (SAR) global mosaic dataset from 1996 to 2020 to develop long-term maps of mangrove extent and change globally. sequentially. The study employed a map-to-image approach to detect changes, where a baseline map (GMW v2.5) was updated using thresholding and a background mangrove change mask. This approach was applied to all image-date pairs, yielding 10 maps per epoch that were aggregated to produce a global mangrove time series. The resulting map of mangrove extents was estimated with an accuracy of 87.4% (95th conf.int.: 86.2-88.6%), although the individual gain and loss change categories were less accurate at 58.1% (52.4-63.9% ) and 60.6% (56.1-64.8%).
Sources of error include misregistration of SAR mosaic datasets, which can only be partially corrected, but also clutter in scattered areas of mangroves, such as around aquaculture ponds. Overall, the mangrove area was determined to be 152,604 km2 (133,996-176,910) in 1996, a decrease of -5,245 km2 (-13,587-3686), resulting in a total area of 147,359 km2 (127,925-168,895) in 2020, Estimated 3.4% loss over 24 years. Global Mangrove Watch Version 3.0 represents the most comprehensive record of global mangrove change to date and is expected to support a wide range of activities, including ongoing monitoring of the global coastal environment, identification and assessment of progress towards conservation goals, protected area planning and Risk assessment of global mangrove ecosystems.
Data Connections:
You can download the dataset here and read the paper here
Disclaimer: All or part of the description of this dataset is provided by the authors or their works.
Preprocessing
The raster tiles are mosaiced so that all extensions and related rasters fit into a single collection. Date ranges were later added to raster and vector layers.
Disclaimer: All or part of the description of this dataset is provided by the authors or their works.
Preprocessing
The raster tiles are mosaiced so that all extensions and related rasters fit into a single collection. Date ranges were later added to raster and vector layers.
Citation:
Bunting, P.; Rosenqvist, A.; Hilarides, L.; Lucas, R.M.; Thomas, T.; 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 Sensing. 2022
Dataset citation:
Bunting, Pete, Rosenqvist, Ake, Hilarides, Lammert, Lucas, Richard, Thomas, Nathan, Tadono , Takeo, Worthington, Thomas, Spalding , Mark, Murray,
Nicholas, & Rebelo, Lisa-Maria. (2022). Global Mangrove Watch (1996 - 2020) Version 3.0 Dataset (3.0) [Data set]. Zenodo. https://doi.org/10.5281/
zenodo.6894273
GEE code
var extent_raster = ee.ImageCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/GMW_V3");
var extent_1996 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_1996_vec");
var extent_2007 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2007_vec");
var extent_2008 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2008_vec");
var extent_2009 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2009_vec");
var extent_2010 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2010_vec");
var extent_2015 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2015_vec");
var extent_2016 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2016_vec");
var extent_2017 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2017_vec");
var extent_2018 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2018_vec");
var extent_2019 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2019_vec");
var extent_2020 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/extent/gmw_v3_2020_vec");
Changes since 1996
var change_f1996_raster = ee.ImageCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/change_f1996");
var change_f1996_2007 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2007_vec");
var change_f1996_2008 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2008_vec");
var change_f1996_2009 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2009_vec");
var change_f1996_2010 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2010_vec");
var change_f1996_2015 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2015_vec");
var change_f1996_2016 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2016_vec");
var change_f1996_2017 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2017_vec");
var change_f1996_2018 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2018_vec");
var change_f1996_2019 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2019_vec");
var change_f1996_2020 = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/change/gmw_v3_f1996_t2020_vec");
merged data
var gmw_union_raster = ee.Image("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/union/gmw_v3_mng_union");
var gmw_union_vector = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/union/gmw_v3_union_vec");
var gmw_core_raster = ee.Image("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/core/gmw_v3_mng_core");
var gmw_core_vector = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/core/gmw_v3_core_vec");
Earth Engine Snippet: Tiles¶
var tiles = ee.FeatureCollection("projects/earthengine-legacy/assets/projects/sat-io/open-datasets/GMW/gmw_v3_tiles");
Resolution: approx 30m
License & Usage¶
Attribution 4.0 International CC BY 4.0.
Curated in GEE by: Samapriya Roy
Keywords: Global, Mangrove, GMW, 1996, 2020
Last updated: 2022-09-16