The Global Mangrove Watch—A New 2010 Global Baseline of Mangrove Extent
Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth SY23 3DB, UK
Solo Earth Observation (soloEO), Tokyo 104-0054, Japan
School of Biological, Earth and Environmental Sciences (BEES), University of New South Wales (UNSW), High Street, Kensington, NSW 2052, Australia
International Water Management Institute, Regional Office for SE Asia and The Mekong, P.O. Box 4199, Vientiane
Wetlands International, 6700AL Wageningen, The Netherlands
Earth System Science Interdicsiplinary Center, University of Maryland/NASA Goddard Space Flight Center, College Park, MD 20742, USA
Remote Sensing Technology Center of Japan (RESTEC), Tsukuba Office, Ibaraki 305-8505, Japan
School of Science and Engineering, Tokyo Denki University, Saitama 350-0394, Japan
Institute for Land, Water and Society, Charles Sturt University, Albury, NSW 2640, Australia
Author to whom correspondence should be addressed.
Received: 31 July 2018 / Revised: 14 September 2018 / Accepted: 18 October 2018 / Published: 22 October 2018
This study presents a new global baseline of mangrove extent for 2010 and has been released as the first output of the Global Mangrove Watch (GMW) initiative. This is the first study to apply a globally consistent and automated method for mapping mangroves, identifying a global extent of 137,600 km
. The overall accuracy for mangrove extent was 94.0% with a 99% likelihood that the true value is between 93.6–94.5%, using 53,878 accuracy points across 20 sites distributed globally. Using the geographic regions of the Ramsar Convention on Wetlands, Asia has the highest proportion of mangroves with 38.7% of the global total, while Latin America and the Caribbean have 20.3%, Africa has 20.0%, Oceania has 11.9%, North America has 8.4% and the European Overseas Territories have 0.7%. The methodology developed is primarily based on the classification of ALOS PALSAR and Landsat sensor data, where a habitat mask was first generated, within which the classification of mangrove was undertaken using the Extremely Randomized Trees classifier. This new globally consistent baseline will also form the basis of a mangrove monitoring system using JAXA JERS-1 SAR, ALOS PALSAR and ALOS-2 PALSAR-2 radar data to assess mangrove change from 1996 to the present. However, when using the product, users should note that a minimum mapping unit of 1 ha is recommended and that the error increases in regions of disturbance and where narrow strips or smaller fragmented areas of mangroves are present. Artefacts due to cloud cover and the Landsat-7 SLC-off error are also present in some areas, particularly regions of West Africa due to the lack of Landsat-5 data and persistence cloud cover. In the future, consideration will be given to the production of a new global baseline based on 10 m Sentinel-2 composites.
This is an open access article distributed under the Creative Commons Attribution License
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
Share & Cite This Article
MDPI and ACS Style
Bunting, P.; Rosenqvist, A.; Lucas, R.M.; Rebelo, L.-M.; Hilarides, L.; Thomas, N.; Hardy, A.; Itoh, T.; Shimada, M.; Finlayson, C.M. The Global Mangrove Watch—A New 2010 Global Baseline of Mangrove Extent. Remote Sens. 2018, 10, 1669.
Bunting P, Rosenqvist A, Lucas RM, Rebelo L-M, Hilarides L, Thomas N, Hardy A, Itoh T, Shimada M, Finlayson CM. The Global Mangrove Watch—A New 2010 Global Baseline of Mangrove Extent. Remote Sensing. 2018; 10(10):1669.
Bunting, Pete; Rosenqvist, Ake; Lucas, Richard M.; Rebelo, Lisa-Maria; Hilarides, Lammert; Thomas, Nathan; Hardy, Andy; Itoh, Takuya; Shimada, Masanobu; Finlayson, C. M. 2018. "The Global Mangrove Watch—A New 2010 Global Baseline of Mangrove Extent." Remote Sens. 10, no. 10: 1669.
Show more citation formats
Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
[Return to top]
For more information on the journal statistics, click here
Multiple requests from the same IP address are counted as one view.