Madagascar's burned area from Sentinel-2 imagery (2016-2022): Four times higher than from lower resolution sensors.

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Version: Author's accepted manuscript
License: CC BY 4.0
Serval ID
serval:BIB_B72A78B06554
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Madagascar's burned area from Sentinel-2 imagery (2016-2022): Four times higher than from lower resolution sensors.
Journal
The Science of the total environment
Author(s)
Fernández-García Victor, Franquesa Magí, Kull Christian A.
ISSN
1879-1026 (Electronic)
ISSN-L
0048-9697
Publication state
Published
Issued date
08/01/2024
Peer-reviewed
Oui
Volume
914
Pages
169929
Language
english
Abstract
Madagascar is one of the most burned regions in the world, to the point that it has been called the 'Isle of fire' or the 'Burning Island'. An accurate characterization of the burned area (BA) is crucial for understanding the true situation and impacts of fires on this island, where there is an active scientific debate on how fire affects multiple environmental and socioeconomic aspects, and how fire regimes should be in a complex context with differing interests. Despite this, recent advances have revealed that BA in Madagascar is poorly characterised by the currently available global BA products. In this work, we present, validate, and explore a BA database at 20 m spatial resolution for Madagascar covering the period 2016-2022. The database was built based on 75,010 Sentinel-2 images using a two-phase BA detection algorithm. The validation with independent long-term reference units showed Dice coefficients ≥79 %, omission errors ≤24 %, commission errors ≤18 %, and a relative bias ≥ - 8 %. An intercomparison with other available global BA products (GABAM, FireCCI51, C3SBA11, or MCD64) demonstrated that our product (i) exhibits temporal consistency, (ii) represents a significant accuracy improvement, as it reduces BA underestimations by about eightfold, (iii) yields BA estimates four times higher, and (iv) shows enhanced capability in detecting fires of all sizes. The observed BA spatial patterns were heterogeneous across the island, with 32 % of the grasslands burning annually, in contrast to other land cover types such as the dense tropical forest where <2 % burned every year. We conclude that the BA characterization in Madagascar must be addressed using imagery at spatial resolution higher than MODIS or Sentinel-3 (≥250 m), and temporal resolution higher than Landsat (16 days) to deal with cloudiness, the rapid attenuation of burn scars signals, and small fire patches.
Keywords
Madagascar, fire, wildfire, remote sensing
Pubmed
Research datasets
Funding(s)
Other / Swiss Network for International Studies
Other / SR22 100062 British Ecological Society
Create date
16/01/2024 16:41
Last modification date
21/02/2024 7:16
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