TITLE:
Detection of Burned Areas through Spectral Indices Analysis of Sentinel-2A Satellite Images in the Abokouamékro Wildlife Reserve (Central, Côte d’Ivoire)
AUTHORS:
Bob Kouakou Kouadio, Sié Ouattara, Alain Clément, Jean-Marc Gala Bi Zaouri, Jean-Luc Kouadio Kouassi Jean-Luc, Edouard Kouakou N’guessan
KEYWORDS:
Spectral Indices, Wildfire, Burned Areas, Abokouamékro Wildlife Reserve, Côte d’Ivoire
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.14 No.1,
January
31,
2024
ABSTRACT: In
C?te d’Ivoire, the recurring and unregulated use of bushfires, which
cause ecological damage, presents a pressing concern for the custodians of
protected areas. This study aims to enhance our comprehension of the dynamics
of burnt areas within the Abokouamékro Wildlife Reserve (AWR) by employing the
analysis of spectral indices derived from satellite imagery. The research
methodology began with the calculation of mean indices and their corresponding
spectral sub-indices, including NDVI, SAVI, NDWI, NDMI, BAI, NBR, TCW, TCG, and
TCB, utilizing data from the Sentinel-2A satellite image dated January 17,
2022. Subsequently, a fuzzy classification model was applied to these various
indices and sub-indices, guided by the degree of membership α, with the
goal of effectively distinguishing between burned and unburned areas. Following
the classification, the accuracies of the classified indices and sub-indices
were validated using the coordinates of 100 data points collected within the
AWR through GPS technology. The results revealed that the overall accuracy of all indices and sub-indices
declines as the degree of membership α decreases from 1 to 0. Among the
mean spectral indices, NDVI-mean, SAVI-mean, NDMI-mean exhibited the highest overall
accuracies, achieving 97%, 95%, and 90%, respectively. These results closely mirrored those obtained by sub-indices using band 8
(NDVI-B8, SAVI-B8, and NDMI-B8), which yield respective overall accuracies of
93%, 92%, and 89%. At a degree of membership α = 1, the estimated burned areas for the most effective indices encompassed 2144.38 hectares for
NDVI-mean, 1932.14 hectares for mean SAVI-mean, and 4947.13 hectares for mean
NDMI-mean. A prospective approach involving the amalgamation of these three
indices could have the potential to yield improved outcomes. This study could
be a substantial contribution to the discrimination of bushfires in C?te
d’Ivoire.