Identified main fire hotspots and seasons in Côte d’Ivoire (West Africa) using MODIS fire data

Tionhonkélé D. Soro; Moussa Koné; Aya B. N’Dri; Evelyne T. N’Datchoh

doi:10.17159/sajs.2021/7659

Authors

Tionhonkélé D. Soro Laboratory of Ecology and Sustainable Development, Faculty of Natural Sciences, Nangui Abrogoua University, Abidjan, Côte d’Ivoire https://orcid.org/0000-0003-2195-6194
Moussa Koné Laboratory of Ecology and Sustainable Development, Faculty of Natural Sciences, Nangui Abrogoua University, Abidjan, Côte d’Ivoire
Aya B. N’Dri Laboratory of Ecology and Sustainable Development, Faculty of Natural Sciences, Nangui Abrogoua University, Abidjan, Côte d’Ivoire https://orcid.org/0000-0002-6333-6279
Evelyne T. N’Datchoh Atmospheric Physics Laboratory, Faculty of Structure of Matter and Technology Sciences, Félix Houphouët Boigny University of Cocody, Abidjan, Côte d’Ivoire https://orcid.org/0000-0003-3139-6581

DOI:

https://doi.org/10.17159/sajs.2021/7659

Keywords:

active fires, fire density, fire hotspot, fire season, remote sensing

Abstract

Biomass burning has become more frequent and widespread worldwide, with a significant proportion occurring in tropical Africa. Fire dynamics have been generally studied at global or regional scales. At local scale, however, fire impacts can be severe or catastrophic, suggesting local analyses are warranted. This study aimed to characterise the spatio-temporal variations of vegetation fires and identify the main fire hotspots in Côte d’Ivoire, a country of West Africa, one of the world’s burn centres. Using MODIS-derived fire data over a 10-year period (2007–2016), the number of fire days, active fires and fire density were assessed across the entire country. In the southern part dominated by forests, fire activity was low. Three main fire hotspots were identified between 2°30’–8°30’W and 7°00’–10°30’N in the North-West, North-East and Central areas all dominated by savannas. In these areas, Bafing, Bounkani and Hambol regions recorded the highest fire activity where fire density was 0.4±0.02, 0.28±0.02 and 0.18±0.01 fires/km²/year, respectively. At national scale, the annual fire period stretched from October to April with 91% of fires occurring between December and February, with a peak in January. Over the decade, there was a decreasing trend of fire activity. Fire density also was negatively correlated with rainfall >1000 mm for the synchronic analysis, whereas fire density was positively correlated with rainfall in the previous years. Results suggest that the positive relationship between the previous year’s rainfall and fire activity could operate on a cycle from 1 to 4 years.

Significance:

Three fire hotspots were found primarily in savanna vegetation, which burns more regularly than forestdominated vegetation.
The fire season occurs over 7 months, the majority of active fires (91%) occurring in just 3 months (December-January-February) with a peak in January (39%).
Fire activity has declined over the past decade with a return time of above-average fires from 1 to 4 years.
Fire density is positively correlated to the amount of rainfall in preceding years, whereas fire density and rainfall of the same year were negatively correlated in the region of rainfall >1000 mm.