PREVENTION CONTRE LES FEUX DE VEGETATION EN AFRIQUE DE L'OUEST, CAS DU DISTRICT DU ZANZAN, NORD-EST DE LA COTE D'lVOIRE: ANALYSE DU PHENOMENE ET DES SEUILS CLIMATIQUES FAVORABLES/ PREVENTION AGAINST VEGETATION FIRE IN WEST AFRICA, CAS DISTRICT ZANZAN, NORTHEAST OF THE IVORY COAST: THE PHENOMENON AND ANALYSIS OF THRESHOLD FAVOURABLE CLIMATE

Wildfires issues are part of a global problem. In Côte d'Ivoire, these phenomena are recurring and reduce, by the degradation of plant cover, crop yield. Official reports indicate each year many cases of wildfires in Zanzan with their impact on the local economy and human settlements. The present study aims to analyze the climatic conditions that trigger these lights for, identify critical thresholds of climate parameters in question to help prevent against this disaster. From data of ESA satellites ERS-1 and ENVISAT, the descriptive statistics and correlation analysis were used to conduct the study. The results show that during the year, vulnerable periods of wildfires go from december to March with an early occurrence in Bouna. They also show a strong dependence of fire with climatic conditions including high temperatures, low air and soil humidity and easterly dry wind regime. El Nino conditions are also critical for local fire occurrence in the district. Critical thresholds for triggering fires in Zanzan can be summarized by above 30 degrees Celsius for temperatures, below 40 percent for air relative humidity and less than 5 mm for the soil moisture. The analysis of the Angstrom index shows that this indicates is appropriate for characterize fire danger in the District Zanzan.