Société d'Exploitation et de Développement Aéroportuaire, Aéronautique et Météorologique, Direction de la Météorologie Nationale, Abidjan, Côte d'Ivoire
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.
This study aims to show the effect of the climatic variability on the productions of coffee and cocoa of the area of Daoukro which is the principal producing area in the Ivory Coast. The methodological approach is summarized in two steps: first, the characterization and analysis of the impact of climate variability on water resources second monitoring developments in the production of coffee and cocoa (1964-2005) through statistical analysis. The centered and reduced index shows a great interannual variability of rainfalls which is organized in two climatic periods, a humid period (1956-1970) and a dry period (1971-2009). The rainfall deficit evaluated in the area of Daoukro reaches an average of 11% and fluctuated between 5% and 15%. Analysis of the average rainfalls of the wettest four months (March-June) every 10 years during five decades of Daoukro station shows that the period of the great season of rains fell from 4 months to 3 months. The decrease of the rainfall consecutive with the effects of the dryness involved a decrease of the agricultural production (the production of coffee and cocoa). The climate variability from 1964 to 2005 caused interannual fluctuation of the production of coffee and cocoa. Cocoa production in 2004-2005 is only 36% of that of 1981-1982 and that of coffee 43% of the production of 1981-1982.