29-years dynamic of the vegetation and climatic variables in Dimbokro Department, Central Côte d'Ivoire

Résumé

The combined effects of both temperature increasing and human activities intensification in the Tropics have a direct consequence as the perturbation on the natural vegetation cover. In order to better understand this process, the present study was undertaken in Dimbokro Department through a mapping and analysis of the spatial and temporal evolution of land cover types based on 29-year period (1988-2017) satellite images (Landsat 4 TM and Landsat 8 OLI/TIRS). A diachronic analysis of satellite data and a supervised classification using OLI 5/6/4 colorful compositions allowed a better discrimination of the land use types. The forests of plateaus, the riparian forests and the nude soils or localities decreased in area, while the shrubby savannas, the forests plantations and the fallows or crops lands increased in area. The overall accuracies for the classified images were 96.76% (1988) and 97.70% (2017), while the Kappa coefficients were estimated at 0.96 (1988) and 0.97 (2017). The riparian forests and the nude soils or localities were the land use types that have lost the most area with respective rates of change of -30.36% and -47.45%.