EVALUATION OF THE SPATIO-TEMPORAL DYNAMICS OF THE FÉTORÉ SUB-BASIN BETWEEN 1990 AND 2020

The Fétoré sub-basin, a tributary of the Konkouré River, is located in the Fouta-Djalon massif, an area known as the "water tower of West Africa." For several decades, this territory has faced increasing pressure from human activities specifically agricultural expansion, land clearing, and urbanization compounded by climate variability. These factors contribute to gradual headwater degradation and disrupt the basin's hydrological functioning.
This study analyzes the spatiotemporal dynamics of land use in the Fétoré sub-basin between 1990 and 2020/2022 to identify key changes and their underlying drivers. The methodology combines basin delineation using a digital elevation model, supervised classification of Landsat satellite imagery, result validation via a confusion matrix and Kappa coefficient, and change analysis using a transition matrix and field surveys.
The results reveal a continuous decline in natural vegetation cover, whereas open forests have expanded significantly, rising from 20.12 % in 1990 to 41.15 % in 2022. Cropland and fallow land, bare rock, and water bodies have also changed. These transformations, driven primarily by population pressure, agricultural expansion, and rainfall variability, exacerbate the hydrological vulnerability of the sub-basin and the Fouta-Djalon headwaters. They highlight the need to implement appropriate integrated management and restoration strategies.