Land Use Mapping of the Bandama Blanc Watershed: Implications for the Kossou Hydroelectric Dam (Côte d’Ivoire)

Land use and Land Cover (LULC) plays a crucial role in the water cycle, directly influencing the availability and quality of water resources, which is essential for activities such as hydroelectric production and drinking water supply. Understanding the evolution of LULC is very important for the sustainable management of water resources. This study, therefore, takes a close look at the evolution of land use in the Bandama Blanc watershed in Côte d’Ivoire, an important region for the Kossou hydroelectric dam. Using Landsat ETM+ (2000, 2011) and OLI (2021) satellite images and supervised classification using the maximum likelihood algorithm, the results show high overall accuracy (97% to 99%) and a Kappa index ranging from 0.98 to 0.99, attesting to the reliability of the classifications obtained. Despite this, confusion persists between certain classes, in particular between savannah and crop/fallow and degraded forest areas. Spatio-temporal analysis reveals a regression in forest, savannah, and water surface areas in favor of habitats/bare ground and crops/fallow over the period 2000–2021. These changes are attributed to bushfires and population growth, which intensifies anthropogenic pressures such as slash-and-burn agriculture, livestock breeding, and hunting. Falling rainfall and sediment deposits in lakes are also contributing to the reduction in water surface areas. These results underline the need for sustainable management strategies to mitigate anthropogenic pressures and preserve ecosystems in the Bandama Blanc watershed.