Spatio‑Temporal Dynamics of Land Cover and Ecosystem Degradation in Madarounfa and Gabi, Niger

Across the Sahel, the combination of rapid population growth, extensive agriculture, uncontrolled livestock grazing, and high demand for fuelwood has led to accelerated degradation of vegetative resources. This study assesses, through remote sensing (Landsat MSS and 7 imagery) and geographic information systems (GIS), the spatio-temporal dynamics of land cover in the communes of Madarounfa and Gabi (Niger) between 1987 and 2017. Five land cover classes were mapped: water bodies, gallery forests, savanna, steppe, and bare soil. Results reveal severe ecological degradation: savanna declined by 8,752 ha and gallery forest by 9,083 ha, while bare soil expanded dramatically from 47,583 ha to 59,069 ha (57% of the total area). The expansion of the steppe likely reflects the degradation of formerly wooded formations. These changes are attributed to intense anthropogenic pressures including deforestation, agricultural expansion, uncontrolled grazing, and high population density combined with climatic variability, characterised by 17 rainfall-deficient years over a 32-year period. Together, these drivers accelerate desertification, threaten biodiversity, and undermine critical ecosystem services. The study confirms the effectiveness of remote sensing for monitoring landscape change over time and underscores the urgent need to implement integrated strategies for sustainable land management, ecological restoration, and community-based awareness to reverse this critical environmental trend.