Land Degradation Assessment Using Remote Sensing in Semi-Arid Regions of Yobe State, North East Nigeria

Land degradation in the semi-arid zone of North East Nigeria represents a critical environmental and food security challenge, driven by deforestation, overgrazing, and rainfall variability. This study assessed the extent and severity of land degradation in Yobe State using multi-temporal satellite imagery and vegetation index analysis. Landsat data from 2010, 2016, and 2022 were processed to generate land cover maps and track changes in the Normalised Difference Vegetation Index and bare soil index over time. Ground-truth surveys were conducted to validate remote sensing classifications and document degradation indicators including gully formation, vegetation thinning, and sand encroachment. Results indicated progressive land degradation affecting approximately 42 percent of the surveyed area, with the most severe degradation concentrated in areas with high livestock densities and cleared croplands lacking vegetative cover between growing seasons. Expanding sand dunes were documented encroaching on previously vegetated rangelands in three local government areas. The Normalised Difference Vegetation Index showed statistically significant declining trends over the study period at degraded sites. The study recommends establishment of shelterbelts using drought-resistant tree species, enforcement of grazing management zones, and integration of land degradation mapping into Yobe State's environmental management planning framework. Keywords: land degradation, remote sensing, semi-arid, Yobe State, vegetation index.