Assessment of Desertification and Land Use Change in Yobe State Using Remote Sensing

This study assesses the extent and rate of desertification and associated land use change in Yobe State, North East Nigeria, using multi-temporal remote sensing imagery analysis. Yobe State is located in the Sahel transition zone and has experienced progressive land degradation driven by reduced rainfall, overgrazing, deforestation for fuel wood, and wind erosion, contributing to declining agricultural productivity and increasing food insecurity. Landsat satellite imagery from 2009, 2015, and 2022 was processed to produce land cover classification maps using a supervised classification approach with field-verified training sites. Change detection analysis was performed using post-classification comparison. Vegetation condition was assessed using the normalised difference vegetation index, and bare soil expansion was quantified from the change maps. Results show that bare or sparsely vegetated land increased from 28 percent to 44 percent of the state area between 2009 and 2022, representing a net expansion of degraded land of approximately 3,800 square kilometres. Shrubland and grassland experienced the largest area losses, while agricultural cropland showed modest expansion into areas cleared from degraded woodland. Wind erosion indicators including deflation surfaces and barchan dune encroachment are evident in northern districts bordering the Sahara. NDVI trends show statistically significant greening in some areas following tree planting interventions but widespread browning in unmanaged areas. The study provides a quantitative baseline for monitoring the effectiveness of the Great Green Wall initiative in Yobe State. Keywords: desertification, land degradation, remote sensing, Yobe State, land use change.