Remote Sensing Assessment of Land Degradation Trends in Borno State, 2000 to 2023

Land degradation resulting from a combination of climatic aridification, conflict-induced land abandonment, and unsustainable land use practices has significantly altered the productive landscape of Borno State, North East Nigeria, over the first two decades of the twenty-first century. This study uses multi-temporal remote sensing data to assess spatial and temporal land degradation trends across Borno State from 2000 to 2023. Landsat 7 ETM+, Landsat 8 OLI, and Sentinel-2 imagery acquired at approximately five-year intervals were processed to generate land use and land cover maps using supervised maximum likelihood classification. The Normalised Difference Vegetation Index was used as a proxy for vegetation productivity, with Mann-Kendall trend analysis applied to annual NDVI time series to identify statistically significant degradation and recovery trends. Soil-adjusted vegetation index and bare soil index were computed to characterise areas of severe topsoil exposure. The study integrates the Land Degradation Neutrality assessment framework endorsed by the United Nations Convention to Combat Desertification, using three indicators: land cover change, land productivity dynamics, and soil organic carbon. Conflict displacement data from the Internal Displacement Monitoring Centre are correlated with detected land cover change to evaluate the human security dimension of land degradation. Results provide actionable evidence for the Borno State Environmental Protection Agency and international restoration programmes. Keywords: land degradation, remote sensing, Borno State, NDVI trends, land degradation neutrality.