Spatio-temporal Assessment of Desert Encroachment in Maigatari Local Government Area, Jigawa State, Nigeria, Using Ndvi-Base Change Detection (2005-2025)

Desert encroachment poses a critical threat to dryland ecosystems and rural livelihoods in the Sudano-Sahelian region of northern Nigeria. This study assesses the spatiotemporal dynamics of vegetation change and desertification intensity in Maigatari Local Government Area (LGA), Jigawa State, between 2005 and 2025. Using multi-temporal Landsat satellite imagery (Landsat 5 TM, Landsat 8 OLI, and Landsat 9 OLI), the Normalized Difference Vegetation Index (NDVI) was computed and classified into three land cover categories: bare land, sparse vegetation, and moderate vegetation. Change detection analysis was performed to quantify transitions across two decadal intervals (2005–2015 and 2015–2025). Results reveal a substantial expansion of bare land from 0.0032 km² (0.0013%) in 2005 to 67.06 km² (26.21%) in 2015, representing an 80% increase, indicating accelerated degradation during the first decade. Sparse vegetation declined sharply from 97.66% to 45.06% over the same period. Between 2015 and 2025, bare land continued to expand to 74.70 km² (29.21%), while moderate vegetation increased locally from 28.72% to 38.59%, suggesting partial recovery in isolated areas. The overall trajectory, however, confirms progressive desert encroachment with net vegetation loss. The findings underscore the urgent need for integrated land management strategies, including sustainable grazing, agroforestry, and farmer-managed natural regeneration. This study demonstrates the efficacy of NDVI-based change detection within a GIS framework as a tool for evidence-based environmental planning and desertification monitoring in semi-arid regions.