SPATIO-TEMPORAL MAPPING OF DESERTIFICATION DYNAMICS IN THE FRONTLINE STATES OF NORTHERN NIGERIA USING REMOTE SENSING AND GIS
Authors: L.N. Sambe, B.A. Osunmadewa, C.O. Adeofun and J.A. Oyedepo
L.N. Sambe: Department of Social and Environmental Forestry, Joseph Sarwuan Tarka University Makurdi, Nigeria & Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Nigeria.
B.A. Osunmadewa: Dresden University of Technology, Institute for Remote Sensing and Photogrammetry, Helmholtz straße 10, 01069, Dresden, Germany.
C.O. Adeofun: Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Nigeria.
J.A. Oyedepo: Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Nigeria.
ABSTRACT
Desertification remains a critical environmental challenge in Northern Nigeria, with far-reaching implications for livelihoods and ecosystem sustainability. This study employed remote sensing and Geographic Information Systems (GIS) to assess the spatio-temporal extent and trends of desertification across the frontline states from 1984 to 2022. Multi-temporal Landsat (TM, ETM+, and OLI) and Sentinel imagery were processed using supervised and unsupervised classification techniques, with the Normalized Difference Vegetation Index (NDVI) serving as a key indicator of vegetation health and density. Results revealed a substantial decline in vegetation cover, with 83.16% of the area exhibiting low NDVI values (0.12–0.22) in 2022 compared to 54.51% in 1984. Very high vegetation density (0.72–0.92) was virtually absent, while only 0.72% of the area retained high vegetation density. Land-use/land-cover (LULC) change analysis showed a 53.16% decline in dense vegetation (annual rate: –6.25%) and a 55.45% increase in light vegetation (annual rate: 2.37%). Bare land decreased slightly (–2.49%), built-up areas expanded by 0.63% (annual rate: 3.36%), and water bodies reduced by –0.43% (annual rate: –1.47%). These findings underscore the accelerating rate of vegetation degradation and the urgent need for sustainable land-use planning and afforestation interventions in Northern Nigeria.
Keywords: Desertification, NDVI, Remote Sensing, GIS, Land-Use/Land-Cover Change, Northern Nigeria