Spatial Assessment of Dry-Season Vegetation Condition using Sentinel-2 NDVI in the Guinea Savanna Landscape of Elaite, North-Central Nigeria
DOI:
https://doi.org/10.33003/fjs-2026-1022-6068Keywords:
NDVI, Vegetation stress, Guinea savanna, Sentinel-2, Dry season, Elaite, land degradationAbstract
Despite increasing dry-season vegetation stress in Guinea savanna communities in North-Central Nigeria under the combined pressures of climatic seasonality and anthropogenic land-use change, fine-scale, community-level spatial evidence remains limited. This study presents dry-season vegetation conditions in Elaite using Sentinel-2 Level-2A imagery acquired on 15th February 2026. We calculated the normalised difference vegetation index (NDVI) in QGIS and classified it into four vegetation-stress categories using thresholds calibrated against known Guinea savanna benchmarks. The NDVI values ranged from 0.0 to 0.44, indicating high spatial variability in vegetation condition. Built-up and sparsely vegetated surfaces dominated the landscape (87.85%; 1,113 ha; mean NDVI = 0.15), indicating high physiological stress under peak dry-season conditions. Cultivated and fallow lands covered 10.42% (132 ha; mean NDVI = 0.23) and showed moderate stress. Dense shrubland (3 ha; mean NDVI = 0.38) was limited to riparian corridors and covered 0.24% of the area. Wetland and open-water surfaces (19 ha; 1.5%) had negative NDVI values. The lowest NDVI values are concentrated in human-modified zones, and the highest NDVI values are restricted to hydrologically buffered riparian zones, consistent with drought response theory, which predicts that residual soil moisture availability mediates vegetation resilience under moisture deficits. The results provide a baseline for monitoring land degradation, assessing drought, and planning climate-change adaptation in Guinea savanna environments.
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Copyright (c) 2026 Jesse Abraham Eyasoko, Happy John-Nwagwu, Ngozi Gloria Johnson
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