SPATIO-TEMPORAL INVESTIGATION OF VEGETATION DYNAMICS AND ITS EFFECTS ON CLIMATIC VARIABILITY IN TANGAZA, SOKOTO STATE, NIGERIA

Vegetation dynamics has significant impacts on climatic variability by influencing factors like surface temperature, precipitation patterns, and the water cycle. As vegetation changes, it can alter local and regional climates, for example, the albedo effect phenomenon and evapotranspiration. However, the impact of vegetation changes in relation to desert encroachment as an environmental challenge in Tangaza, Sokoto State, has not been investigated, constituting a research gap. Tangaza, in Sokoto State, Nigeria, is one of the locations experiencing desertification. The presence of sand dunes in Tangaza provides physical evidence of desert encroachment with impacts such as land degradation and reduced crop yield. This study investigates how changes in vegetation dynamics influence climatic variability in Tangaza. Using Landsat 8 Operational Land Imager and Digital Elevation Model (DEM) data, the research evaluates vegetation dynamics via Normalized Difference Vegetation Index (NDVI) values for dry and rainy seasons across 2013 and 2018. It explores the relationship between stream order and vegetation density, revealing how hydrological features influence vegetation patterns. Key findings indicate that rainy seasons exhibit higher NDVI values due to increased rainfall, while the dry season shows vegetation decline, particularly near lower-order streams. For 2013, NDVI values for sparse vegetation increased by 17% between dry and rainy seasons (-0.275 – 0.06 and 0.063 – 0.170) respectively. For 2018, NDVI values for low vegetation increased by 4% only, between dry and rainy seasons (-0.219 – 0.095 and -0.146 – 0.173) respectively. These insights underscore the role of sustainable land management in mitigating vegetation loss, controlling desert encroachment, and promoting ecological resilience.