Spatiotemporal Assessment of Climate Change Using Land Surface Temperature and NDVI Dynamics in Bauchi LGA, Nigeria: A Geospatial Analysis (2013-2023)Spatiotemporal Assessment of Climate Change Using Land Surface Temperature and NDVI Dynamics in Bauchi LGA, Nigeria: A Geospatial Analysis (2013-2023)

Abstract

Changes in land use and land cover due to the expansion of cities and towns, agriculture, and deforestation have intensified surface thermal dynamics in sub-Saharan African cities, raising serious concerns about environmental sustainability and climate resilience. This paper looks into the spatiotemporal variations of Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) in Bauchi Local Government Area (LGA), Nigeria, for three epochs: 2013, 2018, and 2023, to identify the relationship of vegetation cover decline with surface thermal intensification over time. Remote sensing data and geospatial analysis methods were used to track and measure changes in LST and NDVI over the three periods. In addition, regression and correlation analyses were conducted to determine the strength and direction of the LST-NDVI relationship. The study found a steady, gradual rise in LST in the entire research area throughout the ten years from 2013 to 2023. In 2018, there was a significant reduction in the extent of the coolest surface areas, and the warming zones had increased as vegetation had decreased, and the bare ground was more exposed. The year 2023 witnessed very few areas with cool thermal signatures, and almost the entire study area was exhibiting high surface temperature which is a clear sign of the land's declining capacity for natural heat regulation. The NDVI results illustrated the gradual decline of vegetation cover during the timeframe under review. Vast, green swathes of vegetation, which were seen in 2013, gradually became smaller and less green in 2018 and 2023, reflecting substantial vegetation loss and low ecosystem productivity. By examining correlation and regression patterns, a steady inverse association between NDVI and LST was confirmed in all three study years. In 2013, NDVI had a very weak influence on LST (R² = 0.0064), which means that the variability in vegetation explained less than 1% of that in LST, probably because the land-cover types were uniform. The strength of the association or the proportion of heat variation explained by the vegetation cover increased to 26.3% as indicated by the coefficient of determination (R² = 0.2632) in 2018, which was a result of greater shading and evapotranspiration. But the power of vegetation in explaining the variation in LST went down to 13.1% (R² = 0.1305) in 2023 when LST values were in the range of 43 °C to 47 °C, implying that anthropogenic and climatic factors not related to vegetation had taken the lead in determining surface thermal conditions. The findings from this research carry a significant implication for SDG 13 (Climate Action) and SDG 15 (Life on Land). They indicate the very pressing need for Bauchi LGA and other similar semi-arid cities in Nigeria to develop evidence-based urban greening initiatives, enforce land restoration measures, and introduce adaptive environmental planning practices to tackle the problem of increasing thermal stress and ecological degradation.