Quantifying Urban Warming: A Geospatial Assessment of Land Cover Transformations and Land Surface Temperature in Rapidly Urbanizing Osogbo, Nigeria (2003–2023)

Contexte and Background: Rapid global urbanization heavily drives the Urban Heat Island (UHI) effect through extensive land use and land cover (LULC) transformations. This poses significant climate and environmental challenges, particularly in rapidly developing intermediate African cities where unplanned growth exacerbates local impacts. Goal and Objectives: This study quantifies urban warming and assesses spatio-temporal LULC impacts on Land Surface Temperature (LST) in rapidly urbanizing Osogbo, Nigeria (2003, 2013, 2023). Our goal was to analyze the relationship between land cover changes and surface temperature increases in this representative urban environment. Methodology: We used multi-temporal Landsat imagery with advanced Remote Sensing and GIS techniques. The research employed a multi-index approach, calculating NDVI, NDBI, NDWI, and NDBaI, alongside detailed LST retrieval. Statistical correlation and Geographically Weighted Regression (GWR) analyses were applied to understand these relationships. Results: Analysis showed a significant increase in built-up areas, replacing natural land covers, directly correlating with a progressive rise in LST. Strong negative correlations existed between LST and NDVI (vegetation's cooling effect), and robust positive correlations between LST and NDBI (built-up warming). GWR further revealed spatial heterogeneity in these relationships, pinpointing localized thermal vulnerabilities. These findings highlight the urgent need for integrating climate adaptation into urban planning for sustainable and resilient cities.