Influence of Topographic Elements on Land Surface Temperature: A Case Study Using Remote Sensing and GIS

International audience Land surface temperature (LST) is influenced not only by human activities but also by topographic and vegetation factors. This study analyzed the effects of topography and vegetation on LST in Ibadan, Nigeria, using Landsat 8 OLI/TIRS thermal imagery from December, 2024 and AW3D30 DEM-derived parameters, including elevation, slope, aspect, and hillshade. NDVI was incorporated to quantify the effect of vegetation cover. LST was retrieved using a Radiative Transfer Equation-based approach, and a grid-based method was employed to extract LST and topographic attributes at consistent spatial locations. Statistical analyses, including bivariate correlations and multiple linear regression, were performed to quantify the relationships between LST and the environmental variables. Results indicate that topographic variables alone exert weak influences on LST, with R² values ranging from 0.0006 to 0.0243, but their combined effect is statistically significant. Vegetation has a strong cooling effect, with NDVI showing a negative correlation with LST (r = –0.7604, R² = 0.5782). The combined model of topography and NDVI explains 59% of LST variability, highlighting vegetation as the dominant factor controlling surface temperature in this tropical urban environment. These findings provide insights for urban heat mitigation and support evidence-based urban planning strategies, including vegetation management and sustainable land-use planning in tropical cities.