Assessment of the Impact of Urban Expansion on Thermal Characteristics in Gombe Metropolis Gombe State, Nigeria

Urban expansion is rapidly reshaping cities globally, with significant consequences for local environments and human wellbeing. In sub-Saharan Africa, especially Nigeria, this growth is often rapid and unplanned, resulting in marked land use changes and heightened environmental vulnerabilities. This study examines the impact of urban expansion on the thermal characteristics of Gombe Metropolis, the capital of Gombe State, over a 30-year period (1994–2024). Employing multi-temporal Landsat satellite imagery integrated with Geographic Information Systems (GIS) and advanced remote sensing techniques, the research quantifies changes in land use and land cover (LULC) and their influence on land surface temperature (LST), a key indicator of urban heat. Findings indicate that built-up areas increased markedly from 10.8% to nearly 40%, while vegetation cover declined by over 58%. Concurrently, mean annual surface temperatures rose by approximately 1.2°C, with the urban heat island effect intensifying as urban-rural temperature differentials grew from 0.8°C to 1.5°C. Statistical analyses reveal strong positive correlations between increased built-up and bare land areas and elevated temperatures, whereas vegetation and farmland exhibited significant cooling effects. Spatial analysis identifies thermal hotspots concentrated in dense urban cores and rapidly expanding peri-urban zones where natural surfaces have been replaced by impervious materials. The study underscores the environmental and public health implications of unregulated urban sprawl in semi-arid Nigerian cities and advocates for urban greening, climate-sensitive land use policies, and sustained environmental monitoring to promote sustainable urban development. By filling a critical research gap, this work provides empirical evidence linking urban growth to microclimate alteration, offering transferable methodologies and insights for planners addressing similar challenges in rapidly urbanizing contexts across the Global South.