Spatiotemporal characteristics of population density, heat stress vulnerability, and effects of urban green spaces in Lagos, Nigeria

Rapid urbanization in Lagos, Nigeria, has intensified population density and altered local microclimates, exposing residents to increased risks of heat stress. As one of Africa’s largest megacities, Lagos faces challenges in balancing urban growth with environmental sustainability. This study investigates the spatiotemporal characteristics of heat stress vulnerability and the moderating effects of urban green spaces (UGSs) across 11 local government areas (LGAs) in Lagos, Nigeria. Land surface temperature (LST) for 2013, derived from Landsat 8 Operational Land Imager imagery, was analyzed alongside 2013 population statistics and household questionnaire data collected from residents nearest to 15 observation sites. Each LGA was represented as a polygon feature in ArcGIS. Exposure indicators included LST, population density, and LST hotspot clusters; sensitivity indicators included vulnerable age groups (0–4 and 65+ years), low educational attainment, and income classes; and adaptive-capacity indicators included ownership of air conditioners and fans, proximity to water bodies, and proximity to grass or green spaces. Results reveal five population density categories across the metropolis. Yaba exhibits extremely high density (93,320–339,100 persons/km2), while areas such as Abule-Egba, Mushin, Ilupeju, and Shomolu fall within high to moderately high density ranges. LST hotspot analysis indicates that Amuwo-Odofin, Isolo, Yaba, Ilupeju, Shomolu, Alagbado, and Ikotun are statistically significant hotspot locations at the 95–99% confidence level. Conversely, Oko-Afo, Ajangbadi, City Hall, Marina market, and Abule-Egba were not classified as hotspots due to inherent adaptive capacities, while Oshodi and Ejigbo emerged as cold spots. Adaptation measures vary across the metropolis. Ownership of air conditioners and fans, along with proximity to vegetation and water bodies, were the dominant strategies for mitigating heat exposure. The study underscores the critical role of UGSs in reducing heat stress vulnerability and highlights the need for strategic urban planning interventions to enhance adaptive capacity in Lagos.