Theoretical and Empirical Contributions to Understanding Urban Heat Island Dynamics in West African Cities Using Remote Sensing

Urban heat island research in sub-Saharan Africa remains methodologically and theoretically underdeveloped relative to the intensity of urbanisation-driven thermal change experienced by cities across the region. This study makes theoretical and empirical contributions to understanding urban heat island dynamics in West African cities, with empirical analysis conducted across Port Harcourt, Ibadan, Enugu, and Maiduguri. Landsat 8 and 9 thermal infrared imagery spanning 2016 to 2023 is processed to derive land surface temperature time series for each city. Diurnal and seasonal UHI intensity patterns are characterised and related to urban morphological variables including sky view factor, building height, green cover fraction, and impervious surface ratio derived from Sentinel-2 and building footprint data. A theoretical model of West African tropical UHI dynamics is developed that extends existing temperate-city UHI theory to account for the dominant role of wet season vegetation recovery and harmattan dust aerosol effects on thermal dynamics. The model's predictive accuracy is evaluated across all four cities and across dry and wet season regimes. Keywords: urban heat island, West African cities, land surface temperature, thermal dynamics, remote sensing