Variations in urban surface temperature: an assessment of land use change impacts over Lagos metropolis
Année de publication
This study aims to investigate seasonal and diurnal variations in urban temperature, as well as the contributions of different land uses to land surface temperature (LST). A time series of MODIS data was used in this study. Average seasonal LST differentials between day and night from 2002 to 2014 were estimated. The results reveal substantial changes in land use over the study period; in particular, urban centre and urban fringe surface area increased by 15.93 and 94.49% respectively, while forest land and wetland surface area decreased by approximately 5 and 8% respectively. Average LST increases by nearly 3 degC during the daytime in the dry seasons, compared with the wet season, for all land use/land cover (LULC) classes. In all seasons, the average LST of urban areas is nearly 1.5 degC higher than the LST values for the surrounding rural areas. The explanations for these variations are obvious: the majority of urban centres in Lagos metropolis have dense buildings and slight vegetal cover; thus they appear to have less energy loss due to latent heat by evaporation from the impervious urban surfaces. The study concludes by proposing improved urban planning in Nigeria through implementation of urban planning policies.