Land surface temperature and heat fluxes over three cities in Niger Delta

Abstract

This study examines the implications of land use change on land surface temperature (LST) and heat fluxes over three cities in the Niger Delta region, using satellite data. The study was carried out in three major urban areas in the Niger Delta of Nigeria: Benin City, Port Harcourt and Warri. Both in situ and satellite climatological data were used in this study to estimate the variations in heat fluxes over different land use/land cover in three major urban areas around the Niger Delta region in Nigeria. The results showed a general increased in the mean LST, with an average of 1.43 °C increase between the year 2004 and 2015 over different urban land use. The estimated heat flux ranges from 30.55 to 102.05 W/m 2 in the year 2004 but increased ranges from 33.25 to 120.06 W/m 2 in the year 2015. The average heat flux was nearly 30.12 W/m 2 during wet season, but much higher during the dry season with average heat flux nearly 215.75 W/m 2 . Increase in LST appeared to be a result of changes in landuse/landcover in the cities. The results further show that different land uses exhibit different degree of LST during both wet and dry seasons, with temperature nearly 2 °C higher in dry seasons compare to wet seasons. These results imply that urban expansion in the Delta has resulted in variation in boundary currents and higher temperatures in the cities area compared to their immediate rural areas. The major findings of this study are that urban climate, urban heat redistribution and other hydrosphere processes are determined by the change in land use. The study established the potential health implications of increasing in LST and heat flux in the cities. Though, lack of long-term and quality health data made it very difficult to attribute the expansion or resurgence of diseases to change in urban LST, the review of literature has shown that thermal conditions usually contributes to heat syndrome, one of the health issues in the cities.