An assessment of urban heat island of Lokoja Town and surroundings using LandSat ETM data.

Abstract

The urban centre and its suburban environment are largely influenced by changes driven by people as a result of urbanization and other anthropogenic activities. Urbanization impacts on air and water quality, local climate and biodiversity. This study assesses the Urban Heat Island (UHI) of Lokoja town and surroundings from LandSat ETM satellite imagery of 2001 using remote sensing techniques. Band 3, 4 and 6 of the imagery were use in the estimation of NDVI, land surface emissivity and surface temperature. The results show that urban heat island in Lokoja town is significant, with average Land surface temperature values range from 301.13K to 336.14K., and maximum urban/suburban temperature difference reaching 10.9 o C. This suggests that vegetation is the principal determinant controlling the spatial distribution of land surface heat flux. This approach was found to be more effective in assessing urban heat island than using the conventional "in situ" temperature estimation.