An evaluation of the effect of land use/cover change on the surface temperature of Lokoja town, Nigeria

Abstract

This research integrated remote sensing and Geographic Information Systems (GIS) to identified land use/cover types in Lokoja, including their temporal transformation and association with surface temperatures from the LandSat TM and LandSat ETM imageries of 1987 and 2001 respectively. As the built-up area increased in size (2667.6%) so was the surface temperature (6.48^oC), vacant land (872%: 9.65^oC), cultivated land (104.4%: 1.2^oC) and water bodies (64.3%:0.94^oC) while vegetation cover increased by 2.44^oC while its area extent decreased (316.7%). These changes were responsible for the rise in the mean surface temperature from 38.39^oC in 1987 to 42.61^oC in 2001, indicating a 4.22^oC increase in 14 years. The study revealed a direct relationship between the changing pattern among the various landuse/cover types and the variations in the surface temperatures of these landuse/cover types within the study period. If the rate of decline in vegetation covers is not checked, Lokoja may witness continuous increase in its radiant surface temperature as the cooling effect of vegetation cover is lost to impervious surfaces that litter the urban landscape. Therefore, policies that will help to provide more vegetation cover should be adopted to curb the effect of urban heat island on the environment and health of the residents.

Key words: GIS, land Sat, landuse/cover, remote sensing, temperature, thermal.