Analysis of Urban Surface Temperature Using Remote Sensing and Geographic Information System (GIS)

Abstract

The study analysed variation in surface temperature (ST) in Makurdi Urban Area (MUA), Northcentral Nigeria. A total of 12 Landsat TM/ETM+ images were acquired in January, April and June of 1991, 1996, 2001 and 2006. The ST was estimated from the 12 Landsat TM/ETM+ images, grouped into seven classes, and the area of each ST class was determined using remote sensing and Geographic Information System (GIS). The ST magnitudes vary spatially from 27.5^oC (water bodies) to 50.7^oC (built-up land), representing an intensity of 23.2^oC. The mean seasonal ST varies from 32.4^oC-34.5^oC (cool-dry season), 35.5^oC-38.8^oC (hot-dry season) and 30.8^oC-31.4^oC (hot-wet season). The mean annual ST has increased from 32.9^oC (1991) to 35.9^oC (2006) with ST intensity of 3.0^oC. The ST classes of 27^oC-29^oC and 33^oC-37^oC recorded the highest loss and gain in area of -126.5km² and 94.5km² whereas ST classes of 29^oC-33^oC and 41^oC-45^oC recorded the least and highest per centage change in area of 22% and 768%. The result showed decreasing and increasing trends in the areas of cooler and warmer surfaces, which are attributed to increase in anthropogen surface materials, with higher heat storage capacities, due to urbanisation.