Change Detection in Land Surface Temperature and Cooling Efficiency of Green Space in Phase One of the Federal Capital City, Abuja, Nigeria

This study uses geospatial techniques to detect changes in land surface temperature and cooling efficiency of green space in Phase One of the Federal Capital City, Abuja, Nigeria. Administrative boundaries shape file of 2023, Landsat imageries 4TM, 7ETM, 8OLI and 9TIRS and Thermal Near-infrared (7ETM, 8OLI and 9TIRS) were acquired from USGS Earth Explorer. The analyses of imageries were done within the ArcGIS 10.8 environment. In 1992 and 2002 green spaces covered the largest land area followed by built-up areas. In 2012 and 2022 built-up areas claimed the largest coverage area. From 1992 to 2002, the built-up area experienced the most significant change, showing an increase of 2.85 km2. During the same period, there was a loss in green space amounting to -2.13 km2, while the bare surface increased by 2.27 km2, from 2002 and 2012, the bare surface exhibited the most substantial change, experiencing an increase of 8.97 km2, while the built-up area also increased by 6.75 km2. Conversely, there was a significant decrease in green spaces, amounting to -18.72 km2 during the same period. From 2012 to 2022, the built-up area experienced the most substantial change, showing a 9.93 km2 increase. In contrast, bare surfaces decreased by -8.43 km2, and green spaces also decreased by -1.52 km2. From 1992 to 2002, an area with excellent cooling efficiency increased by 5.7 km2, an area with good cooling efficiency increased by 1.81 km2, and an area with normal cooling efficiency increased by an infinitesimal area of 0.37 km2. There was a decrease in an area with a bad cooling efficiency of -1.97 km2, area with a worse cooling efficiency was reduced by -5.91 km2. From 2002 to 2012, an area with excellent cooling efficiency decreased to -5.59km2, an area with good cooling efficiency decreased to -0.85km2, an area with normal cooling efficiency increased to an infinitesimal area of 0.82km2 and there was an increase in area with bad cooling efficiency with 1.55km2, an area with worse cooling efficiency increased with 4.07km2. From 2012 to 2022, an area with excellent cooling efficiency decreased by -1.22 km2, an area with good cooling efficiency decreased by -1.03 km2, and an area with normal cooling efficiency increased with a minute area of 0.73 km2 (1.187%). There was also an increase in area with a bad cooling efficiency of 0.82 km2, and worse cooling efficiency increased with 0.7 km2.