Nexus Between Land Surface Temperature and Normalized Difference Vegetation Index in the Bole District in Ghana

Land surface temperature (LST) is the skin temperature of the ground which influences interactions between land surface and atmosphere through processes that play a key role in climate change at the local and global scales. Normalized difference vegetation index (NDVI) is most commonly used vegetation index to observe greenery globally. Accurate understanding of LST and NDVI at the local and regional levels is helpful to evaluate land surface and atmospheric exchange processes. This study analyzes the relationship between LST and NDVI in the Bole District in the Savannah region of Ghana using Landsat 7 ETM+ images for 2010 and 2020. ArcGIS software was used to process, classified the images using Maximum likelihood classifier, and to produce Land use land cover change (LULC) maps. Bands 3 and 4 were used determined NDVI, as well as the land surface emissivity. LST was determined from band 6 by converting the Digital Numbers to Top of Atmosphere radiance and then to reflectance in order to correct for satellite brightness with land surface emissivity as input. The results show that NDVI values vary with seasons, with less vegetation in the dry season and moderate vegetation in the wet season. From the LULC, LST and NDVI maps, areas with lower LST and higher NDVI values had more vegetation, while areas with medium and high LST and lower NDVI values were barren land or settlements. A strong positive correlation was found between NDVI and LST, except for the 2020 image, which had a weak correlation with LST. More vegetation was recorded in 2020 compared to 2010, possibly due to the government’s tree planting campaign. Further research on LST and NDVI is recommended for the district to ascertain the findings of this study and to aid future environmental planning and to promote ecological comfort for sustainable development.