Spatio-temporal analysis of land surface temperature variations in the rapidly developing Akure and its environs, southwestern Nigeria using Landsat data
The study attempted to assess land surface temperature (LST) variations in Akure, a millennium development city, and its environs, in Nigeria. The importance of LST as a vital component in global climate change cannot be over emphasized because as the greenhouse gases in the atmosphere increases, the LST also increases. Spatio-temporal assessment of LST variation is therefore becoming imperative to identify the contributing factors and the corresponding magnitude of contributions to the variation using remote sensing and GIS techniques. Landsat TM image of 1991, Landsat ETM+ image of 2002 and Landsat OLI/TIRS of 2015 were used and processed using ArcGIS 10.1, IDRISI and Erdas imagine 9.3 to generate indices such as Normalized Difference Vegetation Index NDVI, Land Use Land Cover (LULC) and Land Surface Temperature (LST). The finding showed that the changes, both spatial and temporal within the land uses influenced the temperature variations in the study area. The built-up, rock outcrops, farmland and vegetation land uses recorded mean temperature change of 4.91±0.7, 3.53±0.3, 3.14±0.2 and 1.87±0.3 respectively, with their respective yearly temperature increase estimated at 0.21°C, 0.15°C, 0.14°C and 0.08°C between 1991 and 2015. The study concludes that the observed increasing variations in LST in all the land uses has been precipitated by rapid land use conversion and modification that may have strong tendency to usher in climate related problems such as flood, human discomfort and other associated environmental hazards. An effective land use policy is therefore suggested to complement Federal Government ‘green policy’ urban environment.
Keywords: LST variation, Land Use Land Cover, NDVI, GIS, Remote sensing technique, Nigeria