GIS and remote sensing-based analysis of the impacts of land use/land cover change (LULCC) on the environmental sustainability of Ekiti State, southwestern Nigeria

摘要

Analysis of land use/land cover change (LULCC) and their impacts on the natural environment is essential in policy decision for an effective solution to the sustainability of the earth system. This study employed supervised image classification (maximum likelihood) algorithm to map changes in land use/land cover for a period of 4.5 decades (1972-2017) in Ekiti State. Vegetation and temperature dynamics were examined for the selected years using normalized difference vegetation index (NDVI) and land surface temperature (LST), respectively. NDVI and LST were statistically compared to understand the potential impacts anthropogenic activities on the environment. Resultant LULC maps indicated a decrease in forests and woodlands at a change rate of 51.25 and 0.72% over the last 4.5 decades in Ekiti State, while built-up areas, croplands, rocks/bare soils and water bodies have increased about 267.58, 197.30, 714.11 and 4421.43%, respectively. Agricultural lands (now occupying 47.13%) are the major contributor to the net change in forests (decreasing). LST showed a negative correlation with NDVI (r = -0.672). Mean LST are in the order 22.7 degrees C (1984) < 23.84 degrees C (1991) < 27.17 degrees C (2017) < 28.16 degrees C (2000). As the LULC pattern is changing, its imprint is reflected on LST and NDVI. Built-up areas, rocks/bare soils exhibit the highest surface radiant temperature, while vegetated surfaces and water bodies recorded the least. The study demonstrated that changes in land covers through urban development have affected the natural functioning of ecosystems. As such, proper natural resource management and effective policies are required to ensure sustainable development.