Spatiotemporal changes on land surface temperature, land and water resources of host communities due to artisanal mining.

Abstract

Assessment of land use/land cover change (LULCC) and its effects on the natural environment are important in policy decision making for sustainable environment. This study investigated and assessed the environmental impacts of artisanal and small-scale mining operations on environmental degradation resulting from such activities in selected host communities (Akoko Edo, Ijero and Ilesa). Vegetation, water, built-up expansion and land surface temperature dynamics were examined and analysed using appropriate indices for the years 1987, 2002 and 2017. A gradual decrease in the normalised difference vegetation index (NDVI) values was observed across Akoko Edo and Ijero Ekiti with a corresponding change in the highest NDVI values while Ilesa witnessed a higher NDVI value in 2017 relative to the previous years. The majority of the normalised difference water index (NDWI) values for 2017 appear to be above 0 in all the host communities. Mean land surface temperature (LST) values are in the order 24.63 °C (1986) < 25.26 °C (2002) < 26.32 °C (2017) for Ijero Ekiti study area while mean LST values are in the order 24.30 °C (1986) < 24.46 °C (2002) < 25.82 °C (2017) in Ilesa study area. Modified Normalized Difference Water Index (MNDWI) seemed a more reliable indicator as the index was able to enhance the water surfaces more clearly as indicated in the case of Akoko Edo study area. Due to its high heat capacity, high land surface temperatures were experienced over urban areas and uncultivated bare land during all the periods of study. The study showed that changes in land covers have affected the normal functioning of the habitats through urbanisation. Adequate natural resource management is therefore necessary to ensure sustainable development through effective policy formulation.