Assessment of Gold Mining Impact on the Vegetation of Itagunmodi-Igun Drainage Basin, Southwestern Nigeria from 1972–2011: A Remote Sensing

Abstract

Abstract. A GIS-based Normalized Differential Vegetation Index (NDVI) was analyzed using space-based data between 1972 and 2011 as Input data. The result of the NDVI using Landsat 7 ETM+ shows clearly that the values range from 0.19 to −0.31. Mountains and highlands of the Itagunmodi-Igun area revealed stressed vegetation cover between 0.11 to −0.31. The NDVI was also performed on Landsat imageries of four different epoch: 1972, 1986, 2000, and 2010. Results showed that vegetation index ranged from −0.105 to 0.033, −0.25 to 0.480, −0.313 to 0.19 and −0.29 to 0.5 in 1972, 1986, 2000 and 2010 respectively. The analysis revealed that the study area experienced an increase in biomass between 1972 and 1986 but with some areas experiencing outright disappearance of vegetation as indicated by the lower bands of index values in 1972 (−0.105) and 1986 (−0.25). The result showed that the Basin experienced a rapid and significant increase in biomass between 2000 and 2010, as indicated by the lower bands of index values in 2000 (−0.291) and 2010 (0.5). The results of the NDVI in 1972 ranged from −0.105 to 0.033 while NDVI in 1986 ranged from −0.25 to 0.480 which indicated a significant increase in the vegetation index. The results of the NDVI in 2000 ranged from 0.291 to 0.5 also indicated a significant increase in the vegetation index. The study concluded that artisanal mining could cause land and vegetation degradation with consequent loss of biodiversity, ecological modification.

The Environmental Impact of Mining Activities in the Local Community: A Structural Equation Modelling Approach

“…In a comparable study which was analysed using the remote sensing approach, Oluwafemi et al (2021) showed that artisanal mining could cause land and vegetation degradation which might consequently result in loss of biodiversity, habitat displacement and ecological modification. Having collected time series data on vegetation, land use and biomass, the authors applied the GIS-based Normalized Differential Vegetation Index (NDVI) to analyse the space-based data ranging from 1972 to 2011.…”

“…The results of the data analysis hinted that the NDVI values of the input data were in excess of their upper bands but within their lower bands. It therefore follows that mining activity represents push and pull factors to economic prosperity and environmental sustainability of the communities (Oluwafemi et al, 2021). Earlier, a GISfocused research by Atejioye and Odeyemi (2018) Given the lead poisoning outbreak in Zamfara, Nigeria in 2010, Bartrem et al (2022) investigated the vulnerabilities and complexities of challenges faced by gold mining villages in Zamfara.…”