Application of remote sensing to assess the environmental impacts of artisanal and semi-mechanized gold mining: a case study of Bekao (Adamawa, Cameroon)
摘要
The environmental impacts caused by resource exploitation are a constant source of concern, as they affect both environmental and human safety. For better protection and management of mine environment, this article has highlighted the importance of remote sensing in pollution monitoring of mine environment. The present investigation assessed the six-year environmental effects of gold mining operations at Bekao, Adamawa, Cameroon. Remote sensing research was used to evaluate the spatiotemporal change of spectral indices and land use and land cover (LULC) by using Sentinel-2 satellite images (2016, 2019, and 2022). Spectral indices were computed and mapped to determine the different impacts of the mining activities. Analysis of land use changes in the study area that savannah increased by 61.42 and 128.34 ha in 2019 and 2022, respectively, forest decreased by 41.62 and 218.01 ha in 2019 and 2022 respectively, Bare soil decreased by around 26.16 ha in 2019 then increased by 41.88 ha in 2022. Surface water increased by 23.66 ha in 2019, then by 17.08 ha in 2022, while the exploited area, which did not exist in 2016, expanded by 10.36 ha in 2019, then by 3.91 ha in 2022. The environmental impacts of mining activities deducted from spectral indices were mainly composed of the destruction of vegetation cover, landscape modification, reduction in the water regime, soil degradation, soil salinization and loss of topsoil. These results revealed significant environmental degradation in the study area due to mining activities. And could provide useful tools for successful environmental monitoring and reclamation work.