Land Cover Changes in Open-Cast Mining Complexes Based on High-Resolution Remote Sensing Data

Abstract

Remote sensing technologies may play a fundamental role in the environmental assessment of open-cast mining and the accurate quantification of mine land rehabilitation efforts. Here, we developed a systematic geographic object-based image analysis (GEOBIA) approach to map the amount of revegetated area and to quantify the land-use changes in open-cast mines in the Carajás region situated in the eastern Amazon. Based on high-resolution satellite images from 2011 to 2015 from different sensors (GeoEye, WorldView-3 and Ikonos), we quantified forests, cangas (natural metalliferous savanna ecosystems), mine land, revegetated areas and water bodies. Based on the GEOBIA approach, threshold values were established to discriminate land cover classes using spectral bands, and the NDVI and NDWI indices and LiDAR digital ground and slope models. The overall accuracy was higher than 90%, and the Kappa indices varied between 0.82 and 0.88. During the observation period, the mining complex expanded; for that, canga and forest vegetation was converted to mine land. At the same time, the amount of revegetated area increased. Thus, we conclude that our approach is capable of providing consistent information regarding land cover changes in mines, with a special focus on the amount of revegetation necessary to fulfill environmental liabilities.

Continuous Monitoring of the Mining Activities, Restoration Vegetation Status and Solar Farm Growth in Coal Mine Region Using Remote Sensing Data

“…In some areas of R. N. Macedonia, land-cover changes around large surface mines have already harmed the environment. Both sustainable and green mining necessitate ongoing monitoring of these changes in order to determine the long-term effects on the environment [8,9,10]. Remote sensing has emerged as the most effective and impartial approach for tackling this problem.…”

DNA-Based Arthropod Diversity Assessment in Amazonian Iron Mine Lands Show Ecological Succession Towards Undisturbed Reference Sites

“…The region is dominated by evergreen and semideciduous submontane forest formations that cover hillsides and lower portions of the landscape. On mountain tops, banded iron formations outcrop, forming a patchy, hyperdiverse, endemic savanna-like ecosystem, locally known as canga (Nascimento et al, 2019). Open-cast iron mining has transformed evergreen forests and cangas into mine pits and waste piles, which require environmental rehabilitation (Gastauer et al, 2020b).…”

“…Open-cast iron mining has transformed evergreen forests and cangas into mine pits and waste piles, which require environmental rehabilitation (Gastauer et al, 2020b). During the mining process, the native vegetation is cut back, the topsoil removed, and together with mine waste, deposited in waste piles (Nascimento et al, 2019). To achieve environmental rehabilitation, the waste-pile benches are hydroseeded with a mix of fertilizers, organic composts, and fastgrowing, non-native, non-invasive plant species, to achieve rapid vegetation cover, establish photosynthesis on the site, incorporate biomass into the system, and to attract seed-dispersing fauna.…”