Abstract
M.A.
The mining industry is an important contributor to the South African economy, but is also a major contributor to surface water and groundwater contamination. It is therefore essential for mining operations to comply with legislative requirements in terms of preventing and/or rehabilitating areas impacted by mining activities. Ensuring this compliance requires effective and frequent monitoring of impacts and associated rehabilitation caused by mining operations. Remote sensing and geographical information systems (GIS) offer innovative tools for executing effective monitoring efforts related to mining impacts; and although they do not replace conventional methods of environmental monitoring, these tools can enhance the analysis and decision-making of such efforts.
This study is aimed at identifying and mapping the extent and direction of flow of contamination plumes originating from slimes and tailings dams at the Venetia Mine in the Limpopo Province by using remote sensing and GIS tools to illustrate these tools’ effectiveness and to create a simplified database and support system for continued monitoring. With the implementation of a number of image enhancement techniques such as the false-colour composite, the Tasselled Cap transformation and the normalised difference vegetation index (NDVI) on LANDSAT satellite imagery; together with the interpolation of borehole water quality data, contamination plumes could be mapped and interpreted. The results and interpretation of the processed satellite imagery (indicating a decrease in plant growth from 2001 to 2006) were verified by the results of the interpolated water quality data (which indicated high concentrations of total dissolved solids in 2006). The final reclassified image of the NDVI provided a simplified version of the findings which could be presented to the laymen whereby decision-making could be augmented. Accordingly, the study concluded that the utilisation of more innovative monitoring tools such as remote sensing and GIS could enhance monitoring efforts and decision-making with regard to environmental management plans and legal compliance.