oa Environmental Monitoring in The Mining Industry Integrating Remote Sensing and Ground Geophysical Data

Pollution associated with the mining of Witwatersrand gold-bearing conglomerates may be<br>mapped and monitored using hyperspectral scanner imagery. Analysis of such data allows the<br>identification of the type and abundance of oxides, clays and polluting sulphates. Vegetation<br>types associated with acid mine drainage can also be identified.<br>In searching potential pollution in surface and ground waters thermal data may be used to map<br>near-surface aquifers, “eyes “, and seepage points close to riverbanks. Thermal imagery has also<br>been useful in locating dykes and sometimes depicts near-surface groundwater flow across these.<br>Furthermore, this kind of data may be useful in locating potential sinkhole sites in dolomite areas.<br>A very good correlation is observed between thermal and resistivity data. Where follow-up high<br>resolution resistivity surveys have been carried out to better define the cross-section of a<br>pollution plume, for optimal siting of pollution monitoring boreholes, Thermal anomalies can be<br>linked to highly conductive ground The resistivity adds value in being able to differentiate between diffuse plumes over weathered bedrock and confined plumes running along faults or dykes. Use of the integrazed data products include:<br>• baseline study database for existing mining/pollution areas<br>• suitability studies for slimes dam and reduction plant siting<br>• slimes dam and rock dump pollution and stability studies<br>• baseline environmental studies for potential new mining sites<br>• optimal placement of monitoring boreholes or sampling point's<br>• remediation effectiveness studies<br>• groundwater recharge potential and boreholes siting