Tools and Methods
Optical satellite data
Conventional satellite data such as Landsat Thematic Mapper (TM) and ASTER, very high resolution satellite optical sensors (IKONOS, Quickbird, SPOT 5, etc.) will be used. Very high resolution sensors in particular have proven their invaluable contribution in mapping surface features related to mining areas and their surroundings, in particular mining infrastructures and settlements.
Based on commercially available satellite imagery, mine sites and their individual surroundings will be mapped at different scales. At regional scale relevant land-cover and land-use classes will be mapped. Time series analysis will focus on current and on-going spatial changes, taking changes in infrastructure and settlements into account. This information, in conjunction with census data, generates the basis for further analysis of the environmental and social dynamic within the region under investigation. On a local scale mining related infrastructure (processing infrastructure, tailings dams, waste dumps, drainage pattern, etc.) will be mapped. Spatial information that can be related directly to mining and remediation activities are:
- size of the mine site,
- area of waste dumps, area under direct rehabilitation measures,
- volume of piled material,
- (potential) regional impact caused by direct and/or diffuse pathways of mined or piled materials,
- (potential) affected drainage / groundwater area,
- mined area vs. undisturbed area (risk analysis, "environmental value" of surroundings),
- indices that may describe the efforts the mining company made to protect the environment, etc.
Mapping techniques will include image interpretation and classification techniques, using spectral and/or morphology/texture criteria.
To these data sets, a change in detection analysis will be applied. This information will be used as input data toward predicting the spatial change in 2 to 10 years under certain conditions. This approach will be practical for both mining companies and environmental observers to predict possible future damage to the area so that preventive measures may be undertaken.
