How does resource extraction affect Earth systems and how is rehabilitation achieved?
Analyse the effects of resource extraction on Earth systems and evaluate rehabilitation
A focused answer to the WACE Year 12 Earth and Environmental Science dot point on extraction impacts. Covers mining methods, effects on the geosphere, hydrosphere, atmosphere and biosphere, acid mine drainage and rehabilitation, with Australian examples.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
SCSA wants you to analyse impacts across the spheres and evaluate how well rehabilitation works. A strong answer connects a specific extraction method to a specific impact and a management response, rather than listing harms in isolation.
Extraction methods
The method depends on the resource and how deep it lies.
- Open-cut (open-pit) mining removes overburden to reach near-surface ore. Most Pilbara iron ore and Darling Range bauxite are mined this way.
- Underground mining follows deeper ore bodies through shafts and tunnels.
- In-situ and solution methods extract some resources by pumping fluids underground.
- Extraction of groundwater and fossil fuels uses wells and bores.
Impacts on the geosphere
Mining physically removes rock and reshapes the land. Open-cut pits, waste rock dumps and tailings storage change landforms permanently. Removing vegetation and topsoil exposes the ground to erosion, and subsidence can occur over underground workings. Tailings, the fine waste left after the valuable mineral is removed, must be stored to prevent collapse and leakage.
Impacts on the hydrosphere
Mining can lower water tables when pits are dewatered, drawing down aquifers that ecosystems and towns rely on. A major hydrosphere risk is acid mine drainage: when sulfide minerals such as pyrite are exposed to air and water, they oxidise to produce sulfuric acid that dissolves heavy metals. The resulting acidic, metal-laden water can contaminate rivers and groundwater for decades.
Impacts on the atmosphere
Extraction releases dust from blasting, hauling and crushing, which reduces air quality and can settle on vegetation. Diesel machinery and processing release carbon dioxide and other gases. Processing some ores, and burning fossil fuels, adds greenhouse gases that connect to the climate content of Unit 4.
Impacts on the biosphere
Clearing land for mines removes habitat and fragments ecosystems, reducing biodiversity. Noise, light and altered water flows disturb wildlife. In biodiverse areas such as the jarrah forest of the Darling Range, bauxite mining clears forest that supports many endemic species, so the biosphere impact is significant even where the area mined at any one time is limited.
Rehabilitation and its limits
Rehabilitation tries to reverse damage and is usually a legal condition of mining.
- Reshaping pits and dumps to stable, free-draining landforms.
- Replacing stockpiled topsoil, which holds seeds and soil organisms.
- Revegetating with local native species and controlling weeds and erosion.
- Treating or capping acid-generating waste and monitoring water quality.
Rehabilitation can restore stable landforms and vegetation cover, but rebuilding the full structure and species diversity of an original ecosystem can take many decades and may never fully succeed. This is why minimising disturbance and progressive rehabilitation during operations are emphasised.