Mine Slope Protection & Rehabilitation

Mining is the process of extracting useful minerals from earth’s surface (Britannica). It encompasses several environmental impacts that may occur in either local, regional, and global scales. Mining affects the environment as it permits loss of biodiversity, soil erosion, and contamination of surface and ground water.

Common problems arise because of drastic modification of the original site that disturbs ecosystems and species habitat. Surface mining, for example, creates large hole or pit (open pit) to extract minerals from the soil. Likewise, quarrying involves the removal of blocks at hillsides to extract ornamental and quality stones. Mining operations generally trigger physical destruction of lands and deterioration of area’s biodiversity. 

The removal of top soil layers and original vegetation makes the area susceptible to soil erosion. Bare slope surfaces created by successive quarrying and excavation may be easily eroded during rainfall. Erosion of soil sediments in the long run would lead to siltation and contamination of rivers, lakes, and other adjacent water bodies. This could also harm residents of adjoining communities.

Immediate rehabilitation of degraded and mined-out areas must be implemented to prevent unexpected hazards caused by disturbed soil. Partial restoration of mining sites can be achieved by bringing back vegetative cover on the soil. However, revegetation using native plant species normally fails because the stripped and replaced soil covers are at low nutrient conditions. Selection of some preferred weed species that could thrive at this condition may be adapted to trigger soil revegetation. 

Bioengineering techniques may be used to prevent soil erosion while the grass are not yet fully grown. Coconets and logs can be installed on slopes to minimize erosion caused by rainfall. This method offers temporary yet immediate solution at much cheaper cost. Temporary drainage structures may also be constructed at hill sides if volume of surface runoff is too high to resist by net covers.