ABSTRACT
Though the mining companies are required by law to submit plans and commit funds for the rehabilitation of the mined land when once the mine is closed, enforcement has not always been strict enough. It is particularly difficult in the case of artisanal miners (“here today, gone tomorrow’’). Though the climate, soil and hydrological characteristics and methods of mining
vary greatly in different areas, there are some common elements in the techniques of rehabilitation: (i) Removal and retention of top soil, to be respread in the area that is being rehabilitated, (ii) Reshaping the degraded areas and waste dumps in such a manner that they are stable, well drained, and suitably landscaped for the desired longterm use, (iii) Minimizing the likelihood for wind and water erosion, (iv) Deep ripping of the compacted surface, (v) Revegetating with appropriate plant species in order to control erosion, and facilitate the development of a stable ecosystem compatible with the projected long-term use. Amelioration methods can be custom-made for a given situation, as follows
(Chadwick et al., 1987): (i) Low pH (usually<5): Amelioration by liming. Acidtolerant speciesmay be planted; (ii) High pH (usually>8): Salt contentmay be removed by leaching. Salt/alkali-tolerant plants may be grown; (iii) Low nutrient status: Nitrogen deficiency may be ameliorated by nitrogenous fertilization or by growing legumes; (iv) Low moisture levels: Ridging, furrowing and mulching, etc. and growing droughttolerant plants; (v) Soil amendment: use of other wastes, such as fly ash, slag, etc., and (vi) Planting of artificial wetlands for the treatment of acid mine drainage and polluted runoff.
