Over the last two centuries, vast amounts of mining waste have been accumulated in the Upper Silesian Coal Basin area. They were stored mainly in spoil tips, but a significant part was also used for leveling the terrain, backfilling subsidence troughs, building embankments along rivers, and recently road construction. Many of the heaps are very large - over 60 m high, over 1 km2 in area, and over 10 million m3 in volume. Mining waste is susceptible to physical weathering - coal shale disintegrates within a few months, clay shales decompose slower, and sandstones the slowest. The waste is also characterized by a very high content of water-soluble salts. In the case of rapidly progressing weathering and erosion processes, new parts of toxic material are exposed. The leaching processes cause the migration of toxic compounds and their accumulation in the foreground of the heaps. Some of the older and smaller dumps in the Upper Silesian Coal Basin have already been largely washed away by rainfall. The process of leaching harmful substances in them is nowadays smaller than in the case of newly created spoil tips. Infiltration washing of chlorides from several meters high spoil tips may take up to a dozen or so years, while sulfates - at least several dozen years. The waste is moved at various distances from the place of deposit - as a result of surface runoff over a distance of several to 200-300 meters, as a result of aeolian transport over a distance of several kilometers, and the farthest distance through rivers - over a distance of several to several dozen kilometers. Land degradation in coal mining areas is related to covering soils with anthropogenic grounds and their mixing which can reach a depth of over one meter.
Mots clés : coal mining|spoil tips|land degradation|Upper Silesian Coal Basin
A105354RD