Oil shale mining and processing impact on landscapes in north-east Estonia

As the worldʹs largest commercial oil shale reserve, the Estonian Oil Shale Deposit has been exploited since 1916. As a result of mining, storing of solid wastes from the oil shale separation, combustion in the power plants and its thermal processing, the landscape in northeastern Estonia has been essentially changed and the man-made landforms have developed: the new microreliefs of natural and artificial structure are formed, as well as ‘mountainousʹ and hilly reliefs in the form of waste heaps, ash plateaus, coke-ash dumps etc. Deformed (stable) and undeformed (unstable) areas from underground mining currently cover about 220 km2. About 90 km2 (80%) of the area damaged by open pits are recultivated and reformed as forested and agricultural (grassland) areas. The total area occupied by solid waste has reached up to 26 km2. New technogenic landscape units, i.e. made by technical means, will essentially influence the environment.