Mining changes on the example of the Walbrzych Basin relief (The Sudetes, Poland)

The Walbrzych Basin is located in the Sudetes over an area of 95 km(2). Up to the last decade of the 20th century it was the biggest area of coal mining in that mountain range. In 1997 r. the mines were abandoned; however the remnants of them are still visible in the form of mining constructions and substantial relief changes. The intensive anthropogenic relief-forming cycle connected with coal mining began in that area in 1865, and lasted for about 130 years. The biggest relief transformations in the Walbrzych Basin took place in two valleys: Walbrzych and Kuznice. The anthropogenic relief in that area contains forms typical of coal mining areas, such as: subsidence basins, dumps and settling ponds. There are no caving zones. The biggest part of the researched area is covered with subsidence basins, which evolved from 37% of the terrain. Dumps and settling ponds cover 4 % of the grounds. In the Walbrzych Basin the transformations of natural relief features were more substantial than in the Kuznice Basin (63 % and 35 % of the regions area respectively). The sizes of some dumps in the Walbrzych Basin are bigger than natural ground elevations in the Basins, and the subsidence basins cover a greater surface than the natural depression areas. Because of the diversified mountain relief in the area there is a plenitude of different types of dumps; more than in other mining areas. Anthropogenic relief of the research area has structural character - it relates to the structure of the substrate of the Walbrzych Coal Basin. In anthropogenic relief one forms are present within other forms, which is connected with simultaneous influence of different anthropopression factors on the ground. As a result of coal mining, the research area underwent anthropogenic inversion of relief. In the years 1865-1997 the coal mining was the main relief factor in the researched area causing bigger changes in the relief features than the natural factors.