Original paper

Impact of mining subsidence on the relief of the Rybnik Plateau, Poland

Dulias, Renata

Abstract

Rybnik Plateau is in the south-western part of the Upper Silesian Coal Basin. During 215 years of mining, in 13 mines, 1.74 billion tons of hard coal and waste rock were extracted mainly by means of a roof-fall method. Of this, almost 87% was extracted after the year 1950. The volume of mining workings was estimated at 1.18 km3, and the volume of mining subsidence at 0.74 km3. During the years 1792-2006, the area under mining impact (about 164 km2) was lowered by 4.54 m on average. The surface lowering rate equalled 21 mm/year on average, but varied in time and space from 0.005 mm/year between 1792-1850 to 101 mm/year during 1981-1990, and 24 mm/year in the “Rydułtowy” area up to 289 mm/year in the “Moszczenica” coal mine area. For several areas during the study period lowering rates were calculated from hypsographic curves and morphological profiles for pre-mining and mining periods. Their values are as a rule higher than the rates estimated theoretically. The results indicate that on the basis of cartographic materials dating from different periods one can draw conclusions on the changes in relief caused not only by direct, but also indirect human impact occurring during short time periods of several dozen or even a dozen or so years.

Keywords

mining subsidenceanthropogenic denudationmorphometric analysesupper silesian coal basin