Antropogenicznie uwarunkowane przełomy Suminy i Wierzbnika jako przykład naturalizacji sztucznych koryt rzecznych (zlewnia Rudy)

Abstract

The article describes anthropogenic transformations of relief features associated with former economic use of rivers and the changes that occurred in individual sections of artificial canals as a result of their naturalisation. The study was carried out in two river valleys – of the Sumina and Wierzbnik Rivers, which are located in the Ruda River catchment (within the Odra River drainage basin), on the boundary of the Rybnik Plateau and the Racibórz Basin. The use of water in these rivers for the purposes of former grain mills, sawmills and other industrial facilities as well as fish ponds involved the construction of bypasses. The deep erosion gullies recorded in the relief of the Sumina and Wierzbnik River valleys are in fact transformed anthropogenic forms: artificial river channels and old bypasses. In the Wierzbnik River valley, these canals – today dead, but still visible in relief, reflect the technical solutions which were once used to protect ponds from damage during floods. The sections of old artificial canals such as the man-made channel of the Sumina River, are still subject to naturalisation processes, being were later transformed by natural fluvial processes. This is reflected in an increase in channel sinuosity and the development of meanders. It is proposed that the erosive forms described in the article be referred to as anthropogenically determined river gorges.