Landforms and morphogenetic processes in the locality of Geodetic Observatory Pecný, Ondřejovská vrchovina Highland

Abstract

The presented paper deals with physical-geographical environment and landform patterns in the locality of Geodetic Observatory Pecný (GOPE) in the Ondřejovská vrchovina Highland. Landforms transience of the Ondřejovská vrchovina Highland by erosion and denudation processes is proportional to a high potential energy of the relief due to progressive tectonic uplift of the central part of the Bohemian Massif in the late Cenozoic. The Seradovský potok Brook valley between the Pecný Ridge (545 m a.s.l.) and the Sázava valley bottom (284 m a.s.l.) intersects several levels of planation surfaces and its source area erodes the etchplain exhumed during the Palaeogene. In the lower part of the valley, the stream deepened during the late Quaternary by approximately 50 m, whereas the relatively steep erosional slopes of the canyon-like part of the antecedent Sázava valley have a relative height of 60-75 m. In the rugged terrain of the GOPE locality, there are visible marks of regelation and frost processes, gully and fluvial erosion, slow slope movements and anthropogenic activities. Intensity of recent morphogenetic processes with its maximum in spring corresponds to combination of seasonal changes of air and soil temperature and at the same time to increased water content in the rock massif and in the weathered mantle. The suitable geodynamic location of scientific observatories on the Pecný ridge, stable from engineering-geological and geomorphological point of view, and in its near neighbourhood is menaced by increasing intensity of anthropogenic activities in the landscape.