Open AccessVLIV LITOLOGIE A MORFOLOGIE VYSOKOGRADIENTOVÝCH KORYT NA DNOVÉ SEDIMENTY: PŘÍKLADOVÁ STUDIE VODNÍHO TOKU KOBYLSKÁ (VSETÍNSKÉ VRCHY, ČESKÁ REPUBLIKA)
Author(s) -
Tereza Macurová,
Václav Škarpich,
Tomáš Galia
Publication year - 2018
Publication title -
geologické výzkumy na moravě a ve slezsku v roce .../geologické výzkumy na moravě a ve slezsku v roce ...
Language(s) - English
Resource type - Journals
eISSN - 2336-4378
pISSN - 1212-6209
DOI - 10.5817/gvms2018-1-2-21
Subject(s) - geology , bedrock , sediment , lithology , flysch , geomorphology , bed load , grain size , structural basin , sediment transport , hydrology (agriculture) , streams , fluvial , geochemistry , geotechnical engineering , computer network , computer science
High-gradient streams are integral parts of the fluvial systems, which connect the mountainous landscapes with lowland rivers in the sense of water and sediment transport. We analysed downstream grain-size characteristics of bed sediments and sphericity of grains with respect to the local flysch lithology and channel geometry in the 5.4 km long reach of the high-gradient Kobylská Stream (the Vsetín highlands, Outer Western Carpathians, Czech Republic). Results showed a high variability of bed-sediment sizes in the longitudinal course of the Kobylská stream. This condition is given by the occurrence of anthropogenic impact in the studied channel (local bank stabilisations, grade-control structures) and lateral sediment input from the adjacent landslides and bank failures. The lithology of the flysch nappe structure of the basin significantly influenced variations of bed sediment grain-sizes. Different bedrock resistance resulted into inverse correlation between the local river gradient and related bed grain-sizes. Especially the mudstone bedrock layers had significant impact on the fining of bed sediment in the upper steep part of the basin (D50 ≤ 40 mm) and by contrast, sandstone bedrock caused the coarsening of the bed sediment in the middle and lower parts (D50 up to 50 mm) characterised by lower bed gradients.