Geographia Polonica (2023) vol. 96, iss. 1

Causes and mechanisms of the disappearance of braided channel patterns (the example of the Białka River, Western Carpathians)

Elżbieta Gorczyca, Kazimierz Krzemień, Michał Łyp, Andrzej Strużyński

Geographia Polonica (2023) vol. 96, iss. 1, pp. 145-172 | Full text
doi: https://doi.org/10.7163/GPol.0250

The channels of multi-threaded (braided) rivers occur commonly in areas that fulfill certain conditions such as substantial influx of bed material and gradients large enough to create significant energy of flowing water. Natural conditions favoring the formation of multithreaded channels are present in the Carpathians in Poland in Podhale – a large basin located in the piedmont area of the high-mountain Tatra massif. The area had experienced glaciation in the Pleistocene. Yet the 20th century – and especially its second half – was a period of rapid and irreversible elimination of braided channels across the region. The Białka is considered to be the last braided river in the Carpathians in Poland. Many parameters like: structure (morphologic reach sequence), degree of braiding (BI index, W/D) and also a number of hydrodynamic ones (unit stream power,critical stress, shear stress, others) were investigated in order to assess a current stage of development of the Białka river channel. The Białka river channel appears to be a complex system with a differentiated structure.Its channel system is a mosaic of different types described by the following sequence: straight-sinuous-braided.It represents an intermediate type that is somewhere between a single- and a multi-threaded channel. Future evolution of the Białka river channel appears to include further degradation and transformation into a poorer channel ecosystem.

Keywords: multi-threaded river channel, wandering channel, hydromorphologic analysis, human impact, Białka River, Polish Carpathians

Elżbieta Gorczyca [elzbieta.gorczyca@uj.edu.pl], Institute of Geography and Spatial Management Jagiellonian University in Kraków Gronostajowa 7, 30-387 Kraków: Poland
Kazimierz Krzemień [kazimierz.krzemien@uj.edu.pl], Institute of Geography and Spatial Management Jagiellonian University in Kraków Gronostajowa 7, 30-387 Kraków: Poland
Michał Łyp [michal.lyp@gmail.com], Jacobs Engineering Marii Konopnickiej 31, 30-302 Kraków: Poland
Andrzej Strużyński [rmstruzy@cyf-kr.edu.pl], Department of Water Engineering and Geotechnics University of Agriculture in Kraków Mickiewicza Ave. 21, 31-120 Kraków: Poland