Response of channel dynamics to recent meander neck cut-off in a lowland meandering river with artificial training history: the Morava River, Czech Republic

ABSTRACT

One-decade-long observations of post-cut-off channel development and oxbow lake formation are presented to offer insight into the morphological response of the Morava River to neck cut-off. The main objectives were: calculation of the amount of sediment released to the channel by collapse of the meander neck; comparison of floodplain erosion and deposition rates before and after cut-off; and description of the rate and pattern of oxbow lake sedimentation. The amount of sediment released due to cut-off (~35 000 m³) equalled 2–5 years of sediment input by lateral erosion averaged for the past six decades. Bank erosion rates substantially exceeded long-term averages (0.63–6.21 m year⁻¹, post cut-off). Despite a low entrance angle, alluvial plugs in a newly formed oxbow lake were established within a few months. Between 2006 and 2016, sedimentation of the alluvial plugs proceeded at an average rate of 0.55 m year⁻¹, reflecting the time since cut-off and the frequency of overbank flows.

KEYWORDS:

• neck cut-off
• meander
• Morava River
• oxbow
• sedimentation

Editor A. Castellarin Associate editor G. Di Baldassarre

Editor A. Castellarin Associate editor G. Di Baldassarre

Acknowledgements

The authors would like to thank Lenka Ondráčková and Martin Knot for their help during the field campaigns. Two anonymous reviewers are highly acknowledged for their valuable comments and recommendations, which helped to improve the previous version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Department of Geography, Masaryk University, under project MUNI/A/1315/2015: Integrated research of environmental changes in the landscape sphere, and further by the Slovak Research and Development Agency under contract no. APVV-0625-11 and the Visegrad Fund under strategic grant no. 31210058.