Strážnické Pomoraví—Holocene Evolution of a Unique Floodplain and Aeolian Landforms

Abstract

The Morava River drainage basin is the largest fluvial system of theeastern part of the Czech Republic. The Morava enters the Dolnomoravskyuval Basin (northern tip of the Vienna Basin) at its lower course, wherea 3.5 km wide floodplain is developed. The most interesting section offloodplain may be found between the towns Veseli nad Moravou andHodonin, where Pleistocene and Holocene sediments of the Morava Riverare accompanied by the unique complex of lacustrine sediments remodelledby the wind action to the shape of up to 10 m high sand dunes. TheMorava river was branching into many large as well as small arms in itsfloodplain, creating an anastomosed channel pattern. Diverse mosaic ofaquatic and (semi) terrestrial habitats were present as it is displayedon old maps of the floodplain. The majority of small anastomosedchannels vanished due to the river regulation works started in thenineteenth century and most of the river flow was concentrated into onedominant channel. This channel was affected by substantial deepening,widening and lateral migration in the second half of the twentiethcentury triggered by river regulation in 1930s. The aerial extent offloodplain inundation was reduced to approximately one-fourth of itsoriginal extent due to the construction of flood defence dykes. TheStraznicke Pomoravi region is one of last remaining examples of alowland meandering river with more or less preserved natural dynamics offluvial processes in the Czech Republic.