Geography Reference
In-Depth Information
Study Area
Case Study Site
Morava is a typical example of a meandering river that has been influenced by
regulation (except for the study area of Litovelsk´ pomorav´). Regulation markedly
simplified the shape of the river. A direct channel was created from the initially
differentiated meandering channel. Floods are now contained within the narrow
area between the levees. The natural attenuation of floods by spilling onto the
natural floodplain area and thus slowing the downstream progress into lower basin
areas does not occur. However, the dyke systems do not provide sufficient flood
protection; for example, dams on the Austrian side of the river failed during floods
in the spring of 2006. Cutoff lakes, which are isolated outside the dykes, are
filling in.
The Kenick
´
Meander National Nature Reserve is situated in the territory of
Litovelsk
´
Pomorav
´
PLA (Protected landscape area) at 250.3 km of the Morava
River. It is located in Ramena
ˇ
eky Moravy National Nature Reserve, which
includes the main channel and streams of the Morava River. The natural
(unregulated) lowland river basin and adjacent bank communities of herbs and
wood species, which preserve their original species composition, are protected. The
Kenick´ National Nature Reserve is located on the right bank of the river to the
west of the Kenick´ meander and contains hardwoods (alluvial forests with pre-
dominantly hardwood trees such as oak and ash) between the main channel of the
Morava Mlynsk´ potok River (occasionally called Stˇedn´ Morava or Mal´ voda).
This study focuses on a section of the main channel of the Morava River between
transverse profiles No. 8 and No. 18 in the Kenick´ Meander Nature Reserve
(Fig.
1
).
The flow of the Morava River is unregulated through the Kenick´ meander and
causes natural channel development and geomorphologic activities. In the basin,
large numbers of alluvial trees and gravelsand deposits significantly influence the
flow and affect its further development. The changing shoals and pools cause
changes in the speed of the flow; the river forms alluvial sediments due to short-
term losses of energy, and it erodes banks and the channel bottom when the energy
increases in faster parts of the river. Due to the quantity of water that flows through
the basin, the basin is large and particularly deep (M
´ˇ
ka and Krej
ˇ´
2006a
). These
characteristics allow the basin to efficiently drain floodwaters; however, the
groundwater level decreases in times of drought, which can negatively impact the
water regime of the surrounding alluvial forests.
A typical feature of water in meanders is its sinuous flow. In the top part of the
meander, the streamline flows near the gibbous bank; here, the flow contributes to
lateral erosion. If there are several consecutive meanders, the streamline flows
towards the next gibbous bank (which is on the opposite side of the river as the
previous one). In straight sections, the flow is usually concentrated approximately
in the middle of the river. In some cases,
the flow is not clear due to the
