Wetlands in River Valleys as an Effect of Fluvial Processes and Anthropopression - Wetlands and Water Framework Directive: Protection, Management and Climate Change - page 70

Fig. 5.4 The scheme of the regulated mountain river pro le

As a result, the mountain rivers fl flow with a smaller slope in straight and slightly

incised river channels (Fig. 5.4 ).
Apart from short periods of unusual fl oods, fl fluvial processes are “ frozen ” in

these channels. High flows destroy the stable bed cover. However, these phe-

nomena do exist and because of their violent nature they cause damage to river
structures (Michalik et al. 1999 ; Ksi

fl

ek, Michalik 2002 ). Therefore, the regulated
watercourses need the periodic application of repair works. At present, the EU
countries introduce the Water Frame Directive which creates favoured conditions to
improve status of transformed water bodies. It is possible to employ bedload
controlling dams instead of traditional check dams (Kopka 1998 ). Similarly, step
cascades may be replaced by using special

ąż

fish-penetrable structures. These
structures ensure the stability of watercourses but simultaneously improve the hy-
dromorphological parameters as well as restore the ecological corridor function of
rivers.

5.3 Description of the Research Areas

Wetland restoration reconnaissance was performed in the Upper Vistula Basin
(Poland) within the few projects running by the Department of Water Engineering
and Geotechnics, the University of Agriculture in Krak w. The examples of per-

formed in situ measurements are presented within the order: (a) the Vistula River
near the town of Sandomierz, (b) the Nida River between the village of R

ó

ę b ó w and

the Pi bianka Stream in the near outlet sections (Mszana

Dolna district), (d) the Czarny Dunajec River at the natural reach in the town of
Wr

ń cz ó w town, (c) the Por ę

wka. Although the regarded river reaches differ in many aspects (Table 5.1 ),
they are all located in areas of possible wetland appearance.

ó bl ó

The Vistula River
The Vistula River is planned to become a waterway. For this reason the reach near
Sandomierz (Fig. 5.5 ) is embanked and regulated by groins. Flood corridor within