Sunday, 16 October 2016

We participated the river restoration conference in Cracow

Tomáš Galia, Jan Hradecký and Václav Škarpich participated the conference 'Towards the Best Practice of River Restoration and Maintenance', which took place 20-23/9 in Cracow (PL) under organisation of Ab Ovo Association, Institute of Water Engineering and Water Management, Krakow University of Technology, University of Agriculture in Krakow, Institute of Nature Conservation, Polish Academy of Sciences in Krakow, Institute of Geography, Pedagogical University of Krakow and Regional Water Management Board in Krakow. Tomáš Galia spoked about effects of check-dams on channel morphologies and bed sediment parameters and he also presented some possibilities to restore such type of managed streams. Václav Škarpich discussed the role of human impact connected with the increase in stream power in managed gravel-bed rivers. Many interesting topics were presented through the conference, which dealt with natural function of rivers, ecosystem services and river restorations (see the book of abstracts free available for download).  

The 3-day field trip took place immediately after the conference in a smaller group of scientists. Colleagues from Poland showed us their study locations (e.g. Czarny Dunajec, Kamienica, Biala, Bialka), where we could see incision tendencies of Carpathian gravel-bed rivers as same as 'close-to-natural' reaches with wandering river patterns and development of islands or a mountain stream with log-jams. Also the approaches of local river restorations or a flood hazard by instream wood transport were illustratively demonstrated in the field. This trip was held in a very friendly atmosphere, giving us a great opportunity to discuss (not only) the issues of gravel-bed streams with well-known colleagues from abroad. We would like to thank especially to Bartek Wyzga and Joanna Zawiejska for the preparation and organisation of this field trip and conference.      
Restored check-dam with a fish-passage (the Krzczonówka Stream). 

Newly constructed erodible corridor in the Raba River

Demonstration of instream wood flood hazard in the Czarny Dunajec

Incision in the Bialka River (Polish-Slovakian border)

Deposited instream wood after a flood in the Czarny Dunajec upstream the Czorstyn Reservoir

Logjam in the Kamienica Stream (Gorce Mts.)

Erodible corridor in the Biala River

Monday, 3 October 2016

The effects of river patterns on riparian vegetation: A comparison of anabranching and single-thread incised channels

On September 2016, study about channel changes of the Morávka River and their effect on riparian vegetation was published.
Riparian vegetation reflects the current conditions and the dynamics of streams. The floodplain vegetation along the watercourse of the Morávka River was subject to study in this project. In some reaches, the river has the natural character of an anabranching gravel-bed stream; in contrast, other Morávka R. reaches are incised into the bedrock. These cases were used to assess potential changes in vegetation conditions as evidence of negative processes taking place in the gravel-bed streams of the Beskydy Mts. The results demonstrate a higher biodiversity in the floodplain along the anabranching river channel. In contrast, the floodplain along the incised river channel shows low biodiversity values. Redundancy analysis was used to determine the relationships between plant species composition, distance from the main channel and relative elevation from the mean water level of the main channel. In addition, the results show a higher degree of change in plant species composition on the floodplain along the incised river channel. The analysis of floodplain groundwater fluctuations shows a decreasing trend in the annual maximum groundwater level.
The paper has been recently published in Moravian Geographical Reports journal.

The Morávka R.: A – single-thread bedrock-incised channel river; B – anabranching channel river reach
Photo: V. Škarpich.
A – Shannon-Wiener index and B – Simpson's index of phytosociological relevés in the study area of the Morávka River floodplain. Source: authors’ elaboration.