Gravel-bed channel changes upstream of a reservoir: The case of the Dunajec River upstream of the Czorsztyn Reservoir, southern Poland

Development of sediment slug upstream from the Czorsztyn Reservoir (southern Poland) and its interaction with river morphology

“…This allows a detailed reconstruction of the pattern of in-channel sedimentation upstream from the CR and its morphological effects in the broader context of the local geomorphic history of this specific site, where the sediment storage section existed at the end of the nineteenth century, now, providing the large amount of sediments stored in floodplains that may be easily remobilized by bank erosion. Previous studies conducted in this study area documented significant channel widening during the period with a large flood in 1997 and hypothesized that it may have been an effect of the intensive in-channel deposition and bank erosion caused by backwater effects during the large flood (Liro, 2015). However, a pattern of the development of this in-channel sedimentation zone was not reconstructed, and the potential relationship between in-channel sedimentation and bank erosion and their morphological effects were not quantified.…”

“…1B) testifying to the large amount of gravel sediment storage in this section from the end of the nineteenth century. An analysis of aerial photos indicate that the backwater (up to 1.5 km upstream from the CR, see Section 3.1) and at some distance upstream (up to 2.4 km upstream from the CR) channel widening is more than two times greater during a large flood than in the above section (Liro, 2015). The present channel slope of the studied river section changes markedly at the place corresponding to the intersection of the normal water level at the CR (529 m asl) and the channel bed profile at 0.65 km upstream from the CR, from 0.00085 to 0.00405.…”

“…Dam construction in a river valley causes the upstream base level to rise, which can influence water and sediment transport in the river channel, leading to its morphological adjustment (e.g., Leopold et al, 1964;Maddock, 1966;Lusby and Hadley, 1967;Leopold and Bull, 1979;Van Haveren et al, 1987;Bhowmik et al, 1988;Klimek et al, 1990;Xu, 1990Xu, , 2001aŁajczak, 2006;Xu and Shi, 1997;Evans et al, 2007;Skalak et al, 2013;Csiki and Rhodes, 2014;Liro, 2015). Despite the large increase in the number of large dams all over the world in the last century from about 400 to 50,000 (ICOLD, 1988, after Brandt, 2000and ICOLD, 2007, after Kummu et al, 2010 and their widely recognized downstream effects on channel depositional forms (e.g., Brandt, 2000;Petts and Gurnell, 2005;Grant, 2012), relatively less is known about the development of in-channel sediment storage zones upstream from these structures (Leopold et al, 1964;Knighton, 1998) and the interaction of stored sediments with the gravel-bed channel morphology.…”

“…Despite the large increase in the number of large dams all over the world in the last century from about 400 to 50,000 (ICOLD, 1988, after Brandt, 2000and ICOLD, 2007, after Kummu et al, 2010 and their widely recognized downstream effects on channel depositional forms (e.g., Brandt, 2000;Petts and Gurnell, 2005;Grant, 2012), relatively less is known about the development of in-channel sediment storage zones upstream from these structures (Leopold et al, 1964;Knighton, 1998) and the interaction of stored sediments with the gravel-bed channel morphology. However, the sediment storage zones upstream from low-head dams (e.g., Evans et al, 2007;Csiki and Rhodes, 2014) and large dam reservoirs (e.g., Skalak et al, 2013;Liro, 2015) are typically larger than several channel widths and exist in a river channel over a time period above the event scale. The similar, large, spatial-temporal scale depositional forms, or form assemblages associated with the disequilibrium in fluvial systems, are termed by Nicholas et al (1995) as sediment slugs.…”

A Dráva horvát-magyar szakaszán a vízjárás és a mederdinamika vizsgálata

“…A folyóra épített keresztgátak mind folyásirányban felfelé, mind lefelé jelentősen befolyásolják a meder morfológiáját (Kiss és Blanka 2012), azonban eltérő folyamatok jelentkeznek a különböző irányokban (Liro 2015). A hatásoknak az erőssége a műtárgytól távolodva egyre inkább mérséklődik.…”