The Evolution of Gravel-Bed Rivers during the Post-Regulation Period in the Polish Carpathians

Abstract

This study provides a conceptual model of the functioning of gravel-bed rivers during the post-regulation period in Poland and forecasts their subsequent evolution. The main difference between fluvial processes during the pre-regulation and post-regulation period is that they are limited to a zone that is currently several times narrower and trapped in a deep-cut channel. During the river post-regulation period, the construction of additional river training works was significantly limited in river channels. Moreover, all forms of economic activity were significantly reduced in the channel free migration zone, particularly bed gravel extraction operations. As a result of these changes, a limited recovery of the functioning and hydromorphology of the river channel occurred via a return to conditions in effect prior to river regulation. In recovering sections of river, the channel gradually broadens, and its sinuosity and number of threads increase. The overall process can be called spontaneous renaturalization, which yields a characteristic post-regulation river channel. The conceptual model was developed on the basis of the evolution of the gravel-bed river, the Raba River, during the post-regulation period in the Polish Carpathian Mountains.

Reconstruction of Nineteenth-Century Channel Patterns of Polish Carpathians Rivers from the Galicia and Bucovina Map (1861–1864)

“…The Raba was a braided river with a meandering lower course. The existence of short anabranching reaches in the foothills was already postulated by Wy żga [27] and this study confirms the thesis concerning the braiding of the historical Raba [27,102]. The Dunajec was an anabranching river, determined by long reaches in intramontane basins and foothills.…”

Evaluation of sediment transport empirical equations: case study of the Euphrates River West Iraq

“…There are number of equations that deal with total load transport in rivers. Some of the equations used to compare the calculated load relative to field-measured loads are listed below (Gorczyca et al 2020;Yang 1996):…”

Quantitative Evaluation to the Sediment Load at a Part of Euphrate River in Center of Iraq

“…Most of rivers transported sediment with their streams periodically or ultimately, and then deposit materials in river bed or floodplains for creating new formation to riparian lands (Cheng, 2016;Hughes and Croke, 2011).Typically, the suspension materials that transported with running water is played a decisive role in river dynamic system where sediment can identify lowlands and builds landscapes (Bettes 2008; Khullar et al, 2010). In another view, the natural sediment that locally eroded from the bed and riverbanks and transport by stream power can increase sedimentations in downstream regions by increasing bed load availability (Diplas, et al, 2008).The change in morphology of fluvial river is as a result of complex interaction between series of physical processes such as; sediment transport, flow variation, and bed deformation (Cheng, 2016;Simon, 2006;Gorczyca et al, 2020) Therefor, estimating sediment transport from field investigation are essential for constructing significant view for effective management strategies (Rickenmann, and Recking 201; Mays, 2010).…”