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Using 1D and 2D computer models when predicting hydrodynamic and morphological parameters of a boulder block ramp: Poniczanka stream, Carpathians

Plesiński Karol K., Radecki-Pawlik Artur, Rivera-Trejo Fabian

Journal of Water and Land Development

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2022

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Special Issue

34--48

EN

When modelling flow and/or sediment transport in streams and rivers, one must frequently use the computer software of differing levels of complexity. The level of sophistication, accuracy, and quality of results are the parameters by which models can be classified as being 1D, 2D, or 3D; it seems certain that in the future, there will also be 4D and 5D models. However, the results obtained from very sophisticated models are frequently questionable, and designers in the field of hydraulic structures must have considerable experience distinguishing important information from irrelevant information. Thus, this paper aims to investigate the effect of the selected boulder block ramp hydraulic structure at Poniczanka stream on the bed-load transport. We evaluated sediment transport using the CCHE2D numerical model. We analysed several scenarios depending on the river bed type (erodible, non-erodible, rocky) and examined the rock blocks used for hydraulic structure construction. The obtained results were compared with the Hjulström and the Shields graph, which are a classic approach for identifying fluvial processes in river channels. In addition to these two methods, numerical modelling using the 1D HEC-RAS (Hydrologic Engineering Center’s River Analysis System) modelling were conducted, which included the determination of horizontal and vertical changes to the river bed morphology of the examined section of river reach as well as providing the basic hydrodynamics parameters which, from the practical point of view, designers involved in the process of designing ramps could use.

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Radarowe obrazy satelitarne Sentinel-1 - nowe źródło danych w badaniach procesów korytowych i zjawisk lodowych na dolnej Wiśle

Kryniecka Klaudia, Magnuszewski Artur

Gospodarka Wodna

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2022

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Nr 6

18--23

PL

Nowym źródłem informacji o środowisku są satelitarne obrazy radarowe, uzyskiwane ze stacji Sentinel-1, umieszczonej na orbicie przez Europejską Agencję Kosmiczną ESA. Obrazy radarowe są rejestrowane co 2-3 dni i dostępne w krajowym punkcie odbioru i archiwizacji Sat4Envi w Krakowie. W pracy przedstawiono proces przygotowania obrazu z produktu GRDH za pomocą programu SNAP. Na przykładzie fragmentu koryta dolnej Wisły w km 879-883 pokazano, jak wygląda spływ śryżu zarejestrowany na obrazach Sentinel-1 w dniach 17 I 2018 r. i 28 II 2018 r. Obraz z dnia 28 II 2018 r. pokazuje, jak dużą rolę w kształtowaniu nurtu i strumienia śryżu odgrywają piaszczyste ławice i przemiały między nimi. Zaletą obrazów Sentinel-1 jest duża częstotliwość rejestracji, niezależna od pory dnia i stopnia zachmurzenia. Obrazy radarowe mogą znaleźć zastosowanie jako dodatkowe źródło danych przy sporządzaniu raportów lodowych i prowadzeniu akcji lodołamania.

EN

Satellite radar images sent by Sentinel-1, placed in the orbit by the European Space Agency, constitute a new source of information on the environment. Radar images are recorded every 2-3 days and are gathered in the national point for receiving and archiving satellite data, SAT4Envi in Krakow. The article presents the process of the GRDH product image processing with the SNAP software. Using a fragment of the lower Vistula River riverbed at km 879-883 as an example, it shows the flow of slush ice on the Sentinel-1 images of 17/1/2018 and 28/2/2018. The image of 28/2/2018 shows how important is the role of sandbanks and material flowing between them in shaping the ice flush current and stream. An advantage of the Sentinel-1 images is high frequency of recording, independent on the time of the day and degree of cloudiness. Radar images may be used as an additional source of data while preparing ice reports and conducting ice-breaking actions.

3

Spatial distribution pattern of macroinvertebrates in relation to morphohydraulic habitat structure : perspectives for ecological stream assessment

Pastuchova Z., Greskova A., Lehotsky M.

Polish Journal of Ecology

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2010

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Vol. 58, nr 2

347-360

EN

The relationship between the river channel parameters - morphological, hydraulic and substrate - and the composition and distribution of macrozoobenthos communities was studied on the 75 m channel reach of the stream (Teplicka brook, Strazovske vrchy Mts., Slovakia) located at the altitude of 256 m; with average width 4 m, depth 0.25m, average current velocity 0.32 m s[^-1] and discharge in sampling season 0.2 m[^3]s[^-1]. Following the River Morphology Hierarchical Classification (RMHC), the fluvial geomorphological research was realised on the selected channel reach - taxon defined in accordance to RMHC. The plane bed and a riffle-pool channel types have been identified in the investigated channel reach. At the habitat level morphological and hydraulic features represent an alternative approach of habitat assessment in order to gain representative macroinvertebrate sample in stream assessment according to the Water Framework Directive (WFD). The morphological units defined in terms of Froude (Fr) and Reynolds (Re) numbers differed in the extent of the shear stress and turbulence of the water environment. Also Fr and Re values rose in the row of flow types: standing water (SW) - scarcely perceptible flow (SP), smooth flow (S) - rippled (R) - unbroken standing waves (USW) - broken standing waves (BSW) - chute (CH). Different taxa and feeding groups preferred different morphological units and flow types. In terms of morphological units, runs, bars, edgewaters and scours were generally inhabited by the lowest abundance of all invertebrate groups; only Gastropoda reached the higher abundance in these habitats. Glides, pools and backwaters were inhabited by somewhat higher numbers of invertebrates, Oligochaeta and Bivalvia dominated here. Units with organic substrate (moss on boulder clusters and roots) together with rapids and riffles were characterised by high abundance mainly of Gammaridae and Simuliidae. Regarding flow types, standing water separated from others by its low abundances of taxa group but Gastropoda and Bivalvia. SP, S and R types were preferred by Oligochaeta and Chironomidae, while Gammaridae and Simuliidae dominated in standing waves (USW, BSW) and chutes. Also distribution of feeding groups followed the gradient of local environmental conditions. Significant correlations of feeding groups and flow types, current velocity, Fr, Re and depth were observed. Organic substrates played an important role in distribution and abundance of the macrozoobenthos. Overall abundance and also abundance of Ephemeroptera, Trichoptera, Coleoptera and Diptera was significantly higher in the moss or roots compared to other habitats.. Benthos communities of these habitats showed similarities with habitats in the highly turbulent environment (riffles, rapids).