Wyniki wyszukiwania

1

Critical velocities for non-cohesive grounds

100%

Zelazo J.

Annals of Warsaw Agricultural University. Land Reclamation

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1987

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tom 23

2

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Turbulent intensity and scales of turbulence after hydraulic jump in rectangular channel

100%

Koziol A., Urbanski J., Kiczko A., Krukowski M., Siwicki P.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2016

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tom 48

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nr 2

3

Habitat selection by Anodonta cygnea L. in the Nida valley

86%

Zajac K.

Folia Malacologica

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1999

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tom 07

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nr 4

4

The evaluation of hydrodynamic balance at the Wkra River estuary

86%

Siwicki P., Urbanski J., Hejduk L., Gladecki J.

Meteorology Hydrology and Water Management. Research and Operational Applications

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2016

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tom 04

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nr 2

The river bed stability analysis at the Wkra estuary reach is presented in this paper. When a flood appears, channel and river bed erosion can reach a significant size. During such a situation, flow and water velocity exceed critical values for particular bed sediment grain sizes. This causes the breakage of bed armouring, and then bed mass motion begins. For the estimation of the sandy Wkra River bed the criteria of average velocity and bed armouring were applied with the use of ARMOUR software. The two Wkra River cross-sections at km 1+000 and km 3+200 distance were analysed. The calculation of the characteristics of bed sediment velocities was performed on the basis of, among other factors, probable river flow data, longitudinal slope, and grain size distribution of the bed. The results of the calculations were compared with average velocities in the analysed cross-sections. The results indicate the there is a threat to the stability of the Wkra River bed, especially during long-lasting high water stages. The prognosis of river bed stability loss performed by use of ARMOUR software shows that the bed armour breakage will take place in both considered cross-sections at relatively low water stages (about 40 cm), and mass motion of bed sediments in cross-section P-2 will occur at a flow of slightly lower than Q50% ,and in cross-section P-1 at flows greater then Q0,3%.

5

Response of riverine ecosystem after a flood event in the Smortawa valley

86%

Adynkiewicz-Piragas M., Krzeminska A.

Journal of Water and Land Development

|

2004

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nr 08

6

Analysis of riverbed transformation in the long term on the examples of the tributaries of the upper Vistula river

86%

Lapuszek M.

Infrastruktura i Ekologia Terenów Wiejskich

|

2013

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nr 2/IV

7

Effects of human impact on the beds of minor watercourses of the Aegean Island of Icaria (Greece)

86%

Tsermegas I.

Quaestiones Geographicae

|

2012

|

tom 31

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nr 1

8

Effects of cypress knee roughness on flow resistance and discharge estimates of the Turkey Creek watershed

86%

Miroslaw-Swiatek D., Amatya D. M.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2017

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tom 49

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nr 3

9

The usefulness of low-altitude aerial photography for the assessment of channel morphodynamics of a lowland river

86%

Ostrowski P., Falkowski T., Karczmarz D., Madrzycki P., Szkudlarz H.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2017

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tom 49

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nr 2

10

Identification of vegetation parameters for compound channel discharge as inverse problem

86%

Kiczko A., Koziol A., Kubrak J., Krukowski M., Kubrak E., Brandyk A.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2017

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tom 49

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nr 4

11

Variability of morphological conditions of the Vistula river channel in the section Czerwińsk-Kępa Polska

86%

Popek Z., Wasilewicz M.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2015

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tom 47

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nr 1

Variability of morphological conditions of the Vistula river channel in the section Czerwińsk-Kępa Polska. The paper presents an assessment of morphological changes that occurred in the Vistula river channel in selected section of about 33 km long, located in the middle of the Vistula river course between Czerwińsk and Kępa Polska (km 576–609). Based on the analysis of archival material from 1972–2009, a characteristics of river channel changes, taking primarily into account the horizontal layout (shape in the plan), was obtained. An attempt was made to estimate the trends and rate of transformation of the following parameters in the river channel: width, length, and position of the riverbanks, abundance and size of islands and fluvial deposits, as well as their percentage in the total area of the main river channel and the floodplain area between levees.

12

Turbulent kinetic energy of water in a compound channel

86%

Koziol A. P.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2011

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tom 43

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nr 2

13

An attempt of quantitative and qualitative evaluation of benthofauna in Warta old river bed

86%

Jezierska-Madziar M., Pinskwar P., Przybyl A.

Animal Science. Scientific Papers of Agricultural University of Poznan

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1999

|

tom 01

14

Variability of the river bed system and morphology in the region of the block ramp impact (the case of the Porebianka river)

72%

Plesinski K.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2018

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tom 17

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nr 1

The paper presents the influence of block ramp on system and morphological riverbed. One of twentyfive block ramp structures, located in the Porębianka River and situated in the central part of the cascade, was chosen for testing. In the observed section of the river, high morphological variability of the riverbed was observed in the years 2010–2011, caused by freshets. Additionally, in one period, the morphological changes were also caused by river training work, consisting in repairing block ramps of increased roughness, which were destroyed during the freshets, as well as damaging involvement with the riverbed. Despite the anthropogenic impact on the river channel, the research has shown that the morphology of the riverbed is returning to its natural structures, which are characteristic of the braided rivers. This confirms the thesis that the block ramps of increased roughness cause differentiation in river morphology, and restoration of the braided character of the channel. Therefore, we can conclude that river defends itself against damaging human activity. In addition, the paper describes the beginning of the movement of the debris, for the grain of boulder located in the Porębianka River, in the hydrodynamic conditions persisting during field measurement series. These conditions were based on Shields’ diagram and the graph showing the relationship of threshold shear stress for the given grain diameter of boulders.

15

Studies on riverbed erosion on the Raba river close to the Stroza gauging station

72%

Lapuszek M.

Infrastruktura i Ekologia Terenów Wiejskich

|

2011

|

nr 12

The aim of the paper is to present the studies on the riverbed erosion on the upper course of Raba river, located from km 81.829 to km 77.751, close to the Stróża gauging station located in km 80.600. This part of the river course is completely changed due to the Project concerning the extension of the Zakopianka road located close to the Raba river. The results of simulation of riverbed evolution before and after the Project carried out by two 1D models (RubarBE and Metoda) are analysed and discussed. The results of computation obtained by both models are verified by field observations carried out in 2001 (before the Project), and in 2009 year (after the Project). The trends of erosion and deposition correspond to the field observations for the dates before and after the Project. Another verification is possible to make for the Stróża cross-section, where observations of cross-sectional geometry and water stages have been carried out from 1900 year till now. The statistical model of riverbed erosion developed for Stróża also confirm the trends obtained there by 1D models.

16

Ostracoda (Crustacea) of the river bed in the lower course of a large lowland river system exemplified by the Oder River (Poland)

72%

Szlauer-Lukaszewska A., Kowaluk-Jagielska B.

Zeszyty Naukowe. Acta Biologica. Uniwersytet Szczeciński

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2011

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tom 18

The study was carried out in the main branches of the Lower Oder River, differentiated in terms of sediments composition. The aim was performing a comparative studies on the differences in Ostracoda fauna inhabiting various types of sediments. Following bottom sediments were distinguished: hard, sapropel/hard, sapropel and Chironomidae mat. The packet of CANOCO v.4.5 programs was used to investigate the interdependence between the species composition and environmental parameters. Eighteen taxa were found of which 16 were identified to the species level. It was a comparatively high number considering the fact that the samples were collected exclusively from the benthic zone and solely from the main river bed, without floodplain. Physocypria kraepelini was an eudominant and Darwinula stevensoni and Cypria ophtalmica were dominants. The samples collected from the sapropel were characterised by the highest density. The case of hard sediments the status of domination was retained as above, but there appeared a new dominant, i.e. Potamocypris unicaudata . The most unique structure of domination was observed in the case of Chironomidae mat, with Limnocythere inopinata as an eudominant and Cypridopsis vidua and P. unicaudata as dominants. As for the species diversity, the hard sediments were characterised by the highest value of Shannon-Wiener Diversity Index, the sapropel/hard sediment was the lowest. The type of river bottom to a great extent affects the density and taxonomic composition of the Ostracoda in rivers. The waters of the Oder River, rich in oxygen, provide favourable conditions for the development of ostracods even on the surface of sapropel sediment.

17

Sklad uziarnienia rumowiska jako wskaznik lokalnej degradacji koryta rzecznego

72%

Ksiazek L., Michalik A., Sladowski T.

Acta Scientiarum Polonorum. Formatio Circumiectus

|

2008

|

tom 07

|

nr 4

3-12

18

Applying laser scanning technology to studying alluvial flume-bed topography in laboratory conditions

72%

Kiraga M., Razumnik M., Popek Z., Chmielewski L.

Acta Scientiarum Polonorum. Formatio Circumiectus

|

2018

|

tom 17

|

nr 4

The aim of the research was to compare alluvial bed topography description in laboratory conditions using the “traditional”, currently applicable method with an original approach, based on LiDAR technology. LiDAR application in local scours shape investigation in based on the grounds of introducing the autonomic measuring module, which, placed above the bed on dedicated controllable arrangement of guideways, describes the landform as a cloud of coordinates. The result of the performed experiment was obtainment of point clouds (x, y, z), reflecting the bed shape before and after local scour formation during twenty measurement series with varying hydraulic conditions. Objects of the study were basic geometry properties of the scour hole and its volume. The measurement with laser scanner technology application allowed for obtaining much more accurate results in shorter time, comparison to disc probe survey, and also relatively fast conversion of numerical data into figures. The device equipped with portable computer, precise stepper motors and dedicated software permitted the introduction of automation into laboratory work. The effect is not only measurements accuracy, but also significant acceleration of data gathering. The adopted grid is characterized by significant density, which – in connection with meaningfully high accuracy – allows very precise surface description. Bed shape can be presented in numerical or graphical form. It must be pointed out that disc probe method application would never give such accuracy as in the case of introducing laser scanning technology in similar studies.

19

Dynamics of water flow on degraded sectors of Polish mountain stream channels

72%

Michalik A., Ksiazek L.

Polish Journal of Environmental Studies

|

2009

|

tom 18

|

nr 4

665-672

Our study is aimed at determining the hydrodynamic changes of mountain stream channels caused by degradation that was initiated by uncontrolled mining of bed material. The study was conducted on Mszanka and Targaniczanka streams in which the collected data included: longitudinal profiles, cross-sections of the channels, the geometry of bed forms and analysis of particle composition of the bed material. The results show that hydrodynamic parameters have changed downstream from the studied sectors and along the cross-sections. Bed degradation also was linked to bank erosion, which intensified morphological changes of channels effecting the spatial distribution of flow velocity, shear stresses and stream power. The investigation also demonstrated that the bedload movement was in accordance with channel changes and more sediments were deposited than transported along the studied area. Finally, local aggradation and unstable channel capacity were observed.

20

Invertebrate and fish environmental preferences as the key factor for lowland riverbed biodiversity

72%

Oglecki P.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2008

|

tom 40

Ograniczanie wyników

Critical velocities for non-cohesive grounds

Turbulent intensity and scales of turbulence after hydraulic jump in rectangular channel

Habitat selection by Anodonta cygnea L. in the Nida valley

The evaluation of hydrodynamic balance at the Wkra River estuary

Response of riverine ecosystem after a flood event in the Smortawa valley

Analysis of riverbed transformation in the long term on the examples of the tributaries of the upper Vistula river

Effects of human impact on the beds of minor watercourses of the Aegean Island of Icaria (Greece)

Effects of cypress knee roughness on flow resistance and discharge estimates of the Turkey Creek watershed

The usefulness of low-altitude aerial photography for the assessment of channel morphodynamics of a lowland river

Identification of vegetation parameters for compound channel discharge as inverse problem

Variability of morphological conditions of the Vistula river channel in the section Czerwińsk-Kępa Polska

Turbulent kinetic energy of water in a compound channel

An attempt of quantitative and qualitative evaluation of benthofauna in Warta old river bed

Variability of the river bed system and morphology in the region of the block ramp impact (the case of the Porebianka river)

Studies on riverbed erosion on the Raba river close to the Stroza gauging station

Ostracoda (Crustacea) of the river bed in the lower course of a large lowland river system exemplified by the Oder River (Poland)

Sklad uziarnienia rumowiska jako wskaznik lokalnej degradacji koryta rzecznego

Applying laser scanning technology to studying alluvial flume-bed topography in laboratory conditions

Dynamics of water flow on degraded sectors of Polish mountain stream channels

Invertebrate and fish environmental preferences as the key factor for lowland riverbed biodiversity