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1
Content available A comparison between the suspended sediment concentrations derived from DELFT3D model and collected using transmissometer – a case study in tidally dominated area of Dithmarschen Bight
100%
Rahbani M.
Oceanologia
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2015
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tom No. 57 (1)
44--49
EN
The objective of this investigation is to verify the deficiencies that incorporate both modelled and measured suspended sediment concentrations (SSC) data in a tidal dominated area. For this purpose a tidal channel, in the North Sea, was considered as the case study. The profiles of SSC from a model were compared with those from the field, in which some dissimilarity was observed. Intensive investigations were carried out to detect that the most discrepancies occur in shallow parts of the area and also during the low velocities. The origin of the shortcomings in regard with the modelling and measuring technique are discussed.
2
Content available Short-term dynamics of river water turbidity
100%
Chalov S. R. , Tsyplenkov A. S.
Geography and Tourism
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2018
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tom Vol. 6, No. 1
7--14
EN
An overview of the recently collected datasets of highly discrete water turbidity measurements has allowed for the first hydrological and geographical analysis of short-term fluctuations in water turbidity and the composition of suspended sediments. The novel methodology has been developed to estimate a value of TI, which is the ratio of the difference between the maximum and minimum turbidity for a short period of time (ΔTi) (1 hour with the measurement frequency of 20 minutes) and the total turbidity difference for the water regime phase under study (ΔTHE). Higher TI values correspond to a greater contribution of diurnal (20-minute) turbidity fluctuations to the seasonal variability of sediment yield. Rivers have been grouped according to the value of water turbidity fluctuations within one hour (20-minute): glacier-fed rivers (the Tarfala, the Dzhankuat) (TI amounts to 0.17-0.22); volcanic rivers (0.22–0.25) and lowland rivers (the Selenga, the Western Dvina) (0.09).
3
Selected results of numerical investigation of Wloclawek reservoir sedimentation
100%
Banasik K. , Skibinski J.
Zeszyty Naukowe Akademii Rolniczej we Wrocławiu. Melioracja
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1988
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nr 31
4
Content available remote Temporal variations of suspended sediment concentration during period of high water stages in the lower course of the Obra River (Western Poland)
75%
Młynarczyk Z. , Słowik M.
Archives of Environmental Protection
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2008
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tom Vol. 34, no. 1
33-49
EN
Research concerning temporal variations of suspended sediment concentration during period of high water stages was done in the lower course of the Obra River near Międzyrzecz (Western Poland). The analysis regarding dependence of mean suspended sediment concentration and discharge allowed to determine the way of suspended sediment supply to the river bed during high water stages. It was supposed that exposures of glacial and fluvioglacial sediments in high concave banks could be an important factor influencing the amount of delivery of suspended material. Besides, normal hystcretic loops (oriented clockwise) were observed in cross-sections 4 and 5. That fact would suggest that transported material originates form the Obra River bed or its vicinity. The process of sediment accretion was observed on a fragment of drowned floodplain during high water stages. Collection of samples of freshly deposited sediment and grain size analysis allowed to illustrate the mechanism of forming floodplain sediments. It also was possible to draw near conditions of forming such sediments in the past.
PL
Badania nad zmianami koncentracji materiału zawieszonego w okresie występowania wysokich stanów wody przeprowadzono w dolnym odcinku rzeki Obry, w okolicach Międzyrzecza. Analiza związku pomiędzy średnią koncentracją materiału zawieszonego a przepływem umożliwiła wstępne określenie sposobu dostawy materiału do koryta rzecznego. Ważną rolę mogły tu pełnić odsłonięcia osadów glacjalnych i fluwioglacjalnych znajdujących się w wysokich brzegach wklęsłych koryta Obry. Ponadto na dwóch z pięciu badanych przekrojów pomiarowych zaobserwowano efekt histerezy o przebiegu normalnym, co świadczyłoby o autochtonicznym pochodzeniu transportowanego osadu. Ponadto zaobserwowano proces depozycji osadów na fragmencie równiny zalewowej w okresie występowania wysokich stanów wody. Podjęto w ten sposób próbę przedstawienia mechanizmu tworzenia się litofacji środowiska pozakorytowego. Pozwoliło to na przybliżenie warunków, w jakich osady powodziowe dna doliny Obry były kształtowane w przeszłości.
5
Content available Quantification of solid particle transport in suspension in a stream : Case of Wadi Zeddine Ain-Defla, Algeria
75%
Bouleknafet Z. , Elahcene O.
Journal of Water and Land Development
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2023
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tom no. 56
102--108
EN
Arid and semi-arid areas are characterised by differentiation in meteorological conditions. Sometimes the rains are rare and not very intense and at other times they are dense and very intense, resulting in torrents that often lead to strong soil erosion. Most of the time, the losses occur at the solids level because the erosion effect is too high. In this study, we want to evaluate the transfer of solid sediments as a function of liquid transport in the basin of Wadi Zeddine at Ain Defla in Algeria. To understand this phenomenon, we used the data of liquid flows (Ql, m3∙s-1) and concentration of suspended sediments (C, g∙dm-3), transported in the river, the data collected by the NWRA (National Water Resources Agency), over 24 years have been used to find a relationship between these two quantities, to estimate the quantity of solid transport Qs (kg∙s-1) in the watercourse of the catchment area studied. The results obtained show a good correlation between solid and liquid flows, with a correlation coefficient estimated at 90%, and the average annual sediment supply recorded at the outlet of the Wadi Zeddine watershed is estimated at around 88,048 Mg, which corresponds to 202 Mg∙km-2∙y-1 erosion rate. This value is comparable to those found in other regions with similar hydrological regimes.
6
Content available Suspended sediment concentration and yield in snowmelt flood events in a small lowland river
75%
Hejduk A. , Banasik K.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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2010
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tom 42
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nr 1
61-68
EN
Results of investigation on suspended sediment delivery from small lowland, agriculturally used catchment of Zagożdżonka River, located in central Poland, during snowmelt periods of 2001– –2007 are presented. The study catchment‘s area, upstream of the well equipped gauging station at Czarna, is 23.4 km2. Suspended sediment concentration and sediment yield has been calculated and analysed for 15 snowmelt flood events. The relationship between suspended sediment concentration and the discharge has been analyzed. It has been found that the relation, in majority of the cases, has the form of clockwise hysteresis, however the existance of other types of hysteresis i.e. anticlockwise and “8” shape, have been also confi rmed. Signifi cant relation between suspended sediment yield and runoff volume of snowmelt flood events has been also found.
PL
W pracy przedstawiono wyniki badań transportu rumowiska unoszonego, przeprowadzonych w małej zlewni nizinnej (A = 23,4 km2) położonej na Równinie Radomskiej. Przeanalizowano 15 wezbrań z lat 2001–2007, dla których zarejestrowano kompletne dane obejmujące zasilanie zlewni, przepływ i koncentracje. Analiza zależności koncentracji z przepływem wskazuje na występowanie w większości z analizowanych zdarzeń histerezy prawostronnej (tj. zgodnej z ruchem wskazówek zegara). Koncentracja rumowiska unoszonego wzrastała wraz z przepływem, a jej kulminacja w większości z badanych przypadkach wystąpiła przed kulminacją przepływu. Ustalono zależność, statystycznie istotną, wydatku rumowiska od objętości wezbrania.
7
Content available Appraisal of suspended sediment concentration on reference level according to van Rijn’s method
63%
Michalec B.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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2008
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tom 40
8
Content available remote Influence of diffusion angle on sediment concentration in front inflow forebay of pumping station
63%
Fan X. , Zhang J. , Yao W. , Dong C. , Wang L. , Tian H.
Ecological Chemistry and Engineering. S
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2024
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tom Vol. 31, nr 3
398--409
EN
The numerical simulation and field investigation of solid-liquid two-phase flow are carried out in a large-scale forward intake forebay with various diffusion angles at the Jingtaichuan Pumping Irrigation Project in Gansu Province, China. The purpose is to investigate the properties of sediment deposition in the pumping station forebay. The results indicate that the low-sediment concentration area is in the forebay’s centre, whereas the high-sediment is near the two side walls flanks. The sediment concentration increases dramatically from the centre to the sides. Both the high-sediment concentration area and the sediment concentration increase with water depth. The forebay’s narrowing diffusion angle causes the high-concentration area to gradually decrease while the low-concentration area gradually increase. Furthermore, the amount of siltation and sediment deposition efficiency decrease, resulting in a large increase in forebay sediment concentration and sedimentation efficiency. The sediment concentration and water flow velocity reveal a quadratic polynomial relationship. This study can provide a guide and reference for the design and construction of comparable large-scale pumping station forebays.
9
Problem of siltation of small reservoirs in Algeria
63%
Errih M. , Bekhti B. , Benamar B. , Benshila B. , Boudjename N. , Ladouani A. , Sad-Chemloul N.
Zeszyty Naukowe Akademii Rolniczej we Wrocławiu. Inżynieria Środowiska
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1992
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tom 01
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