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122. Bacteria transport and retention in intact calcareous soil columns under saturated flow conditions

Creator:
Farrokhian Firouzi, Ahmad, Homaee, Mehdi, Klumpp, Erwin, Kasteel, Roy, and Tappe, Wolfgang
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
bacteria transport, calcareous soil, Pseudomonas fluorescens, and saturated flow
Language:
Slovak
Description:
Study of bacterial transport and retention in soil is important for various environmental applications such as groundwater contamination and bioremediation of soil and water. The main objective of this research was to quantitatively assess bacterial transport and deposition under saturated conditions in calcareous soil. A series of leaching experiments was conducted on two undisturbed soil columns. Breakthrough curves of Pseudomonas fluorescens and Cl were measured. After the leaching experiment, spatial distribution of bacteria retention in the soil columns was determined. The HYDRUS-1D one- and two-site kinetic models were used to predict the transport and deposition of bacteria in soil. The results indicated that the two-site model fits the observed data better than one-site kinetic model. Bacteria interaction with the soil of kinetic site 1 revealed relatively fast attachment and slow detachment, whereas attachment to and detachment of bacteria from kinetic site 2 was fast. Fast attachment and slow detachment of site 1 can be attributed to soil calcium carbonate that has favorable attachment sites for bacteria. The detachment rate was less than 0.02 of the attachment rate, indicating irreversible attachment of bacteria. High reduction rate of bacteria was also attributed to soil calcium carbonate.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

123. Bank erosion - prognosis of the retreat of bank line of reservoirs

Creator:
Šlezingr, Miloslav
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
bank erosion, bank abrasion, dam, bank stability, břehová abraze, údolní nádrž, stabilita břehů, and sanace břehů
Language:
Slovak
Description:
The problematics of creation and development of bank erosion, follow-up repairs of abrasion damaged banks and development of abrasion progress prognostic methods is often discussed. One of the contributions to this discussion is presentation of ''Modificated Methods of Abrasion Terminal Line Determination''. The prognosis of bank erosion advance is determined also in areas, where original condition of bank is unknown. This method was successfully verified during years 1998-2001 at Brno Reservoir on the Svratka River and can be used at other dam reservoirs as well. and O problematice vzniku a rozvoje břehové abraze, o návrzích následné sanace abrazí poškozených břehů a vývoji prognostických metod postupu abraze se v posledních letech diskutuje stále častěji. Jedním z příspěvků k této diskusi je i prezentace ''modifikované metody určení abrazní terminanty''. Jedná se zde o stanovení prognózy postupu břehové abraze, a to i v oblastech, ve kterých neznáme původní stav pobřeží. Tato metoda byla úspěšně ověřována v letech 1998-2001 na údolní nádrži Brno na řece Svratce a je široce použitelná i na jiných vodních dílech.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

124. Bank erosion of the Tŕstie stream: BANCS model predictions vs. real bank erosion

Creator:
Allmanová , Zuzana, Vlčková , Mária, Jankovský , Martin, Jakubis , Matúš, and Allman , Michal
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
BANCS model, bank erosion, and prediction curves
Language:
Slovak
Description:
This paper focused on predicting the bank erosion through the Bank Assessment for Non-point source Consequences of sediment (BANCS) model on the Tŕstie water stream, located in the western Slovakia. In 2014, 18 experimental sections were established on the stream. These were assessed through the Bank Erosion Hazard Index (BEHI) and the Near Bank Stress (NBS) index. Based on the data we gathered, we constructed two erosion prediction curves. One was for BEHI categories low and moderate, and one for high, very high, and extreme BEHI. Erosion predicted through the model correlated strongly with the real annual bank erosion – for low and moderate BEHI, the R2 was 0.51, and for high, very high and extreme BEHI, the R2 was 0.66. Our results confirmed that the bank erosion can be predicted with sufficient precision on said stream through the BANCS model.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

127. Basset force in numerical models of saltation

Creator:
Lukerchenko, Nikolay, Dolanský, Jindřich, and Vlasák, Pavel
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Basset force, bed load transport, numerical model, particle-bed collision, Bassetova historická síla, pohyb splavenin, numerický model, and kolise částice se dnem
Language:
Slovak
Description:
In numerical models of fluid flow with particles moving close to solid boundaries, the Basset force is usually calculated for the particle motion between particle-boundary collisions. The present study shows that the history force must also be taken into account regarding particle collisions with boundaries or with other particles. For saltation - the main mode of bed load transport - it is shown using calculations that two parts of the history force due to both particle motion in the fluid and to particle-bed collisions are comparable and substantially compensate one another. The calculations and comparison of the Basset force with other forces acting on a sand particle saltating in water flow are carried out for the different values of the transport stage. The conditions under which the Basset force can be neglected in numerical models of saltation are studied. and V numerických modelech proudění tekutin s pevnými částicemi v blízkosti pevné stěny je Bassetova historická síla obvykle počítána pro pohyb částice mezi jejími jednotlivými kolisemi se dnem. Předložená studie ukazuje, že při výpočtu Bassetovy historické síly je nutné brát v úvahu kolisi částice s pevným dnem nebo s jinými částicemi. Pro saltaci, hlavní typ pohybu splavenin u dna koryta, je na základě použitých výpočtů ukázáno, že dvě části Bassetovy historické síly, tj. síly způsobené pohybem částice v tekutině a kolisí částice se dnem, jsou srovnatelné a mohou se vzájemně významně kompensovat. Výpočet Bassetovy historické síly a její srovnání s ostatními silami působícími na písčitou částici při jejím saltačním pohybu ve vodě je uskutečněn pro různé hodnoty tzv. transport stage (poměr aktuálního a kritického smykového napětí na dně). Zároveň byly studovány podmínky, za nichž může být Bassetova historická síla v numerických modelech zanedbána.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

128. Bayesian estimation of the hydraulic and solute transport properties of a small-scale unsaturated soil column

Creator:
Moreira, Paulo H. S., van Genuchte, Martinus Th., Orlande, Helcio R. B., and Cotta, Renato M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Markov Chain Monte Carlo method, Metropolis-Hastings algorithm, hydraulic parameters, transport parameters, and soil column experiment
Language:
Slovak
Description:
In this study the hydraulic and solute transport properties of an unsaturated soil were estimated simultaneously from a relatively simple small-scale laboratory column infiltration/outflow experiment. As governing equations we used the Richards equation for variably saturated flow and a physical non-equilibrium dual-porosity type formulation for solute transport. A Bayesian parameter estimation approach was used in which the unknown parameters were estimated with the Markov Chain Monte Carlo (MCMC) method through implementation of the Metropolis-Hastings algorithm. Sensitivity coefficients were examined in order to determine the most meaningful measurements for identifying the unknown hydraulic and transport parameters. Results obtained using the measured pressure head and solute concentration data collected during the unsaturated soil column experiment revealed the robustness of the proposed approach.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

129. Bedload equation analysis using bed load-material grain size

Creator:
Haddadchi, Arman, Omid, Mohammad H., and Dehghani, Amir A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
sediment transport, grain size, gravel-bed river, and evaluation
Language:
Slovak
Description:
Twelve predictive bedload sediment transport equations are rated against 14 sets of gravel-bed river field data collected by handheld bedload sampler in Narmab River, northeastern Iran. To evaluate these formulas two types of grain size namely bedload and bed material were used. The results show that the equations of Engelund and Hansen, Van Rijn and Einstein perform well with bed material grain size, while Shocklitsch, Meyer-Peter and Mueller, and Frijlink yield the best results using the bedload grain size.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

130. Bedload transport and morphological effects of high-magnitude floods in small headwater streams - Moravskoslezské Beskydy Mts. (Czech Republic)

Creator:
Galia, Tomáš and Hradecký, Jan
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
incipient motion, bedload transport, headwater stream, Moravskoslezské Beskydy Mts., počátek pohybu, dnový transport, pramenný tok, and Moravskoslezské Beskydy
Language:
Slovak
Description:
Bedload transport observed during a flood in May 2010 gave rise to several forms of accumulations in small headwater basins located in the Western Flysch Carpathian Mountains, Czech Republic. We have investigated critical conditions of incipient motion of the largest boulders deposited during a c. Q100 flood event (flood competence method). We have tested several formulas designed for high gradient streams in two small basins in the conditions of local mid-mountain relief. The results show that a flood of such a magnitude is able to transport almost all surface bed material and that bedload transport in steep headwater streams (A ≤ 1 km2 ) is probably less selective as for the grain size than that in lower gradient gravel-bed streams. The authors discuss the importance of local basin predispostion factors in order to determine critical conditions for the onset of bedload transport. and Dnový transport sedimentů zapříčinil během květnových povodní v roce 2010 vznik různých typů akumulací v malých pramenných tocích nacházejících se ve flyšových pohořích Západních Karpat. Studie se zaměřuje na určení kritických podmínek nutných pro uvedení největších klastů do pohybu, jež byly následně uloženy do akumulací během této cca Q100 povodně (metoda účinnosti povodně). V rámci výzkumu byly ověřeny některé rovnice vytvořené pro vysokogradientové toky na dvou malých povodích v podmínkách reliéfu hornatin. Výsledky ukazují, že povodeň takové intenzity je schopna transportovat téměř celou povrchovou vrstvu sedimentů a dnový transport je na malých povodích pravděpodobně méně velikostně selektivní než v tocích s nižším gradientem dna. Důraz byl kladen také na lokální predizpoziční faktory ovlivňující kritické podmínky pro uvedení určité velikostní frakce sedimentů do pohybu.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public