Areal Sorting of Bed-Load Material: The Hypothesis of Velocity Reversal: Discussion

Teleki, Paul G.

doi:10.1130/0016-7606(1972)83[911:asobmt]2.0.co;2

Cited by 23 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Velocity reversal may occur at any discharge and is not necessarily limited to high flows around bankfull (e.g., Teleki 1972;Bhowmik and Demissie 1982;Carling 1991). Numerical modeling revealed that velocity reversal requires that pools are hydraulically rougher (i.e., coarser) than riffles, or that riffles are substantially wider than pools.…”

Section: Riffles Are Not Always Coarser Than Poolsmentioning

confidence: 99%

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

Bunte¹,

Abt²

2001

521

553

View full text Add to dashboard Cite

show abstract

Section: Riffles Are Not Always Coarser Than Poolsmentioning

confidence: 99%

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

Bunte¹,

Abt²

2001

521

553

View full text Add to dashboard Cite

show abstract

“…This influence may decrease with increasing discharge as depth increases to 'drown out' the feature (relatively), but complete equalization of depth, mean velocity or surface gradient through the reach may require some modification of the bed itself, a process which cannot as yet be incorporated in this simulation model. A reversal effect in bed velocity (Keller (1971)) or bed shear (Teleki (1972)) is not, however, precluded; these results apply only to mean velocity, and there may be a more rapid convergence for bed shear than for other variables because it incorporates the changes in depth and slope. A final point to emerge from this initial application is that the hydraulic geometry plots involve data which systematically depart from the simple power-law model.…”

Section: Applicationsmentioning

confidence: 97%

Simulation of flow geometry in a riffle‐pool stream

Richards

1978

Earth Surf. Process.

View full text Add to dashboard Cite

SUMMARYThe nature of the flow in most natural streams is gradually varied rather than uniform. This is particularly true of streams with coarse gravel bed material organized into relatively stable riffle and pool features. In spite of this, there are few applications of the gradually varied flow models (e.g. the Bernoulli equation) to such streams. This paper presents some initial results of a simulation of flow patterns in two riffle-pool reaches, using an open channel flow profile computation method based on an equation defining an energy balance between successive cross-sections separated by an incremental distance.

show abstract

“…A este fenômeno, Keller (1971) denominou reversão da velocidade. Teleki (1972) criticou esta denominação, afirmando que a reversão da veloci-dade implica mudança de sentido do fluxo. No en-tanto, o termo continua em uso.…”

Section: Soleiras E Depressões Definição E Origemunclassified

“…Clifford & Richards (1992) analisaram 12 trabalhos e constataram que em seis, os autores aceitam a reversão de uma ou mais características hidráulicas do fluxo tais como velocidade média, força de tração do fluxo ou potência do rio (Keller, 1971;Andrews, 1979;Lisle, 1979;Teisseyre, 1984;Ashworth, 1987;Petit, 1987;O'Connor et al, 1996;); três autores aceitam que a reversão hidráulica pode ser considerada como um ponto de partida para posteriores investigações (Richards, 1976;Jackson & Beschta, 1981;Carling, 1991) e os demais rejeitam categoricamente qualquer tipo de reversão (Teleki, 1972;Bathurst, 1982;Bhowmik & Demissie, 1982). Posteriormente, outros autores (Sear, 1996e Thompson et al, 1999, também constataram a ocorrência de reversão hidráulica.…”

Section: Soleiras E Depressões Definição E Origemunclassified

Seqüência de Soleiras e Depressões no Córrego Guavirá, Marechal Cândido Rondon, Região Oeste do Paraná.

Fernandez¹,

Sander²,

Rebelatto³

2002

Rev. Bras. Geomorfol.

View full text Add to dashboard Cite

RESUMOO trabalho descreve as características físicas e granulométricas de uma seqüência de soleiras e depressões identificadas no córrego Guavirá, município de Marechal Cândido Rondon, oeste do Estado do Paraná. As soleiras constituem porções elevadas do leito compostas por sedimentos grosseiros e as depressões superfícies rebaixadas capeadas por sedimentos mais finos. O trecho estudado possui 105 m e compreende um segmento retilíneo e sinuoso do córrego. O estudo consistiu no mapeamento do traçado das margens do canal fluvial e na obtenção da cota do leito e da lâmina d'água nas soleiras e depressões, mediante método de nivelamento taqueométrico. O levantamento foi realizado em dezembro de 1999, num período de estiagem. As observações mostraram a influencia do substrato e do gradiente do leito sobre a distribuição das soleiras e depressões e a variação das características granulométricas dos sedimentos de fundo. No segmento superior do trecho em estudo, onde o canal é retilíneo e o gradiente do leito mais acentuado, a separação média entre as feições é de 20 m e o material de fundo é representado por grânulos. No trecho inferior, sinuoso e com gradiente do leito menos acentuado, o espaçamento entre as soleiras e depressões diminui para 9 m e o material de fundo é composto por sedimentos tamanho areia grossa.Palavras chave: Morfologia fluvial, Sedimentologia; Soleira e depressão. ABSTRACTThe work describes the physical and sedimentological characteristics of a sequence of riffles and pools identified in the stream Guavirá, Marechal Cândido Rondon, west of the State of Paraná, Brazil. The riffles constitute high portions of the bed composed by coarse sediments and the pools lowered surfaces hidden by finer sediments. The studied was made along 105 m with straight and meandering segments. In December 1999 during a drought period, a survey of the planimetric and longitudinal form of the study reach was completed using standard level, leveling pole and compass. The observations show influences of the substratum and the bed gradient about the distribution of riffles and pools and sedimentological characteristic of the bottom sediments. In the upper segment of the study in study, where the channel is straight the gradient of the bed more accentuated, the medium separation among the features is of 20 m and the bottom sediment is represented by granules. In the low reach, sinuous and with gradient of the bed less accentuated, the spacing between the riffles and pools decreases to 9 m and the bottom material is composed by coarse sand.

show abstract

Areal Sorting of Bed-Load Material: The Hypothesis of Velocity Reversal: Discussion

Cited by 23 publications

References 0 publications

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

Simulation of flow geometry in a riffle‐pool stream

Seqüência de Soleiras e Depressões no Córrego Guavirá, Marechal Cândido Rondon, Região Oeste do Paraná.

Contact Info

Product

Resources

About