Equivalent roughness of gravel-bed rivers

The relation between the equivalent roughness and different grain size percentiles of the sediment in gravel-bed rivers was determined under the hypothesis that the vertical distribution of the flow velocity follows a logarithmic law. A set of 954 data points was selected from rivers with gravel siz...

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Detalhes bibliográficos
Autores: López Alonso, Raúl, Barragán Fernández, Javier
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2008
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositório:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10459.1/47025
Acesso em linha:https://doi.org/10.1061/(ASCE)0733-9429(2008)134:6(847)
http://hdl.handle.net/10459.1/47025
Access Level:Acceso aberto
Palavra-chave:Bed roughness
Flow resistance
Gravel
Mountain streams
Fluvial hydraulics
Rius -- Hidràulica
Enginyeria hidràulica
Descrição
Resumo:The relation between the equivalent roughness and different grain size percentiles of the sediment in gravel-bed rivers was determined under the hypothesis that the vertical distribution of the flow velocity follows a logarithmic law. A set of 954 data points was selected from rivers with gravel size sediment or larger, with a non-sinuous alignment and free of vegetation or obstacles. According to the results, the ks roughness is equivalent to approximately 2.4D90, 2.8D84, and 6.1D50. No correlation was detected between the sediment sorting and the sediment mobility index on one hand, and, on the other, the coefficient of proportionality of each grain size percentile.