Why do large rivers tend to form multichannel? A field study in the Upper Paraná River
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.20502/RBG.V22I4.2014 http://hdl.handle.net/11449/221854 |
Resumo: | Anastomosed rivers include a diverse group of fluvial forms with multiple and interconnected alluvial channels. They occur in a wide range of climates and reliefs and constitute the typical pattern of the mega rivers (Qm > 17,000 m3 s-1). Several authors have assumed that the development of an anabranching formation is the mechanism by which a channel maintains its maximum efficiency. However, this has only been tested by mathematical studies. In this study, we confirm this theory in a 58-km anabranching reach of the Upper Paraná River, through a hydraulic and bathymetric survey of 14 cross-sections. We conclude that where the slope can't increase, the channel reduces its w:d ratio, thereby maintaining its efficiency in the wider sections, according to the specific stream power equation (ω = ρgQs/w). The channel width and alluvial plain width are controlled by allochthonous factors (tectonic lineaments and bank composition). Although the nodal sections have the greatest efficiency, we confirmed that flow efficiency is maintained at a constant level of bedload transport and specific stream power along the anabranching reach. |
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Why do large rivers tend to form multichannel? A field study in the Upper Paraná RiverPor que grandes rios tendem à canalização múltipla? Um estudo de campo no rio Paraná SuperiorAnabranching riverLarge riverMaximum efficiency conceptParaná RiverSpecific stream powerAnastomosed rivers include a diverse group of fluvial forms with multiple and interconnected alluvial channels. They occur in a wide range of climates and reliefs and constitute the typical pattern of the mega rivers (Qm > 17,000 m3 s-1). Several authors have assumed that the development of an anabranching formation is the mechanism by which a channel maintains its maximum efficiency. However, this has only been tested by mathematical studies. In this study, we confirm this theory in a 58-km anabranching reach of the Upper Paraná River, through a hydraulic and bathymetric survey of 14 cross-sections. We conclude that where the slope can't increase, the channel reduces its w:d ratio, thereby maintaining its efficiency in the wider sections, according to the specific stream power equation (ω = ρgQs/w). The channel width and alluvial plain width are controlled by allochthonous factors (tectonic lineaments and bank composition). Although the nodal sections have the greatest efficiency, we confirmed that flow efficiency is maintained at a constant level of bedload transport and specific stream power along the anabranching reach.Centro de Estudos Ambientais e Marinhos, Universidade de AveiroCentro Nacional de Pesquisa em Energia e MateriaisBoise State UniversityGraduate Program in Geography Universidade Federal do Mato Grosso do Sul Campus de Três Lagoas, MSGraduate Program in Geoscience and Environment UNESP IGCE, SPGraduate Program in Geography Western State of Paraná UNIOESTE/Marechal Cândido Rondon, PRGraduate Program in Geography of the State University of Western Paraná (UNIOESTE), Francisco Beltrão, RGraduate Program in Geoscience and Environment UNESP IGCE, SPUniversidade Federal do Mato Grosso do SulUniversidade Estadual Paulista (UNESP)UNIOESTE/Marechal Cândido RondonGraduate Program in Geography of the State University of Western Paraná (UNIOESTE)Stevaux, José C.Gon, Priscila P. [UNESP]Leli, Isabel T.Fujita, Rafaela H.2022-04-28T19:40:57Z2022-04-28T19:40:57Z2021-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article967-985http://dx.doi.org/10.20502/RBG.V22I4.2014Revista Brasileira de Geomorfologia, v. 22, n. 4, p. 967-985, 2021.2236-56641519-1540http://hdl.handle.net/11449/22185410.20502/RBG.V22I4.20142-s2.0-85108827320Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengRevista Brasileira de Geomorfologiainfo:eu-repo/semantics/openAccess2022-04-28T19:40:57Zoai:repositorio.unesp.br:11449/221854Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462022-04-28T19:40:57Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River Por que grandes rios tendem à canalização múltipla? Um estudo de campo no rio Paraná Superior |
title |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River |
spellingShingle |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River Stevaux, José C. Anabranching river Large river Maximum efficiency concept Paraná River Specific stream power |
title_short |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River |
title_full |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River |
title_fullStr |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River |
title_full_unstemmed |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River |
title_sort |
Why do large rivers tend to form multichannel? A field study in the Upper Paraná River |
author |
Stevaux, José C. |
author_facet |
Stevaux, José C. Gon, Priscila P. [UNESP] Leli, Isabel T. Fujita, Rafaela H. |
author_role |
author |
author2 |
Gon, Priscila P. [UNESP] Leli, Isabel T. Fujita, Rafaela H. |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade Federal do Mato Grosso do Sul Universidade Estadual Paulista (UNESP) UNIOESTE/Marechal Cândido Rondon Graduate Program in Geography of the State University of Western Paraná (UNIOESTE) |
dc.contributor.author.fl_str_mv |
Stevaux, José C. Gon, Priscila P. [UNESP] Leli, Isabel T. Fujita, Rafaela H. |
dc.subject.por.fl_str_mv |
Anabranching river Large river Maximum efficiency concept Paraná River Specific stream power |
topic |
Anabranching river Large river Maximum efficiency concept Paraná River Specific stream power |
description |
Anastomosed rivers include a diverse group of fluvial forms with multiple and interconnected alluvial channels. They occur in a wide range of climates and reliefs and constitute the typical pattern of the mega rivers (Qm > 17,000 m3 s-1). Several authors have assumed that the development of an anabranching formation is the mechanism by which a channel maintains its maximum efficiency. However, this has only been tested by mathematical studies. In this study, we confirm this theory in a 58-km anabranching reach of the Upper Paraná River, through a hydraulic and bathymetric survey of 14 cross-sections. We conclude that where the slope can't increase, the channel reduces its w:d ratio, thereby maintaining its efficiency in the wider sections, according to the specific stream power equation (ω = ρgQs/w). The channel width and alluvial plain width are controlled by allochthonous factors (tectonic lineaments and bank composition). Although the nodal sections have the greatest efficiency, we confirmed that flow efficiency is maintained at a constant level of bedload transport and specific stream power along the anabranching reach. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-01-01 2022-04-28T19:40:57Z 2022-04-28T19:40:57Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.20502/RBG.V22I4.2014 Revista Brasileira de Geomorfologia, v. 22, n. 4, p. 967-985, 2021. 2236-5664 1519-1540 http://hdl.handle.net/11449/221854 10.20502/RBG.V22I4.2014 2-s2.0-85108827320 |
url |
http://dx.doi.org/10.20502/RBG.V22I4.2014 http://hdl.handle.net/11449/221854 |
identifier_str_mv |
Revista Brasileira de Geomorfologia, v. 22, n. 4, p. 967-985, 2021. 2236-5664 1519-1540 10.20502/RBG.V22I4.2014 2-s2.0-85108827320 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Revista Brasileira de Geomorfologia |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
967-985 |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1803046482619662336 |