Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil

Detalhes bibliográficos
Autor(a) principal: Morais, Eduardo S. [UNESP]
Data de Publicação: 2016
Outros Autores: Rocha, Paulo C. [UNESP], Hooke, Janet
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://dx.doi.org/10.1016/j.geomorph.2016.07.026
http://hdl.handle.net/11449/162053
Resumo: Channel changes in meandering rivers naturally exhibit complex behaviour, and understanding the river dynamics can be challenging in environments also subject to cumulative human impacts. Planform changes were analysed on four reaches of the lower course of the Peixe River, Brazil, at decadal scales over the period 1962-2008 from aerial photographs and satellite imagery, complemented by a historical map from 1907. Analysis of the spatial and temporal patterns of channel change mechanisms and morphometry of bends and of the sinuosity and morphodynamic variations of the reaches demonstrates major changes in planform characteristics. Sinuosity in all reaches decreased from similar to 2.6 to similar to 1.7, average wavelength of bends has increased from similar to 200 to similar to 500 m, and the planform has become much simpler. Changes have been progressive from downstream to upstream, with higher intensities of processes, particularly cutoffs first in downstream reaches then more recently in upstream reaches. It is suggested that channel changes represent a morphological adjustment to human interventions, such as reservoir construction and land use. However, evidence of the autogenic behaviour of meanders is highlighted in which the existence of compound meanders reveals control over the spatial variation in the reaches. The results suggest that geomorphic thresholds associated with the compound meander formation and the bend evolution should be considered, even in impacted meandering rivers, because they exert primary controls on the spatial-temporal adjustment of channels. (C) 2016 Elsevier B.V. All rights reserved.
id UNSP_09d8eda8815dcd6cff8c526d0b7ba05f
oai_identifier_str oai:repositorio.unesp.br:11449/162053
network_acronym_str UNSP
network_name_str Repositório Institucional da UNESP
repository_id_str 2946
spelling Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, BrazilMeandering riverChannel changeCutoffCompound meanderFluvial adjustmentPeixe RiverChannel changes in meandering rivers naturally exhibit complex behaviour, and understanding the river dynamics can be challenging in environments also subject to cumulative human impacts. Planform changes were analysed on four reaches of the lower course of the Peixe River, Brazil, at decadal scales over the period 1962-2008 from aerial photographs and satellite imagery, complemented by a historical map from 1907. Analysis of the spatial and temporal patterns of channel change mechanisms and morphometry of bends and of the sinuosity and morphodynamic variations of the reaches demonstrates major changes in planform characteristics. Sinuosity in all reaches decreased from similar to 2.6 to similar to 1.7, average wavelength of bends has increased from similar to 200 to similar to 500 m, and the planform has become much simpler. Changes have been progressive from downstream to upstream, with higher intensities of processes, particularly cutoffs first in downstream reaches then more recently in upstream reaches. It is suggested that channel changes represent a morphological adjustment to human interventions, such as reservoir construction and land use. However, evidence of the autogenic behaviour of meanders is highlighted in which the existence of compound meanders reveals control over the spatial variation in the reaches. The results suggest that geomorphic thresholds associated with the compound meander formation and the bend evolution should be considered, even in impacted meandering rivers, because they exert primary controls on the spatial-temporal adjustment of channels. (C) 2016 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Estadual Paulista, Programa Posgrad Geog, Campus Presidente Prudente, Presidente Prudente, SP, BrazilUniv Liverpool, Sch Environm Sci, Dept Geog & Planning, Roxby Bldg, Liverpool L69 7ZT, Merseyside, EnglandUniv Estadual Paulista, Programa Posgrad Geog, Campus Presidente Prudente, Presidente Prudente, SP, BrazilFAPESP: 2011/11208-6FAPESP: 2012/00959-3Elsevier B.V.Universidade Estadual Paulista (Unesp)Univ LiverpoolMorais, Eduardo S. [UNESP]Rocha, Paulo C. [UNESP]Hooke, Janet2018-11-26T17:06:40Z2018-11-26T17:06:40Z2016-11-15info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article348-360application/pdfhttp://dx.doi.org/10.1016/j.geomorph.2016.07.026Geomorphology. Amsterdam: Elsevier Science Bv, v. 273, p. 348-360, 2016.0169-555Xhttp://hdl.handle.net/11449/16205310.1016/j.geomorph.2016.07.026WOS:000385323700027WOS000385323700027.pdfWeb of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengGeomorphologyinfo:eu-repo/semantics/openAccess2024-06-19T13:48:06Zoai:repositorio.unesp.br:11449/162053Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T17:35:45.168389Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
title Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
spellingShingle Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
Morais, Eduardo S. [UNESP]
Meandering river
Channel change
Cutoff
Compound meander
Fluvial adjustment
Peixe River
title_short Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
title_full Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
title_fullStr Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
title_full_unstemmed Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
title_sort Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
author Morais, Eduardo S. [UNESP]
author_facet Morais, Eduardo S. [UNESP]
Rocha, Paulo C. [UNESP]
Hooke, Janet
author_role author
author2 Rocha, Paulo C. [UNESP]
Hooke, Janet
author2_role author
author
dc.contributor.none.fl_str_mv Universidade Estadual Paulista (Unesp)
Univ Liverpool
dc.contributor.author.fl_str_mv Morais, Eduardo S. [UNESP]
Rocha, Paulo C. [UNESP]
Hooke, Janet
dc.subject.por.fl_str_mv Meandering river
Channel change
Cutoff
Compound meander
Fluvial adjustment
Peixe River
topic Meandering river
Channel change
Cutoff
Compound meander
Fluvial adjustment
Peixe River
description Channel changes in meandering rivers naturally exhibit complex behaviour, and understanding the river dynamics can be challenging in environments also subject to cumulative human impacts. Planform changes were analysed on four reaches of the lower course of the Peixe River, Brazil, at decadal scales over the period 1962-2008 from aerial photographs and satellite imagery, complemented by a historical map from 1907. Analysis of the spatial and temporal patterns of channel change mechanisms and morphometry of bends and of the sinuosity and morphodynamic variations of the reaches demonstrates major changes in planform characteristics. Sinuosity in all reaches decreased from similar to 2.6 to similar to 1.7, average wavelength of bends has increased from similar to 200 to similar to 500 m, and the planform has become much simpler. Changes have been progressive from downstream to upstream, with higher intensities of processes, particularly cutoffs first in downstream reaches then more recently in upstream reaches. It is suggested that channel changes represent a morphological adjustment to human interventions, such as reservoir construction and land use. However, evidence of the autogenic behaviour of meanders is highlighted in which the existence of compound meanders reveals control over the spatial variation in the reaches. The results suggest that geomorphic thresholds associated with the compound meander formation and the bend evolution should be considered, even in impacted meandering rivers, because they exert primary controls on the spatial-temporal adjustment of channels. (C) 2016 Elsevier B.V. All rights reserved.
publishDate 2016
dc.date.none.fl_str_mv 2016-11-15
2018-11-26T17:06:40Z
2018-11-26T17:06:40Z
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/10.1016/j.geomorph.2016.07.026
Geomorphology. Amsterdam: Elsevier Science Bv, v. 273, p. 348-360, 2016.
0169-555X
http://hdl.handle.net/11449/162053
10.1016/j.geomorph.2016.07.026
WOS:000385323700027
WOS000385323700027.pdf
url http://dx.doi.org/10.1016/j.geomorph.2016.07.026
http://hdl.handle.net/11449/162053
identifier_str_mv Geomorphology. Amsterdam: Elsevier Science Bv, v. 273, p. 348-360, 2016.
0169-555X
10.1016/j.geomorph.2016.07.026
WOS:000385323700027
WOS000385323700027.pdf
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Geomorphology
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 348-360
application/pdf
dc.publisher.none.fl_str_mv Elsevier B.V.
publisher.none.fl_str_mv Elsevier B.V.
dc.source.none.fl_str_mv Web of Science
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_ 1808128831276449792