Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil
Autor(a) principal: | |
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Data de Publicação: | 2016 |
Outros Autores: | , |
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. |
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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 |