Por que grandes rios tendem à canalização múltipla? Um estudo de campo no rio Paraná Superior
| Autor: | Priscila Panzarini Gon, Isabel Terezinha Leli, Rafaela Harumi Fujita, José Cândido Stevaux |
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| Přispěvatelé: | 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) |
| Rok vydání: | 2021 |
| Předmět: |
QE1-996.5
Maximum efficiency concept Paraná River padrão multicanal padrão anastomosado potência de fluxo específica rio paraná conceito de eficiência máxima de fluxo Fluvial Geology Alluvial plain Tectonics Anabranching river Large river Specific stream power Bathymetry Alluvium Geomorphology Stream power Earth-Surface Processes Bed load Communication channel |
| Zdroj: | Scopus Repositório Institucional da UNESP Universidade Estadual Paulista (UNESP) instacron:UNESP Revista Brasileira de Geomorfologia, Vol 22, Iss 4 (2021) |
| ISSN: | 2236-5664 1519-1540 |
| DOI: | 10.20502/rbg.v22i4.2014 |
| Popis: | Made available in DSpace on 2022-04-28T19:40:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Centro de Estudos Ambientais e Marinhos, Universidade de Aveiro Centro Nacional de Pesquisa em Energia e Materiais Boise State University 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. Graduate Program in Geography Universidade Federal do Mato Grosso do Sul Campus de Três Lagoas, MS Graduate Program in Geoscience and Environment UNESP IGCE, SP Graduate Program in Geography Western State of Paraná UNIOESTE/Marechal Cândido Rondon, PR Graduate Program in Geography of the State University of Western Paraná (UNIOESTE), Francisco Beltrão, R Graduate Program in Geoscience and Environment UNESP IGCE, SP |
| Databáze: | OpenAIRE |
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