The impact of channel capture on estuarine hydro-morphodynamics and water quality in the Amazon delta

The impact of channel capture on estuarine hydro-morphodynamics and water quality in the Amazon delta

•Natural diversion connected Araguari River to Amazon River in Eastern Amazon.•Up to 98% in flowrate reduction to lower estuary and flow direction inversion.•Flowrate reduction to estuary causes accelerated siltation process in river mouth.•Water quality changed downstream and not affected upstream...

Full description

Saved in:
Bibliographic Details
Published in:The Science of the total environment Vol. 624; pp. 887 - 899
Main Authors: Silva dos Santos, Eldo, Pinheiro Lopes, Paula Patrícia, da Silva Pereira, Hyrla Herondina, de Oliveira Nascimento, Otávio, Rennie, Colin David, da Silveira Lobo O'Reilly Sternberg, Leonel, Cavalcanti da Cunha, Alan
Format: Journal Article
Language:English
Published: Netherlands Elsevier B.V 15-05-2018
Subjects:
Araguari River
Channel capture
Estuarine morphodynamic
Landscape change
Water budget
Water quality
Water budget
Landscape change
Araguari River
Channel capture
Estuarine morphodynamic
Water quality
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Natural diversion connected Araguari River to Amazon River in Eastern Amazon.•Up to 98% in flowrate reduction to lower estuary and flow direction inversion.•Flowrate reduction to estuary causes accelerated siltation process in river mouth.•Water quality changed downstream and not affected upstream river diversion.•Future studies are necessary to evaluate impacts to water communities. [Display omitted] Due to progressive erosion of the new Urucurituba Channel, the Amazon River has recently captured almost all discharge from the lower Araguari River (Amapá-AP, Brazil), which previously flowed directly to the Atlantic Ocean. These recent geomorphological changes have caused strong impacts on the landscape and hydrodynamic patterns near the Araguari River mouth, especially the alteration of the riverine drainage system and its water quality. Landsat images were used to assess the estuarine landscape morphodynamic, particularly the expansion of the Urucurituba Channel, 80km from the Araguari River mouth, chronicling its connection to the Amazon River. The results suggest that the Urucurituba developed by headward migration across the Amazon delta; this is perhaps the first observation of estuarine distributary network development by headward channel erosion. The rate of Urucurituba Channel width increase has been ≈5m/month since 2011, increasing drainage capacity of the channel. We also collected in situ hydrodynamic measurements and analyzed 17 water quality parameters. Having 2011 as baseline, the flowrate of Araguari River has been diverted by up to 98% through Urucurituba Channel, with substantial changes in net discharge recorded at 3 monitoring stations. Statistically significant differences in water quality (p<0.05) were observed between 2011 and 2015, associated with the change in the flow pattern. Estuarine salinity and solids concentrations have increased. Overall, we demonstrate changes in landscape, hydrodynamics and water quality of the lower Araguari River.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0048-9697
1879-1026
DOI:10.1016/j.scitotenv.2017.12.211