Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variations
The present work describes spatial and seasonal variability in grain-size, pH and elemental characteristics (TOC, TIC, TN and C/N) in superficial sediments, as well as salinity, temperature and oxygen in the water, within the intertidal range of the Guadiana Estuary, SW Iberian Peninsula, during the year 2010. The results indicate that environmental parameters in the estuary are strongly dependent on spatial patterns, which reflect seasonal oscillations in freshwater discharge. The sediment is generally poorly sorted, with a symmetrical to very finely skewed distribution, in accordance with the low-energy conditions typical of the deposition areas. During winter, heavy rains forced the continuous discharge of Europes largest reservoir, the Alqueva dam, creating exceptional hydrodynamic conditions and causing coarser sediment deposition in the estuary. High marsh areas are controlled by flood tides, promoting vertical accretion of muddy sediments, especially silts. The lower areas of the saltmarsh and-mud flat areas are controlled by the ebb, with more efficient export of fines toward the platform and retention of sands, sometimes with significant amounts of bioclasts. In winter (average Q = 654 m³s-1), salinity remained low throughout the estuary with the highest values (< 3) recorded up to 3 km inland from the river mouth, except in the most confined environments subject to greater evaporation. In summer (average Q = 52 m³s-1), the estuarine waters are better mixed and significant saltwater intrusion extends approximately 8 km inland. The seasonal variation in surface water temperature was very high, with a difference of ca 14 ° C in the maximum temperature recorded in winter and summer.
Main Authors: | , , , , |
---|---|
Format: | Digital revista |
Language: | English |
Published: |
Associação Portuguesa dos Recursos Hídricos
2014
|
Online Access: | http://scielo.pt/scielo.php?script=sci_arttext&pid=S1646-88722014000100011 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
id |
oai:scielo:S1646-88722014000100011 |
---|---|
record_format |
ojs |
spelling |
oai:scielo:S1646-887220140001000112014-07-21Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variationsCamacho,SaritaMoura,DelmindaConnor,SimonBoski,TomaszGomes,Ana Guadiana Estuary saltmarsh sediments; granulometry organic matter pH physico-chemical proprieties The present work describes spatial and seasonal variability in grain-size, pH and elemental characteristics (TOC, TIC, TN and C/N) in superficial sediments, as well as salinity, temperature and oxygen in the water, within the intertidal range of the Guadiana Estuary, SW Iberian Peninsula, during the year 2010. The results indicate that environmental parameters in the estuary are strongly dependent on spatial patterns, which reflect seasonal oscillations in freshwater discharge. The sediment is generally poorly sorted, with a symmetrical to very finely skewed distribution, in accordance with the low-energy conditions typical of the deposition areas. During winter, heavy rains forced the continuous discharge of Europes largest reservoir, the Alqueva dam, creating exceptional hydrodynamic conditions and causing coarser sediment deposition in the estuary. High marsh areas are controlled by flood tides, promoting vertical accretion of muddy sediments, especially silts. The lower areas of the saltmarsh and-mud flat areas are controlled by the ebb, with more efficient export of fines toward the platform and retention of sands, sometimes with significant amounts of bioclasts. In winter (average Q = 654 m³s-1), salinity remained low throughout the estuary with the highest values (< 3) recorded up to 3 km inland from the river mouth, except in the most confined environments subject to greater evaporation. In summer (average Q = 52 m³s-1), the estuarine waters are better mixed and significant saltwater intrusion extends approximately 8 km inland. The seasonal variation in surface water temperature was very high, with a difference of ca 14 ° C in the maximum temperature recorded in winter and summer.info:eu-repo/semantics/openAccessAssociação Portuguesa dos Recursos HídricosRevista de Gestão Costeira Integrada v.14 n.1 20142014-03-01info:eu-repo/semantics/articletext/htmlhttp://scielo.pt/scielo.php?script=sci_arttext&pid=S1646-88722014000100011en10.5894/rgci452 |
institution |
SCIELO |
collection |
OJS |
country |
Portugal |
countrycode |
PT |
component |
Revista |
access |
En linea |
databasecode |
rev-scielo-pt |
tag |
revista |
region |
Europa del Sur |
libraryname |
SciELO |
language |
English |
format |
Digital |
author |
Camacho,Sarita Moura,Delminda Connor,Simon Boski,Tomasz Gomes,Ana |
spellingShingle |
Camacho,Sarita Moura,Delminda Connor,Simon Boski,Tomasz Gomes,Ana Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variations |
author_facet |
Camacho,Sarita Moura,Delminda Connor,Simon Boski,Tomasz Gomes,Ana |
author_sort |
Camacho,Sarita |
title |
Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variations |
title_short |
Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variations |
title_full |
Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variations |
title_fullStr |
Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variations |
title_full_unstemmed |
Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variations |
title_sort |
geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the guadiana, southeast portugal): spatial and seasonal variations |
description |
The present work describes spatial and seasonal variability in grain-size, pH and elemental characteristics (TOC, TIC, TN and C/N) in superficial sediments, as well as salinity, temperature and oxygen in the water, within the intertidal range of the Guadiana Estuary, SW Iberian Peninsula, during the year 2010. The results indicate that environmental parameters in the estuary are strongly dependent on spatial patterns, which reflect seasonal oscillations in freshwater discharge. The sediment is generally poorly sorted, with a symmetrical to very finely skewed distribution, in accordance with the low-energy conditions typical of the deposition areas. During winter, heavy rains forced the continuous discharge of Europes largest reservoir, the Alqueva dam, creating exceptional hydrodynamic conditions and causing coarser sediment deposition in the estuary. High marsh areas are controlled by flood tides, promoting vertical accretion of muddy sediments, especially silts. The lower areas of the saltmarsh and-mud flat areas are controlled by the ebb, with more efficient export of fines toward the platform and retention of sands, sometimes with significant amounts of bioclasts. In winter (average Q = 654 m³s-1), salinity remained low throughout the estuary with the highest values (< 3) recorded up to 3 km inland from the river mouth, except in the most confined environments subject to greater evaporation. In summer (average Q = 52 m³s-1), the estuarine waters are better mixed and significant saltwater intrusion extends approximately 8 km inland. The seasonal variation in surface water temperature was very high, with a difference of ca 14 ° C in the maximum temperature recorded in winter and summer. |
publisher |
Associação Portuguesa dos Recursos Hídricos |
publishDate |
2014 |
url |
http://scielo.pt/scielo.php?script=sci_arttext&pid=S1646-88722014000100011 |
work_keys_str_mv |
AT camachosarita geochemicalcharacteristicsofsedimentsalongthemarginsofanatlanticmediterraneanestuarytheguadianasoutheastportugalspatialandseasonalvariations AT mouradelminda geochemicalcharacteristicsofsedimentsalongthemarginsofanatlanticmediterraneanestuarytheguadianasoutheastportugalspatialandseasonalvariations AT connorsimon geochemicalcharacteristicsofsedimentsalongthemarginsofanatlanticmediterraneanestuarytheguadianasoutheastportugalspatialandseasonalvariations AT boskitomasz geochemicalcharacteristicsofsedimentsalongthemarginsofanatlanticmediterraneanestuarytheguadianasoutheastportugalspatialandseasonalvariations AT gomesana geochemicalcharacteristicsofsedimentsalongthemarginsofanatlanticmediterraneanestuarytheguadianasoutheastportugalspatialandseasonalvariations |
_version_ |
1756003416026382336 |