Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery
This paper deals with the application of satellite images to study turbidity and water circulation patterns in San Blas channel during a theoretical tidal cycle. Eight Landsat TM and ETM images acquired under clear-sky conditions and representing different tidal stages were selected from a pool of L...
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| Format: | Article |
| Language: | English |
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Universidade de São Paulo
2011-09-01
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| Series: | Brazilian Journal of Oceanography |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592011000300004 |
| _version_ | 1819038447811166208 |
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| author | Débora Beigt Diana G. Cuadrado María C. Piccolo |
| author_facet | Débora Beigt Diana G. Cuadrado María C. Piccolo |
| author_sort | Débora Beigt |
| collection | DOAJ |
| description | This paper deals with the application of satellite images to study turbidity and water circulation patterns in San Blas channel during a theoretical tidal cycle. Eight Landsat TM and ETM images acquired under clear-sky conditions and representing different tidal stages were selected from a pool of Landsat images provided by the argentinean National Commission of Space Activities (CONAE) and the US Geological Survey. Standard digital image processing techniques were used to perform geometric and radiometric corrections on the visible and near-infrared bands. An image-based atmospheric correction (COST method by CHAVEZ, 1996) was applied. An ISODATA unsupervised classification was performed in order to identify different turbidity levels throughout the channel and adjacent areas. The results suggest that suspended sediment transport towards the channel mouth by ebb currents occurs along both flanks. These currents carry suspended sediment into the open sea, generating an ebb tidal delta which tends to rotate in a clockwise direction. Flood currents trigger turbidity mostly over the southern flank of the channel, generating a flood tidal delta with elongated banks extending in the direction of the tidal currents. From the elongated shape of the turbidity plumes, general tidal circulation patterns were identified.<br>Este trabalho analisa a turbidez e a circulação da agua no canal San Blas durante um ciclo de maré teórico através de imagens satelitais. Foram utilizadas 8 imagens Landsat TM e ETM adquiridas em condições de céu claro e ao longo de diferentes momentos da maré. As imagens foram proporcionadas pela Comisión Nacional de Actividades Espaciales (CONAE) y pelo Serviço Geológico dos Estados Unidos (USGS). As correções geométricas e radiométricas foram realizadas nas bandas do espectro visível e do infravermelho próximo, utilizando técnicas padrões de processamento digital. Foi aplicada a correção atmosférica COST (CHAVEZ, 1996). Foi realizada uma classificação ISODATA não supervisionada para identificar diferentes níveis de turbidez al longo do canal e zonas adjacentes. Os resultados sugerem que o transporte de sedimento em suspensão para a boca do canal se da ao longo de ambos flancos, pela ação das correntes de refluxo. Estas correntes geram um delta de refluxo com uma tendência de rotação para a direção sul. As correntes de fluxo provocam turbidez principalmente sobre a costa sul do canal, gerando um delta de fluxo com bancos alargados na direção das correntes de maré. As plumas de turbidez permitiram identificar padrões gerais de circulação da maré. |
| first_indexed | 2024-12-21T08:37:28Z |
| format | Article |
| id | doaj.art-89e8f33c33bc4df8ae5ebce8eb2042b7 |
| institution | Directory Open Access Journal |
| issn | 1679-8759 1982-436X |
| language | English |
| last_indexed | 2024-12-21T08:37:28Z |
| publishDate | 2011-09-01 |
| publisher | Universidade de São Paulo |
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| series | Brazilian Journal of Oceanography |
| spelling | doaj.art-89e8f33c33bc4df8ae5ebce8eb2042b72022-12-21T19:10:01ZengUniversidade de São PauloBrazilian Journal of Oceanography1679-87591982-436X2011-09-0159324125210.1590/S1679-87592011000300004Study of the surface water circulation in San Blas channel (Argentina) using landsat imageryDébora BeigtDiana G. CuadradoMaría C. PiccoloThis paper deals with the application of satellite images to study turbidity and water circulation patterns in San Blas channel during a theoretical tidal cycle. Eight Landsat TM and ETM images acquired under clear-sky conditions and representing different tidal stages were selected from a pool of Landsat images provided by the argentinean National Commission of Space Activities (CONAE) and the US Geological Survey. Standard digital image processing techniques were used to perform geometric and radiometric corrections on the visible and near-infrared bands. An image-based atmospheric correction (COST method by CHAVEZ, 1996) was applied. An ISODATA unsupervised classification was performed in order to identify different turbidity levels throughout the channel and adjacent areas. The results suggest that suspended sediment transport towards the channel mouth by ebb currents occurs along both flanks. These currents carry suspended sediment into the open sea, generating an ebb tidal delta which tends to rotate in a clockwise direction. Flood currents trigger turbidity mostly over the southern flank of the channel, generating a flood tidal delta with elongated banks extending in the direction of the tidal currents. From the elongated shape of the turbidity plumes, general tidal circulation patterns were identified.<br>Este trabalho analisa a turbidez e a circulação da agua no canal San Blas durante um ciclo de maré teórico através de imagens satelitais. Foram utilizadas 8 imagens Landsat TM e ETM adquiridas em condições de céu claro e ao longo de diferentes momentos da maré. As imagens foram proporcionadas pela Comisión Nacional de Actividades Espaciales (CONAE) y pelo Serviço Geológico dos Estados Unidos (USGS). As correções geométricas e radiométricas foram realizadas nas bandas do espectro visível e do infravermelho próximo, utilizando técnicas padrões de processamento digital. Foi aplicada a correção atmosférica COST (CHAVEZ, 1996). Foi realizada uma classificação ISODATA não supervisionada para identificar diferentes níveis de turbidez al longo do canal e zonas adjacentes. Os resultados sugerem que o transporte de sedimento em suspensão para a boca do canal se da ao longo de ambos flancos, pela ação das correntes de refluxo. Estas correntes geram um delta de refluxo com uma tendência de rotação para a direção sul. As correntes de fluxo provocam turbidez principalmente sobre a costa sul do canal, gerando um delta de fluxo com bancos alargados na direção das correntes de maré. As plumas de turbidez permitiram identificar padrões gerais de circulação da maré.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592011000300004TurbidezCirculação da águaImagens LandsatCanal San BlasTurbidityWater circulationLandsat imagerySan Blas channel |
| spellingShingle | Débora Beigt Diana G. Cuadrado María C. Piccolo Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery Brazilian Journal of Oceanography Turbidez Circulação da água Imagens Landsat Canal San Blas Turbidity Water circulation Landsat imagery San Blas channel |
| title | Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery |
| title_full | Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery |
| title_fullStr | Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery |
| title_full_unstemmed | Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery |
| title_short | Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery |
| title_sort | study of the surface water circulation in san blas channel argentina using landsat imagery |
| topic | Turbidez Circulação da água Imagens Landsat Canal San Blas Turbidity Water circulation Landsat imagery San Blas channel |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592011000300004 |
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