Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/21428 |
Resumo: | The importance of monitoring phytoplankton communities and variables related to their constituents such as chlorophyll-a is undeniable due to its relation to the quality of the water. Even so, further improvements are necessary on the representativeness of the samples, aiming spatial and temporal pattern recognition of the given variables. Data and techniques of remote sensing have been mentioned as a viable alternative to supply this demand. In contrast, the remote estimation of phytoplankton chlorophyll-a concentration may still be seen as a challenge, mainly in bodies of water of case 2 classification, mostly due to the effects of different optically-active components on the sensing data, including the distinct phytoplankton organisms. For this purpose, algorithms were and currently are being developed. Among those, there are empirical models of a unique spectral band obtained in analysis of simple linear regression. However, this technique is only applicable when a single independent variable affects the dependent variable, which does not occur in bodies of water case 2 classification. Within this context, the general objective of the present work was to verify the adequacy of empirical models developed by simple linear regression to estimate phytoplankton chlorophyll-a from reflectance data in a unique spectral band and to demonstrate that phytoplankton organisms can be considered distinct optically-active components in the water. In order to meet this objective, phytoplankton organisms classified as Cyanophyceae, Euglenophyceae and Chlorophyceae were isolated and cultivated; samples of inorganic sediments were processed and geometries of illumination and acquisition of radiometry data were determined and controlled to perform this experiment in laboratory level, which consisted basically of water reflectance measurements in a tank, in distinct treatments related to the optically-active components present on it. The correlation analysis, simple linear regression and mean squared error, showed that the empirical models of a unique spectral band, developed by simple linear regression, may miscount the concentration of chlorophyll-a even when the water contains only phytoplankton, as the phytoplankton organisms cultivated have promoted distinct and reverse reflectance variation in relation to chlorophyll-a concentration variation and they may be considered distinct optically-active components in the water. In the presence of inorganic suspended solids the estimation errors may be even larger, as additive effects of this component on the reflectance of water variations are not subtracted by the model, but rather considered as being caused by chlorophyll-a. Therefore, the empirical models developed by simple linear regression from reflectance data of a single spectral band are inappropriate for estimating chlorophyll-a phytoplankton in bodies of water, as there is no single wavelength in the visible and infrared regions next to the electromagnetic spectrum that is affected only by the independent variable chlorophyll-a, even when there are only phytoplankton in the water. |
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Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônicaEffects of different optically-active components on the reflectance of water to the remote estimation of phytoplankton chlorophyll-aReflectânciaFitoplânctonEstimativa remota da clorofila-aReflectancePhytoplanktonRemote estimation of chlorophyll-aCNPQ::CIENCIAS HUMANAS::GEOGRAFIAThe importance of monitoring phytoplankton communities and variables related to their constituents such as chlorophyll-a is undeniable due to its relation to the quality of the water. Even so, further improvements are necessary on the representativeness of the samples, aiming spatial and temporal pattern recognition of the given variables. Data and techniques of remote sensing have been mentioned as a viable alternative to supply this demand. In contrast, the remote estimation of phytoplankton chlorophyll-a concentration may still be seen as a challenge, mainly in bodies of water of case 2 classification, mostly due to the effects of different optically-active components on the sensing data, including the distinct phytoplankton organisms. For this purpose, algorithms were and currently are being developed. Among those, there are empirical models of a unique spectral band obtained in analysis of simple linear regression. However, this technique is only applicable when a single independent variable affects the dependent variable, which does not occur in bodies of water case 2 classification. Within this context, the general objective of the present work was to verify the adequacy of empirical models developed by simple linear regression to estimate phytoplankton chlorophyll-a from reflectance data in a unique spectral band and to demonstrate that phytoplankton organisms can be considered distinct optically-active components in the water. In order to meet this objective, phytoplankton organisms classified as Cyanophyceae, Euglenophyceae and Chlorophyceae were isolated and cultivated; samples of inorganic sediments were processed and geometries of illumination and acquisition of radiometry data were determined and controlled to perform this experiment in laboratory level, which consisted basically of water reflectance measurements in a tank, in distinct treatments related to the optically-active components present on it. The correlation analysis, simple linear regression and mean squared error, showed that the empirical models of a unique spectral band, developed by simple linear regression, may miscount the concentration of chlorophyll-a even when the water contains only phytoplankton, as the phytoplankton organisms cultivated have promoted distinct and reverse reflectance variation in relation to chlorophyll-a concentration variation and they may be considered distinct optically-active components in the water. In the presence of inorganic suspended solids the estimation errors may be even larger, as additive effects of this component on the reflectance of water variations are not subtracted by the model, but rather considered as being caused by chlorophyll-a. Therefore, the empirical models developed by simple linear regression from reflectance data of a single spectral band are inappropriate for estimating chlorophyll-a phytoplankton in bodies of water, as there is no single wavelength in the visible and infrared regions next to the electromagnetic spectrum that is affected only by the independent variable chlorophyll-a, even when there are only phytoplankton in the water.A importância do monitoramento da comunidade fitoplanctônica e de variáveis relacionadas aos seus organismos constituintes, como a clorofila-a, é indubitável, devido às sua relação com a qualidade das águas, mas, ainda são necessários avanços acerca da representatividade das amostras, visando o reconhecimento de padrões espaciais e temporais da referida variável. Dados e técnicas de sensoriamento remoto têm sido referenciados como uma alternativa viável para suprir esta demanda. Por outro lado, a estimativa remota das concentrações de clorofila-a fitoplanctônica ainda pode ser vista como um desafio, principalmente em corpos de água do caso dois, em grande parte devido aos efeitos dos diferentes componentes opticamente ativos sobre os dados de sensoriamento remoto, inclusive dos distintos organismos fitoplanctônicos. Algoritmos foram e estão sendo desenvolvidos para este propósito, dentre eles os modelos empíricos de uma única banda espectral obtidos em análises de regressão simples, apesar de esta técnica ser aplicável somente quando uma única variável independente afeta a variável dependente, o que não ocorre em corpos de água do caso dois. Neste contexto, o objetivo geral do presente trabalho foi verificar a adequabilidade de modelos empíricos desenvolvidos por regressão simples para estimar a clorofila-a fitoplanctônica a partir de dados de reflectância de uma única banda espectral e demonstrar que organismos fitoplanctônicos podem ser considerados distintos componentes opticamente ativos das águas. Para cumprir com o referido objetivo, organismos fitoplanctônicos classificados como Cyanophyceae, Euglenophyceae e Chlorophyceae foram isolados e cultivados, amostras de sedimentos inorgânicos foram processadas e geometrias de iluminação e de aquisição dos dados radiométricos foram determinadas e controladas para a realização de um experimento em nível laboratorial, que constou basicamente de medições da reflectância da água de um tanque, em distintos tratamentos relacionados aos componentes opticamente ativos presentes na mesma. As análises de correlação, regressão simples e o erro quadrático médio, mostraram que os modelos empíricos de uma única banda espectral, desenvolvidos por regressão simples, podem estimar erroneamente as concentrações de clorofila-a, mesmo que na água contiver apenas fitoplâncton, porque os organismos fitoplanctônicos cultivados promoveram variações distintas e inversas da reflectância em função das variações nas concentrações de clorofila-a e podem ser considerados distintos componentes opticamente ativos das águas. Na presença de sólidos suspensos inorgânicos os erros de estimativa podem ser ainda maiores, porque os efeitos aditivos desse componente sobre a variação da reflectância da água, não são subtraídos pelo modelo, mas sim considerados como sendo ocasionados por clorofila-a. Portanto, os modelos empíricos desenvolvidos por regressão simples a partir de dados de reflectância de uma única banda espectral são inadequados para estimar clorofila-a fitoplanctônica em corpos de água, mesmo porque, não há um único comprimento de onda das regiões de visível e infravermelho próximo do espectro eletromagnético que seja afetado somente pela variável independente clorofila-a, mesmo que na água contiver apenas fitoplâncton.Universidade Federal de Santa MariaBrasilGeografiaUFSMPrograma de Pós-Graduação em GeografiaCentro de Ciências Naturais e ExatasCassol, Robertohttp://lattes.cnpq.br/0745996287597257Benedetti, Ana Caroline PaimSpinelli, JuçaraLinton, Maria Angelica OliveiraCruz, Rafael CabralGross, Joceli Augusto2021-07-14T20:05:03Z2021-07-14T20:05:03Z2019-08-30info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfhttp://repositorio.ufsm.br/handle/1/21428porAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2021-07-15T06:03:33Zoai:repositorio.ufsm.br:1/21428Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2021-07-15T06:03:33Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica Effects of different optically-active components on the reflectance of water to the remote estimation of phytoplankton chlorophyll-a |
title |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica |
spellingShingle |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica Gross, Joceli Augusto Reflectância Fitoplâncton Estimativa remota da clorofila-a Reflectance Phytoplankton Remote estimation of chlorophyll-a CNPQ::CIENCIAS HUMANAS::GEOGRAFIA |
title_short |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica |
title_full |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica |
title_fullStr |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica |
title_full_unstemmed |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica |
title_sort |
Efeitos de diferentes componentes opticamente ativos na reflectância da água para a estimativa remota das concentrações de clorofila-a fitoplanctônica |
author |
Gross, Joceli Augusto |
author_facet |
Gross, Joceli Augusto |
author_role |
author |
dc.contributor.none.fl_str_mv |
Cassol, Roberto http://lattes.cnpq.br/0745996287597257 Benedetti, Ana Caroline Paim Spinelli, Juçara Linton, Maria Angelica Oliveira Cruz, Rafael Cabral |
dc.contributor.author.fl_str_mv |
Gross, Joceli Augusto |
dc.subject.por.fl_str_mv |
Reflectância Fitoplâncton Estimativa remota da clorofila-a Reflectance Phytoplankton Remote estimation of chlorophyll-a CNPQ::CIENCIAS HUMANAS::GEOGRAFIA |
topic |
Reflectância Fitoplâncton Estimativa remota da clorofila-a Reflectance Phytoplankton Remote estimation of chlorophyll-a CNPQ::CIENCIAS HUMANAS::GEOGRAFIA |
description |
The importance of monitoring phytoplankton communities and variables related to their constituents such as chlorophyll-a is undeniable due to its relation to the quality of the water. Even so, further improvements are necessary on the representativeness of the samples, aiming spatial and temporal pattern recognition of the given variables. Data and techniques of remote sensing have been mentioned as a viable alternative to supply this demand. In contrast, the remote estimation of phytoplankton chlorophyll-a concentration may still be seen as a challenge, mainly in bodies of water of case 2 classification, mostly due to the effects of different optically-active components on the sensing data, including the distinct phytoplankton organisms. For this purpose, algorithms were and currently are being developed. Among those, there are empirical models of a unique spectral band obtained in analysis of simple linear regression. However, this technique is only applicable when a single independent variable affects the dependent variable, which does not occur in bodies of water case 2 classification. Within this context, the general objective of the present work was to verify the adequacy of empirical models developed by simple linear regression to estimate phytoplankton chlorophyll-a from reflectance data in a unique spectral band and to demonstrate that phytoplankton organisms can be considered distinct optically-active components in the water. In order to meet this objective, phytoplankton organisms classified as Cyanophyceae, Euglenophyceae and Chlorophyceae were isolated and cultivated; samples of inorganic sediments were processed and geometries of illumination and acquisition of radiometry data were determined and controlled to perform this experiment in laboratory level, which consisted basically of water reflectance measurements in a tank, in distinct treatments related to the optically-active components present on it. The correlation analysis, simple linear regression and mean squared error, showed that the empirical models of a unique spectral band, developed by simple linear regression, may miscount the concentration of chlorophyll-a even when the water contains only phytoplankton, as the phytoplankton organisms cultivated have promoted distinct and reverse reflectance variation in relation to chlorophyll-a concentration variation and they may be considered distinct optically-active components in the water. In the presence of inorganic suspended solids the estimation errors may be even larger, as additive effects of this component on the reflectance of water variations are not subtracted by the model, but rather considered as being caused by chlorophyll-a. Therefore, the empirical models developed by simple linear regression from reflectance data of a single spectral band are inappropriate for estimating chlorophyll-a phytoplankton in bodies of water, as there is no single wavelength in the visible and infrared regions next to the electromagnetic spectrum that is affected only by the independent variable chlorophyll-a, even when there are only phytoplankton in the water. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-08-30 2021-07-14T20:05:03Z 2021-07-14T20:05:03Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufsm.br/handle/1/21428 |
url |
http://repositorio.ufsm.br/handle/1/21428 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Geografia UFSM Programa de Pós-Graduação em Geografia Centro de Ciências Naturais e Exatas |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Geografia UFSM Programa de Pós-Graduação em Geografia Centro de Ciências Naturais e Exatas |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
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1805922143286853632 |