algorithm atmospheric correction backscattering Barra Bonita bio-optical cascading clorophyl coefficient concentration dados hidroacústicos data quality datasets geoestatística imagens inland water landsat mapeamento nova avanhadava parametrization particle phytoplankton remote sensing reservoir São Paulo sentinel Submerged aquatic vegetation total suspended matter tropical reservoir TSM visual analytics
2016 |
![]() @article{Alcântara2016b, title = {An investigation into the particle volume scattering function variability in a cascading reservoir system}, author = {Enner Herenio de Alcântara and Thanan Walesza Pequeno Rodrigues and Fernanda Sayuri Yoshino Watanabe and Nariane Marselhe Ribeiro Bernardo}, doi = {10.1007/s40808-016-0149-z}, issn = {2363-6211}, year = {2016}, date = {2016-06-08}, journal = {Modeling Earth Systems and Environment}, volume = {2}, number = {2}, pages = {89}, abstract = {This work analyzed the spectral and spatial distribution of the particle volume scattering function, βp, in a cascading reservoir system. During fieldworks water quality parameters and scattering data were sampled in a predetermined stations. The βp was estimated using the ECO-BB9 equipment that measures the volume scattering function, β at 117 [β(117)]. The estimated βp(117) were compared with the remote sensing reflectance, Rrs, and the chlorophyll-a (Chl-a) concentration, total suspended matter (TSM) concentration and the transparency (measured using a Secch disk). The results showed that in a hypertrophic environment the βp is dominated by the phytoplankton scattering and in an oligotrophic water system, the scattering by a suspended matter dominates. The βp(117) variability from a hypertrophic to an oligotrophic aquatic system affects the remote sensing reflectance (R rs) spectral shape. Due to this, the parametrization of a unique bio-optical model to estimate the optically active components in the water will be challenging.}, keywords = {cascading, particle, reservoir, volume scattering function, vsf}, pubstate = {published}, tppubtype = {article} } This work analyzed the spectral and spatial distribution of the particle volume scattering function, βp, in a cascading reservoir system. During fieldworks water quality parameters and scattering data were sampled in a predetermined stations. The βp was estimated using the ECO-BB9 equipment that measures the volume scattering function, β at 117 [β(117)]. The estimated βp(117) were compared with the remote sensing reflectance, Rrs, and the chlorophyll-a (Chl-a) concentration, total suspended matter (TSM) concentration and the transparency (measured using a Secch disk). The results showed that in a hypertrophic environment the βp is dominated by the phytoplankton scattering and in an oligotrophic water system, the scattering by a suspended matter dominates. The βp(117) variability from a hypertrophic to an oligotrophic aquatic system affects the remote sensing reflectance (R rs) spectral shape. Due to this, the parametrization of a unique bio-optical model to estimate the optically active components in the water will be challenging. |
![]() @article{Alcântara2016a, title = {The variability of particle backscattering coefficient in an oligo-to-hypertrophic cascading reservoir system: implications to TSM bio-optical model development}, author = {Enner Herenio de Alcântara and Fernanda Sayuri Yoshino Watanabe and Nariane Marselhe Ribeiro Bernardo and Thanan Walesza Pequeno Rodrigues}, doi = {10.1007/s40808-016-0146-2}, issn = {2363-6211}, year = {2016}, date = {2016-06-06}, journal = {Modeling Earth Systems and Environment}, volume = {2}, number = {2}, pages = {84}, abstract = {The particle backscattering coefficient (b bp ) has been obtained either by equipment or semi-analytically based on relations between b bp and the remote sensing reflectance (R rs ). Correlation between b bp and R rs can be significantly high allowing the development of bio-optical model to estimate the total suspended matter concentration [TSM] on water surface from satellite images. The development of such model to monitor cascading reservoir systems can be challenging since this type of water resources changes their biogeochemical composition from upstream to downstream; the water in such system can range from hypertrophic to oligotrophic state. The scientific question raised in this letter is that: in an oligo-to-hypertrophic water system the models based on b bp will keep their good agreement or the influence of organic matter (e.g. chlorophyll-a) can affect this relationship? The aim of this letter was to analyze the b bp variability in a cascading reservoir system and search for empirical models that can capture the relationship between the b bp and [TSM]. The results showed that there are not only differences in the biogeochemical concentrations but also in the b bp from upstream to downstream. In addition there is an influence of chlorophyll-a concentration [Chl-a] on the relationship between b bp and [TSM] which prevents the bio-optical model development.}, keywords = {algorithm, backscattering, bio-optical, cascading, coefficient, hypertrophic, model, oligotrophic, particle, reservoir, total suspended matter, TSM}, pubstate = {published}, tppubtype = {article} } The particle backscattering coefficient (b bp ) has been obtained either by equipment or semi-analytically based on relations between b bp and the remote sensing reflectance (R rs ). Correlation between b bp and R rs can be significantly high allowing the development of bio-optical model to estimate the total suspended matter concentration [TSM] on water surface from satellite images. The development of such model to monitor cascading reservoir systems can be challenging since this type of water resources changes their biogeochemical composition from upstream to downstream; the water in such system can range from hypertrophic to oligotrophic state. The scientific question raised in this letter is that: in an oligo-to-hypertrophic water system the models based on b bp will keep their good agreement or the influence of organic matter (e.g. chlorophyll-a) can affect this relationship? The aim of this letter was to analyze the b bp variability in a cascading reservoir system and search for empirical models that can capture the relationship between the b bp and [TSM]. The results showed that there are not only differences in the biogeochemical concentrations but also in the b bp from upstream to downstream. In addition there is an influence of chlorophyll-a concentration [Chl-a] on the relationship between b bp and [TSM] which prevents the bio-optical model development. |
![]() @article{Alcantara2016, title = {Estimating total suspended matter using the particle backscattering coefficient: results from the Itumbiara hydroelectric reservoir (Goiás State, Brazil)}, author = {Enner Herenio de Alcântara and Marcelo Curtarelli and José Stech}, doi = {10.1080/2150704X.2015.1137646}, year = {2016}, date = {2016-01-01}, journal = {Remote Sensing Letters}, volume = {7}, number = {4}, pages = {397--406}, abstract = {ABSTRACTIn this study, a quasi-analytical algorithm (QAA)-based model was parameterized using remote-sensing reflectance (Rrs, units in sr-1), total absorption coefficient (at) and total suspended matter (TSM) concentration. The model was based on the particle backscattering at 561 nm (bbp(561)) and was derived from the QAA and TSM concentration. The aim of this work was to parameterize a QAA-based model to estimate the TSM concentration using the Landsat-8 Operational Land Imager (OLI) sensor in the Itumbiara hydroelectric reservoir, Brazil. The results demonstrated that the calibrated model}, keywords = {backscattering, coefficient, Goiás, Itumbiara, particle, reservoir, total suspended matter, TSM}, pubstate = {published}, tppubtype = {article} } ABSTRACTIn this study, a quasi-analytical algorithm (QAA)-based model was parameterized using remote-sensing reflectance (Rrs, units in sr-1), total absorption coefficient (at) and total suspended matter (TSM) concentration. The model was based on the particle backscattering at 561 nm (bbp(561)) and was derived from the QAA and TSM concentration. The aim of this work was to parameterize a QAA-based model to estimate the TSM concentration using the Landsat-8 Operational Land Imager (OLI) sensor in the Itumbiara hydroelectric reservoir, Brazil. The results demonstrated that the calibrated model |