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 reservoir São Paulo Sensoriamento Remoto Submerged aquatic vegetation sugarcane total suspended matter tropical reservoir TSM visual analytics
2016 |
![]() @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{doi:10.1080/2150704X.2016.1177242, title = {Estimating the CDOM absorption coefficient in tropical inland waters using OLI/Landsat-8 images}, author = {Enner Herenio de Alcântara and Nariane Marselhe Ribeiro Bernardo and Fernanda Sayuri Yoshino Watanabe and Thanan Walesza Pequeno Rodrigues and Luiz Henrique da Silva Rotta and Alisson Fernando Coelho do Carmo and Milton Hirokazu Shimabukuro and Stela Rosa Amaral Gonçalves and Nilton Nobuhiro Imai}, doi = {10.1080/2150704X.2016.1177242}, year = {2016}, date = {2016-01-01}, journal = {Remote Sensing Letters}, volume = {7}, number = {7}, pages = {661--670}, abstract = {ABSTRACTColoured dissolved organic matter (CDOM) is the most abundant dissolved organic matter (DOM) in many natural waters and can affect the water quality, such as the light penetration and the thermal properties of water system. So the objective of this letter was to estimate the CDOM absorption coefficient at 440 nm, aCDOM(440), in Barra Bonita Reservoir (São Paulo State, Brazil) using operational land imager (OLI)/Landsat-8 images. For this two field campaigns were conducted in May and October 2014. During the field campaigns remote sensing reflectance (Rrs) were measured using a TriOS hyperspectral radiometer. Water samples were collected and analysed to obtain the aCDOM(440). To predict the aCDOM(440) from Rrs at two key wavelengths (650 and 480 nm) were regressed against laboratory-derived aCDOM(440) values. The validation using in situ data of aCDOM(440) algorithm indicated a goodness of fit}, keywords = {absorption, cdom, coefficient, imagens, inland water, landsat, tropical reservoir}, pubstate = {published}, tppubtype = {article} } ABSTRACTColoured dissolved organic matter (CDOM) is the most abundant dissolved organic matter (DOM) in many natural waters and can affect the water quality, such as the light penetration and the thermal properties of water system. So the objective of this letter was to estimate the CDOM absorption coefficient at 440 nm, aCDOM(440), in Barra Bonita Reservoir (São Paulo State, Brazil) using operational land imager (OLI)/Landsat-8 images. For this two field campaigns were conducted in May and October 2014. During the field campaigns remote sensing reflectance (Rrs) were measured using a TriOS hyperspectral radiometer. Water samples were collected and analysed to obtain the aCDOM(440). To predict the aCDOM(440) from Rrs at two key wavelengths (650 and 480 nm) were regressed against laboratory-derived aCDOM(440) values. The validation using in situ data of aCDOM(440) algorithm indicated a goodness of fit |
![]() @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 |
![]() @article{doi:10.1080/2150704X.2016.1145361, title = {Field measurements of the backscattering coefficient in a cascading reservoir system: first results from Nova Avanhandava and Barra Bonita Reservoirs (São Paulo, Brazil)}, author = {Enner Herenio de Alcântara and Fernanda Sayuri Yoshino Watanabe and Thanan Walesza Pequeno Rodrigues and Nariane Marselhe Ribeiro Bernardo and Luiz Henrique da Silva Rotta and Alisson Fernando Coelho do Carmo and Marcelo Curtarelli and Nilton Nobuhiro Imai}, doi = {10.1080/2150704X.2016.1145361}, year = {2016}, date = {2016-01-01}, journal = {Remote Sensing Letters}, volume = {7}, number = {5}, pages = {417--426}, abstract = {ABSTRACTIn this study, a data set of total suspended matter (TSM), chlorophyll-a (Chl-a), total backscattering coefficient (bb) and the remote sensing reflectance (Rrs) were measured in the euphotic zone of two hydroelectric reservoirs at 71 stations during field surveys in the wet and dry seasons. These two reservoirs are located in a cascading system in Tietê River, São Paulo State, Brazil. The limnological and optical data were interpolated using the ordinary kriging technique to map their spatial distribution. The differences in TSM, Chl-a and in bb in space and time were investigated. The profiling data from bb were analysed. All these data were used to explain the resulting Rrs spectra in these two reservoirs. For both reservoirs, the inorganic fraction of TSM was responsible for the bb variability and therefore modulates the Rrs spectra. The seasonally difference in the optical data will help to understand how the inherent optical properties and the apparent optical properties changes in a cascading reservoir system.}, keywords = {backscattering, Barra Bonita, cascading, coefficient, field, nova avanhadava, São Paulo}, pubstate = {published}, tppubtype = {article} } ABSTRACTIn this study, a data set of total suspended matter (TSM), chlorophyll-a (Chl-a), total backscattering coefficient (bb) and the remote sensing reflectance (Rrs) were measured in the euphotic zone of two hydroelectric reservoirs at 71 stations during field surveys in the wet and dry seasons. These two reservoirs are located in a cascading system in Tietê River, São Paulo State, Brazil. The limnological and optical data were interpolated using the ordinary kriging technique to map their spatial distribution. The differences in TSM, Chl-a and in bb in space and time were investigated. The profiling data from bb were analysed. All these data were used to explain the resulting Rrs spectra in these two reservoirs. For both reservoirs, the inorganic fraction of TSM was responsible for the bb variability and therefore modulates the Rrs spectra. The seasonally difference in the optical data will help to understand how the inherent optical properties and the apparent optical properties changes in a cascading reservoir system. |