Please use this identifier to cite or link to this item:
http://repositorio.ufc.br/handle/riufc/69395
Type: | Artigo de Periódico |
Title: | Remote analysis of the chlorophyll-a concentration using sentinel-2 MSI images in a semiarid environment in Northeastern Brazil |
Authors: | Aranha, Thaís Regina Benevides Trigueiro Martinez, Jean-Michel Souza, Ênio Pereira de Barros, Mário Ubirajara Gonçalves Martins, Eduardo Sávio Passos Rodrigues |
Keywords: | Remote sensing;Water quality;Chlorophyll-a;Reservoirs;Semiarid |
Issue Date: | 2022 |
Publisher: | Water |
Citation: | MARTINS, E. S. P. R. et al. Remote analysis of the chlorophyll-a concentration using sentinel-2 MSI images in a semiarid environment in Northeastern Brazil. Water, [s.l], v. 14, n. 3, 2022. DOI: https://doi.org/10.3390/w14030451 |
Abstract: | In this paper, the authors use remote-sensing images to monitor the water quality of reservoirs located in the semiarid region of Northeast Brazil. Sentinel-2 MSI TOA Level 1C reflectance images were used to remotely estimate the concentration of chlorophyll-a (chl-a), the main indicator of the trophic state of aquatic environments, in five reservoirs in the state of Ceará, Brazil. A three-spectral band retrieval model was calibrated using 171 water samples, collected from November 2015 through July 2018 in 5 reservoirs. For validation, 71 additional samples, collected from August 2018 through December 2019, were used to ensure a robust accuracy assessment. The TOA Level 1C products performed very well, achieving a relative RMSE of 28% and R2 = 0.80. Data on wind direction and speed, solar radiation and reservoir volume were used to generate a conceptual model to analyze the behavior of chl-a in the surface waters of the Castanhão reservoir. During 2019, the reservoir water quality showed strong variation, with concentration fluctuating from 30 to 95 µg/L We showed that the end of the dry season is marked by strong eutrophic conditions corresponding to very low water inflows into the reservoir. During the rainy season there is a large decrease in the chl-a concentration following the increase of the lake water storage. During the following dry season, satellite data show a progressive improvement of the trophic state controlled by wind intensity that promotes a better mixing of the reservoir waters and inhibiting the development of most phytoplankton. |
URI: | http://www.repositorio.ufc.br/handle/riufc/69395 |
ISSN: | 2073-4441 |
Access Rights: | Acesso Aberto |
Appears in Collections: | DEHA - Artigos publicados em revista científica |
Files in This Item:
File | Description | Size | Format | |
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2022_art_edsprmartins.pdf | 26,4 MB | Adobe PDF | View/Open |
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