Author(s): Gomes, Ana Carolina Campos [UNESP] ; Bernardo, Nariane [UNESP] ; do Carmo, Alisson Coelho [UNESP] ; Rodrigues, Thanan ; Alcântara, Enner [UNESP]
Date: 2018
Persistent ID: http://hdl.handle.net/11449/176637
Origin: Oasisbr
Subject(s): Bio-optical models; Light attenuation; Satellite images; Water quality; Bio-optical models; Bio-optical models; Light attenuation; Light attenuation; Satellite images; Satellite images; Water quality; Water quality
Made available in DSpace on 2018-12-11T17:21:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-01
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
The kd(490) is a vertical light attenuation coefficient and an important parameter for water quality. The kd estimates are often based on empirical and semi-analytical algorithms, designed for oceanic and coastal waters. However, there is a lack of information about the performances of these models to inland waters dominated by chromophoric dissolved organic matter (CDOM). Therefore, to contribute to this investigation, nine empirical models based on the blue-to-green and blue-to-red ratios and chlorophyll-a (Chl-a) concentration were evaluated, as well as three semi-analytical models using bands from the Operational Land Imager (OLI)/Landsat-8. The errors (mean absolute percentage error, MAPE > 80%) presented by the empirical models confirmed that the blue-to-green ratio failed in retrieving kd(490) in an environment dominated by CDOM. Similar failures occurred with the models using the Chl-a concentration (MAPE ~60%) as input. A semi-analytical approach showed the lowest error (MAPE = 41.04%) in the estimate of the inherent optical properties for complex waters in order to reduce the errors above. After retrieval of kd(490) using the semi-analytical model, seasonal patterns were observed, and high values of kd(490) were detected in the dry season possibly due to the increase of the concentration of the optically-significant substances (OSS).
Department of Cartography São Paulo State University (Unesp)
Federal Institute for Education Science and Technology of Pará State
Department of Environmental Engineering São Paulo State University (Unesp)
Department of Cartography São Paulo State University (Unesp)
Department of Environmental Engineering São Paulo State University (Unesp)
