Distribuição espacial das concentrações de clorofila-a e sólidos suspensos totais no reservatório de Rosana-SP utilizando imagens do sensor OLI/Landsat-8
The monitoring of reservoirs through water sampling can be a very costly and time consuming process due to the large areas of water bodies, thus remote sensing can arise as a good alternative for resolving the issue. Some components such as chlorophyll-a and suspended solids are good indicators of the trophic state of water bodies and can be identified by remote sensing. This study aimed the fitting of models to map the spatial distribution of those two components in Rosana-SP reservoir. The hyperespectral data and water samples were collected in 20 points for determination of chlorophyll-a and total suspended solids (TSS) concentrations. The model calibration was conducted using the bands of OLI sensor simulated from the field data. The models were fitted with one and two bands (ratios), using the hyperspectral data and the simulated bands. The best correlation based on hyperspectral data was obtained for the ratio between 700 and 680 nm both for the chlorophyll-a and TSS with 43.42% and 22.25% of root mean square error (RMSE), respectively. The best model based on simulated bands of OLI sensor was found for the ratio between the green and blue bands, with 34.95% of RMSE for chlorophyll-a and 45.97% for TSS. This model was then applied on the image to generate a map with the spatial distribution of the two components.