Determination of the fraction of absorbed photosyntetically active radiation by agrosystems and vegetal cover in the Cerrado Goiano

Abstract

The use of the vegetation biophysical index fraction of photosynthetically active radiation absorbed (fAPAR) has become an essential variable in monitoring plant productivity and evaluating the global carbon balance. Thus, the objective was to evaluate the variations in the fAPAR index in the forms of vegetation in the municipality of Serranópolis using the 2020-2021 time series of Sentinel-2 data. For this purpose, fAPAR information was produced using Sentinel-2 images and the RTM PROSAIL model, processed on the SNAP Toolbox platform. As results, grain agriculture and sugar cane presented R²=0.903 and RMSE= 0.065 and R²=0.847 and RMSE= 0.059 respectively. The pasture planted in good conditions presented R² = 0.889 and RMSE = 0.058, the shaded pasture with R² = 0.742 and RMSE = 0.064 and the pasture planted with low quality and R² = 0.856 and RMSE = 0.047. For the Cerrado, the coefficient of determination was R² = 0.5465 and RMSE = 0.059. For forest formation, the coefficient of determination was R² = 0.6158 and RMSE = 0.070.