Obtenção dos fluxos de superfície a partir da assimilação de dados do IVDN Modis/Terra no modelo BRAMS na região cerrado do Amapá.

Abstract

This study aims to make a comparative analyses of the surface flow, obtained by numeric simulations of BRAMS 5.1 model, before and after of the NVDI data incorporation, Estimated by Terra/MODIS / satellite. We performed two simulations, in the driest period, for homogeneous areas selected in the cerrado (Savana) region of Amapá. The aim was to evaluate the behavior of surface flows. We estimate the normalized difference vegetation index (NVDI), the Radiation Balance (Rn) and the heat flux in the soil (G0). The latent (H) and latent (LE) heat fluxes were obtained by the S-SEBI algorithm, from Terra/MODIS satellite images in the period of 13-20/ 08/2002, 29-05/09/2006, 21-28/ 08/2015. The results of the IVDN obtained by the satellite showed that they present variabilities according to vegetation type and soil cover. The substitution of cerrado sensu stricto for eucalyptus forest caused an increase of Rn and LE, and a reduction of G0 and H. When we comparing the Rn measured data obtained by the tower with the data obtained by Terra/MODIS, the percentage error was of the order of 4.4% and are in agreement with other works found in the literature. However, the errors observed in the validation of the BRAMS simulations for some energy balance variables in some areas were high. We emphasized that this study can be improved with the improvement of other initial conditions and configuration of the simulations.