Variabilidade dos fluxos de calor sensível e latente em áreas de cerrado sensu stricto

Abstract

Evapotranspiration is one of the most important regulator factors for hydric availability, climate and weather, both in global and local scale. The constraints due local measuring motivated the development of techniques involving remote sensing information to estimate evapotranspiration in large areas. The objective of this work was to evaluate the accuracy of SEBAL algorithm in the estimation of the components of surface energy balance equation. 28 images of the Terra/MODIS sensor were used to test the algorithm. The estimated data using SEBAL was analyzed by comparison with local measures, obtained by correlation of turbulent vortexes. The results indicate that the methodology used in this paper presented variations of 57% in latent heat fluxes and overestimation 1,6 mm/dia the evapotranpiration in cerrado sensu stricto areas. The low spatial resolution of the images could have contributed significantly in the increment of the error of the obtained values, because of the various types of land use and land cover contained in the image resolution cell. Nevertheless, the preliminary results confirm the Terra/MODIS sensor potential in the estimation of instantaneous evapotranspiration.