Estimate of evapotranspiration in eastern Amazonian using SEBAL

Abstract

In this study, estimates of flows of latent and sensible heat were analyzed by Acqua / MODIS for Caxiuanã National Forest, Melgaço-Pa. To this end, we used data from satellite images combined with the observational data from LBA (Experiment of the Large Scale Biosphere-Atmosphere Experiment in Amazonia), collected in 2008 in micrometeorological tower. The results showed that, despite the monthly evapotranspiration estimated to have submitted an overestimate January-June and July-December underestimation, it remained at a relatively high rate throughout the year, with average values very similar to those reported in the literature for the Amazon region. The estimated daily evapotranspiration was overestimated for the rainy season and underestimated for the dry season, but also presenting the maintenance of a relatively high ET, just as the observed daily ET. The variation between the two streams of sensible heat (estimated and observed) revealed a very similar pattern, with significantly smaller differences, especially in the rainy season. These results suggest that due to the ET was higher in the dry season, the previous season (rainy) played a decisive role, suggesting that in the dry season, sweating is the main source for the ET region, which in turn is related to the primary production of the forest.