Aplicação do algoritmo SEBAL para estimativa da evapotranspiração na mesorregião do sul goiano.

Abstract

Concerns over land use have permeated many scientific studies at the national and international, aimed at assessing the environmental impacts caused by agricultural activities. Some processes of the hydrological cycle, such as the present evapotranspiration significant changes, due to constant changes in land uses. Thus, this paper seeks to highlight the problem of rapid and intense changes in land use arising from the expansion of agricultural activities and their impacts on the environment, especially on the process of regional evapotranspiration in southern Goiás Greater Region, a region typical of cerrado located in central Brazil. The application of the algorithm "Surface Energy Balance Algorithm for Land - SEBAL" was the core of the methodology used for the estimation of energy fluxes and evapotranspiration on a regional scale, based on the obtained solution of the surface energy balance, supplemented by data of air temperature and wind speed acquired in weather stations (PCDs) installed in the study area. We used data from MODIS / TERRA the years 2006, 2007, 2008, 2009 and 2010. The algorithm was tested in its classic form and modified by changes in the criteria for selecting pixels anchors used in the procedure of estimating the sensible heat flux. It can be concluded that the change in criteria positively influenced the results obtained and the values of evapotranspiration in the study area, indicated the potential of the methodology used for the systematic monitoring of the components of energy balance on a regional scale.