The evapotranspiration (ET) is one of the most important components of the water cycle. On this aspect, this study aims to analyze the space-time behavior of the energy balance and the real daily evapotranspiration in the area of environmental preservation of Ilha de Santa Rita, Alagoas, Brazil. The methodology used involves the use of algorithm SEBAL, satellite images of Landsat 5 TM and complementary data of meteorological station located in the study area. The daily estimate of real ET24h varied from 0 to 1mm.day-1 for exposed soil and city; to 6mm.day-1 for water bodies and mangrove, with a mean value of 3.78mm.day-1, 3.45mm.day-1 and 4.75mm.day- 1, in the days 09/03/2003, 08/26/2006 and 03/17/2011, respectively, for the entire study area. The results obtained by the algorithm SEBAL (SURFACE ENERGY BALANCE ALGORITHMS FOR LAND) can be used in weather conditions that are similar to the ones in the preservation area of Ilha de Santa Rita/ Alagoas. The distributions of each component of the energy balance are: radiation balance, soil heat flow (sensible and latent), presented significant influence in the different types of use and coverage of the soil. The approach used is very suitable for a real satellite data exploration, and it can be used to estimate the number of parameters in the continuous soil-plant-atmosphere.
Sebal; Energy balance; Evapotranspiration
