Aplicação de técnicas de sensoriamento remoto para quantificação do albedo no perímetro irrigado de Ponto Novo, Bahia.

Abstract

When the solar radiation reaches the planet surface three processes can take place, that is, radiation is reflected, absorbed or transmitted. The reflected fraction is important for imaging of targets at the surface by remote sensors on orbit. Remote sensing techniques has been largely applied in water management research, including the estimation of latent heat transfer to the atmosphere from vegetated and non-vegetated surfaces, as in irrigated areas. The objective of this work is to demonstrate the application of the SEBAL algorithm (Surface Energy Balance Algorithm for Land) for the estimation of the albedo in the upper region of the Itapicuru river basin, northeast of Bahia. The area includes the Ponto Novo Irrigation District, with a total area of 3000 ha from which 400 ha are actually under irrigation. A Landsat 5 TM image of the region taken on 04/11/13 was used. Minimum and maximum value of albedo was 3,6% and 40,0%, respectively, with an average of 21,6%. A frequency histogram is also presented.