Surface albedo through TM-Landsat 5 images and Digital Terrain Model/Albedo da superficie por meio de imagens TM-Landsat 5 e modelo numerico do terreno

This study aimed at to estimate the surface albedo in the Corumbatai River Basin, State of Sao Paulo, Brazil, using TM-Landsat 5 images, together with the Digital Terrain Model (DTM), in order to take into account the terrain slope, as well as the Mapping Evapotranspiration at High Resolution and with Internalized Calibration (METRIC) model. Available ancillary data from a meteorological station located in the study area, and ten images from 01/02/2009, 04/02/2010, 22/04/2009, 24/05/2009, 12/06/2010, 08/07/2008, 30/07/2010, 31/08/2010, 13/09/2009 and 31/10/2009, were also used. The use of TM-LANDSAT 5 images with the METRIC model and the DTM, allowed to identify the spatial and temporal variations of different coverages on the mapping of surface albedo of the Corumbatai River Basin. The data were consistent with those presented in the literature for sugarcane, water, pasture and eucalypt, for satellite images of clear-sky days. Key words: river basin remote sensing reflectivity METRIC Objetivou-se, na presente pesquisa, estimar o albedo da superficie na Bacia do Rio Corumbatai, localizada no Estado de Sao Paulo, Brasil, com uso de imagens do Mapeador Tematico (TM) do satelite Landsat 5, juntamente com o Modelo Numerico do Terreno (MNT) para considerar a inclinacao e o sentido de declive do terreno, alem da aplicacao do algoritmo Mapping Evapotranspiration at High Resolution and with Internalized Calibration (METRIC). Utilizaram-se dados complementares disponiveis em estacao meteorologica localizada na regiao de estudo e dez imagens datadas de 01/02/2009, 04/02/2010, 22/04/2009, 24/05/2009, 12/06/2010, 08/07/2008, 30/07/2010, 31/08/2010, 13/09/2009 e 31/10/2009. O uso de imagens TM-Landsat 5 com o algoritmo METRIC e o MNT permitiu identificar as variacoes espaciais e temporais de diferentes coberturas no mapeamento do albedo da superficie da Bacia do Rio Corumbatai. As avaliacoes foram consistentes com os valores obtidos na literatura para os alvos cana-de-acucar, agua, pastagem e eucalipto, nas imagens em dias de ceu claro. Palavras-chave: bacia hidrografica sensoriamento remoto refletividade METRIC