BALANÇO DE RADIAÇÃO EM ÁREAS IRRIGADAS UTILIZANDO IMAGENS LANDSAT 5 - TM

RADIATION BALANCE IN IRRIGATED SURFACE USING LANDSAT 5 TM s IMAGES The main objective of the present study was the determination of the balance of radiation at surface, based on seven spectral bands of Landsat 5 Thematic Mapper. Two images, taken on December 04, 2000 and October 04, 2001, covering irrigated areas of Nilo Coelho Project, part of the Sobradinho Lake, native vegetation and part of the urban areas of Petrolina, PE and Juazeiro, BA, were considered. It was applied the Surface Energy Balance Algorithm for Land SEBAL, in order to calculate the albedo and the land surface temperature for each pixel of the images. The incoming short wave radiation and the incoming long wave radiation were assessed by data from a weather station. In general, the net radiation of the scene as a whole was larger in 2000, when it reached an aerial average value of 615.0 W.m-2. It might be caused by the occurrence of some rainfall events in the studied area on December of 2000 that would have affected the albedo and the land surface temperature of the non-irrigated areas. In 2001, the averaged Rn value reached 583.9 Wm-2, although in some selected areas within the studied scene with Rn been larger in 2001 as compared to 2000. The results obtained for irrigated orchards, when compared with other studies, show that the approach applied is confidant and have great importance.

[1]  Jie Song,et al.  An Improved Method to Derive Surface Albedo from Narrowband AVHRR Satellite Data: Narrowband to Broadband Conversion , 1999 .

[2]  W. Bastiaanssen.  Regionalization of surface flux densities and moisture indicators in composite terrain. A remote sensing approach under clear skies in Mediterranean climates. , 1995 .

[3]  Brian L. Markham,et al.  Thematic Mapper bandpass solar exoatmospheric irradiances , 1987 .

[4]  R. Dubayah.  Estimating net solar radiation using Landsat Thematic Mapper and digital elevation data , 1992 .

[5]  Jeff Dozier,et al.  Topographic distribution of clear‐sky radiation over the Konza Prairie, Kansas , 1990 .

[6]  W. Bastiaanssen.  SEBAL-based sensible and latent heat fluxes in the irrigated Gediz Basin, Turkey , 2000 .

[7]  R. Granger.  Satellite-derived estimates of evapotranspiration in the Gediz basin , 2000 .

[8]  Eva Boegh,et al.  Evaluating evapotranspiration rates and surface conditions using Landsat TM to estimate atmospheric resistance and surface resistance , 2002 .

[9]  Paul A. Davis,et al.  Estimation of broadband planetary albedo from operational narrowband satellite measurements , 1987 .

[10]  A. Holtslag,et al.  A remote sensing surface energy balance algorithm for land (SEBAL)-1. Formulation , 1998 .

[11]  F. Becker,et al.  The impact of spectral emissivity on the measurement of land surface temperature from a satellite , 1987 .

[12]  S. Liang.  Narrowband to broadband conversions of land surface albedo I Algorithms , 2001 .

[13]  José A. Sobrino,et al.  Land surface temperature estimation from AVHRR thermal infrared measurements: An assessment for the AVHRR Land Pathfinder II data set , 2002 .

[14]  Craig S. T. Daughtry,et al.  Spectral estimates of net radiation and soil heat flux , 1990 .

[15]  Herbert Jacobowitz,et al.  Impact of Scene Dependence on AVHRR Albedo Models , 1995 .