Evapotranspiration estimation in urban areas through TM digital images - Landsat 5

Abstract

Evapotranspiration (ET) has great relevance in the air temperature and contributes to the climate balance in urban areas. In this context, this study aimed to estimate evapotranspiration in the city of Recife-PE in order to analyze the intra-urban differences in the various types of roofing. Six digital images of the TM - Landsat 5 sensor regarding orbit 214 and points 65, 66 were used. The density of sensible heat and latent heat fluxes were calculated based on SEBAL algorithm. The evapotranspiration results were consistent when compared with values obtained by the method of FAO-Penman-Monteith, with absolute error between 0.18 and 1.23 mm d-1, minimum and maximum, respectively, and average of 0.86 mm d-1. The highest evapotranspiration rates were found in protection units and water bodies between 5.0 and 6.0 mm d-1, approximately, while in surfaces with intense constructive densification, values close to 1.0 mm d-1 were found. The methodology used consistently represented the various types of roofing and can promote a significant advance in the monitoring of the urban climate.

Keywords

• Clima urbano
• Sensoriamento remoto
• Sebal
• Urbanização
• Áreas verdes