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Universidade Federal Rural de Pernambuco (2013)

Estimativa da evapotranspiração real para áreas de caatinga utilizando SEBAL

Medeiros Bezerra Joel

Titre : Estimativa da evapotranspiração real para áreas de caatinga utilizando SEBAL

Auteur : Medeiros Bezerra Joel

Université de soutenance : Universidade Federal Rural de Pernambuco

Grade : Mestre em Engenharia Agricola 2013

Despite being the only natural Brazilian biome whose boundaries are entirely restricted to the national territory, little attention has been given to the conservation of the diverse and striking landscape of Caatinga. Given the importance and scarcity of field data to monitor evapotranspiration of vegetation of this biome in semiarid regions of northeastern Brazil, this study aimed to evaluate the dynamics space-temporal component of surface energy balance and evapotranspiration in real hourly and daily, through techniques and remote sensing products using the SEBAL algorithm. Estimated data was validated by comparison with measurements obtained in surface automatic weather station. The study area included the conservation unit of the National Park of the Furna Feia and its surroundings, being situated in the municipalities of Mossoró and Baraúna (RN, Brazil). To conduct the study were obtained six images orbital sensor Thematic Mapper (TM) Landsat 5 satellite, in orbit 216 and point 63, the dates of 28/09/2007, 12/07/2008, 19/12/2008, 31/07/09, 03/10/09 and 23/01/10, to determine the seasonality of spatial dynamics. With the aid of GIS tools were performed calibrations for atmospheric images, generating thematic maps, expressing the spatial variability of biophysical parameters : surface albedo, Vegetation Index (IVDN), net radiation (Rn) and daily instant, and daily evapotranspiration (ETSEBAL24h). Descriptive statistics were used to determine the magnitude of the differences due to the seasonality of the local climate and human actions, and the determination of statistical errors. Rn values estimated by the snapshot journal and showed SEBAL growing relations with the surface data station, however overestimating the same. There were differences in biophysical parameters and components of energy balance in response to the type of land use, and climate variations for the period. Finally, we conclude that the SEBAL model was efficient in mapping the spatial distribution of biophysical parameters and daily actual evapotranspiration in semiarid areas of Caatinga. The thematic maps of ETSEBAL24h showed high values in areas of native vegetation of Caatinga, around 2.0 to 8.0 for periods of drought and winter, respectively. In all the scenes analyzed the highest values of ET are located in areas of dense vegetation Caatinga, at high altitudes

Mots clés  : Fluxo de energia ; Sensoriamento remoto ; Caatinga ; Agrometeorologia ; Energy flux ; Remote sensing ; Agrometeorology

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Page publiée le 16 janvier 2016, mise à jour le 21 février 2019