Data/hora: 09/06/2024 13:57:52

Provedor de dados: | 90
País: | Brazil
Título: | The combined use of reflectance, emissivity and elevation Aster/Terra data for tropical soil studies
Autores: | Breunig,Fábio Marcelo; Galvão,Lênio Soares; Formaggio,Antonio Roberto; Couto,Eduardo Guimarães.
Data: | 2009-12-01
Ano: | 2009
Palavras-chave: | Digital elevation model; Soil constituents; Remote sensing; Topography.
Resumo: | Reflectance, emissivity and elevation data of the sensor ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer)/Terra were used to characterize soil composition variations according to the toposequence position. Normalized data of SWIR (shortwave infrared) reflectance and TIR (thermal infrared) emissivity, coupled to a soil-fraction image from a spectral mixture model, were evaluated to separate bare soils from nonphotosynthetic vegetation. Regression relationships of some soil properties with reflectance and emissivity data were then applied on the exposed soil pixels. The resulting estimated values were plotted on the ASTER-derived digital elevation model. Results showed that the SWIR bands 5 and 6 and the TIR bands 10 and 14 measured the clay mineral absorption band and the quartz emissivity feature, respectively. These bands improved also the discrimination between nonphotosynthetic vegetation and soils. Despite the differences in pixel size and field sampling size, some soil properties were correlated with reflectance (R² of 0.65 for Al2O3 in band 6; 0.61 for Fe2O3 in band 3) and emissivity (R² of 0.65 for total sand fraction in the 10/14 band ratio). The combined use of reflectance, emissivity and elevation data revealed variations in soil composition with topography in specific parts of the landscape. From higher to lower slope positions, a general decrease in Al2O3 and increase in total sand fraction was observed, due to the prevalence of Rhodic Acrustox at the top and its gradual transition to Typic Acrustox at the bottom.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000600027
Editor: | Sociedade Brasileira de Ciência do Solo
Relação: | 10.1590/S0100-06832009000600027
Formato: | text/html
Fonte: | Revista Brasileira de Ciência do Solo  v.33 n.6 2009
Fonte: | info:eu-repo/semantics/openAccess