| Full text | |
| Author(s): |
Breunig, Fabio Marcelo
[1]
;
Galvao, Lenio Soares
;
Formaggio, Antonio Roberto
;
Couto, Eduardo Guimaraes
[2]
Total Authors: 4
|
| Affiliation: | [1] INPE, Div Sensoriamento Remoto, BR-12201970 Sao Jose Dos Campos - Brazil
[2] Univ Fed Mato Grosso, Fac Agron & Med Vet, BR-78060900 Cuiaba 78060900, MT - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Revista Brasileira de Ciência do Solo; v. 33, n. 6, p. 1785-1794, NOV-DEC 2009. |
| Web of Science Citations: | 4 |
| Abstract | |
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. (AU) | |
| FAPESP's process: | 05/01737-0 - Use of Aviris hyperspectral data in the reflectance characterization of tropical soils |
| Grantee: | Lenio Soares Galvão |
| Support Opportunities: | Regular Research Grants |