A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

Discriminating Land Cover Types and Conversions in the Brazilian Cerrado UsingEO-1 Hyperion Hyperspectral ImageryT. Miura 1* , A. Huete 1 , and L. Ferreira 21 Terrestrial Biophysics and Remote Sensing Laboratory, Department of Soil, Water andEnvironmental Science, University of Arizona, Tucson, AZ 85721, U.S.A.Tel.: +1-520-626-2086, Fax: +1-520-621-1791, *Email: tomoaki@ag.arizona.edu2 Universidade Federal de Goias, Instituto de Estudos Socio-Ambientais, Campus Samambaia -Cx Postal 131, Goiania, GO, 74.001-970, BrazilAbstractThe savanna, typically found in the sub-tropics and seasonal tropics, are the dominant vegetationbiome type in the southern hemisphere, covering approximately 45 % of the South America. InBrazil, the savanna, locally known as "cerrado", is the most intensely stressed biome with rapidand aggressive land use conversions. Better characterization and discrimination of cerrado landcover types are needed in order to improve assessments of the impact of these land coverconversions on carbon storage, nutrient dynamics, and the prospect for sustainable land use inthe Amazon region. In this study, we explored the utility of hyperspectral remote sensing inimproving discrimination and biophysical/biochemical characterization of the cerrado land covertypes by taking an advantage of a newly available satellite hyperspectral imaging sensor, "EO-1Hyperion". A Hyperion image was acquired over study sites located in the Brasilia NationalPark and surrounding areas on July 20, 2001. The study sites included cerrado grassland, shrubcerrado, cerrado woodland, and gallery forest as undisturbed vegetation cover types, and pastureas a converted land cover. The high resolution spectral signatures clearly depicted thedifferences between pasture, gallery forest, and other cerrado land cover types. The pasturespectral signatures exhibited an overall high reflectance with a red absorption peak shiftedtoward shorter wavelengths which is associated with yellowing of pasture leaves. Spectralsignatures in the visible and near-infrared (NIR) regions for undisturbed cerrado vegetation types(physiognomies) showed small differences, rendering the discrimination or classification amongthese land cover types based on the red-NIR reflectance contrast. On the other hand, thereflectance values at the shortwave-infrared (SWIR) region (1400 – 2500nm) and the lignocelluloseabsorptions at 2090nm and around 2300nm wavelengths showed larger differencesamong these land cover types. Cerrado land cover types with less arboreous cover showedhigher SWIR reflectances and deeper ligno-cellulouse absorptions. These preliminary analysesshowed a great potential of hyperspectral data in biophysical/biochemical characterization aswell as discrimination of the land cover types in the Brazilian cerrado.