Mapeamento espectral de áreas carbonáticas a partir de imagens TM/ LANDSAT na região

próximo artigo 93 4

Anais XIV Simpósio Brasileiro de Sensoriamento Remoto, Natal, Brasil, 25-30 abril 2009, INPE, p. 3309-3315.

Mapeamento espectral de áreas carbonáticas a partir de imagens TM/ LANDSAT na região de Água Fria, Goiás
Pedro Paulo Pires de Deus Rocha1
Marina Marques Dalla Costa1
Marina Lima Queiroz1
Ana Carolina Argolo Nascimento1
Cássia Cristina Pinheiro1
Nexcy Carolina Carvajal de León1
Adriana Chatack Carmelo1
José Elói Guimarães Campos1
1

Universidade de Brasília – UnB/IG
Campus Universitário Darcy Ribeiro, 70910-900, Brasília DF, Brasil
{marina28.09, caromurci}@gmail.com
{anargolo, cassia.pinheiro, marinadalla, piresss}@aluno.unb.br
{chatack, eloi}@unb.br

Abstract. This work applies thematic classification and transformation techniques in the spectral domain of
TM/LANDSAT satellite images of the Água Fria region, Goiás, in order to outline carbonatic rocks, which correspond to the Sete Lagoas Formation (Bambuí Group) and to the Psammitic-Pelitic-Carbonated Unit of the
Paranoá Group. Additionally, we aim to refine previously established geological contacts, since the strong weathering of these rocks restricts their definition by traditional geological mapping. Spectral band ratios were calculated and the Normalized Difference Vegetation Index (NDVI) was applied with an aim to individualize areas with low and high biomass. Parallelepiped and Isodata classifications were tested and the obtained product was integrated with field data showing high correlation between outcrops observed in the field and low biomass (no vegetation) areas in the image. The routines applied to discriminate carbonates and hydrous minerals did not produce satisfactory results, probably due to low spectral, radiometric and spatial resolution of the TM/LANDSAT images.
As a final result, it was possible to individualize three potential areas for carbonate occurrence: alpha, beta and delta, corresponding, respectively, to high, medium and