Correlation between the variations of clay content in soils and sediments and the spectral behavior of superjacent vegetation using spectir hyperspectral images

This work approaches geobotany in southeastern Brazil within terrains comprising Forested Savannas, Gallery and Riparian Atlantic forests developed over fluvial-lacustrine sediments and rocks. The notion was to test the ability of SpecTIR V-S hyperspectral imagery (357 VNIR-SWIR channels; spatial resolution of 1m) to identify the variation of clay content in soils/sediments based on spectral patters yielded by the overlying vegetation. Samples were collected for granulometric analysis in the center of 30 plots with 20x20m each. Vegetation was grouped by floristic similarity. Tailored spectral indices were applied to the SpecTIR V-S data. Different indices were needed to extract parameters of the physical environment from varying vegetation. Results indicate that the physiognomies investigated are influenced differently by clay content in soils and that the vegetation also responds distinctly due to subtle textural variations in the subjacent terrains.