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Preliminary Results in the Detection of Amazonian Black Earth Sites using Hyperspectral Satellite Imagery

Michael Palace, Complex System Research Center, University of New Hampshire, (Presenting)
Michael Keller, Complex System Research Center, University of New Hampshire, CENA/USP, International Institute of Tropical Forestry,
Bobby Braswell, Complex System Research Center, University of New Hampshire,
Stephen Hagen, Complex System Research Center, University of New Hampshire,
Plinio de Camargo, CENA/USP,
William Saturno, Dept. of Archaeology, Boston University,

The pre-Columbian indigenous population estimates of the Amazon Basin lowlands are highly uncertain and the subject of considerable controversy. Proponents of the low population density suggest that the forest is pristine, delicate, and sensitive to human disturbance. If populations were high, it is likely that Amazonian forest vegetation had been significantly altered and may be thought of as a cultural artifact, resilient to human disturbance and not an undisturbed forest. One of the archaeological sources used in reconstruction of Amazonian societies are Amazonian black earths (ABE) or in Portuguese, terra preta soils. The immense size of Amazonia, remoteness of many areas, forest vegetation, and lack of archaeological field surveys, make remote sensing beneficial to archaeological studies in this region. Remote sensing allows for comparison and analysis of vegetation across vast areas. Previous research has shown that hyperspectral image data can detect vegetation canopy chemistry differences, associated with soil nutrients and chemistry. This literature suggests that the high nutrient content of ABE soils will cause detectable changes in vegetation structure, phenology, and/or foliar chemistry. Hyperspectral remote sensing with dense coverage of the spectral reflectance of vegetation canopies will provide a key to detection of high nutrient ABE sites. The broad spatial coverage afforded by the proposed research allows for the unique opportunity to begin to quantify the Pre-Columbian human impact in Amazonia through the analysis of the distribution of ABE sites across the region. We conducted a preliminary analysis to demonstrate our conceptual plan and identify potential spectral differences between ABE sites and non-ABE sites using hyperspectral data from the Hyperion satellite. Our preliminary analysis indicates that, at three pairs of sites near Santarem, there are spectral differences between ABE and non-ABE sites. There are nine portions of the spectrum where the three ABE sites are completely separable from the three non-ABE sites. This limited demonstration analysis highlights the important opportunity that Hyperion data provide for identifying and mapping ABE sites. As much as our current knowledge of this forest expands, it is still limited by ignorance of past disturbance and dynamics as well as the populations and agricultural practices of previous human societies.

Science Theme:  LC (Land Use and Land Cover Change)

Presentation Type:  Poster (view presentation (268 KB))

Abstract ID: 26

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