Context matters : GIS-based spatial analysis of the Nasca geoglyphs of Palpa

In this chapter we report on the GIS-based analysis of the Nasca geoglyphs of Palpa, Peru, undertaken in the course of the Nasca Palpa Archaeological Project. We focus here on the analysis of spatial relationships between the geoglyphs and the surrounding landscape in terms of visibility and orientation. Our motivation for this contextual analysis was to gain a better understanding of the function and meaning of the geoglyphs by virtually assuming the viewpoints of the people who conceived, built, and used the geoglyphs between approximately 400 BC and 800 AD. In this sense our study of geoglyph visibility and orientation is a contribution to current attempts to incorporate cultural variables into the quantitative environment of GIS, thereby rendering GIS a more useful instrument for archaeological research. This approach required the development of new GIS tools tailored to the specific needs of archaeological analysis. The results of our study indicate that the geoglyphs can be understood as stages for public rites performed by social groups, whereas the incorporation of the surrounding landscape through visual links was apparently not a major concern