GEOMORPHOLOGICAL AND ARCHITECTURAL SCANNING OF PRE-COLUMBIAN EARTHWORKS IN SOUTHERN PERU

Ground based lidar provides an innovative technique to document and understand the erosion of pre-Columbian architectural structures, ceremonial sites and agrarian systems, in southern Peru and the geomorphic processes in hyper-arid environments. The fine-scale surface mapping allows for creation of micro-elevation models that serve as starting point for reconstructing past landscapes, pre-Columbian agricultural architecture, surface processes operating in the region, and most importantly document archaeological patrimony. The integration of the disciplines of geomorphology and archaeology aid the understanding degradation processes and also provides direction for preservation efforts. Ground based Lidar is well-suited for sub-centimeter resolution surface mapping of architectural features and terraced landscapes; this technique provides larger areal coverage compared to more traditional mapping methods. Preliminary work concentrated on agrarian systems and structures near known pre-Columbian settlements, agrarian storage units, and major architectural landmarks due to the vast expanse of terraced hillsides in southern Peru. Three sites are examined as case studies: the Inka (1450-1532 CE) administrative center of Sabaya, the Wari (600-1000 CE) administrative center at Cerro Baul and Estuquiña and Inka agrarian systems in Camata and Pampa Colorada. This superimposed anthropogenic landscape has evidence of advanced erosion in some areas by development of rills and gullies, some of them enhanced by recent anthropogenic activities. In addition, wash processes have affected the agricultural terraces and have caused the height terrace risers to decrease considerably. The documentation and quantifycation of the pattern and rate at which these constructed landforms degrade is of paramount importance for finding a balance between preservation of the delicate arid landscapes and the sustainable development in these impoverished regions. Recognizing their potential for agricultural productivity of the agrarian systems, the local government is developing plans to reactivate the systems for modern agriculture; therefore detailed mapping of structures and agrarian systems provides information on preservation, construction methods and past irrigation methods.