From Waterscape to Landscape: Structural and Technological Modifications between Aztec Period and Modern Chinampas of Xochimilco associated with Long-term Social and Ecological Changes

Archaeologists have long recognized structural and functional differences between pre-Hispanic and historic or modern chinampas in the Basin of Mexico. Nonetheless, ethnographic chinampa systems have often been used as an analog for modeling the Late Aztec period raised fields in the southern basin. Computing and software advances since Pedro Armillas' seminal analysis of relic fields visible in historic air photos have enabled the digitization of more than 1,000 hectares of Aztec period chinampas in the former Xochimilco lakebed. The contiguous 1,000 hectare relic field sample represents the best preserved Aztec fields depicted in historic air photos because the area persisted as marshland fewer than two decades before the drained lakebed was photographed from above beginning in 1936. The empirical relic field data permit a spatial and quantitative comparison of Aztec, historic, and modern chinampa systems. The temporal transformation of Xochimilco chinampas can be understood in the context of social and ecological landscape changes over the past 500 years. In spite of substantial structural and functional changes between pre-Hispanic and modern systems, Xochimilco chinampas remain a very productive agricultural system. In addition to a comparative analysis, this paper addresses technological changes in the chinampa system associated with long-term socio-cultural and ecological changes in the southern Basin of Mexico. The chinampa canals we boat along, the organic dark soils we see, and the farming strategies we observe all have a deep pre-Hispanic ancestry; however, the continually changing social and ecological landscape gives rise to novel and altered farming strategies for maintaining productivity.

The presenter is completing his dissertation titled Modeling the Aztec Agricultural Waterscape of Lake Xochimilco: A GIS Analysis of Lakebed Chinampas and Settlement at the Pennsylvania State University. He began his Mesoamerica archaeology career in the mid-1990s as a crew member on Late Archaic and Early Formative projects in the Soconusco, Chiapas while receiving his BA and MA in Anthropology from UC Santa Barbara. He worked as a field archaeologist in the Southwest US for four years before taking a BS in Geography (GIS) at Penn State and working as a GIS professional. Most recently, he enrolled in the Anthropology PhD program at Penn State combining his background in archaeology and GIS to model the development and structure of the southern lakebed chinampa system during the Late Aztec period. Additionally, he has continued working as a seasonal archaeologist for the National Park Service in the Southwest US.