A LiDAR-based geopedologic approach to address pre-Hispanic agricultural landscapes in Northern Michoacán, West Mexico

Abstract

The methodical exploitation of arable lands in pre-Hispanic Mesoamerica has been recognized since the 16th century, but the Spanish Conquest caused cultivated landscapes to be dramatically modified. Thus, general amazement remains great when remote sensing techniques (RS) like airborne laser scanning (LiDAR) uncover fossilized farmlands. Recent studies demonstrated that agrarian features are widespread among the remains revealed by LiDAR-derived models. Efforts are being made to map these features but few studies have focused directly on the landforms and soils which they modify. Concurrently, while paleopedology has refined the identification of anthropogenic features within soils, spatial approaches correlating soil covers and archaeological sites have received less attention as perspectives often diverge between archaeological mapping, which often focuses on intra-site elements, and soil mapping, which generally encompasses broader areas. Yet, geoscientists have used RS to predict soil parameters and demonstrated that it could increase accuracy in knowledge-based soil maps. Today, while LiDAR-derived data are facilitating archaeological mapping beyond settlement limits, high-resolution RS also offers opportunities for more accurate soil mapping and calls for harmonization of perspectives. We present a method that combines LiDAR-based RS and fieldwork in archaeology and soil science to address pre-Hispanic cultivated landscapes based on a case study in West Mexico. It focuses on the Zacapu area, where long-lasting archaeological and geoecological research offered a solid background. We used LiDAR visualizations, modeling, and satellite images to detect anthropogenic and geopedologic features. The latter was verified through field surveys and test pits. Archaeological material and soil analyses followed. All data were mapped on GIS. As a result, we were able to update and improve significantly both the archaeological and geopedologic maps. The approach further provided an unprecedented reconstruction of landscape appropriation from the 6th to the 15th century AD. It demonstrates that archaeology, geomorphology, and pedology can efficiently complete each other to address more comprehensively pre-Hispanic cultivated landscapes.