Utility of UAS Photogrammetry and Thermal Sensors for Identifying Locations and Understanding Functions of Puebloan Gravel Mulch Fields in Northern New Mexico

Abstract

This article presents results from an unmanned aircraft system (UAS) aerial remote sensing study to improve understanding of Pueblo agricultural features in the Northern Rio Grande area of New Mexico that were in use by the 13th century ad. It builds on previous archaeological research that has focused on recording precontact and historic Pueblo agricultural practices, pollen analyses and paleoclimatic reconstruction. Evidence suggests that Pueblo people were successfully growing crops including maize, cotton and wheat, in areas where, based on environmental conditions, they could not necessarily grow. This study seeks to better understand the environmental modifications employed by Pueblo peoples to enable growth of these crops. Cobble-bordered gravel mulch field systems, thought to retain heat and moisture, are located throughout the study area. This article discusses the utility of airborne photogrammetry to locate and map gravel mulch fields on the landscape. Geographic information system (GIS) analysis of the UAS-derived digital surface model includes slope, aspect and water flow direction and sink to shed light on gravel mulch field function. The article also discusses the potential of handheld and airborne infrared imaging for assessing the thermoregulation of these fields. Final consideration of how the survey results align with the priorities of the Tewa people for future arid-land farming demonstrates additional utility of the approach.