Beyond the magic wand: methodological developments and results from integrated Lidar survey at the ancient Maya Center El Pilar

Abstract

Large-scale Lidar surveys have revitalized interest in regional settlement studies in the Maya Lowlands. Remotely identified features in Lidar imagery must be verified on the ground, with results of ground-truthing studies forming the basis of reliable, comparative databases for understanding ancient Maya land use and modification. The El Pilar Project integrates data generated by established survey methods with Lidar imagery to construct more complete pictures of settlement distribution, landscape modification, and human-environment interactions. This paper describes the results of Lidar-guided survey at El Pilar along with the protocol our project developed to systematize data collection and increase the efficiency of survey. The methods we describe have proven effective for investigating Maya settlement patterns at the site scale and locating features difficult to discern in Lidar imagery.

Detecting Classic Maya Settlements with Lidar-Derived Relief Visualizations

“…Unsurprisingly, the findings of this study suggest that larger plazuelas and archaeological features are generally more discernable in the lidar-derived relief visualizations, although this relationship is inconsistent among smaller features, due to the size of structures and plazuelas and vegetation cover. This study emphasizes both the utility of relief visualization for the detection of archaeological features and the importance of ground-truthing and pedestrian survey [17]. These findings further our understanding of the extent and density of Classic Maya settlements in previously undocumented survey zones, highlighting the variations in the relief visualization techniques, continued need for pedestrian survey in conjunction with remote sensing, and the utility and shortcomings of remote archaeological prospection.…”

“…Scholars studying prehistoric hillforts in Slovakia [29] and Slovenia [30] used SVF for the identification of archaeological features. SVF was successfully applied to the detection of ancient Maya plazuelas and structures at El Pilar [17]-which is a protected forest reserve-as well as Chichén Itzá [35]. SVF proved less successful both on the UAP data and in the Northern Maya Lowlands at Ucanha [6].…”

“…Factoring in a 14.7% rate for false positives, the number of new possible plazuelas is still over 1150. The ability to remotely detect large plazuelas informs the extent of the settlement system, but the inability to detect more than half of the surveyed plazuelas groups, and especially smaller plazuelas groups often associated with hinterland households [49], highlights the need for ground-truthing in conjunction with remotely identified archaeological features [17,35].…”

“…The differences in ground returns are due to variations in sensors [46,61] and vegetation cover and density. Variations in vegetation include semi-urban and developed areas [41], shifting agricultural cycles [6,8,9], vegetation types in different microenvironments [10], and heavily forested regions such as preserves, reserves, and parks that have not undergone major anthropogenic modifications for decades [2,8,17]. Old forest growth on protected lands results in cleaner point clouds that facilitate the ability to detect archaeological remains on the resulting relief visualizations [62].…”

“…Particularly in the past two decades, novel technologies such as Light Detection and Ranging (lidar) revolutionized the use of remote sensing for archaeological prospection. In the tropics, these technologies can improve archaeological prospection through the remote and digital identification of archaeological features [11][12][13][14][15][16], thus increasing the efficiency of pedestrian archaeological survey [17,18]. Here, I assess the applicability of four methods (three relief visualization techniques and an object-based image analysis (OBIA)) based on aerial lidar-derived data, to remotely detect small archaeological features associated with hinterland settlements in the Maya Lowlands.…”