A consortium of 18 scholars from U.S., Europe and Guatemalan institutions including the Ministry of Culture and Sports were enabled by the Fundación PACUNAM (Mayan Heritage and Nature Foundation) to analyze lidar data covering over 2,100 square kilometers of the Maya Biosphere Reserve.
"Since LiDAR technology is able to pierce through thick forest canopy and map features on the earth's surface, it can be used to produce ground maps that enable us to identify human-made features on the ground, such as walls, roads or buildings," Canuto said.
The PACUNAM LiDAR INITIATIVE (PLI), is the largest single lidar survey in the history of Mesoamerican archaeology. The collaborative scientific effort has provided fine-grained quantitative data of unprecedented scope to refine long-standing debates regarding the nature of ancient lowland Maya urbanism. Specifically, the key identifications of this study are:
- 61,480 ancient structures in the survey region, resulting in an estimated population of 7 to 11 million at height of the Late Classic period (650-800 CE). The structures include isolated houses, large palaces, ceremonial centers and pyramids.
- 362 square kilometers of terraces or otherwise modified agricultural terrain and another 952 square kilometers of viable farmland, demonstrating a landscape heavily modified for the intensive agriculture necessary to sustainably support massive populations for many centuries.
- 106 square kilometers of causeways within and between urban centers and numerous, sizeable defensive earthworks. This substantial infrastructure investment highlights the interconnectivity of cities and hinterlands as well as the scale of Maya warfare.
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Ancient lowland Maya complexity as revealed by airborne laser scanning of northern Guatemala
Marcello A. Canuto, Francisco Estrada-Belli, Thomas G. Garrison, Stephen D. Houston, Mary Jane Acuña, Milan Kováč, Damien Marken, Philippe Nondédéo, Luke Auld-Thomas, Cyril Castanet, David Chatelain, Carlos R. Chiriboga, Tomáš Drápela, Tibor Lieskovský, Alexandre Tokovinine, Antolín Velasquez, Juan C. Fernández-Díaz, and Ramesh Shrestha
Science 28 Sep 2018:Vol. 361, Issue 6409, eaau0137
DOI: 10.1126/science.aau0137
INTRODUCTION
Lowland Maya civilization flourished from 1000 BCE to 1500 CE in and around the Yucatan Peninsula. Known for its sophistication in writing, art, architecture, astronomy, and mathematics, this civilization is still obscured by inaccessible forest, and many questions remain about its makeup. In 2016, the Pacunam Lidar Initiative (PLI) undertook the largest lidar survey to date of the Maya region, mapping 2144 km2 of the Maya Biosphere Reserve in Guatemala. The PLI data have made it possible to characterize ancient settlement and infrastructure over an extensive, varied, and representative swath of the central Maya Lowlands.
RATIONALE
Scholars first applied modern lidar technology to the lowland Maya area in 2009, focusing analysis on the immediate surroundings of individual sites. The PLI covers twice the area of any previous survey and involves a consortium of scholars conducting collaborative and complementary analyses of the entire survey region. This cooperation among scholars has provided a unique regional perspective revealing substantial ancient population as well as complex previously unrecognized landscape modifications at a grand scale throughout the central lowlands in the Yucatan peninsula.
RESULTS
Analysis identified 61,480 ancient structures in the survey region, resulting in a density of 29 structures/km2. Controlling for a number of complex variables, we estimate an average density of ~80 to 120 persons/km2 at the height of the Late Classic period (650 to 800 CE). Extrapolation of this settlement density to the entire 95,000 km2 of the central lowlands produces a population range of 7 million to 11 million. Settlement distribution is not homogeneous, however; we found evidence of (i) rural areas with low overall density, (ii) periurban zones with small urban centers and dispersed populations, and (iii) urban zones where a single, large city integrated a wider population.
The PLI survey revealed a landscape heavily modified for intensive agriculture, necessary to sustain populations on this scale. Lidar shows field systems in the low-lying wetlands and terraces in the upland areas. The scale of wetland systems and their association with dense populations suggest centralized planning, whereas upland terraces cluster around residences, implying local management. Analysis identified 362 km2 of deliberately modified agricultural terrain and another 952 km2 of unmodified uplands for potential swidden use. Approximately 106 km of causeways within and between sites constitute evidence of inter- and intracommunity connectivity. In contrast, sizable defensive features point to societal disconnection and large-scale conflict.
CONCLUSION
The 2144 km2 of lidar data acquired by the PLI alter interpretations of the ancient Maya at a regional scale. An ancient population in the millions was unevenly distributed across the central lowlands, with varying degrees of urbanization. Agricultural systems found in lidar indicate how these populations were supported, although an irregular distribution suggests the existence of a regional agricultural economy of great complexity. Substantial infrastructural investment in integrative features (causeways) and conflictive features (defensive systems) highlights the interconnectivity of the ancient lowland Maya landscape. These perspectives on the ancient Maya generate new questions, refine targets for fieldwork, elicit regional study across continuous landscapes, and advance Maya archaeology into a bold era of research and exploration.
Lowland Maya civilization flourished in the tropical region of the Yucatan peninsula and environs for more than 2500 years (~1000 BCE to 1500 CE). Known for its sophistication in writing, art, architecture, astronomy, and mathematics, Maya civilization still poses questions about the nature of its cities and surrounding populations because of its location in an inaccessible forest. In 2016, an aerial lidar survey across 2144 square kilometers of northern Guatemala mapped natural terrain and archaeological features over several distinct areas. We present results from these data, revealing interconnected urban settlement and landscapes with extensive infrastructural development. Studied through a joint international effort of interdisciplinary teams sharing protocols, this lidar survey compels a reevaluation of Maya demography, agriculture, and political economy and suggests future avenues of field research.