World leaders in the use of LiDAR in archaeology gather at UCT conference

“I remember as a graduate student that textbooks represented hot and tropical environments as places where civilisations went to die,” quipped Professor Marcello Canuto, the director of Middle American Research at Tulane University in the United States (US), as he opened his presentation. 

One such tropical community referred to is that of the late-classical Mayans. Everyone knows of the Mayan pyramids, such as those that rise up out of the jungle at Tikal, Guatemala, or Calakmul in the Yucatan Peninsula, Southern Mexico. And that where there are pyramids, there were people. But consensus held that people lived in modest groups around such buildings, leaving the swathes of jungle in between largely empty and pristine. 

Today this colonial-era assumption is being resoundingly flipped. The use of ground-breaking laser-imaging and mapping technology is unveiling not only the vast scale of historical settlements, but the complex social, political, agrarian and economic organisation it would have taken to sustain them. 

Professor Canuto was presenting at the LidArc Conference and Workshop, held at the University of Cape Town’s (UCT) Graduate School of Business, which drew archaeology and engineering experts from across the continent, the US, South America and Italy, as well as luminaries in archaeology from UCT. 

Mayan megalopolis exposed after 1 000 years of solitude 

What was unknown until recently and hidden for over 1 000 years by a sea of impenetrable tropical jungle is the sheer extent of the population that spanned the parts of Mexico, Guatemala and Belize – dubbed the Central Mayan Lowlands.

It is only recently that, thanks to ground-breaking Light Detecting and Ranging (LiDAR) technology, with its ability to capture 3D images of man-made structures through vegetation, that the full extent of this civilisation is beginning to be exposed at what Canuto described as “daily levels of discovery”. 

“The baking, scrubby hills of northern Johannesburg are proving to be places where civilisations once thrived. 

Far from the scattered million or so once believed to have existed here, population estimates now sit at a staggering 16 million people. In the sweltering, densely vegetated, rain-soaked tropics, LiDAR is exposing the expansive, interconnected, late-classical Mayan megalopolis that burgeoned there between 600 and 900 CE.

Far from modest-living, agrarian households, LiDAR is now shining light on extensive agricultural terracing and irrigation canals, raised causeways linking communities, fortresses and suburban residential clusters sprawling from coveted hillsides into the damper valleys below. 

Far from being places where civilisations came to die, places like the Mayan Lowlands, or indeed the baking, scrubby hills of northern Johannesburg, are proving to be places where civilisations once thrived. 

Revolutionising global archaeology 

On screen is the projected image of the pyramid at Calakmul, buried deep in lush jungle that stretches out in an emerald carpet to the distant horizon. Nothing hints at anything but wilderness. 

“And yet, the community stretched from here to the distant horizon, as far as the eye can see,” said Dr Luke Auld-Thomas, assistant professor at Northern Arizona University. “Our picture of lowland Mayan civilisation has been utterly shaped by the inability to readily see its remains, because everything is hidden by vegetation.”

But, he added, the jungle has served to exquisitely preserve these millennium-year-old urban landscapes. 

Being presented over a two-week conference, were the early results and technological expertise behind Global Digital Heritage’s (GDH) substantial LidArc Initiative. 

“The LidArc Initiative is one of the largest archaeological mapping projects in the world.”

The Hitz Foundation donated US$10 million towards the initiative, to be spent over five years towards the LiDAR mapping of such historical sites; as well as towards the digital preservation of multiple historical sites that range from Malawi, to Uzbekistan, Jordan, Scotland, Alaska and many more. 

“The LidArc Initiative is one of the largest archaeological mapping projects in the world, and it’s made possible by the foundation,” said Siddique Motala, scientific director for GDH Afrika (GDHA) and associate professor at UCT’s Department of Civil Engineering. 

The ambitious mapping project uses LiDAR, which harnesses laser pulses from plane or drone to cut through vegetation and capture high-resolution, 3D images of the remains of built environments below at scale, while GPS receivers offer pinpoint geographical accuracy. 

The democratisation of science 

Alongside GDHA’s commitment to documenting, monitoring and preserving global and local cultural heritage is its commitment to the democratisation of science. All data gathered across all sites is freely available to everyone. 

And so it is with the KGOSING Project, which has to date mapped 16 500 km north-east of Johannesburg. With the ability to process 1 000 km of data a day, the project is unveiling the scalloped stone walls of household after household, in numbers that are rewriting history. 

“What is known about the indigenous people of South Africa is not enough. We look forward to changing that.” 

In an area just north of Rustenburg, for example, Dr Herbert Maschner, the president of GDH and GDHA, chief scientist at GDH and chairperson of the conference, had originally estimated there to be in the region of 1 000 households, but in fact these have now been revealed by LiDAR to number 3 600 in this area alone.

Motala said: “We are proud of what we have achieved in a short time.The results are remarkable and have at least doubled the number of homesteads that were known. What is known about the indigenous people of South Africa is not enough. We look forward to changing that.