Using airborne lasers, a team of archaeologists from the University of Sydney discovered that climate change destabilised the Cambodian city’s water system, contributing to its demise nearly 600 hundred years ago.
The findings are relevant even today because they relate to the vulnerability of low-density urbanism to climate change, explains Professor Roland Fletcher of the University of Sydney, who leads the Greater Angkor Project in Cambodia.
Angkor had been the largest pre-industrial city in the world, covering an area of about 1,000 square kilometres. In comparison, the Mayan city of Tikal in Guatemala was only between 100 and 150 square kilometres.
Using remote sensing technology called LiDAR, the team discovered that in order to support such a dispersed, low-density ‘urban sprawl’, the city relied on a complicated water management network that stored and dispersed water throughout the area. They also found that the demise of Angkor was related to extremely unstable climate change that caused severe damage to the water network.
LiDAR technology aims a light beam at the ground to map everything in 3D from the tops of the trees to the ground, enabling the archaeologists to uncover the form of the ground surface under the dense forest cover – an important tool in a region like central Angkor that is still densely forested.
Their groundbreaking work is the subject of a two-part documentary called Angkor Wat’s Hidden Megacity. Part one was aired on Sunday in Australia.