Image: Tom Chandler and Monash UniversitySaturday, 17 March 2007
Ancient city fell due to climate change
University of Sydney
Climate change and an inflexible water supply were key factors in the demise of the medieval city of Angkor, according to new discoveries by University of Sydney archeologists and their international colleagues.
Based on radar images taken by NASA technology, researchers have shown the temples of Angkor, the famous World Heritage Site, lay at the heart of the largest single pre-industrial, low density urban complex on the planet.
"Angkor was the Los Angeles or greater New York of its time. At its maximum size in the 12th-13th century CE it would have covered about 1,000-square kilometres," says Roland Fletcher, Associate Professor of Archeology at the University of Sydney.
To sustain a population of 750,000 the Khmers cleared large tracts of land to grow rice and build housing says A/Professor Fletcher. "The city was criss-crossed by the built channels and embankments - an enormous, meticulously organised water management system capable of flood management and providing controlled water for agriculture."
A/Professor Fletcher and his colleagues with The Greater Angkor Project (an international collaboration between the University of Sydney, French researchers and the Cambodian managers of Angkor) have now discovered two large structures that played a key role in this system. Built by Khmer engineers using their expertise in masonry construction, they controlled water coming out of a reservoir in central Angkor.
The city was mysteriously abandoned some 500 years ago - some believe the Khmers deserted the city after a Thai army ransacked it. But these recent discoveries confirm A/Professor Fletcher's theory that a water supply crisis was the real reason for the city's demise.
One of the new-found structures that controlled the water system was a 40m by 80m spillway, the other was a 100m by 40m outlet channel. Professor Fletcher says the structures were found to have been blocked, suggesting the water management network began to break down later in the history of Angkor.
These latest discoveries come on top of previous field work which led A/Professor Fletcher's team to conclude the city was abandoned when destabilised river flows (due to land clearing) and new monsoon patterns (due to climate change) made the site unsustainable.
"As the canals filled with sand, it appears water broke through their embankments, badly damaging this essential infrastructure. It now appears the city was abandoned during the transition from the medieval warm period to the little ice age."
Whether or not Angkor, in Cambodia, had a vast water management system has been a topic of intense debate. "Up until the 1980s it was thought that Angkor did not have an irrigation system, merely reflective ponds and water channels for aesthetic and ritual purposes", says A/Professor Fletcher.
Michael Coe, the Grant McCurdy Emeritus Professor of Anthropology at Yale University and author of a recent major book on Angkor, says the latest findings by the Greater Angkor Project "has pretty much laid this debate to rest" (see Science March 2007 Vol 311:1367).
Professor Fletcher says this latest finding shows us it is probably "unwise to build oneself into a single, very big, very complicated interconnected water management system".
Based on radar images taken by NASA technology, researchers have shown the temples of Angkor, the famous World Heritage Site, lay at the heart of the largest single pre-industrial, low density urban complex on the planet.
"Angkor was the Los Angeles or greater New York of its time. At its maximum size in the 12th-13th century CE it would have covered about 1,000-square kilometres," says Roland Fletcher, Associate Professor of Archeology at the University of Sydney.
To sustain a population of 750,000 the Khmers cleared large tracts of land to grow rice and build housing says A/Professor Fletcher. "The city was criss-crossed by the built channels and embankments - an enormous, meticulously organised water management system capable of flood management and providing controlled water for agriculture."
A/Professor Fletcher and his colleagues with The Greater Angkor Project (an international collaboration between the University of Sydney, French researchers and the Cambodian managers of Angkor) have now discovered two large structures that played a key role in this system. Built by Khmer engineers using their expertise in masonry construction, they controlled water coming out of a reservoir in central Angkor.
The city was mysteriously abandoned some 500 years ago - some believe the Khmers deserted the city after a Thai army ransacked it. But these recent discoveries confirm A/Professor Fletcher's theory that a water supply crisis was the real reason for the city's demise.
One of the new-found structures that controlled the water system was a 40m by 80m spillway, the other was a 100m by 40m outlet channel. Professor Fletcher says the structures were found to have been blocked, suggesting the water management network began to break down later in the history of Angkor.
These latest discoveries come on top of previous field work which led A/Professor Fletcher's team to conclude the city was abandoned when destabilised river flows (due to land clearing) and new monsoon patterns (due to climate change) made the site unsustainable.
"As the canals filled with sand, it appears water broke through their embankments, badly damaging this essential infrastructure. It now appears the city was abandoned during the transition from the medieval warm period to the little ice age."
Whether or not Angkor, in Cambodia, had a vast water management system has been a topic of intense debate. "Up until the 1980s it was thought that Angkor did not have an irrigation system, merely reflective ponds and water channels for aesthetic and ritual purposes", says A/Professor Fletcher.
Michael Coe, the Grant McCurdy Emeritus Professor of Anthropology at Yale University and author of a recent major book on Angkor, says the latest findings by the Greater Angkor Project "has pretty much laid this debate to rest" (see Science March 2007 Vol 311:1367).
Professor Fletcher says this latest finding shows us it is probably "unwise to build oneself into a single, very big, very complicated interconnected water management system".
1 comment:
It is an interesting article. But I'd like prof. Fletcher to elaborate more the findings with some precise evidence, please!!!!
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