25 June 2009
One of archaeology’s great mysteries has been solved. According to the team headed by Professor Roland Fletcher, the great medieval city of Angkor was abandoned due to the combined effects of climate change, the vast extent of city, extensive clearance of forest and the massive scale of its complicated water system.
The findings were based on the research of the Greater Angkor Project, a collaboration between the University, the great French research agency EFEO and APSARA the Cambodian agency that manages Angkor. A decade of research studying the decline of urbanism at Angkor has now been combined with new tree-ring-dating evidence that uses long-lived species in the region such as the 900-year-old po mu tree. Evidence that extreme fluctuations between drought and heavy monsoons were occuring between the 1350s and the about 1500 was found in the annual growth rings of the tree.
At its height from the 12th to 14th centuries, the elaborate city of Angkor had a population of about 750,000 and was the most extensive, low density urban development of the preindustrial world. Yet by the 17th century, the city was in ruins and abandoned.
The archaeological team investigating the phenomena of Angkor includes the University of Sydney’s Professor Fletcher, and paleoclimatologist Dr Dan Penny. The tree ring evidence has been provided by paleoclimatologist Brendan Buckley of New York’s Columbia University.
The researchers hypothesise that the decline of the city was due to extensive problems with the massive structures of its vast, and complicated water system and the compound effect of a series of droughts and monsoonal floods in the mid-14th to late 15th centuries.
In an article in The National Geographic Professor Fletcher said, “Angkor really had no fat to burn. The city was more exposed to the threat of drought than at any other time in its history. Prolonged and severe droughts, punctuated by torrential downpours, would have ruined the water system.”
The findings have important lessons for contemporary readings of climate change. As experts debate the effects of human-made climate change, the tree rings of the po mu tree around Angkor reveal that even natural variations in weather can bring about catastrophe.
Source: The University of Sydney
Contact: Sarah Stock
Phone: 02 9351 4312 or 0419 278 715
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