Climate change doomed Khmer empire

via CAAI News Media

Kalyan Ray, march 30, New Delhi:

A long-held mystery on what contributed to the demise of one of Asia's longest and the most well-known Hindu empires was revealed thanks to advanced research into the region's climatic conditions.

Scientists have now found that long spells of droughts interspersed with intense monsoon have brought curtains over Cambodia’s Khmer empire, which flourished from the ninth to the thirteenth Century.

At the Proceedings of the National Academy of Sciences on Monday, researchers said two of the worst droughts—in the middle of the 13th Century and early14th Century—combined with intermittent spells of heavy rain was one of the factors that resulted in the downfall of the empire more known for the majestic Angkor Vat temple.

Though the 13th Century drought stretched on for several decades, the dry spell that hit the region on the early 14th century was found to be the sharpest.

The drought in 1403 was reflective of moisture stress in the soil. “It was an extra-ordinarily dry event,” principal investigator Brendan Buckley from Lamont Doherty Earth Observatory at Columbia University in New York told Deccan Herald.

“Droughts of the magnitude we describe here would have had deleterious effects on the Angkor citizenry,” he said.

Scientists unravelled the weather conditions by reconstructing the monsoon period (March to May) for 759 years (AD1250-2008 ) through extraction of climate information stored inside ancient trees in a Vietnam national park.

Vulnerable infrastructure

The Khmer empire relied on a sprawling water supply system that covered an area of nearly 1000 sq km and connected the main city with its extensive suburbs. By the end of the 12th century, it became a vast and convoluted web of canals, embankments and reservoirs.

The infrastructure was huge by any stretch of imagination. The largest reservoir, West Baray, has an area of 16 sq km.

Such a massive infrastructure is “resistant to change” and “vulnerable to the risk of massive damage,” says the team comprising researchers from the US, Australia, Japan, Vietnam and Thailand.

While successive droughts weakened the water supply, the rain that fell heavily in the intervening years had only extended the damage.

The collapsing infrastructure was hard to bear for an empire that struggled to withstand war and other social factors.

“The climate factor was seldom mentioned among the causes of Angkor collapse. The society was already under stress and had very limited strategy to manage a vast and complicated water system that was impossible to rework. They also found themselves under the climate variability that far exceeded their ability to cope,” explained Buckley.

Scientists believe El Nino, the unusually high sea temperature in the Pacific that disturbs climatic conditions across the world, could have been responsible for Cambodia’s seesawing climate. However, they feel more research is required to ascertain this.

DH News Service