Thursday, September 06, 2007

Angkor -- Medieval 'Hydraulic City' -- Unwittingly Engineered Its Environmental Collapse

Angkor at sunset. (Credit: Image courtesy of University Of New South Wales)

September 5, 2007
University Of New South Wales (Australia)

Science Daily — The architects of Cambodia’s famed Angkor – the world's most extensive medieval "hydraulic city" – unwittingly engineered its environmental collapse, says research by UNSW scientists and a team of international scholars.

This revelation, published in the Proceedings of the National Academy of Science, supports a disputed hypothesis by French archaeologist Bernard-Philippe Groslier, who 50 years ago suggested that the vast medieval settlement of Angkor was defined, sustained, and ultimately overwhelmed by over-exploitation and the environmental impacts of a complex water-management network.

A succession of monarchs ruled the Angkor area from about 800 AD, producing the architectural masterpieces and sculpture now preserved as a World Heritage site. By the 13th century the civilisation was in decline, and most of Angkor was abandoned by the early 15th century, apart from Angkor Wat, the main temple, which remained a Buddhist shrine.

Groslier surmised that a network of roads, canals and irrigation ponds established between the 9th and 16th centuries proved too vast to manage. He argued that extensive land clearing for rice fields supporting up to a million people living beyond Angkor's walled city produced serious ecological problems, including deforestation, topsoil degradation and erosion.

Latter-day archaeologists disputed Groslier’s view because he was unable to support his hypothesis with empirical data about the landscape beyond Angkor's central temple complex.

Using modern day aerial photography and high-resolution ground-sensing radar, the international research team, including UNSW’s Professor Tony Milne, studied an area of nearly 3000 square kilometres, confirming Groslier's hypothesis by correlating their images to existing maps, topographic data sets and supporting information from extensive ground-based archaeological investigations.

The team discovered more than 1000 man-made ponds and at least 74 more temple sites in the Angkor region, revealing ruins covering an area of 1000 square kilometres.

The study's radar images were acquired from NASA via an airborne imaging radar (AIRSAR) data instrument capable of accurately reconstructing surface structures through cloud cover.

"The instrument can produce high-resolution images detecting surface structures as small as 20 cms in height and distinguish very subtle differences in surface vegetation and soil moisture,” says Professor Milne from the School of Biological, Earth and Environmental Sciences.

"This was of particular use in uncovering the archaeological landscape at Angkor. The distinctive spatial patterning of features manifests itself primarily in slight variations in topographic relief. This also influences the amplitude or 'brightness' of the radar signal returned to the sensor.”

“Both the topographic relief and the surface brightness can be helpful in identifying the possible location of former roads, canals and rice fields,” says Professor Milne. "When excavations were carried out, they prove to be the site of a canal or temple moat”.

Note: This story has been adapted from a news release issued by University Of New South Wales.

2 comments:

Anonymous said...

French archeologist Bernard Grolier's done so much to save Khmer-Culture,Angkor.....So did French's colony had saved Khmer nation from the 2 hungry neighbours,Yuon-Siem.

Right now the westerners tried to discovery & preserve Khmer-Temples..but they try to forget the suffering Khmer=People, who are the children of Angkor,are living now under Yuon=Colony.
Could they save the races who built Angkor Empire ? or let them die until one day Yuon-Thai will claim that they are Angkorian bloodlines.

Anonymous said...

Without French, Angkor Watt, Siem Reap, Battambong, Po Say, Kg Thom.. provinces are under Thailand just like Surin today... You should thank to French that you are not Thai if you are from Battambong.