Angkor Wat (Nagara vatika, garden-city of Kamboja)
Full text at: http://www.pnas.org/cgi/reprint/0702525104v1
New Angkor Wat map unveils ancient secrets
Tuesday, 14 August 2007
by Hamish Clarke
Sprawling metropolis: The ancient settlement surrounding the main temple at Angkor is now known to be three time bigger than previously suspected. Complex irrigation structures are seen to fan out for 20 to 25 km beyond the main city.
SYDNEY: Radar and aerial photography have helped experts build a detailed new picture of an intricately designed settlement stretching for many kilometres around the ancient Cambodian temples of Angkor Wat.
The research provides a timely warning, revealing how the complex engineering features of Angkor may have led to its downfall by disrupting the local environment.
“Our results show that Angkor, beyond the well-known temples, was a vast collection of interlinked water management devices such as canals and reservoirs interspersed with small, local temples and occupation features such as mounded areas and ponds,” said Damian Evans, from the Spatial Science Innovation Unit at the University of Sydney in Australia.
Archaeologists have been trying to map the boundaries of the sprawling agricultural environs of Angkor in Siem Reap province since the 1950s, but the ancient remains have been subsumed by modern residential and agricultural developments, complicating the task.
Evan’s led a team of Australian, Cambodian and French researchers who cracked the problem by linking information from hand-drawn maps, ground surveys, airborne photography, and ground-sensing radar provided by the U.S. space agency NASA.
Many years of data crunching later, they were able to identify over a thousand previously undetected man-made pond structures and at least 74 long-lost temples, all part of a massive network linked by a single hydraulic system. The system likely provided Angkor’s citizens with a stable water supply despite the unpredictable monsoon season.
Their findings are published today in the U.S. journal The Proceedings of the National Academy of Sciences.
Evans said the size and extent of land use in Angkor was sufficient to have profoundly impacted on the regional ecology. “In the new maps and the excavations… we can see what looks to be evidence of this – breaches in dykes and barrages, attempts to patch up the system and stratigraphies [sediment layers], which suggest chaotic flows of water.”
“For over one hundred years the research focus at Angkor has been on the magnificent temples, and on the sandstone inscriptions that are often found with them,” said Evans. It has only been with the collapse of the brutal Khmer Rouge regime in the 1990s and the opening up of local research centres that people started to “look beyond these great structures to investigate where it actually was that people lived, how they fed themselves, and so on.”
Janice Stargardt a geographer from the University of Cambridge, in England, commented that the re-mapping of Angkor and its extensive hinterland was significant “not only as an exercise in improved mapping using the latest technology, but also because of their sharp focus on the ancient irrigation works, linear embankments and their consequences both for ancient agriculture and settlement patterns.”
Experts now know that the medieval settlement surrounding Angkor – the one-time capital of the illustrious Khmer empire, which flourished between the ninth and 14th centuries – covered a 3,000 square kilometre area. The urban complex was at least three times larger than archaeologists had previously suspected and easily the largest pre-industrial urban area of its kind, eclipsing comparable developments such as Tikal a Classic Maya “city” on the Yucatan peninsula in Mexico.
It remains to be seen whether the engineering feats of Angkor were a cause, a symptom, or a result of the city’s decline. “The new map at least tells us where we ought to be looking for the answers,” said Evans.
with Agençe France-Presse
Vast ancient settlement found at Angkor Wat
22:00 13 August 2007
NewScientist.com news service
Emma Young, Sydney
http://www.newscientist.com/data/images/ns/cms/dn12474/dn12474-1_250.jpg Aerial photos of remnants of Angkor settlement. Occupation mounds and ponds (upper left). Canals and embankments (upper right). Roadway and canal (lower left). Village temple area (lower right) (Image: Proceedings of the National Academy of Sciences)
http://www.newscientist.com/data/images/ns/cms/dn12474/dn12474-2_729.jpg The new map of Angkor Wat combines data from ground-sensing radar with aerial photographs and extensive fieldwork (Image: Proceedings of the National Academy of Sciences)
A huge urban sprawl once surrounded Cambodia’s famous Angkor Wat temple, according to a newly created map. The scale of the settlement makes it more plausible that the inhabitants of Angkor brought on their own society’s collapse through environmental degradation.
The new map uses data from high-resolution, ground-sensing radar and aerial photographs to augment extensive fieldwork. By detecting slight variations in vegetation and ground moisture due to underlying ruins, the radar reveals in unprecedented detail the location of temples – including 94 newly identified temple sites plus another 74 that have yet to be checked on the ground – ponds, roads and canals.
Researchers in the Greater Angkor Project at the University of Sydney in Australia, together with colleagues in Australia, Cambodia and France, used the techniques to survey the entire watershed of the Angkor region.
The area covers nearly 3000 square kilometres, most of which is now blanketed with dense vegetation. Earlier maps suffered from problems with the resolution of aerial photographs and radar data, and from difficulties with accessing remote regions.
The researchers found that about two thirds of this region was once occupied, making it by far the biggest pre-industrial settlement yet documented. The main urban district of about 1000 square kilometres was surrounded by suburbs that seem to spread far beyond the north-western and south-eastern borders of the study site.
In fact, says Damian Evans of the University of Sydney, “there is just no obvious boundary” for the settlement. The population of the area was probably around half a million, he adds, though earlier estimates of a million inhabitants – suggested in the 1970s – could still be correct.
Such extensive settlement may help explain why Angkor, which thrived between the 9th and 16th centuries, had been overwhelmed by vegetation by the time European explorers first encountered the site in the 1860s.
The main theory for Angkor’s abandonment is that the creation of an extensive water management system caused environmental damage that ultimately led to the failure of the system, leading to food shortages. That scenario now seems even more likely.
“This new map lays out definitively what the system would have looked like – and shows that it was capable of significantly impacting on the local environment,” says Evans.
Local people cleared land, creating a complex system to move water from a region of high ground spanning about 500 square kilometres to storage reservoirs in the centre, and on, via canals, to irrigate about another 500 square kilometres of land to the south. This system would have allowed the society to produce surplus rice to feed workers engaged in building monuments such as Angkor Wat.
The new map also reveals apparent failures of the canal system, with multiple dykes at certain sites. “There is massive redundancy in the canal network – and that gives us an indication that things were going wrong,” says Evans.
Researchers have not yet dated these sites to confirm that they coincide with Angkor’s collapse, however. Nor is it clear what exactly might have gone wrong. “We have evidence of a huge water-management system that had the capacity to impact significantly on the environment,” says Evans. “But at the moment, the actual evidence that it did so is pretty thin on the ground.”
Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0702525104)