Ancient spirals in Peruvian desert used as 'sophisticated' irrigation system
|The funnel-like shape helped to draw the wind down into the underground canals |
They said the holes formed part of a 'sophisticated' hydraulic system that allowed the ancient Nazca civilisation to retrieve water from underground aquifers.
The Nazca culture, which flourished around 100BC to 800AD, were the same people who created the vast geoglyphs on the featureless landscape, also known as the Nazca lines.
Rosa Lasaponara, from the Institute of Methodologies for Environmental Analysis in Italy, said the holes appear to have allowed the Nazca to survive in the notoriously drought hit region.
She said the water drawn to the surface by the funnel-shaped holes turned the area into a flourishing landscape able to support agriculture.
Talking to BBC Future: 'What is clearly evident today is that the puquio system must have been much more developed than it appears today.
'Exploiting an inexhaustible water supply throughout the year, the puquio system contributed to an intensive agriculture of the valleys in one of the most arid places in the world.'
Archaeologists have long suspected the puquios were used as part of an aqueduct system, but how they worked has been poorly understood.
They are thought to be distinct from the huge bands of holes that can be seen in the nearby Pico Valley, which are though to have been used by the Nasca for storage.
|The holes were constructed so they spiral downwards in a funnel. While many have|
fallen into disrepair, some appear to be still functioning, meaning some areas of
the desert still receive water from the system [Credit: Getty Images]
They also examined current soil moisture and vegetation change in the region using satellite data.
The group concluded the puquios appear to have helped irrigate the surrounding landscape through the network of channels.
In some cases there is evidence the puquios are still functioning to a lesser degree today.
It is thought they operated by channelling wind into the earth down the corkscrew holes and into a series of underground canals that carried water from aquifers.
This influx of air kept the water moving along the canals, forcing it out into the network of channels in areas where it was needed.
Dr Lasaponara and her colleagues are due to present their findings at the General Assembly of the European Geosciences Union later this month.
In a paper written for the meeting, Dr Lasaponara and Nicola Masini said that despite this feat of engineering, the Nazca were still subject to the whims of nature.
'Despite the arid and extreme nature of the environment, this region was populated by important civilizations, such as Paracas and Nazca, which flourished in the Early Intermediate period (200 BCE-500 AD),' they explained.
'In particular the Nazca civilisation is well-known for its refined and colourful pottery, characterized by a rich icononographic repertory, and, above all, by the huge and mysterious geoglyphs drawn on the arid plateaus of the Rio Grande de Nazca Basin.
'In order to practice agriculture, the Nazca developed adequate strategies to cope with hostile environmental factors and water scarcity, building a very efficient aqueduct system.
'They were aided by the fact that underground water was likely enough close to the surface and accessible by constructing wells and underground aqueducts, known with quechua name of puquios.
'The effectiveness of the techniques of hydraulic engineering depended on the climate and the weather events that sometimes underwent drastic changes, as results of the cyclical phenomenon of El Niño Southern Oscillation.'
The Nazca are perhaps more famous for the giant geoglyphs and images etched into the desert of Peru. Little is known about this civilisation as they had no writing system.
But Dr Lasaponara claims the construction of the puquios shows just how sophisticated they were.
She told the BBC: 'What is really impressive is the great efforts, organisation and cooperation required for their construction and regular maintenance.'
Author: Richard Gray | Source: Dail Mail Online [April 14, 2016]