Over 1,700 years ago, ancient Chinese farmers turned one of the driest deserts on earth into farmland, perhaps using the ancient knowledge of irrigation passed down by travelers to the Route de Silk, according to a new study.

Archaeologists made the discovery using satellite images to analyze the arid foothills of the Tian Shan Mountains in northwest China. These peaks form the northern border of China’s vast Taklamakan Desert and are part of a chain of mountain ranges that have long housed the prehistoric Silk Road routes connecting China to the lands to the west.

Satellite imagery of a particularly dry area has caught the researchers’ attention: an area dubbed Mohuchahangoukou, or MGK, which receives a seasonal trickle of snowmelt and rainfall from the Mohuchahan River. From the ground, the area looks like little more than a scattering of boulders and ruts, but when researchers flew a four-rotor “quadcopter” commercial drone about 100 feet (30 meters) above MGK To capture images, they were able to see the outlines of dams, cisterns and irrigation canals feeding a patchwork of small agricultural fields, the scientists said. [The 10 Driest Places on Earth]

The first excavations at the site confirmed the presence of farms and tombs which, based on radiocarbon dating and other methods, probably date back to the 3rd or 4th century CE, the scientists noted. This ancient farming community was likely built by local herding groups who sought to add crops such as millet, barley, wheat and possibly grapes to their diet, the researchers added.

“It was very surprising to me that a site of this size had not been discovered earlier by scientists, who have studied this region for 100 years,” study author Yuqi Li told Live Science. , archaeologist at the University of Washington in St. Louis.

By supplying farms with river water, this ancient, well-preserved irrigation system has helped people grow crops in one of the world’s driest climates. The area on the edge of the Taklamakan Desert historically receives less than 3 inches (6.6 centimeters) of precipitation per year, or about one-fifth of the water generally considered necessary to grow even the most resistant strains of wheat and millet. drought, the researchers mentioned. The region is drier than the Kalahari in southern Africa, the Gobi Desert in Central Asia and the American Southwest, but not as dry as the Atacama Desert in Chile or the Sahara Desert in North Africa, said Li.

The new findings could help resolve a long-standing debate about how irrigation techniques were first introduced to this arid corner of northwest China’s Xinjiang region. While some researchers suggest that all of the major irrigation techniques were brought to Xinjiang by Han Dynasty troops in China, which lasted from around 206 BC. .

“The most likely scenario is that this irrigation technology comes from the West,” Li said.

Previous work has suggested that so-called agro-pastoral communities, which practiced both agriculture and herding along the mountain ranges of ancient Central Asia, may have spread crops in an area scientists call the corridor. mountain range of inland Asia. This giant exchange network may have spread across much of the Eurasian continent, bringing together former nomadic groups as they moved herds to seasonal pastures, and possibly also spreading techniques of irrigation. [In Photos: Ancient Silk Road Cemetery Contains Carvings of Mythical Creatures]

The researchers noted that irrigation systems similar to MGK’s were also found in the Geokysur River Delta oasis in southeastern Turkmenistan dating from around 3000 BC. almost identical to MGK is seen in the farming community of Wadi Faynan, which was established in a desert environment in southern Jordan during the latter part of the Bronze Age (2500 BC).

In contrast, the irrigation systems known from the Han Dynasty in Xinjiang are larger than those from MGK. For example, while the MGK system irrigates about 500 acres on seven plots, the systems introduced by the Han Dynasty in the Xinjiang communities of Milan and Loulan used wider and deeper rectilinear channels up to about 5.3 miles. (8.5 kilometers) long to irrigate much larger areas. One irrigated over 12,000 acres (4,800 hectares).

“The sophistication of the system at MGK surprised me,” Li said. “Previously, I thought the agro-pastoralists there were randomly growing crops to supplement their diets, but we found an elaborate system. [that they used] to help in their agriculture. It is very likely that they had a very sustainable system for developing agriculture in a desert environment, possibly more sustainable than those built by Han Dynasty troops. “

There is still a lot to discover for scientists in Xinjiang, Li said. “The drone allows me to survey a large area very cost effectively with very little investment of time and energy,” he said. note.

Li and his colleagues detailed their findings in the December issue of journal Archaeological research in Asia.

Original article on Live Science.