Satellites help to retrace travel routes of Bronze Age herders in China

Nov. 4 (UPI) -- To retrace the ancient migration routes taken by Bronze Age herders in northwestern China, researchers turned to space.

Satellite images allowed researchers to map the distribution of archaeological evidence across the 640,000-square-mile autonomous region known as Xinjiang, according to a study published Wednesday in PLOS One.

Interviews with modern-day herders also helped researchers contextualize the data and model the ways ancient herders likely navigated the rugged terrain.

"This detailed model of how Bronze Age people capitalized on the resources in their environment helps greatly in understanding the prehistoric Silk Road," lead author Peter Jia said in a news release.

"For example, our ethnographic studies -- interviews with local herders -- have explained why certain locations were and still are chosen throughout the seasons: for the presence of early and late grass, optimal grazing potential in summer, and the absence of snow cover in the winter," said Jia, an archaeologist with the University of Sydney in Australia.

Local artifacts have previously yielded relatively few insights into where exactly herders in Xinjiang were during different parts of the season, but researchers were able to make headway by taking a bird's-eye view of the archaeological evidence and talking with modern herders in the region.

"Now we have a new validated method for determining the season in which people stayed in a place," said co-author Alison Betts, a professor of archaeology at the University of Sydney.

Domesticated animals helped humans begin to settle across the harsh landscapes of Xinjiang during the Bronze Age, but the region remains a dangerous place to live.

Especially snowy winters can leave goats and cattle without enough food to eat. Conversely, dry winters can leave local human populations without enough water to drink.

Seasonal migrations have long been essential to herders as they attempt to avoid disaster and survive the dangers of cold, rugged terrain.

The authors of the latest study credited their interdisciplinary approach for the success of the investigation. By combining space technologies, archaeological field work and ethnographic surveys, they were able to gain fresh insights into the movements of ancient people.

"Archaeology is one of the few fields that provides insights into how humans have interacted with the environment in the past," said co-author Gino Caspari.

"With exacerbating environmental conditions worldwide, it is crucial to analyze this history. This task requires us to connect academic disciplines and cooperate internationally. Our study is a good example of this," said Caspari, an archaeologist at the University of Sydney.