Space for New Discoveries

(China Daily)--- A type of archaeology, employing remote sensing and a multidisciplinary approach, is helping researchers unearth significant historical sites, Li Yingxue reports.

Often, when people talk about space technology, they are looking outward toward the stars and to worlds beyond our own. However, those same technical systems can also be used to improve knowledge of our own planet and our civilization. So, how exactly can space information technologies be applied to the research, monitoring and protection of cultural and natural heritage? Wang Xinyuan, deputy director of the International Center on Space Technologies for Natural and Cultural Heritage under the auspices of UNESCO, answered this question in an online lecture where he shared projects and discoveries last month.

The online class was held by the center on June 13, China's annual Cultural and Natural Heritage Day.

The center was launched in 2011 in Beijing. As the first UNESCO category II center applying space technologies to the monitoring and conservation of the world's natural and cultural heritage sites, it is hosted by Aerospace Information Research Institute at the Chinese Academy of Sciences.

Wang introduced how his team discovered ancient sites in Gansu province in 2013 and also led international teams to find 10 archaeological sites in Tunisia in 2018 using space information technology.

He said he hopes the online course will inspire more people to devote themselves to protecting the world's cultural and natural heritage.

"It is not only the duty of professionals, the whole of society should also take responsibility," Wang says. "Us scientists have the duty to specify why, what and how to protect them to the public."

Wang says to study world cultural and natural heritage is a comprehensive subject that requires multiple areas of expertise, from geology and geomorphology to paleontology, as well as knowing how to protect and manage them.

Space archaeology is a new branch of archaeology, with highly interdisciplinary attributes that link the natural sciences, sociology and humanities.

As a specialist in this new field of study, Wang says, to protect the cultural and natural sites, we also need to protect the environment around them.

"The task of space archaeology is to reveal the history, characteristics and patterns of human activities in the past, as well as to understand the evolutionary processes guiding the relationship between people and their environment," he says.

Before taking up research in remote sensing, Wang's specialty was geography and geology.

In 2013, Wang's team found five ancient city sites, the remains of more than 10 houses in two residential villages, one ancient channel site, one ancient road site and one pottery kiln site in Guazhou (Anxi)-Shazhou (Dunhuang) section of Gansu province along the major route of the ancient Silk Road.

This discovery, uncovered by using the remote sensing technology which provides abundant physical materials for the study of the history and geography of China's northwest frontier, fills the archaeological gap between sites from the Han Dynasty (206 BC-AD 220) and the Tang Dynasty (618-907) in the west of the ancient city of Bazhou.

"The sites of the places we discovered are in untraversed regions that are quite difficult for people to explore," Wang says. "Dry land is where remote sensing can make full use, especially in difficult-to-reach places."

They first did literature analysis by researching historical documents about the route before using remote sensing to pinpoint areas they suspected could yield results. Then his team worked together with researchers from local museums in Gansu to conduct on-the-spot investigations to verify each site.

"When you are on the ground, it can be difficult to ascertain whether the course of a river is natural or human made, but with the help of the sensors mounted on the space-borne platform which provide a more macroscopic view, you can tell," Wang says.

"The visual field of people is limited, but the emergence of remote sensing technology has given them a pair of eyes in space."

The experience and success in Gansu gave Wang confidence when he led his team to research the project in Tunisia.

Inspired by one of Wang's international students, a Tunisian, the project soon became one of international cooperation.

In 2018, Wang led a space archaeology research team, including scientists from Tunisia, Italy and Pakistan, to discover 10 ancient Roman archaeological sites in Tunisia. They were unearthed at the western end of the maritime Silk Road after two years of remote sensing image processing and field investigation.

Tunisia was an important port for maritime trade under the Roman Empire. The archaeological sites they discovered are located in three Tunisian provinces-Gafsa, Tataouine and Medenine-the 10 sites include three sections of Rome Limes, two military fortifications, one agricultural irrigation system, three tanks and a burial site.

According to Wang, the discoveries are of great significance for not only the study of the empire's military defense systems, agricultural irrigation systems and the relationship between nomadic nationalities and ancient Rome, but also changes in ancient oases and environmental evolution.

"The Lime wall and fortress were used to defend and protect the border and prevent the harassment by the nomads from the south and the west. Meanwhile, the agricultural irrigation system and the water tanks for storing fresh water were used to ensure grain production and serve the living needs of the border soldiers," Wang says.

"It has a similar function to the Great Wall," he adds.

Wang's team used high-resolution satellite remote sensing imagery to judge the suspected sites on the basis of historical information and ancient maps, as well as employing a comprehensive geographic information system for spatial analysis.

In the following field verification process, a joint team of remote sensing experts and archaeologists conducted the survey and verification.

"The precise locations of the site were identified by using the satellite remote sensing along with navigation and positioning systems," he adds.

It was the first time that a Chinese scientist had led such a project-involving major countries in Asia, Europe and Africa-to discover foreign archaeological remains and conduct systematic research by using space information technology in the field survey.

Bai Guangming, a cultural counselor at the Chinese embassy in Tunisia, said in a previous China Daily report that the country's advanced remote sensing technologies will provide great scientific support and strengthen cultural exchanges among countries involved in the Belt and Road Initiative.

This project is funded by the Digital Belt and Road Program, of the Chinese Academy of Sciences.

According to Wang, multiple international cooperation projects have been undertaken by his team. While the COVID-19 pandemic has delayed their plans for international field trips this year, the research and analysis work are still in full swing.

Source: China Daily