Modern technologies aid preservation of millennium-old Potala Palace in SW China’s Xizang

The use of modern technologies and devices has injected fresh vitality into the Potala Palace, a UNESCO World Heritage site with a history of more than 1,300 years in Lhasa, capital of southwest China’s Xizang Autonomous Region.

The Potala Palace is seen near the Lhalu wetland national nature reserve in Lhasa, southwest China's Tibet Autonomous Region, July 17, 2021. (Xinhua/Zhang Rufeng)

With nothing but the click of a mouse, people can observe 3D digital models and murals reproduced in the image of the architectural complex. Nearly 800 sensors placed around the structure have recorded over 10 million sets of data inside the palace compound for roughly the past 10 years. Over 1,500 monitoring devices and about 9 kilometers of sensing fiber optic cables have been installed to comprehensively monitor the conditions in and around the palace.

Dawa Ngodrup, director of the digital center under Potala Palace’s administrative office, has already been working at the palace for 17 years after he got his start back in 2005. Back then, only traditional approaches were employed to record the cultural relics inside the palace.

In 2006, Dawa Ngodrup pursued further vocational studies at the Dunhuang Academy in Dunhuang city, northwest China’s Gansu Province, where he was astonished by many of the technologies being applied there to map and protect the site’s many murals and ancient structures.

After he returned from Dunhuang, Dawa Ngodrup participated in the digitalization of the Potala Palace, starting off by digitalizing several thousand square meters of murals, which was a huge challenge. To collect all of the necessary data on the murals in recorded images, over the years the man often worked extra-long hours and late into the day burning the midnight oil.

Another big challenge was building digital models of the whole architectural complex, given that the palace was built on a mountainside and is characterized by its complicated structure. Many technologies, including UAV aerial photography, 3D laser scanning, and multi-view image reconstruction, were used for rendering the digital modeling of the ancient architectural complex.

“Our efforts have aimed to form a comprehensive database of the palace’s cultural relics, facilitate researchers’ work, and dramatically reduce the risks of damaging cultural relics,” said Thubten Tsering, an official with the administrative office of the Potala Palace.

Yang Na, a professor from Beijing Jiaotong University in Beijing, and her team customized a highly technical system for monitoring the structure of the palace.

After four years of preparations and seven months of installation and trial operations, the first phase of the structure’s monitoring system was officially put into operation in October 2012. The first phase of the system’s operations was mainly applied to monitor key parts of the palace’s wooden structures.

In 2015, Yang’s team and the palace’s administrative office began to conduct feasibility studies on the second phase of the structure’s monitoring system before putting it into operation, with a focus on the walls, foundations and caves featured at the architectural complex.

Staff members can now check data on the palace’s walls via an app on their mobile phones, thanks to the installation of 388 sensors, including crack meters, inclinometers and soil moisture meters, which can realize the real-time monitoring of any movement across surface cracks, ambient temperatures, the angles of inclinations for walls and pillars, among other key parameters. The second phase of the system’s operations, which was put into use in August 2021, can automatically create quarterly analysis reports.

“We have recorded over 10 million sets of data about the palace in about 10 years, which has enabled us to understand the overall changes of the Potala Palace,” said Yang.

“Technologies aid in the preservation of the palace and will help us protect more cultural heritage sites on the plateau,” said Jondan, who is currently serving as the director of the palace’s administrative office.

In addition, an automatic fire alarm system, which consists of multiple detection devices that include 86 video fire detectors and 8,710 meters of sensing fiber optic cables, has been installed inside the Potala Palace in the hope of preventing incidents of fire to the greatest extent possible.

“Digital technologies and multiple monitoring tools help us to better preserve the Potala Palace, a historical and cultural site with a history of over 1,300 years,” Jondan stated.