By Xu Yuyao
The Potala Palace, a cultural site with a history of more than 1,300 years and the only UNESCO World Heritage site in southwest China’s Tibet autonomous region, is glowing with new vitality under the protection of digital technologies.
With just one click, people can observe a 3D replica of the architectural complex on screens; nearly 800 sensors placed around and in the palace have recorded over 10 million sets of data; over 1,500 monitoring devices and about 9 kilometers of sensing fiber optic cables have been installed to record the conditions of the palace…
The digitalization of the palace was initiated by Dawa Ngodrup, director of the digital center under the Potala Palace’s administrative office, who has been working there for 17 years.
He made the decision to do so after he returned from a 2006 visit to the Dunhuang Academy in Dunhuang, northwest China’s Gansu province, during which he was astonished by many of the technologies applied there to map and protect murals and ancient structures at the Mogao Grottoes, a UNESCO World Heritage site in Dunhuang.
In those years, Dawa Ngodrup spent almost all of his time in the Potala Palace. He always worked extra hours until midnight shooting the details of the murals in the palace, because the palace was visited by large numbers of tourists during the daytime.
Apart from acquiring the digital information of thousands of square meters of murals, Dawa Ngodrup also kicked off a digital modeling project of the entire palace.
The digital modeling was a big challenge given that the palace was built on a mountainside and has complicated structures. 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.
“We did this to form a comprehensive database of the palace’s cultural relics, facilitate researchers’ work, and reduce the risk of damaging cultural relics,” said Thubten Tsering, an official with the administrative office of the Potala Palace.
Real-time structural monitoring of the Potala Palace also mirrors the application of modern technologies in the maintenance of the cultural site. The structural monitoring is a premise for the rational operation of the palace, and is important for the protection of it.
The monitoring system was tailored by professor Yang Na and her team from Beijing Jiaotong University. After four years of preparations, the first phase of the system was officially put into operation in October 2012 to monitor the key parts of the palace’s wooden structures.
Studying the impacts from the tourist flow on the palace’s wooden structures, the system helped establish a control mechanism that regulates the number of visitors according to the structural deformation caused by the tourist flow, so as to prevent the palace from being damaged by regular visiting activities.
The second phase of the system commenced in 2015, with a focus on the walls, foundations and caves featured at the architectural complex.
Staff members can now check data of 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, 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.
The Potala Palace has a poor fireproof capability and collects many inflammable cultural relics, such as Buddhist classics and tangka, a type of Tibetan Buddhist painting on cotton and silk. Now, an automatic fire alarming system has been installed in the palace, which consists 1,524 sensors, buttons and modules, 8,710 meters of sensing fiber optic cables, as well as 86 video fire detectors. Besides, a smart system is installed to monitor electricity consumption in the palace, so as to maximumly prevent the risks of fire disasters.
“Digital technologies and multiple monitoring tools help us better preserve the Potala Palace, a historical and cultural site with a history of over 1,300 years,” said Jondan, director of the palace’s administrative office.
These technologies protect not only the Potala Palace, but also more cultural relics on the Qinghai-Tibet Plateau, he added.