Global mural conservation standards gain momentum

Carved into cliffs on the edge of the Gobi Desert in Gansu province, the Mogao Caves have stood for centuries as a testament to cultural exchange along the ancient Silk Road. Renowned for their exquisite murals and painted sculptures, the site is not only a treasure of the past but also a source of knowledge shaping how such heritage is preserved today.

Drawing on decades of conservation experience at sites like the Mogao Caves, China is expanding its role in global heritage protection. It has launched a new international working group on mural conservation standards, bringing together experts from 15 countries.

The International Working Group on Mural Conservation Standards, under the International Organization for Standardization Technical Committee on Cultural Heritage Conservation (ISO/TC 349), was officially established on March 26. It is led by China, with Su Bomin, then director of the Dunhuang Academy, serving as convener.

The move follows ISO's approval of "Conservation of cultural heritage — Mural paintings — Classification of deterioration", the first international standard initiative focused on mural conservation within its global framework.

Developed by experts from 11 countries, including China, the United States, Italy, and France, the standard establishes a unified system for classifying mural deterioration, helping overcome longstanding challenges caused by inconsistent terminology, such as communication barriers and difficulties in data sharing. It also provides a common technical language for identification, documentation, assessment, and conservation decision-making.

The framework categorizes deterioration into types, including optical changes, physical deformation, deposits, material loss, structural damage, biological deterioration, and chemical degradation. Each is clearly defined and supported by visual references to ensure consistent interpretation across contexts.

Experts say the standard will improve the scientific rigor of mural investigation, monitoring, and restoration, while strengthening international cooperation in heritage conservation.

The work builds on decades of research and conservation practices by the Dunhuang Academy, which oversees several major heritage sites, including the Mogao Caves, the Maijishan Grottoes and the Bingling Temple Grottoes, as well as other nationally protected sites.

Wang Wanfu, deputy director of Dunhuang Academy's conservation research department, says digital technologies, especially artificial intelligence, are playing an increasingly important role in mural conservation and restoration in China.

"For instance, we monitor environmental conditions such as temperature and humidity, and conduct surveys to detect cracks and flaking, assessing whether deterioration is active or stable," Wang says.

"AI can process large volumes of data, including high-resolution images, to identify early signs of damage that are difficult to detect with the naked eye."

He notes that early detection enables timely human intervention.

"By identifying problems at a very early stage, we can slow deterioration," he says, comparing the process to medical diagnosis, where early detection is critical for effective treatment.

AI is also being applied in restoration.

"When restoring elements like the ribbons of flying apsaras, AI can analyze styles from different periods and generate multiple restoration options," Wang says.

"These are then evaluated by archaeologists, art historians and conservators to determine the most appropriate solution."

Beyond standard-setting, China is expanding collaboration with Central Asian countries. A China-Kyrgyzstan joint laboratory on cultural heritage conservation under the Belt and Road Initiative has been established to share technologies and experiences in preserving Silk Road sites.

Su says the platform will focus on heritage protection and cultural exchange, aiming to build a science and technology innovation hub for the conservation and research of ancient Silk Road murals, grottoes and earthen sites.

Wang says China's decades of experience in conserving ancient cities, tombs and sections of the Great Wall can be applied to similar environments in Central Asia.

"Through the joint laboratory, we are sharing our technologies and participating in conservation projects in countries such as Kyrgyzstan."

Contact the writers at huyumeng@chinadaily.com.cn