A series of sand control efforts have been implemented to shield the Mogao Grottoes in northwest China's Gansu Province from the relentless forces of wind and sand erosion, yielding remarkable results.
Situated on the edge of a vast desert, the Mogao Grottoes have faced wind and sand threats for centuries. Wind and dust that enter the caves have damaged the murals and colored sculptures, posing significant risks to their preservation.
"Dunhuang is located in an area surrounded by multiple deserts with abundant sand sources. Whenever wind speeds exceed Force four (5.5 meters per second), they stir up sand and dust. The region faces winds of this intensity for over half of the year, posing a major challenge to the preservation of the grottoes," said Qin Xia, a senior engineer at the Dunhuang Meteorological Bureau.
The cliff edge near the Mogao Grottoes is bordered by a vast expanse of gravel Gobi, whose hard texture resists wind-driven sand, allowing it to remain in its natural, untouched state. Adjacent to this gravel Gobi stands a massive A-shaped sand barrier, part of an integrated sand control system.
Beyond the fence, researchers have carefully developed a comprehensive sand control system atop the Mogao Grottoes, designed to effectively block wind and prevent sand erosion.
"This graph shows the sand accumulation in front of the grottoes from 1990 to 2024. In 1990, the sand accumulation was quite high, reaching 28 to 30 kilograms per square meter. However, after the completion of our project, particularly after 2010, the sand accumulation gradually decreased. The amount has stayed remarkably low since 2019. Sand accumulation has dropped by 85 percent from 3,000 cubic meters in the 1980s to less than 200 cubic meters now, which is the most noticeable result," said Zhang Guobin, a researcher at the Dunhuang Academy.
In the fight against wind and sand, the Dunhuang Academy has collaborated with experts from both domestic and international institutions. Together, they have employed a variety of strategies, such as creating sand control trenches, building wooden fences to block sand, and using chemical methods to stabilize the sand. Despite these achievements, efforts to protect the site continue, with ongoing research to develop even more effective solutions against sand erosion.
Sand control measures shield Mogao Grottoes from erosion
