Parts of the Great Wall may collapse and disappear in the near future unless protection efforts are improved, a leading expert has warned.

Only about 20 per cent of the 6,300-kilometre wall is in reasonable shape, another 30 per cent is in ruins, and the rest has disappeared permanently, the China Great Wall Society, a non-governmental organization that champions restoration of the wall, announced on Thursday.

What remains of the wall is "in danger of collapse" because of weathering, erosion and human damage, said Dong Yaohui, secretary-general of the society.

Dong has just finished a 35-day inspection tour of the Great Wall from Shanhaiguan in the east to Jiayuguan in the west. Between 1984 and 1985 he walked the entire length of the wall in 508 days, the first person to do this since 1949.

Tourists visit the Badaling section of the Great Wall during the May Day holiday. Parts of the Great Wall may collapse and disappear in the near future unless protection efforts are improved, a leading expert has warned. [newsphoto]

He said he was distressed to find that even though long-time weathering and erosion have changed the inner structure of many sections of the wall and roots of wild plants have made brick crevices even larger, "no rescue efforts have been made."

Dust is another problem. In some areas it can be as thick as one metre, providing suitable growing conditions for wild plants.  "The situation is especially serious in Beijing, Tianjin and North China's Hebei Province," he warned.

Human damage is also hastening the collapse of the wall. In a village near the Panjiakou section in Hebei's Qianxi County, almost all pigsties and henhouses are built of bricks stolen from the wall, the inspection found.

In Fugu County, Northwest China's Shaanxi Province, local villagers have dug coal mines under the wall. When Dong spoke with a local farmer, the man pointed at the wall and said, "What's the use of this?"

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