Fortunately for Deng, whose plight might have easily been ignored, the desertification which made it nearly impossible for him to eke out a living also fuelled the spring-time dust storms that blow through Beijing, leaving tonnes of sand on the streets.

Seven years ago, with the desert creeping south at the rate of 3 km (2 miles) a year and the dust storms getting worse, the Chinese government decided to act and the solution was typical of a country where the Great Wall stands as the ultimate grand project.

It began building a "Green Great Wall", a 700-km (435 mile) barrier of trees and enclosed grassland which will stretch across Inner Mongolia, Hebei and Shanxi provinces by 2010.

Deng's entire village -- whose 478 residents are all Han Chinese -- were relocated by the government to make room for the green barrier which Beijing hopes will hold back the desert.

"In our hearts we were reluctant to move because we were nostalgic. It's not easy to leave the place I was born and grew up," said the 50-year-old, standing in the living room of the four-room brick house where he now lives.

"But it was getting very hard to earn a living. The government came again and again over half a year to try and convince us," he told reporters on a government-organised trip for foreign media.

Desertification is no longer just a problem for China and the thick yellow dust of the sand storms now reaches as far as South Korea, Japan and at times even the United States and Canada.

The award of the 2008 Olympics to Beijing in 2001 gave further impetus to the project, officials said, even if dust storms never hit the capital in August when the Games will be held.

In 2000, Deng's entire village was cleared out and its residents moved 20 km south to the new village of Fuquan. They were provided with houses, a well, a communal toilet, 2.5 mu (0.411 acres) of land each and a barn to store their produce.

Deng, who lives with his wife, daughter, son and daughter-in-law, said their annual household income was now 10,000 yuan, many times what they made in the hardest years of the late 1990s.

They retain ownership of the 10.5 mu (6 acres) of land where their old home stood and tend the trees that now grow there.

Most importantly, Deng says, transport is much easier without having to negotiate through the sand. His grandchildren can attend school and medical care is within reach.

Overgrazing

Fuquan is in Duolun county, some 350 km north of central Beijing and close to the site of 13th century Mongol Emperor Kublai Khan's summer place Xanadu.

By 2000, overgrazing, deforestation, wind erosion and drought meant nearly 90 percent of Duolun county was affected by desertification.

Since then, 2.63 million trees have been planted, farmers have been forced to switch from wheat to grass production and all grazing has been banned in the worst affected areas.

China's anti-desertification campaign has not been without controversy.

Exile groups accuse the government of using the environment as an excuse to further assimilate the Mongolian community, which is now outnumbered about five to one in Inner Mongolia thanks to decades of migration by Han Chinese.

Duolun county officials stress that local residents, particularly the 8,300 people like Deng who have been relocated, have benefited financially from the changes.

"Before relocation, the average annual income of the farmers and herdsmen was less than 700 yuan ($92), now it's 2,608 yuan," Zhou Feng, vice-mayor of the county, told a news conference.

On a hill in the neighbouring Taipusi County, vice-mayor Zhang Baowen points north beyond the lines of young Mongolian pines snaking over green hills.

"The Hunshandake desert is 5 km over there," he said. "In 2000, the situation was atrocious and then Premier Zhu Rongji stood here and gave the instruction to transform the desert."

In other parts of his county, better soil conditions have enabled the planting of apricot trees, but it is mostly poplars that now populate an area with 385 mm of annual rainfall.

"The trees we have planted, poplars, can grow very well in these conditions," he said. "There has been no situation where trees have died in the drought. This is not like the Gobi desert where if there is no irrigation, the trees will die."

Zhang said the battle was not won but the first goal of stopping the desert moving south had been achieved.

"As far as I know, the encroaching situation has been curbed," he said. "Desertification has been going on since the 1970s. The project only began in 2000. It takes a long time to prevent and control the sand fully. We have a long way to go."