Twenty-two families living on a hillside about 17 km upstream from the Three Gorges dam are to be relocated after local government officials recorded abnormal ground movements in the area.

The relocation will affect all 99 residents of Miaohe, a village in the Maoping Township, in Zigui County, central China's Hubei Province, which sits on the northern bank of the Yangtze, China's longest river.

Zhao Zongzheng, chief of the agricultural office of Zigui county government, said that by late October, all the villagers will have been moved into new government-financed homes some 2 km away.

A report by the Zigui county government said that on April 10, a crack measuring 200 m long was spotted running west to east through Miaohe village.

With the possibility of a major incident occurring, the county government at first planned to move the 99 residents into makeshift shelters built inside a tunnel close to the village by May 18. However, Zhao said that following further monitoring work using GPS (global positioning system), it was apparent that there was no immediate danger.

However, the official didn't rule out the possibility of more serious land movements in the coming months caused by the changing water level of the Yangtze or heavy rainfall in the Three Gorges area.

Cheng Chongjun, director of the Three Gorges division of the Yangtze Three Gorges shipping administration, said the land movement was most likely caused by the changing water level of the Yangtze.

"Villagers told me that the crack began to appear late last year at a time when the water level in the Three Gorges Reservoir fell from its usual mark of 156 m," Cheng said.

The level of the reservoir has been deliberately lowered in preparation for the annual summer floods. The level will be taken down to 144 m.

In addition to putting up warning signs in the area, Zigui county government is working with shipping departments to monitor the situation and has assigned more people to patrol the area.

The Three Gorges Project, the world's largest water control facility, is situated on the middle reaches of the Yangtze River.

It features a 185-m-high dam, which was completed on June 20, 2006 and a five-tier ship lock. Its construction also required the resettlement of more than 1.2 million people.

The lock, which is 6.4 km long and cost 6.2 billion yuan (US$804.6 million), was built into mountainous terrain on the northern bank of the Yangtze and now provides the only navigable route through the dam.

Construction of the lock began in April 1993. Trial operations began 10 years later and it became fully operational in July 2004. By the end of 2005, some 190,000 vessels carrying 89 million tons of cargo, and more than 1.88 million passengers had passed through it.

(China Daily May 8, 2007)