The Yemaomian (wild cat face) landslide is 17 kilometres upstream of
the Three Gorges dam in Hubei province's Zigui county. Chinese experts
identified the old landslide as unstable and prone to collapse in 2003,
when the filling of the Three Gorges reservoir began. As predicted,
several slides have forced residents to flee their homes since then.
Fears were raised again last month when residents of Miaohe village
discovered a 200-metre fissure in the Yemaomian landslide. This week,
99 villagers from 22 households were evacuated as a precautionary
measure in case the landslide, which carries an estimated 12 million
cubic metres of rock and earth, drops into the Yangtze river.
Although the cause of the crack is still unclear, no major rainstorms
or any significant changes in the GPS monitoring network have been
recorded in the reservoir area. But a preliminary investigation cited
by one local official suggests the crack was prompted by water level
fluctuations in the reservoir.
"According to local people, the crack on the Yemaomian slide was caused
by the fluctuation of water levels after the reservoir was filled to
156 metres last October," Cheng Chongjun, director of the Three Gorges
area administration of the Yangtze and Three Gorges Navigation
Administrative Bureau, told Xinhua.
"Our preliminary investigations reveal that the deformation of the
slide is most likely related to these reservoir fluctuations."
Zhao Zongzheng, a county official, said he fears that the deformation
could worsen when the reservoir is lowered to 144 metres in preparation
for the approaching flood season. Although the crack is currently
stable, heavy rainfall or unexpected seismic activity could trigger
further deformation.
Three Gorges dam, the world's biggest, was built in a geologically
unstable area prone to landslides. In 2001, a survey by the Changjiang
Water Resources Commission identified 1,320 zones in the area at risk
of landslides. Senior water engineers warned that impounding a huge
body of water in the 600-km-long reservoir could activate at least 760
landslips � many of which have since broken loose in Hubei province and
beyond.
The county government said that by the end of October, new houses will
be built for the Miaohe evacuees on a flat area just two kilometres
from the reactivated landslide. Xinhua did not report where the displaced villagers will live between now and then.