Aftershocks, avalanches and flooding could bring more geological disasters to China
Pastor Dale Morgan
**Aftershocks, avalanches and flooding could bring more geological
disasters to China*
by Staff Writers
Beijing (AFP) May 22, 2008
Aftershocks, avalanches and flooding could bring more geological
disasters to China's mountainous southwest following last week's
devastating earthquake, a senior government official said Thursday.
The 8.0-magnitude earthquake has increased risks along China's Dragon
Gate seismic fault, a well-known geological landmark, Yun Xiaosu, vice
head of the Ministry of Land and Resources, told reporters.
"As rain increases during the rainy season and coupled with the
continuous aftershocks, it is very probable that geologic hazards in the
disaster area will increase and again bring a large amount of losses,"
he said.
Heavy rains were likely to bring greater instability to the mountains
that had already been greatly shaken by the earthquake and its nearly
170 aftershocks, Yun said.
"This has made the work of monitoring, prevention and mitigation of
potential geologic disasters great and the tasks before us arduous," he
said.
The quake, the biggest to hit China in more than 30 years, has left over
80,000 people dead or missing, and more than five million homeless.
Most of the flattened towns and villages have been along the
200-kilometre (120-mile) long Dragon Gate seismic fault in the Himalayan
foothill region of Sichuan province.
Yun said one of the biggest concerns was the creation of 34 bodies of
water known as "quake" or "barrier" lakes that formed after landslides
blocked rivers. He said they could burst and threaten populated areas.
"We must be aware that the barrier lakes that we have identified are
very serious," said Liu Yuan, vice director of the ministry's geologic
environment department.
"I want to be clear about this in order to ensure safety -- if these
barrier lakes burst, the after effects will be severe over a wide area."
Officials had ordered people in all threatened areas near the quake
lakes to evacuate, he said.
Experts were studying ways to engineer channels around or through the
barriers to alleviate rising waters and reduce the potential dangers,
especially on the Minjiang river, a major tributary of the Yangtze, he said.
The officials further warned that more quake lakes could be formed if
the frequency of aftershocks, landslides and avalanches in the
mountainous region increased during the rainy season, which begins next
month.
On Thursday, the government announced that 167 aftershocks over 4.0
magnitude had struck along the Dragon Gate seismic fault since the May
12 quake, with four registering over magnitude 6.0.
The fault, also known as the Longmenshan fault, runs along the rugged
and steep Dragon Gate mountains, which form a geological border between
the plain of Sichuan province and the towering Himalayan mountains, the
world's highest.
Yun said his ministry had identified more than 4,900 geological hazards
along the Dragon Gate fault before the earthquake struck, of which 158
of them were considered major hazards.