China "quake lake" fears trigger new evacuation
CHENGDU, China (Reuters) - China has evacuated more than150,000 people living below a swollen lake formed by thismonth's devastating earthquake in the mountainous province ofSichuan, state media said on Wednesday.
The Tangjiashan lake was created when landslides caused bythe May 12 earthquake blocked the Jianjiang river above thetown and county of Beichuan, near the epicentre of China's mostdestructive earthquake in decades.
The official death toll from the 7.9 magnitude quake wasraised on Tuesday to 67,183, and was certain to rise further as20,790 are listed as missing. The quake injured nearly 362,000people and new aftershocks toppled 420,000 houses and injureddozens on Tuesday.
Downstream from the lake, residents were evacuatedovernight as engineers dug a diversion channel to preventflooding.
"According to contingency plans, up to 1.3 million peoplefrom 33 townships of Mianyang city could be relocated if thelake barrier collapses entirely," the China Daily said in itsonline edition.
The water level in the lake, one of 35 "quake lakes" formedby the tremor and holding the volume of about 50,000Olympic-size swimming pools, has kept rising and the giantsluice would not be ready for another week, the China Dailyquoted experts as saying.
Immediately below the lake, the river runs in a loopbetween flattened high- and low-rise buildings, but threatenscommunities downstream which held evacuation drills on Tuesday.
In Tianlin village, among the first to be flooded if thelake bursts, gongs and loudspeakers directed 680 villagers torush to surrounding hills within 20 minutes.
"The flood will sweep our village in five or six hours ifthe dam collapses," the village head was quoted as saying.
The lake water level was 727.09 metres on Tuesday, only24.21 metres below the lowest part of the unstable landslipbarrier, according to the Mianyang City Quake Control andRelief Headquarters.
In the last century, about 5,500 people have been killed byflash floods after barrier lakes burst through dams made bylandslides, according to a 2004 paper by geologists at theChinese Academy of Sciences.
In 1786, the breach of a landslide dam 10 days after amajor earthquake killed about 100,000 people in Sichuan.
The region along the faultline is densely packed with dams,raising concerns that if either the quake lakes or the weakeneddams burst, the rush of water could cause other dams to fail.
Apart from the threat of flooding disasters, officials aretrying to stave off epidemics as the temperature rises and therainy season approaches.
A massive relief effort, which involves providing food,tents and clothing for millions and the reconstruction ofhousing and infrastructure, is expected to take up to threeyears.
(Writing by Nick Macfie; Editing by Alex Richardson)