Society

Controlled blasts reduce surging lake water levels

By Shen Gang and Xie Yu (China Daily)
Updated: 2010-08-11 07:55

Rescuers conduct the ninth explosion to blast debris damming a river in order to safely release potential flood waters in the mudslides-hit Zhouqu County, Gannan Tibetan Autonomous Prefecture in northwest China's Gansu Province, Aug.10, 2010. The drainage of the barrier lake was accelerated due to the explosion. [Xinhua]

ZHOUQU, Gansu - Engineers and workers battled on Tuesday to drain an unstable lake created by the country's deadliest landslide in six decades, fearing it could burst and swamp devastated areas where people are still hunting for survivors.

Water levels behind the barrier fell by more than one meter after three controlled explosions on Tuesday created more channels to funnel off some water.

But more explosions will be necessary to further lower the raised riverbed as soon as possible, as consecutive rains are expected in the coming days, officials said.

The county seat of Zhouqu, which was hit by deadly landslides on early Sunday morning, is built along the local Bailong River.

The massive landslide left a 10-meter high blockage in the Bailong River, creating a barrier lake and flooding along the north and south Binhe roads, local government officials said in a statement late Monday.

But experts from the Ministry of Water Resources said the speed of water draining from the lake is not fast enough because rains are expected in the coming days and might form a flood peak that would further raise the water level of the barrier lake.

Therefore, engineers and workers, spurred on by Premier Wen Jiabao's instructions to tackle the problem as soon as possible, were increasingly focused on the loose dam and carried out three controlled explosions on Tuesday to further remove the blockage.

Wang Dekai, deputy director of the Geological Disaster Prevention Institute of the Gansu Academy of Sciences, said the explosions should be controlled very carefully, because an ill-placed blast might cause downstream residences to be flooded.

A bigger potential risk is in the city of Wudu, 80 km downstream from Zhouqu, where the flood prevention ability is relatively weak, he said.

Thousands of people have already been evacuated from villages downstream as a precaution.

Reuters contributed to this story.

Rescuers conduct the ninth explosion to blast debris damming a river in order to safely release potential flood waters in the mudslides-hit Zhouqu County, Gannan Tibetan Autonomous Prefecture in northwest China's Gansu Province, Aug.10, 2010. The drainage of the barrier lake was accelerated due to the explosion. [Xinhua]