By Chris Buckley
DUJIANGYAN, China (Reuters) - A Chinese lake damaged by anearthquake may be about to burst its banks, state media said onSaturday, as President Hu Jintao headed for the epicentre withthe death toll expected to rise to 50,000.
Forty-six seriously injured people needed to be evacuatedimmediately in Beichuan, also at the epicentre of Monday's 7.9magnitude quake, where the water level of a lake was risingrapidly and may burst, Xinhua news agency said.
It did not give details but Hong Kong cable television saidsome 1.2 million people were being evacuated in Qingchuan,about 90 km (55 miles) northeast of Beichuan, as rising watersthreatened to burst a lake's banks there.
Anger has been mounting at the large number of schoolswhich collapsed and there is growing concern about the safetyof dams and reservoirs which have been weakened in themountainous province of Sichuan, an area about the size ofSpain.
Survivors were found on Saturday, five days after thedisaster, including a German tourist who was pulled from rubblein Wenchuan after being buried for 114 hours, Xinhua said.
China has put the known death toll at over 22,000 but hassaid it expects it to exceed 50,000. About 4.8 million peoplehave lost their homes and the days are numbered in whichsurvivors can be found.
"Although the time for the best chance of rescue, the first72 hours after an earthquake, has passed, saving lives remainsthe top priority of our work," Hu told distraught survivorsjust over a week after a jubilant China celebrated the Olympictorch reaching the summit of Mount Everest.
In earthquakes elsewhere in the world, survivors have beenfound a week or more after the disaster. In Baguio in thePhilippines in 1990, a cook was found alive in the rubble of ashattered hotel after two weeks.
He had drunk his own urine and drops of rainwater to stayalive. A man and a woman trapped for 11 days in an elevatorshaft in the hotel were also rescued.
Among other survivors on Saturday, Xinhua said 33 peoplewere dug out of the rubble in Beichuan, one of the worst hitareas. One young man was rescued after being buried for 104hours and troops evacuated 18 scientists trapped in a forest inMianzhu.
Premier Wen Jiabao said the 7.9 magnitude quake was "thebiggest and most destructive" since before the Communistrevolution of 1949 and the quick response had helped reducecasualties.
That compares even with the 1976 tremor in thenorth-eastern city of Tangshan which killed up to 300,000people.
"THE WHOLE MOUNTAIN CHANGED SHAPE"
And as the weather gets warmer, survivors were increasinglyworried about hygiene and asking questions about theirlonger-term future.
"What we don't need now is more instant noodles," saidtruck driver Wang Jianhong in the city of Dujiangyan. "We wantto know now what will happen with our lives."
In Beichuan, thousands of homeless flooded out of mountainsinto the city of Mianyang, many put into military trucks andtaken to a refugee centre.
"It was really bad up there," farmer Dian Minggui said."The whole mountain changed shape and all the homes aretoppled."
Two schools were among demolished buildings in the townshipof Xiang'e, northwest of Dujiangyan.
"All the children were buried," said elderly woman YangXiaoqu. "The lucky ones were those who cut class."
In Sichuan and neighbouring Chongqing, at least 17reservoirs have been damaged, with some dams cracked or leakingwater. Several are on the Min River, which tumbles through theworst-hit areas between the Tibetan plateau and the Sichuanplain.
The Lianhehua dam, built in the late 1950s northwest ofDujiangyan, showed cracks big enough to put a fist in.
"When the dam is in this shape, we cannot feel relaxed,"said farmer Feng Binggui who has moved from his village belowthe dam into the hills.
China is also on precautionary alert against possibleradiation leaks, according to a government website.
China's chief nuclear weapons research lab is in Mianyang,along with several secret atomic sites, but there are nonuclear power stations.
China has sent 130,000 troops to the disaster area, butroads buckled by the quake and blocked by landslides have madeit hard for supplies and rescuers to reach the worst-hit areas.
Offers of help have flooded in and foreign rescue teamsfrom Japan, Russia, Taiwan, South Korea and Singapore havearrived.
(Additional reporting by John Ruwitch in Mianyang, NickMacfie in Beijing and Donny Kwok in Hong Kong; Editing bySanjeev Miglani)
