In addition to about 380 existing man-made dams that were significantly damaged by the quake, the Chinese authorities are faced with an estimated 35 new "natural" dams formed when hills and mountains collapsed into rivers, according to Xinhua.
These natural barriers, which have formed "quake lakes" such as Tangjiashan, pose a particular challenge. "Human factors come into play in an evacuation" from a newly formed dam, the report quoted Andy Hughes, from engineering company Atkins, as saying. "People living downstream may not recognise that there is a real danger because they are not used to having a dam above them."
" But engineers say the Tangjiashan lake emergency should not divert all attention from damaged man-made dams. Most prominent is the 156-metre-high Zipingpu dam, completed in 2006.
Experts add that Chinese dam engineers are among the best in the world, the report said. "They have certainly brought themselves up to the best international standards," said Hughes. But the scale of the disaster is making life hard for the Chinese authorities. "The worst problem for them is the sheer amount of work – and deciding on the order of priorities for the emergency operations," the report quoted Ian Cluckie, from Bristol University, as saying.
See full story