Chinese geological experts have reassured the public that water filling of the Three Gorges reservoir will be safe and reliable amid fears of possible geological disasters such as catastrophic earthquakes.
"The 135-meter-deep reservoir won't cause major geological disasters that would endanger the dam's safety, hamper navigation or incur great losses," said Liu Guangrun, chief scientist of geological disasters prevention at the Three Gorges.
The reservoir's sluice gate was closed on Sunday and the water level is expected to rapidly rise to 135 meters within two weeks.
"China has established its largest-ever system to prevent and control probable geological disasters at Three Gorges area," said Liu, who is also an academician of the Chinese Academy of Engineering.
Liu said the sites where minor geological disasters had been discovered or were at risk were closely monitored or controlled.
Geological disasters like landslides, collapses and muck-rock flows were very common before the construction of the Three Gorges Project, sparking fears about possible calamities after the water storage.
"We are capable of handling geological disasters, given our current engineering technologies," Liu said.
Lin Wenliang, a senior official with the Three Gorges Project Bureau of the Yangtze River Water Resources Committee, agreed that the filling of the Three Gorges reservoir was unlikely to lead to catastrophic earthquakes.
"There is a small possibility the reservoir causing earthquakes because it is belt-shaped, extending 660 km, and in such a big area, the per unit pressure caused by 35 billion cubic meters of water will be insignificant," Lin explained.
Moreover, Lin went on, the Three Gorges Project was built on a complete solid granite structure where no rupture had been recorded for thousands of years, so even if there was an earthquake caused by the reservoir, the intensity would be no bigger than six degrees on the Richter scale, the strongest recorded earthquake in the Three Gorges Area.
"The nearest previous earthquake rupture zone is 39 km from the site of the Three Gorges Dam, but the Three Gorges Project is designed to withstand earthquakes measuring seven degrees on the Richter scale," Lin added.
During the past two years, China has invested four billion yuan (US$482 million) in the prevention and control project of geological disasters in the Three Gorges area.
A geological disasters monitoring and early warning system had also been set up in the Three Gorges reservoir area, said Hu Xuqing, an official in charge of the geological calamities prevention office of the reservoir area, Chongqing, western China's biggest municipality.
"We have launched 24-hour monitoring of the geological situation in the reservoir area and will issue early warnings if necessary," Hu said.
Advanced technologies like satellite remote sensing had also been used in monitoring the geological situation in the reservoir area.
The construction of the Three Gorges Project, the world's biggest hydro-electric project, began in 1993 and is expected to be completed in 2009.
(Xinhua News Agency June 3, 2003)
