Jiao Meiyan, director of the National Meteorological Center, said Sichuan Province and Chongqing Municipality were hit by severe drought in 2006 but both areas have suffered relentless rainstorms this summer.

"The contrasting weather has convinced us that the rumor saying the Three Gorges Project, in particular the dam, had obstructed water vapor from entering Sichuan and Chongqing was not justified, " he said.

Since mid-July, Sichuan and Chongqing have been pounded by heavy rainstorms that could only happen once in a hundred years, leading to a huge number of casualties. By July 20, more than six million citizens were affected by the continuous rainfall in Chongqing.

Jiao said Sichuan and Chongqing came under a strong subtropical high pressure belt in 2006, which caused high temperatures. But the belt has been in a more eastern position this year, which made it much easier for water vapor from the Bay of Bengal and the South China Sea to accumulate over Sichuan and Chongqing.