The severe drought which plagued Southwest China's Sichuan Province and Chongqing Municipality this summer was not caused by the Three Gorges Dam, a meteorological expert said Monday.

"The rare drought was the result of global warming as well as abnormal atmospheric circumfluence," said China Meteorological Administration Climate Centre Director Dong Wenjie, in Beijing.

Dong denied popular speculation that the drought was caused by water being held back by the dam.

Dong said years of research by the State Council's Three Gorges Office and the China Meteorological Administration proved that the dam would not have a major influence on the climate and environment.

The Chinese Academy of Sciences has analyzed the research's results, concluding that: "The construction of the Three Gorges Dam has a tiny influence over the surrounding area."

It also found that the dam's influence on temperature, humidity, winds and fogs is confined to an area of less than 10 kilometres around it.

Dong said the dam only raises the average annual temperature by 0.2 C in an area of less than two kilometres. In summer, the dam cools the area by 0.9 to 1.2 C.

Dong said the international meteorological community generally holds that the water stored in a large reservoir has no significant influence on climate.

Dong said the rainfall between June and August in Sichuan Province and Chongqing Municipality had been the lowest in the past 55 years.

The low rainfall was caused by several factors. One is that a subtropical high over the western Pacific Ocean had been extraordinarily strong, obstructing warm and humid air currents trying to reach Southwest China.

On the other hand, a stable and extraordinarily strong high pressure zone on the Tibetan Plateau dominated the area, restraining convection over Sichuan and Chonqing.