Issue 3: The reservoir has induced major earthquakes

It is not possible that the reservoir could have triggered the Wenchuan earthquake.

Question: In recent years, whenever an earthquake has occurred in western China, it has been attributed to the Three Gorges Project. Is there any basis to such claims?

Investigation: The largest earthquake recorded since the operation of the project was much smaller than the predicted value issued in the preliminary design report.

The Wenchuan earthquake in 2008 occurred along the Longmenshan seismic belt on the northern edge of the Tibetan Plateau. It was a result of a plate collision deep underground. There was no connection between the dam and the quake.

Expert's view: Major earthquakes including Wenchuan and Lushan quakes in southwestern China were not triggered by the Three Gorges reservoir.


Issue 4: The dam has interfered with atmospheric circulation

Extreme weather shows no direct connection with the reservoir

Statement: Since the operation of the Three Gorges reservoir, extreme weather and climate events have frequently affected the reservoir and its surrounding area. These include the severe drought in Sichuan and Chongqing in 2006, the drought in southwestern China from 2009 to 2010, and the severe drought in the middle and lower reaches of Yangtze River in 2011. There is a popular notion that "The Three Gorges dam has interfered with atmospheric circulation and affected the surrounding climate".

Investigation: "The vertical height of atmospheric circulation is 3000 meters, and the dam is only about 180 meters high. It is impossible for the dam to interfere with or block atmospheric circulation," says Chen Fei, general manager of China Three Gorges Group.

An assessment by the Chinese Academy of Engineering states that the Three Gorges reservoir does have a certain impact on the surrounding local weather and climate. It can significantly decrease the temperature above the water surface, but has little impact on the temperature in the wider surrounding area, and the affected area is limited to 20 kilometers.

According to the Three Gorges Project Comprehensive Benefits Climate Assessment Report released by China Meteorological Administration this year, since the operation of the Three Gorges reservoir, there has been an average temperature increase of about 0.2 degrees Celsius compared with years from 1996 to 2003.

Expert's view: An expert from China Meteorological Administration said that the extreme weather in the Three Gorges reservoir and its surrounding area in recent years is closely related to East Asian atmospheric circulation, sea surface temperature changes, and thermal anomalies on the Tibetan Plateau, but has no direct link with the reservoir.