“The time and location of these earthquakes link with the times the reservoirs at Xiangjiaba and Xiluodu on the Jinsha, and Tianhuaban on the Niulan, were being filled,” Yang said in an interview with Chinadialogue.net.
One more earthquake that took place last April was located less than 7 km from the Xiluodu Dam on the Jinsha, he said. Another earthquake in September 2012 took place in 10 km from the Malin Dam on the Luoze River and 60 km from the Xiangjiaba Dam on the Jinsha.
“Construction plans for hydropower dams in the Hengduan Mountains [on the Yunnan-Sichuan border] have overlooked how rivers can become blocked in such geologically active zones,” Yang said. Talking about the fault zones in the area, he said, “There would be earthquakes here even if it wasn’t for the dam reservoirs. But, the reservoirs may result in more powerful levels of stress.”
Hydropower Widely Supported
The government maintains that all dams have been planned and built taking into account the historical seismic activity, and projections about the future based on verifiable factors like fault zones. Efforts by ENR to obtain an official view of dam risks after the recent earthquakes proved unsuccessful.
But one thing is clear: Government seismologists, under pressure to support the government's ambitious dam-building campaign, are backing more hydropower to counter carbon pollution. Coal burning is being drastically reduced as China is trying to alter the energy mix with greater use of gas, nuclear energy and hydroelectricity. Backing the campaign are state-owned and politically astute construction companies, who depend heavily on government-sponsored projects.
As dams slice rivers, fears of seismic activity grow. Government and non-government experts are publicly differing about the dangers of earthquakes, and the role of intensive dam building in seismic zones.
Even government seismologists speak in different voices. For example, Sun’s statement about the Yunnan earthquakes varied with an official release by the Yunnan Seismological Bureau. Bureau Director Yan Fengtong told people of the province last January that they need not worry about their safety because of earthquakes. Quakes in the 5-6 magnitude are "not abnormal phenomena" in the seismic belt where they occur, Yan said.
"The province is located on a seismic belt and will suffer at least one or two earthquakes with up to 5-point magnitude every year," Yan’s statement said.
But experts point at a much larger danger of dam and landslide earthquakes in China.