Category: Zipingpu

The landslide story

(May 22, 2013) Chinese experts in landslide and geohazard protection fear debris flows, triggered by an epic 2008 earthquake in Sichuan Province, may pose a threat to the region for two decades. A tremendous amount of loose material from the landslides is suspended on hillslopes, ready to be washed away by rain. The potential for ongoing landslides and secondary hazards, such as flooding and blocked rivers, they argue, warrants further investigation.

Advertisements

China earthquake points to future risk sites

(April 30, 2013) Nature magazine reports that, while scientists agree that China’s deadly tremor at Ya’an (Lushan county) may hint at where future quakes will strike, they disagree on which seismic fault the next rupture is likely to occur.

Could dams be causing China’s earthquakes?

(April 24, 2013) Another article exploring the brewing debate over the cause or causes of the April 20 Lushan earthquake reports that the quake may have been an aftershock of Sichuan’s 2008 earthquake disaster, which some experts believe was triggered by the Zipingpu Dam reservoir. This issue of “reservoir-induced seismicity” is fast gaining attention as China, the most dammed nation in the world, is particularly at risk to the phenomenon. A 2011 Chinese study, for example, found China’s massive Three Gorges Dam had triggered around 3,000 earthquakes and numerous landslides in the reservoir region, representing a 30-fold increase in seismic activity in the area.

Shifting tectonic plates, aftershock, dam-related, or all three?

(April 22, 2013) Experts are debating whether the 7.0-magnitude earthquake that struck Sichuan province over the weekend was an aftershock of the region’s deadly 2008 Wenchuan earthquake – both quakes occurred along the same fault line. Some attribute Saturday’s event to natural movement in the earth’s crust but according to Fan Xiao, chief engineer at the Sichuan Bureau of Geology and Mineral Resources, the Wenchuan quake is also linked to the nearby Zipingpu Dam reservoir. Speaking to the Global Times, Mr. Fan said large reservoirs built on fault lines can induce earthquakes caused by the pressure of massive water volume on a fracture. “A reservoir with a capacity of over 1 billion cubic meters and a dam more than 100 meters tall would have a 30 percent to 40 percent chance of inducing an earthquake,” he said.

On alert: RIS risk amid rash of earthquakes in China’s Sichuan-Yunnan region

(March 22, 2013) A new report, exclusive to Probe International, calls for urgent monitoring of China’s large dams in areas prone to seismic hazard. These areas may be at increased risk from dam reservoir-induced seismicity (RIS). Scientists have observed that reservoir impoundment may not only increase the risk of strong earthquakes, particularly in areas already vulnerable to high-intensity seismic activity, but may represent a more pronounced risk in the first few years after a dam is filled.

Trouble on the Yangtze

(December 19, 2012) A central government plan to dramatically increase China’s reliance on non-fossil fuels will derive two-thirds of that target from hydropower – “an increase on par with adding nearly one Three Gorges Dam a year,” reports Jane Qiu for Science magazine. In her article on over-development of the country’s river pulse, the once mighty Yangtze, Qiu looks at the threat China’s damming fever poses to river habitats and species, the calamity potential of dam construction in quake-prone regions and mounting criticism of China’s biased environmental impact assessment process.

Mega-dams in China’s earthquake zones could have “disastrous consequences”

(October 31, 2012) “Earthquake Hazards and Large Dams in Western China,” the Probe International report authored by geologist John Jackson, has set China’s academic and industry circles astir. As the debate over Jackson’s findings heats up, the respected Caixin Media magazine, New Century Weekly, looks at both sides of the debate and the specific issues Jackson’s explosive report has raised.