Chinese hydro
Geologists
warn China’s dam-building frenzy in seismically-active regions is
putting millions at risk
7
July, 2012
July
7, 2012 – CHINA – As
the last of the turbines at China’s Three Gorges Dam was connected
to the grid on Wednesday, a dams debate rages over the fate of the
Upper Yangtze River and its main western tributary, the Jinsha River.
Known as the “River of Golden Sands,” the Jinsha is slated for a
cascade of 25 dams designed to generate as much electricity as four
Three Gorges Dams put together. Earlier studies by geologists have
highlighted the seismic, safety, and water security risks of
out-of-control dam building in this fragile region. Experts also warn
against the risk of dam-building in China’s seismically active and
flood-heavy southwest, where one dam break could cause a tsunami that
creates a domino effect of collapsing dams downstream. This occurred
in China in 1975, when a major flood and poor communications caused
dam breaks at 62 sites in Henan Province. The catastrophe killed over
26,000 people – more casualties than any other dam failure in
history. While such massive floods are rare (this was a
once-in-1000-years flood), dam developers have yet to factor in the
affects of climate change on extreme weather events such as droughts
and floods, which are common in the southwest and have serious
implications for dam operation. The valleys in this region, including
those formed by the Lancang/Upper Mekong and Nu/Salween, also
experience disastrous landslides during the rainy season due to the
steepness of the terrain. These can be exacerbated by the clearing of
vegetation for dam construction and by the filling and emptying of
reservoirs. The fluctuating water levels of the Three Gorges
reservoir, for instance, have destabilized hundreds of miles of
slopes and triggered massive landslides. A recent warning sign is the
deadly mudslide that occurred on June 28, 2012, at the Baihetan
Hydropower Station on the lower Jinsha River (it is under
construction by the China Three Gorges Project Corporation). The
mudslide killed four people and left 36 more missing – all workers
and their families at the dam construction zone. –IR
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