lørdag 14. august 2010

Aggressiv damutbygging mulig årsak til jordskredet

Jordskredet i Gansu-provinsen 11. august krevde mer enn 1100 menneskeliv. Ytterligere 600 er savnet.
As of 5:20 p.m. on August 11, the worst mudslide ever to hit Zhouqu
County, which is in Gansu Province’s Gannan Tibetan Autonomous
Prefecture, had claimed 1,117 lives and left 627 people missing. The
place hardest hit by the natural disaster Sanyan Yugou, experienced
large-scale mudslides in 1978, 1989 and 1992. These mudslides destroyed
842 houses, killed two people and left 194 others injured. Nearly every
year mudslides in the area damage roads.

A Xinhua news article published on Wednesday said the causes of the
Zhouqu mudslide were the “mountainous terrain and loss of ground cover”
and, according to the deputy director of the Department of Geological
Environment at the Ministry of Land and Resources, “a lingering drought
lasting almost 9 months in some local areas and the 2008 Sichuan
earthquake that might have loosened the mountainside and caused some
cracks are also reasons behind the devastating mudslide.”

An article from Xinmin Evening News [which is the source for all but the
previous paragraph of this summary] discussed early warnings of a
large-scale mudslide and possible human causes of the disaster.
In the 1980s experts suggested that Zhouqu County be relocated. Five
years ago, county investigations identified 86 places that were in
danger of landslides. In 1997, Ma Dongta, an engineering expert in
natural disaster prevention at the Chinese Academy of Sciences’ Chengdu
Institute of Mountain Hazards and Environment, wrote in a public paper
that if a large-scale mudslide were to occur in Sanyan Yugou, the losses
of the disaster would be greater than those experienced in 1992.

After the earthquake in Wenchuan, Sichuan Province in 2008, the land
ministry was particularly concerned about landslides. A team of
investigators sent by the ministry found 57 areas in Zhouqu at risk of
landslides and also advised that the county be relocated in order to
reduce losses from natural disasters.

Relocation is difficult, however, because more than 30% of county
residents are Tibetan minorities accustomed to living on mountain sides
and making a living raising fruit trees, county funds are tight and
there is nowhere to go.

According to public data, since 2003, several preferential policies
released in the county have spurred the development of hydropower. In
five years, contracts for 53 hydropower construction projects were
signed, with 41 of them either completed or under construction. The
projects have accumulated a slag heap of more than 38 million cubic
meters and estimated soil erosion of 749,000 tons. These projects
account for more than 80% of construction projects in the county.

Geology expert Fan Shao said that although there is currently
insufficient evidence to prove that the mudslides are directly related
to hydropower construction, the effect of large-scale engineering
projects on geological conditions cannot be ignored and may speed soil
erosion. “Hydropower is Gannan’s economic backbone, but if you only
consider short-term economic gain, you may eventually face heavier
environmental and human losses,” Shao said.

Driving along the Bailongjiang River, there are many hydropower stations
of various sizes. “Including all of its tributaries, in total, there
should be nearly 1,000, most of which are small power stations with
capacity of a few hundred kilowatts,” according to Bailongjiang Forestry
Management Administration worker Zhang Qirong.

The hasty development of some of the projects has created potential
danger. One week before the recent mudslide, one hydropower station was
cited for a series of problems including incomplete safety measures at
its materials processing plant and disposal areas. These problems were
found to be causing soil erosion.

“I heard my grandpa say that 50 years ago the mountains were covered in
dense forest,” said a student at Zhouqu’s No. 3 Middle School. “Now,
every year my school takes a trip to plant trees on the mountain side,
but the trees survive only rarely.” From August 1952, when Zhouqu’s
forestry administration was established, until 1990, about 126,500
hectares of county forest were used for lumbering, with 100,000 cubic
meters of forest cut down each year.

At the same time, large-scale cultivation was underway. Zhouqu is an
impoverished county, in which about 90% of residents are farmers. Today,
all of the land in the county with inclines of less than 40 degrees has
been cleared for farming.

Recently, Gansu Province Civil Affairs Bureau Director General Tian
Baozhong said that, though plans remain undecided, it was unlikely that
reconstruction of Zhouqu County would occur in its current location.
According to Tian, a memorial might be erected at the site of the mudslide.

Xinmin Evening News

*Compiled by Green Earth Volunteers' China Environment Brief