The sandstorms in Beijing are actually "dust storms." The dust
is blown to Beijing from dried salt lakes, wasteland, and degraded
grassland, said experts from the Institute of Geology under the
Chinese Academy of Geological Sciences (CAGS) on Wednesday when
attending an academic seminar.
Han Tonglin, a researcher from CAGS, said that on April 16, last
year, a total of 336,000 tons of sand fell in Beijing in the form
of a large sandstorm. After the sandstorm, he and his 7 other
fellow researchers carried out an investigation in Hebei and Inner
Mongolia. Later they wrote two reports on the research results
titled "The Nature of the Sandstorms in Beijing and Tianjin and How
to Handle Them" and "Proposals on the Beijing and Tianjin
Sandstorms Handling Work." The two reports aroused high attention
from the State Development and Reform Commission, which later
responded to their reports. Both reports give scientific analysis
of the sandstorm happening in Beijing on April 16 from geological
environmental perspective. The two reports conclude that the
sandstorm that occurred on that day was caused mainly by dust in
the dried salt lakes in Inner Mongolia, and some by dust from
wasteland and degraded grassland. Since deserts and sand land
contained little dust, they were not the sources for the sandstorm
that occurred on April 16 in Beijing.
For the past 50 years, people in Beijing and Tianjin have tried
to control sandstorms by planting many trees. However, this method
has not been very effective. The reason is because the sandstorms
in Beijing and Tianjin are not actually "sandstorms" but
"duststorms." The dust can be blown to 2,000-3,000 meters high in
the air by wind before it falls down to the ground. Trees can not
stop such dust at all, said Lin Jingxing, one of Han's fellow
researchers.
In order to prevent such duststorms, people should improve the
ecological environment of dried salt lakes. Instead of planting
trees, people should grow more grass on the earth.
(Xinhua News Agency April 13, 2007)