Despite the decade's strongest sandstorms over the last few days,
China's northern areas haven not suffered great losses due to the
warning provided by the accurate sandstorm forecast.
China's meteorological experts say the forecast, for the first time
in domestic meteorological history, gave a precise prediction of
the areas to be hit by sandstorms areas allowing sufficient time
for protective measures.
It
is a notable improvement in China's sandstorm monitoring and
early-warning capability, experts say.
According to Ruan Shuigen, official in charge of disaster forecast
and alleviation with the China Meteorological Administration (CMA),
the central observatory made the tentative forecast almost three
days before the strong sandstorm on Wednesday, following which
there were two predictions daily with the latest sandstorm
information.
Watching closely the dusty weather in northwest China and its rapid
movement towards east, forecasters gave a "strong sandstorm
warning" on Tuesday morning, an all-time record in China's
early-warning history, Ruan said.
Zhang Guocai, general director of the National Meteorological
Center (NMC), said that the accurate and early sandstorm forecast
can be attributed to the mature satellite remote-sensing monitoring
technology as well as to the accumulated experience of
forecasters.
According to Dong Chaohua, director of the National Satellite
Meteorological Center (NSMC), the monitoring scope of an orbiting
meteorological satellite can extend millions of square kilometers,
while a photograph taken by an immobile satellite can cover the
whole China and her neighboring countries.
The pictures from meteorological satellites can be transmitted to
ground within several minutes, which will greatly help the analysis
of sandstorm sources, movement and expansion, Dong says.
He
also says active cooperation between areas where the sandstorm was
expected to start and finish also contributed to the successful
forecast. In addition the central observatory intensified contact
with the sand source areas prior to the sandstorm.
In
addition, the Sandstorm Monitoring and Early-Warning System started
last March also played an important role in the forecast of the
three sandstorms this year.
Yu
Jixin, director of CMA's monitoring network department, said that
under this system, the monitoring range has been enlarged with
observations of sandstorm-related factors, including water content
in different soil depth from zero to 200 centimeters, soil hardness
as well as the density of suspended particulate matter in air.
Yu
said, the first phase of the system construction is expected to be
finished next year with the test and distribution of various
scientific facilities almost completed currently.
The completion of the entire system will take three to five years
at a cost of 30 million yuan (3.6 million U.S. dollars).
(Xinhua News
Agency March 22, 2002)