Experts attending the International Symposium on Sand and Dust Storms (SDS) noted in Beijing Monday that the developing trend of the storms is not optimistic, and that they are likely to affect more places in the world.
Beijing has been tortured by horrible sand and dust storms since 1999. However, the spring was much cleaner and windless in 2003, and many optimistically thought that the terrible weather phenomenon would disappear from the capital.
The holders of this opinion may be discouraged by Dr. Tan Jiqing, director of the Institution of Meteorological Information and Prediction of Disaster Events attached to Zhejiang University, who said analysis and computation on the sand and dust storms should integrate all factors -- including sand content, area coverage and destruction -- not simply count occurrences.
Tan added that sand and dust storm often ebb after several strong years, and last year might have been an example of that.
The severe situation in the northern and northwestern parts of China this year shows the problem is still there, said the expert.
Actually, sand and dust storms are influencing an increasing number of places on the globe year by year, said Tan after his research on the long-term observation results.
China's sand and dust belts are mainly located in the vast northern and northwestern areas, said Dr. Zhang Xiaoye from Chinese Academy of Meteorological Sciences.
The dry climate and damaged vegetation produce a great deal of sand in the areas and the sharp altitude difference between the world roof Qinghai-Tibet Plateau and the surrounding terrain brings concentrated sinking air current to the places, Zhang said.
China has the world's leading SDS early-warning system. It established a specialized forecast mechanism in 2002, which has now evolved into a highly precise digital one sending four reports each day, he said.
Zhang said Beijing launched an early-warning system on Feb. 13,2004, which is able to send alarms 48 hours before the arrival of sand and dust storms. It will also continuously record the particles of the sand and its mineral, chemical components, providing essential data for forecast and research.
Generally speaking, the global SDS forecast and coping capabilities still have much room for improvement, Zhang said, and people cannot yet thoroughly master their changing laws due to lack of data.
Though China established a special fund for SDS research in 1989, Dr. Tan said he "could hardly find any peers" when he started the studies in 1995.
Chinese government has spent totally 30 million yuan (about US$3.6 million) in the SDS research in the past four years, which was far from being enough, said Zhang.
"China's western, northern and Mongolian sand sources have emitted about 70 percent of the aerosols in Asia. China's research in this field will be of significance to Asia and the world as a whole," he said.
The three-day event is jointly sponsored and organized by the World Meteorological Organization (WMO), China Meteorological Administration (CMA), Ministry of Science and Technology, and National Natural Science Foundation of China.
More than 100 scientists and international organization representatives are present at the symposium to study the mechanism of SDS outbreak and evolution, as well as its regional impact.
(Xinhua News Agency September 14, 2004)
