Sandstorm over Beijing clears, but dust warning remains

After being enveloped by sand and dust for a whole day on Monday in the largest sandstorm in a decade, the Chinese capital, Beijing, has cleared up and the yellow warning for sandstorms was lifted, state media reported.
The Central Meteorological Observatory continued to issue blue dust storm warnings on Tuesday morning, as cold air and strong winds brought the powerful sandstorm which started from Mongolia southward, and will continue to hit central and southern China as far as Anhui and Jiangsu provinces until Wednesday morning. 

The Air Quality Index (AQI) climbed to 500 in most provinces, indicating that they will experience severe sand pollution.   

According to weather monitoring, more dusty weather is likely to hit 17 provinces in China from Friday to Saturday with the return of cold air.

Many questioned why China's "green great wall" did not work. The sandstorm hit 12 provinces in northern China from west to east.

Chinese analysts said the role of China's Three-North Shelterbelt Forest Program set up in northwest, north and northeast China, is to block the drifting dust within the forestation zone. The impact of shelterbelt projects is limited if the sandstorm does not originate from the local area but from far away regions.