Orange sky in Beijing for year's biggest sandstorm
March 20, 2010 01:59 EDT

BEIJING (AP) -- The strongest sandstorm so far this year has hit China's north, coating the capital with a thin dusting as residents awoke to orange-tinted skies.

Workers muffled their faces in vast Tiananmen Square as the city's weather bureau gave air quality a rare hazardous ranking.

The sand delayed some flights at Beijing's international airport, and prompted South Korean weather officials to issue a dust warning for Seoul.

China's expanding deserts now cover one-third of the country because of overgrazing, deforestation, urban sprawl and drought. The shifting sands have led to a sharp increase in sandstorms -- the grit from which can travel as far as the western United States.

The Chinese Academy of Sciences has estimated that the number of sandstorms has jumped six-fold in the past 50 years to two dozen a year.