By Yang Jian | 2012-11-20 | ONLINE EDITION
SHANGHAI'S land sank 29 centimeters in the last 40 years and subsidence has become a natural disaster for the city that is only 4 meters above sea level on average, officials said today.
Land subsidence in Shanghai is mainly caused by the overuse of underground water and mushrooming high-rises on loose soil, said Feng Jingming, director of the Shanghai Planning and Land Resources Bureau.
Subsidence occurs when groundwater is drained to build the foundation of a high-rise building.
Local lawmakers are drawing the city's first land subsidence prevention regulations, imposing a fine of up to 500,000 yuan on violators.
"Shanghai's land sank 1.69 meters between 1921 and 1965. The rate of sinking has slowed since 2005 but remains a major hazard to the city," said Gan Zhongze, a lawmaker on the drafting panel.
The city has curbed the digging of large foundation pits for new buildings in an effort to reduce land subsidence. Projects requiring large and deep foundation pits within the Outer Ring Road have to be assessed by authorities for geological impact, the officials said.
The decision came after a 10-meter-long crack emerged on a road in the Lujiazui area early this year. The incident made headlines and stirred public concerns.
Shanghai is among the 50 or so cities in China facing the same problem as urban construction boomed on an unprecedented scale. Cities in the Yangtze Delta region and the North China Plain are the most vulnerable to the disaster of land subsidence.