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Statistics show the surface of Shanghai from the Shanghai Institute of Geological Survey city has been sinking around 10 millimeters annually since the late 1990s, the slowest rate in the past two decades and almost one quarter of the average rate between the 1920s and the 1960s.
In 2000, the surface of the city sank 12.12 millimeters, Tuesday's China's Daily reports.
Experts say the east city started exploiting its underground water in 1860 and the surface of Shanghai has been continuously sinking since 1921.
The tendency of land subsidence, resulting from over-use of underground water, can be eased but is almost impossible to reverse, said Wei Zixin, chief engineer with the institute.
To slow the rate of land subsidence, the Shanghai Municipal Government has demanded since 1995 that each deep well in the city to have an official permit and underground water usage of the city is limited to less than 10 million cubic meters per year.
The city government also began to invest in a global positioning system to monitor land subsidence in the city with a coverage of 700 square kilometers in 1996.
(Xinhua News Agency September 10, 2002)
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