Located at the tip of the alluvial Yangtze River Delta, Shanghai has been evolving in a fragile environment based on clay and sand "as soft as bean curd."

Apart from land subsidence, a common problem to coastal cities worldwide, Shanghai is also trying to fend off rising sea levels as a result of global warming.

According to the State Oceanic Administration, the water level of the East China Sea off Shanghai is rising by about 2 millimetres a year, compared to 1.9 millimetres a century ago.

The city is still in danger of a sea-water invasion, according to the "Shanghai Geological Bulletin 2003" published by the Shanghai Geological Survey Institute.

To safeguard the land, the city has intensified its flood-protection work against the East China Sea and Huangpu River.

After years of construction, the coast along the East China Sea now has 598 kilometres of dykes to block tides at the highest level of the past 100 years and winds of force of 11 or 12.

The wall along the Huangpu River has been raised to 5.9 metres high and 318 kilometres long to protect the city.

China Daily news

(China Daily 07/16/2003 page9)