More people could be forced to leave their homes in east China's Jiangsu Province if the land there sinks further, experts warn.
Yin Shilin, a senior engineer at the Suzhou Seismology Bureau, says that more than 30 families have already been evacuated from Suzhou's Huangdai County. Suzhou is one of the biggest cities in the province.
Excessive usage of underground water has caused the ground to sink, threatening the safety of residents in several parts of the province, especially Suzhou, Wuxi and Changzhou.
Shanghai and part of neighboring Zhejiang Province are also facing the same problem.
"It is because the ground in the county is subsiding continuously. It has even become lower than the surrounding water tables, which causes flooding," Yin said.
Lu Aji lives in the Huangdai County's Yuejin Village. When he built his house in 1988, the groundsill was almost two meters above the surrounding water table.
His house has been sinking and is now about half a meter below the water table.
In order to stop their homes from being submerged, residents have to dam rivers outside the village to keep them from flowing into the village's waterways, and then drain water from the waterways.
According to the village's Party secretary, who would only reveal his surname, Zhou, water is drained every two days on average. But when the rain comes, it must be done continuously.
Every year, the drainage program costs the village about 70,000 yuan (US$8,430).
Counties and villages in the Xiangcheng District of Suzhou are suffering the most. Thousands of villagers have lived there for generations.
Yin said a river used to pass through the area about 40,000 years ago, with a width of 1 to 3 kilometers and a length of about 90 kilometers.
It disappeared over time owing to a buildup of soil and stones, which has since started to sink.
In the mid-1980s, some locals realized that the ground was subsiding more quickly there than in other districts.
At the end of 1997, the Suzhou Seismology Bureau started a formal survey of the earth in some villages.
The bureau discovered that the ancient river was subsiding at a tremendous rate: more than 20 centimeters per year.
"At present, the most serious area is one-and-a-half meters lower than in 1997," said Yin, "and the average speed of subsidence there is more than 10 centimeters per year."
Other districts and cities in the southern part of Jiangsu Province are experiencing the same problem.
"If people continue to pump underground water, the problem will not stop," Yin said.
"Although some measures have already been taken to solve the problem, the most effective way is still to stop the pumping of underground water."
The provincial government has issued rules to control and forbid pumping.
(China Daily April 14, 2004)
