Land subsidence in China occurs predominantly in 17 provinces (cities) situated in the eastern and middle regions of the country, including Shanghai, Tianjin and Jiangsu, and Hebei provinces. It is primarily caused by groundwater overpumping. One of the areas most severely affected by land subsidence is the Yangtze Delta, most of which consists of Shanghai City, the Su-Xi-Chang area (Suzhou, Wuxi and Changzhou cities) of Jiangsu Province, and the Hang-Jia-Hu area (Hangzhou, Jiaxing and Huzhou cities) of Zhejiang Province. The excessive exploitation of groundwater forms in a large regional cone of depression and, consequently, land subsidence is also regional, currently centered in the Shanghai and Su-Xi-Chang areas. In 2002, the maximum cumulative subsidence of Shanghai, Su-Xi-Chang and Hang-Jia-Hu were 2.63 m, 2.00 and 1.06 m, respectively. The land subsidence area is continuing to expand throughout the Yangtze Delta. To study the characteristics and the pattern of this land subsidence, the government has implemented a monitoring system involving the placement of 37 groups of extensometers (layers marks) and drilling of more than 1000 observation wells. These provide an invaluable historical record of deformation and pore water pressure and facilitate studies on the special features of soil deformation when the groundwater level changes due to pumping. Several measures have been taken in recent years to control the development of the land subsidence in the different areas; these include groundwater injection, prohibition of pumping deep confined groundwater, and an adjustment of the pumping depth and magnitude of the groundwater withdrawn. At present, although the subsidence area is still increasing slowly, the subsidence rate is controlled.
[1]
Donald C. Helm,et al.
One‐dimensional simulation of aquifer system compaction near Pixley, California: 2. Stress‐Dependent Parameters
,
1976
.
[2]
Xiaoqing Shi,et al.
Characterization of land subsidence induced by groundwater withdrawals in Su-Xi-Chang area, China
,
2007
.
[3]
Donald C. Helm,et al.
One‐dimensional simulation of aquifer system compaction near Pixley, California: 1. Constant parameters
,
1975
.
[4]
Jichun Wu,et al.
Land subsidence in China
,
2005
.
[5]
Devin L. Galloway,et al.
Land subsidence in the United States
,
1999
.
[6]
Giuseppe Gambolati,et al.
Mathematical simulation of the subsidence of Venice: 1
,
1973
.
[7]
J. F. Poland,et al.
LAND SUBSIDENCE DUE TO WITHDRAWAL OF FLUIDS
,
1969
.
[8]
Wallace E. Pratt,et al.
Local Subsidence of the Goose Creek Oil Field
,
1926,
The Journal of Geology.
[9]
S. Leake.
Interbed storage changes and compaction in models of regional groundwater flow
,
1990
.
[10]
Giuseppe Gambolati,et al.
Mathematical simulation of the subsidence of Venice: 2. Results
,
1974
.
[11]
M. Sneed,et al.
Aquifer-System compaction and land subsidence: Measurements, analyses, and simulations-the Holly Site, Edwards Air Force Base, Antelope Valley, California
,
2000
.