GROUND-WATER RESOURCES MANAGEMENT IN ORDER TO CONTROL LAND SUBSIDENCE IN SHANGHAI CHINA

The magnitude of land subsidence had reached to 2.63m in Shanghai downtown area from 1921 to 1965 because of ground water overexploitation concentrated there. And such consequences appeared as tidal inundating, rainstorm waterlogging, block of navigation under bridge, and damage of infrastructure etc. So Ground-water resources has been managed in order to control land subsidence in Shanghai since "Shanghai Deep Well Regulation" was issued in June 1963. When the pumpage was decreased during 1963 to 1965 and the ground water level was accordingly raised, land began to subside less and less. And as ground water was artificially recharged during 1966 to 1971, land even rebounded a little. A Ground Water Exploitation and Recharge Scheme, in which the status of ground water and land subsidence in last year need to be assessed and an optimal plan of groundwater exploitation in next year need to be suggested based on land subsidence predictions, has been made annually since 1966 along with the monitoring of ground water and land subsidence further enhanced year by year after 1962. The exploitable volume of fresh groundwater in Shanghai has been reassessed in recent years. After situation of groundwater exploitation was compared with the exploitable volume in different administrative districts and different aquifers, overexploitation districts and potential exploitation districts were identified. The management of Shanghai groundwater resources will be further promoted in future based on them.