Land subsidence and uplift due to long-term groundwater extraction and artificial recharge in Shanghai, China

摘要: Increasing artificial water recharge and restriction on groundwater pumpage have caused land displacements in Shanghai (China) to shift from subsidence uplift. On the basis of field laboratory data, characteristics mechanism uplift are analyzed discussed. Under condition long-term extraction, deformation aquifer aquitard units consists elastic, plastic, visco-elastic, visco-plastic components. The recoverable elastic visco-elastic is only a small portion total for both units, especially when level lower than historically lowest values. When rises, whether their expansion occurs immediately or not, depends changing modes they experienced. Even do not always rebound closely following rise them. lagging occurrence arrested uplift, clearly behind can be attributed all consolidation units. Artificial limitation efficient measures controlling subsidence, but earlier actions necessary keep levels above values time, if more effective outcome expected.