Numerical evaluation of land subsidence induced by groundwater pumping in Shanghai

To predict the future behavior of land subsidence in Shanghai due to pumping of groundwater, a numerical model is established. In the proposed model, groundwater flow in three-dimensional conditions and soil deformation in one-dimensional conditions are calculated. The model takes into account the multi-aquifer-aquitard hydrogeological condition of the soft deposit of Shanghai. The variation of the coefficient of compressibility and coefficient of hydraulic conductivity of the soils with the consolidation process are simulated. Relationships among land subsidence, groundwater withdrawal volume, and groundwater level are analyzed. Comparison between the measured value and calculated value shows that the model simulates the measured value fairly well. The future of land subsidence behavior due to groundwater withdrawal is predicted and discussed via consideration of the variation of the following parameters in the future 30 years: net withdrawn volume of groundwater, pumping layer, and pumping region.