Numerical Study on the Parameter Sensitivity of Land Subsidence Caused by Groundwater Withdrawal

Generally, the compaction of the aquitards was recognized as the main component of land subsidence caused by groundwater withdrawal. However, based on the observation of land subsidence in Su (Zhou)-(Wu) Xi-Chang (Zhou) area, the deformation in aquifers is comparable with the deformation in aquitards. Under the situation of the significant compaction in pumped aquifers, the permeability change in the pumped aquifer has to be considered which can significantly affect the water head change calculation. In this study, the numerical method is used to analyze the sensitivity of the parameters (i.e., the relative compressibility of aquifers and aquitards; the permeability in pumped aquifers) influencing the development of the subsidence which may be useful to create land subsidence model incorporating this kind of new finding mentioned above. First, a baseline case model is created to evaluate the effectiveness of the presented numerical model; and subsequently, the parametric study is conducted to analyze the relative importance of the calculated parameters in land subsidence; finally, some discussions and conclusions can be obtained based on the calculation results.