Unraveling elastic and inelastic storage of aquifer systems by integrating fast independent component analysis and a variable preconsolidation head decomposition method.

• Unraveling the elastic and inelastic components of deformation and hydraulic head. • Quantifying the elastic and inelastic parameters at different depths. • The storage parameters are obviously correlated with the depth and lithology. • The percentage of permanent storage volume loss is estimated. Land subsidence is a geological process mainly caused by groundwater overdraft. Numerical modeling of land subsidence is the main method used for its simulation and prediction. The elastic skeletal storage coefficient (S ke), inelastic skeletal storage coefficient (S kv), and the related specific values (S ske and S skv) are fundamental parameters to quantify land subsidence. In this paper, a novel approach integrating fast independent component analysis (Fast-ICA) with variable preconsolidation head decomposition method is proposed to disentangle S ske and S skv at various depth and over time from piezometric and extensometer records. The proposed method is applied to areas affected by severe land subsidence in the North China Plain (Tianzhu, Pinggezhuang and Cangzhou stations). The elastic and inelastic parameters of the aquifer systems are quantified at different depths. It is found that S ske and S skv decrease with depth. The finer the sediment grain size is, the smaller of the ratio S ske / S skv . Moreover, S ke remains almost unchanged over time, while S kv decreases as compaction and land subsidence increase. [ABSTRACT FROM AUTHOR]