Automated analysis of strain-stress curves for aquifer system characterization

Excessive groundwater extraction, often leads to changes in aquifer-system layers, causing  anthropogenic-triggered land subsidence. The reduction in pore pressure due to groundwater withdrawal acts as an external factor, while soil compressibility serves as the primary internal factor of land subsidence. The interaction between stress and strain within an aquifer-system, or specific layers, is typically represented through stress-strain curves. These curves, illustrating the hydrograph data (stress induced by piezometric level variations) against land subsidence compaction records (strain), offer valuable insights into the geomechanical behaviour of the aquifer-system, such as elastic, plastic, elasto-plastic, or visco-elasto-plastic behaviour. Additionally, these curves can be employed to estimate hydrogeological parameters like the storage coefficients of the aquifer-system. Traditionally, determining storage coefficients from stress-strain curves has relied on subjective visual assessments by skilled researchers. In this study, we proposed a MATLAB© application designed to automate and streamline the analysis of land subsidence datasets. The application facilitates the exploration of potential correlations with piezometric levels and allows for the estimation of storage coefficients. This approach reduces the time-cost of analysis and minimizes potential human-interpretation errors. The developed application integrates temporal series of groundwater levels from observation wells and ground deformation measurements o automatically generate stress-strain curves. To illustrate and validate the effectiveness of the proposed application, the proposed app is applied to diverse aquifer-systems worldwide, each exhibiting distinct geomechanical behaviour. The results showcase the tool's capability in efficiently studying and understanding land subsidence, providing a valuable resource for scientists and researchers investigating the impacts of excessive groundwater extraction on land deformation.