2 Theory of 1-D Soil Consolidation and Aquifer Response to Pumping

Stratified systems behave mechanically as if they were one‑dimensional (1‑D) structures, and, although fluid flow may be 3‑D, displacement occurs mostly in the downward vertical direction (Figure 5b). This presentation of the theoretical foundation used to examine anthropogenic land subsidence is a two‑step process. The first step addresses the fluid‑dynamic component. It controls the porous medium’s flow behavior as accounted for by the elastic storage S_s. The second step solves the structural problem by using the spatial gradient of the fluid pore pressure p calculated in the first step as a driving force within the geomechanical medium (which may be over‑ or under‑consolidated and faulted). The spatial gradient of p controls the solid skeleton deformation and subsidence (that is, vertical displacement) at the land surface.