Poroelastic aquifer

A poroelastic aquifer couples pore-fluid storage and flow to elastic compaction of its solid skeleton. Changes in gravity, surface loading, or pore pressure can therefore change groundwater discharge even without changing rainfall.

For a skeleton with Young modulus $E$, undeformed solid fraction ${\varphi }_0$, grain-fluid density difference ${\rho }_s-\rho$, and reference gravity $g_0$, the hydrostatic poroelastic compaction length isIt is the depth over which self-weight changes the solid fraction appreciably.