Dupuit–Forchheimer assumption

Summary

The Dupuit–Forchheimer assumption is an approximation for groundwater flow in an unconfined aquifer. When the water table slopes gently, the flow is taken to be horizontal and uniform over the depth. It reduces the three-dimensional free-boundary problem to a two-dimensional equation for the height of the water table, the Boussinesq equation. It is named after Jules Dupuit and Philipp Forchheimer. It is accurate when the aquifer is much wider than it is thick. It fails near wells and seepage faces, where the flow has strong vertical components.