Semi-infinite aquifer
Assumptions:
✓aquifer is confined, anisotropic on the vertical plane, of semi-infinite extent and thickness;
✓boundary is vertical or lateral, straight, of infinite length;
✓drawdown in the aquifer can be calculated at any distance from the pumping well.
Two kinds of boundary conditions are considered: 1) lateral recharge boundary (Dirichlet); 2) lateral or profile no-flow boundary (Neumann).
a 
b 
c 
d 
Schematic cross-sections of semi-infinite aquifer.
a – profile boundary – top of the aquifer; b – profile boundary – bottom of the aquifer; c – lateral recharge boundary; d – lateral no-flow boundary.