Subtopic: Steady and unsteady flow in confined and unconfined aquifers
Question Statement:
Which of the following assumptions are invoked in Dupuit-Forchheimer theory of steady unconfined groundwater flow?
Options:
(A) Flow is horizontal and uniform across any vertical cross-section
(B) Hydraulic gradient is equal to the slope of the water table ($i = dh/dr$)
(C) Vertical velocity components are neglected
(D) The aquifer is anisotropic and unsteady
Answer Key:
A, B, C
Step-by-Step Solution & Explanation
Dupuit-Forchheimer assumptions:
1. Flow is horizontal, streamlines are parallel, equipotential surfaces are vertical cylinders (A and C).
2. Hydraulic gradient along the flow direction is constant with depth and equal to the tangent of the water table slope (B).
Aquifer is assumed isotropic, homogeneous, and under steady state (making D FALSE).