Steady Flow to Wells: Confined & Unconfined Aquifers
Subtopic: Assumptions of Dupuit-Forchheimer theory
Question Statement:
Which of the following assumptions are invoked in the Dupuit-Forchheimer theory of steady flow to an unconfined well?
Options:
(A) Flow lines are assumed to be horizontal and equipotential surfaces are vertical cylinders
(B) Hydraulic gradient is equal to the slope of the free water table ($dh/dr$)
(C) Well is fully penetrating and aquifer is homogeneous and isotropic
(D) Seepage face at the well bore is accurately modeled with zero drawdown
Answer Key:
A, B, C
Step-by-Step Solution & Explanation
1. Flow lines are assumed essentially horizontal, neglecting vertical flow curvature (A is true).
2. Gradient equals free surface slope (B is true).
3. Homogeneous isotropic aquifer and fully penetrating well are core idealizations (C is true).
4. Dupuit theory actually neglects the existence of the seepage face at the well wall (D is false).