Darcy flux and hydraulic conductivity
Groundwater flow is often approximately linear in hydraulic-head gradient.
Key knowledge
Darcy's law relates macroscopic specific discharge through a porous medium to hydraulic-head gradient and hydraulic conductivity. Conductivity depends on both medium and fluid properties. Darcy flux is discharge per bulk cross-sectional area, not the speed along each pore path.
Values and equations
q = −K dh/dl
- q
- signed specific discharge along coordinate l m s⁻¹
- K
- scalar hydraulic conductivity for stated medium and fluid m s⁻¹
- h
- hydraulic head m
- l
- position along the stated flow direction m
Conditions and scope
- The displayed scalar relation assumes a saturated, constant-density, isotropic continuum in the linear Darcian regime.
- High-flow inertial effects, discrete conduits, anisotropy or variable density require appropriate extensions or other models.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Source-documented sand-column experiments and limitations; no experiment recreated in ARK.
2026-10-10 · Checked continuum, head, conductivity and flux-versus-pore-speed distinction.
Entry details
Permanent link to this entry ↗- Record identity
- earth-groundwater-darcy
- Revision
- university-reference.1
- Structured reference record
- University reference