Table 3.

Quantities used in Darcy’s law for porous media. Here the units are the ones usually used in groundwater hydrology

Symbol	Meaning	Dimension	Unit
q	specific flux in the whole porous media, q = ϕu	length/time	cm/s
K	hydraulic conductivity, K = ρgk/μ	length/time	cm/s
k	intrinsic permeability	length2	2 cm
φ	piezometric head, φ = p/(ρg) + z	length	cm
u	flow velocity in empty space	length/time	cm/s
ϕ	porosity or fraction of empty space	dimensionless
μ	fluid dynamic viscosity	force·time/length2	dyn·s/cm2.
ρ	fluid density	mass/volume	g/cm3
g	gravitational acceleration	length/time2	cm/s2
p	hydraulic pressure	force/area	dyn/cm2
z	height	length	cm