Well,

K (Hydraulic conductivity) = (Cd2 ρ g) / μ

Where C is the proportionality constant depends on the properties of the porous media, which affects the flow, such as the grains radius (d), the irregularity of its distribution (sorting), its degree of roundness and the conditions of packing.

ρ: density

Cd2 : intrinsic permeability

μ: dynamic viscosity

g: gravitational acceleration

Sincerely

Yes, I agree with the reply above. You will have to determine those characteristics in order to estimate your conductivity.

A bit of fluid flow theory here; skip to the bottom if you just want my overall opinion:

Permeability can be shown to be related to porosity and pore size by the following relationship: k = (phi*R2)/(8*T), where phi is the porosity, R is a characteristic pore size, and T is the tortuosity of the porous media (this can be shown by combining Darcy's Law with the Hagen-Poiseuille Flow Equation, or more recently by percolation theory). However, because characteristic pore sizes are so difficult to measure (especially in unconsolidated materials), hydrogeologists prefer proxy measurements. Grain size has been shown to work in some cases (see the Hazen model) but these tend to assume a fairly uniform and narrow distribution of grain sizes (bimodal distributions can really throw grain size permeability models off).

In unconsolidated materials, I have found good results with the surface area to pore volume ratio, or Spor, (where Spor = rho * SSA (1 - phi)/(phi), rho is the grain density, and SSA is the specific surface area). This formulation has the advantage that, approximately, Spor = alpha/R, where alpha is a geometric constant that depends on the pore geometry (=1 for planar pores, =2 for cylindrical pores, =3 for spherical pores). This allows you to derive a form of the Kozeny-Carman equation using Spor, where:

k = C * phi/(T * Spor2),

where C is an empirical constant that will depend on the material you are using. However, this relationship only works to the extent that the inverse proportionality between Spor and R is true, and in consolidated materials this may break down.

Ultimately, I have found that Spor (and thus, specific surface area) is a better proxy for pore size in unconsolidated materials than the grain size is (especially when clays get involved), but many systems exist where grain size models work just fine.

see this article

· Relations Between Specific Surface Area and Soil Physical and Chemical Properties, DOI:

· 10.1097/00010694-199601000-00003