In describing the transport of solutes in a classical porous medium,

the concept of macro-dispersion or differential advection (resulting from conductivity variation) plays a crucial role in field-scale heterogeneous aquifers,

while the concept of micro-dispersion (resulting from velocity variation) decides the resultant transport of solutes to be either advective or dispersive dominant at the microscopic-scale.

In this context, while describing the transport of solutes in a fractured aquifer,

what happens to the concept of macro-dispersion,

if the transport of solutes is modeled

by ignoring the local-scale interaction between high-permeable fracture and low-permeable rock-matrix -  at the larger field-scale?

In fact, at the larger field-scale, it is quite possible that the magnitude of microscopic-dispersion within the fracture alone might be insignificant  - in comparison  - with that of the macroscopic-dispersion resulting from the coupled fracture-matrix interaction:

In turn, won't it affect the resultant direction and magnitude of plume spreading?

Suresh Kumar.

http://www.doe.iitm.ac.in/gskumar/