Models based on a statistical-thermodynamics analogy for the computation of varying diffusivity tensors and integration of the diffusion equation

The possibility is discussed of estimating space and time varying eddy diffusivities tensors based on numerically computed velocity fields of a waterbody. Valid results, are obtained with an approach derived from statistical thermodynamics analogies, which make to correspond the mean free path to the dimension of tidal vortexes. Through the computation of the Lagrangian time scale, the possibility is also shown, to integrate the shear stress with a Fickian equation. Shear stress is evaluated through a modified von Karman formulation. Additional approaches are also prospected in the determination of diffusivity tensors components.