Dispersivity Equations

Equations for the approximating dispersivity in the literature appear in the literature.  These empirical equations are generally based on field observations and use a characteristic length, L.  Listed below are the equations used in the dispersivity calculator.  These have been modified such that all units are in feet.

Xu, M. and Y. Eckstein, 1995. Use of weighted least-squares method in evaluation of the relationship between dispersivity and field scale, Ground Water, 33(6): 905-908.

 Eqn 12b: 

 Eqn 14b: 

Neuman, S. P., 1990. Universal scaling of hydraulic conductivities and dispersivities in geologic media, Water Resources Research, 26(8): 1749-1758.

Ayra, A., 1986. Dispersion and reservoir heterogeneity, Ph.D. Dissertation, University of Texas, Austin, TX.

Other References:

Gelhar, L. W., C. Welty and K. R. Rehfeldt, 1992. A critical review of data on field-scale dispersion in aquifers, Water Resources Research, 28(7): 1955-1974.

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