||Areal Prediction of Water and Solute Flux in the Unsaturated Zone.
Warrick, Arthur W. ;
Amoozegar-Fard, Azizolah ;
||Arizona Univ., Tucson. Dept. of Soils, Water and Engineering.;Robert S. Kerr Environmental Research Lab., Ada, OK.
Soil analysis ;
Flux rate ;
Soil water movement
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
The areal distribution of water and solutes over land was studied. This was done by examining data sets available from previous studies as well as by flow simulations. Most of the simulations of salt and water movement were by the 'crude' Monte Carlo technique. For infiltration, 'Philip's formula was solved once in a scaled form, after which results were algebraic without repeating the laborious steps. Similarly, drainage calculations were made very efficient by utilizing a scaled form of the nonlinear moisture flow equation. Salt distributions were considered for cases of equal irrigation amounts, but with intake rates varying over space. Deterministic calculations based on the mean velocity and apparent diffusion coefficient gave erroneous results for both fluxes and distributions of salts in the profile. The true average distribution is much more dispersed with more salts reaching deep depths and also more salts near the surface. Similarly, the mass emissions of salts averaged over a field appears earlier than would be calculated by using mean velocities.