| Autor: |
John F. Pickens, Robert W. Gillham |
| Rok vydání: |
1980 |
| Předmět: |
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| Zdroj: |
Water Resources Research. 16:1071-1078 |
| ISSN: |
0043-1397 |
| Popis: |
The finite element method based on a Galerkin technique was used to formulate a model for the two-dimensional simulation of the transient movement of water and solutes in saturated-unsaturated soils. The model allows either nonhysteretic or hysteretic water content-pressure head relationships in the unsaturated zone. The finite element model results, including the effect of hysteresis, compared well with experimental and finite difference results for transient flow in an unsaturated sand column and provided confidence in the method of incorporation of the hysteretic relationships. The finite element model was applied to a hypothetical one-dimensional case involving vertical infiltration and redistribution of a slug of water containing a nonreactive tracer in a column of sand. Simulations were conducted using hysteretic properties and also nonhysteretic properties given by either the main drying or the main wetting curve. For the given hydraulic properties and boundary conditions, the simulations indicated that the effect of including or neglecting hysteresis was greatest in the pressure head and water content profiles and was of minor importance in the concentration profiles. Since the measurement of the hysteretic hydraulic properties of a soil material is both costly and time consuming, the illustration of the minor effect of hysteresis is of considerable practical importance in the evaluation of solute transport in unsaturated soils. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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