1
M.Sc, Water Engineewring ,Sharif University of Technology ,Tehran,Iran
2
Associate Professor Department of Civil Engineering ,Sharif University of Technology
Abstract
The assessment of water flow in unsaturated zone is of interest in many hydrological and environmental problems. In this paper, two different forms of governing equations of water flow in unsaturated zone are studied. The influences of discritization schemes, averaging methods of nonlinear interblock hydraulic conductivity, and different convergence criteria on the accuracy and performance of numerical models for these equations are investigated. It is shown that by choosing an appropriate form for determining the hydraulic conductivity and using the secant method for calculating the moisture capacity and implicit method for discritization, is chosen. By doing this, the type of Richards's equation that has pressure as its dependent term gives very close results to the mix type of Richards's equation. This later approach according to the previous studies had given better results.
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