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A numerical model of infiltration processes for hysteretic flow coupled with mass conservation
Author(s) -
Tan YihChi,
Ma KuoChen,
Chen ChuHui,
Ke KaiYuan,
Wang MingTsan
Publication year - 2009
Publication title -
irrigation and drainage
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 38
eISSN - 1531-0361
pISSN - 1531-0353
DOI - 10.1002/ird.403
Subject(s) - conservation of mass , vadose zone , infiltration (hvac) , richards equation , hysteresis , conservation law , boundary value problem , numerical analysis , computer simulation , water content , mechanics , flow (mathematics) , geotechnical engineering , finite difference method , finite difference , mathematics , soil water , soil science , environmental science , geology , physics , thermodynamics , mathematical analysis , quantum mechanics
The study presents a numerical infiltration model of a hysteretic flow coupled with general mass conservation for practical application to unsaturated soil. In unsaturated soil, hysteresis is an important phenomenon in the complicated hydrological processes, and it is usually ignored when simulating the relationship of soil water content. The governing equation of unsaturated flow is the Richards equation, and it is difficult to obtain the analytic solutions because of the variation of temporal boundary conditions and the dynamics of change of soil water content in the vadose zone. The numerical solution is solved by the finite difference method technique with the Picard iteration scheme combined with the hysteresis model derived by Huang et al . (2005) and the mass conservation control within simulation domain. The results showed that the mixed form had better mass conservation. The present numerical solutions with the hysteresis model were verified by Gillham's experimental data of 1979. The results of the present mixed form numerical approximations with hysteresis effect are better than without hysteresis. In order to raise the accuracy of the soil water relationship numerical model, hysteresis and mass conservation are important factors in infiltration processes. Copyright © 2008 John Wiley & Sons, Ltd.