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On the treatment of heterogeneous interfaces in soil
Author(s) -
Schaudt K. J.,
Morrill J. C.
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl014376
Subject(s) - richards equation , infiltration (hvac) , soil water , classification of discontinuities , water potential , soil science , environmental science , flux (metallurgy) , smoothness , mechanics , mathematics , geotechnical engineering , mathematical analysis , geology , materials science , physics , meteorology , metallurgy
At the interface between two dissimilar soils there are typically discontinuities in the water‐content and the gradients of both the flux and the soil matric potential (SMP). As the equation of motion for water depends on the gradient of flux, care must be taken to insure that the solution at such an interface obeys the relevant physical conditions. When a SMP‐based nodal average scheme is applied to a heterogeneous interface, a fundamental assumption (smoothness in the SMP profile) is violated, which typically leads to poor water balance and/or slow convergence with respect to grid size. We solve the water‐content based form of Richards' Equation using continuity in flux and soil matric potential as boundary conditions. Our scheme builds in excellent water balance and typically converges as fast as water‐content based schemes for homogeneous soils. We show results for infiltration into a dry, stratified soil.