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Scaling of Richards' Equation for Infiltration and Drainage
Author(s) -
Warrick A. W.,
Hussen A. A.
Publication year - 1993
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1993.03615995005700010004x
Subject(s) - infiltration (hvac) , hydraulic conductivity , richards equation , scaling , drainage , soil water , flux (metallurgy) , constant (computer programming) , water flow , mechanics , mathematics , soil science , geotechnical engineering , environmental science , materials science , geology , thermodynamics , geometry , computer science , physics , ecology , biology , metallurgy , programming language
Scaling techniques allow a single solution to Richards' equation to suffice for numerous specific cases of water flow in unsaturated soils. Here, such solutions are presented for the well‐known hydraulic functions of Brooks and Corey. Infiltration for a constant water content or a constant flux at the soil surface is considered as well as drainage for a semi‐infinite profile. Although limited to a single form of hydraulic properties, the results are otherwise more general than those previously available. Of particular interest is that the hydraulic conductivity and air‐entry values are embedded within the reduced variables. This is an advantage for computational efficiency, such as when using parameter optimization techniques. Three examples are presented. In the first, a single solution is presented, valid for four combinations of saturated hydraulic conductivity and surface water content. A second example relates to drainage, also with one solution to describe four combinations of physical parameters. The final example is for constant flux infiltration.