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General Solution for Steady Infiltration and Water Uptake in Strip‐Shaped, Rectangular, and Cylindrical Domains
Author(s) -
Communar Gregory,
Friedman Shmulik P.
Publication year - 2011
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/sssaj2011.0088
Subject(s) - line source , infiltration (hvac) , sink (geography) , mechanics , cylinder , point source , water flow , drip irrigation , superposition principle , geometry , common emitter , mathematics , physics , materials science , soil science , mathematical analysis , environmental science , optics , irrigation , thermodynamics , ecology , cartography , optoelectronics , biology , geography
Infiltration of water from arrayed, interacting surface water sources (emitters) and extraction of water by plant roots is of interest in the context of trickle irrigation. In this study, steady flows from subsurface or surface point and line sources in laterally confined soil domains were analyzed on the basis of the linearized Richards equation written in terms of the matric flux potential (MFP). Analytical solutions (Green's functions) were derived for the problems of three‐dimensional infiltration from point sources into confined strip‐shaped, rectangular, and cylindrical domains and for two‐dimensional infiltration from a line source into a strip‐shaped domain. Incorporating these solutions into a coupled source–sink water flow and uptake model enabled analysis of the effects of lateral confinement and various source–sink (emitter–plant) configurations on relative water uptake rates (RWURs). The exact solutions for infiltration into confined strip‐shaped and rectangular domains derived in this study confirmed the accuracy of previously presented RWUR results, by superposition of the solutions for equivalent, arrayed point sources (along a single drip line and in an array of parallel drip lines). An equivalent confining cylinder of the same cross‐sectional area as a square was found to yield RWURs in excellent agreement with those for a square confinement. A bidirectional rectangular confinement increased the RWURs more than a unidirectional strip‐shaped confinement. Among the various simulated emitter–plant configurations, the lowest RWURs were obtained for a configuration of a single plant row irrigated by two lateral drip lines.