Open AccessNew Analytic Solution Related to the Richards, Philip, and Green–Ampt Equations for Infiltration
Author(s) -
Prevedello Celso Luiz,
Loyola Jocely Maria Thomazoni,
Reichardt Klaus,
Nielsen Donald R.
Publication year - 2009
Publication title -
vadose zone journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.036
H-Index - 81
ISSN - 1539-1663
DOI - 10.2136/vzj2008.0091
Subject(s) - infiltration (hvac) , richards equation , homogeneous , soil water , wetting , water retention , soil science , water content , porous medium , water retention curve , characterisation of pore space in soil , geotechnical engineering , similarity solution , porosity , mathematics , environmental science , thermodynamics , geology , physics , boundary layer
Based on physical laws of similarity, an analytic solution of the soil water potential form of the Richards equation was derived for water infiltration into a homogeneous sand. The derivation assumes a similarity between the soil water retention function and that of the soil water content profiles taken at fixed times. The new solution successfully described soil water content profiles experimentally measured for water infiltrating downward, upward, and horizontally into a homogeneous sand and agrees with that presented by Philip in 1957. The utility of this analysis is still to be verified, but it is expected to hold for soils that have a narrow pore‐size distribution before wetting and that manifest a sharp increase of water content at the wetting front during infiltration. The effect of van Genuchten's parameters α and n on the application of the solution to other porous media was investigated. The solution also improves and provides a more realistic description of the infiltration process than that pioneered by Green and Ampt in 1911.