D. A. Barry, M. B. Parlange, J.-Y. Parlange, M.-C. Liu, T. S. Steenhuis, G. C. Sander, D. A. Lockington, F. Stagnitti, J. Selker, D.-S. Jeng, L. Li, R. Haverkamp, W. B. Hogarth

The original model of Green and Ampt is used as a basic tool to obtain quantitative understanding of infiltration and associated soil properties. Indeed, their result is a limiting case of any description of soil-water behavior. At the next level of approximation, most soils can be adequately described by interpolating between two limiting behaviors, one being the Green and Ampt soil, the other being that of a Gardner soil. For the latter, soil profiles do not have to be discontinuous as in the original Green and Ampt model. Also, the time condensation approximation appears as an exact result for this case. Finally, a third level of approximation gives further corrections leading to better descriptions of soil-water profiles and ponding times that can be used to assess the errors of the time condensation approximation.

Link to a part of the chapter:

https://www.eolss.net/Sample-Chapters/C02/E6-03B-05-00.pdf