Abstract
In the modeling process, an issue of concern is the relationship between the development of the model and the physics of the process being represented. An attempt is made to maintain an accurate representation of the process being modeled while providing suitable estimates of parameters utilizing the simulation tool. Recent research has shown that infiltration into layered soil columns consisting of a high hydraulic conductivity material over a layer with a lower hydraulic conductivity is affected by the occurrence of positive soil water potentials. A thorough review of the literature showed that the phenomena of positive soil water potentials has not been included in existing infiltration models. Because of this, the existing models developed to handle infiltration into these layered soils have typically under-predicted cumulative infiltration. Although several authors have acknowledged the occurrence of positive soil water potentials in layered soils, none have incorporated the process in the development of infiltration models. Infiltration models that exclude the effects of positive soil water potentials have been shown to under-predict cumulative infiltration when this phenomena occurs. Thus, this aspect of the infiltration process must be modeled more thoroughly so as to improve predictions of cumulative infiltration. In this study, a procedure is developed for including the effects of positive soil water potentials in layered soils. A modified Green-Ampt model which estimates cumulative infiltration during the occurrence of positive soil water potentials is developed. This is accomplished by implementing a water balance within the existing Green-Ampt in filtration model. The modified model was tested utilizing independent data. Results from simulations revealed that the modified model is able to adequately predict cumulative in filtration during the occurrence of positive soil water potentials.
Deliman, Patrick Nolan (1994). Green-Ampt infiltration in layered soils with positive soil water potentials. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1550394.