Theoretical and Experimental Research of Cumulative Infiltration

The main object of this study is the comparative evaluation of Green & Ampt's (G & A) and Parlange's (P's) models and their ability to describe cumulative infiltration of water through various soil types. Three soil samples of different hydraulic properties were packed separately into a transparent vertical column. A constant head boundary condition was applied at the surface of the soil and the incoming amount of water was measured volumetrically. Soil moisture was measured using TDR waveguides at certain locations of the column. At the early times of cumulative infiltration, sorptivity of each soil sample was estimated. Theoretical research showed that both models converge to the same equation at the early times of infiltration and that the slopes of the two models are the same for large times of infiltration, but the curves of the two models are parallel shifted. P's and G & A's models approximate well the experimental points of cumulative infiltration of the three soil samples at small times of infiltration, but P's model approximates better the experimental points at large times of infiltration.