Approach for predicting the wetting front depth beneath a surface point source: theory and numerical aspect

✍ Scribed by Hammami Moncef; Daghari Hedi; Balti Jelloul; Maalej Mohamed

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 148 KB
• Volume: 51
• Category: Article
• ISSN: 1531-0353
• DOI: 10.1002/ird.60

✦ Synopsis

Using experimental data, the continuity and the cumulative infiltration equations, a new expression for predicting the wetted soil depth was described. Knowing soil hydraulic conductivity K(h f ), initial and wetting front water content, this method enables us to calculate the maximum front depth Z f (t), beneath an emitter, by only measuring its radius R f (t) on the soil surface.

To test this, we used the ADI finite difference method to solve Richards' equation for axisymmetrical water infiltration from a point source on the soil surface. To simulate the evolution of the wetted soil volume dimensions (R f (t) and Z f (t)), proper conditions were fixed for the wetting front boundaries.

The Z f (t) predicted values were compared with those computed and measured during an axisymmetric water infiltration test on a silty soil for three different discharge rates. The results obtained showed good agreement between predicted, computed and measured data.