This webinar by Dr. John Norman, faculty member of the Department of Soil Science and the Department of Atmospheric and Oceanic Science at the University of Wisconsin since 1988, shows how to use a single-ring, dual-head, ponded infiltration technique with the analysis of Reynolds and Elrick to get key parameters for use in a macropore infiltration model. These same measurements can also be used to obtain values of the saturated hydraulic conductivity, which is useful for traditional infiltration models such as the Green and Ampt formulation.
Macropore models that include characterization of the geometry of the macropores tend to be complicated and require more parameters than can be determined from a reasonable set of independent measurements. The M&M model is a relatively simple macropore model that requires only nine parameters. Three or four of these can be determined from a standard description of soil structure. One comes from the Coefficient of Linear Extensibility and four or five are obtained from ponded-infiltration and hydraulic properties measurements. This webinar will focus on the ponded infiltration measurements. The parameters from hydraulic properties will be the subject of another seminar.