HR: 1330h
AN: H13B-16    [Abstracts]
TI: Network Modeling of Saturation Overshoot on Infiltration
AU: * DiCarlo, D A
EM: ddicarlo@ars.usda.gov
AF: USDA/ARS National Sedimentaion Laboratory, 598 McElroy Dr, Oxford, MS 38655
AB: Most, if not all, models of water flow in the vadose zone consist of a continuum approach, where the discreteness of the porous media is replaced by smoothly varying parameters. This continuum approach cannot model certain infiltrations where the saturation at the wetting front is greater than the saturation behind the front. It has been argued that this occurs because the infiltrating water fronts are sharp at the pore-scale. Here we attempt to model water flow at a sharp front by using a physically-based network model that includes viscous effects. The network model includes pore and throat elements of different shapes and sizes, and a connection topology based on geologic media. We show that by adding viscous effects that the saturation overshoot seen in infiltrations can be modeled successfully, suggesting that pore-filling mechanisms control saturation overshoot.
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
DE: 1894 Instruments and techniques
DE: 1899 General or miscellaneous
SC: Hydrology [H]
MN: 2005 Joint Assembly