HR: 1400h
AN: H33B-09    [Abstracts]
TI: Horizontal Flow and Transport in the Vadose Zone
AU: * Pirnie-Fisker, E F
EM: epirnie@nd.edu
AF: Department of Civil Eng. and Geological Sciences. University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556, United States
AU: Silliman, S E
EM: silliman.1@nd.edu
AU: Joseph, P
EM: jpescato@nd.edu
AB: Flow and transport in the vadose zone is sensitive to sediment heterogeneities. Similar to the previous work on capillary barriers that exploited this sensitivity, the present study focuses on taking advantage of substantial differences in unsaturated hydraulic conductivity in coarse versus fine sediments under unsaturated conditions. In the present work we demonstrate that horizontal flow can be induced and controlled in the vadose zone, in regions where fine sediments exist above coarse sediments. Laboratory studies have been conducted under a number of media geometries to demonstrate the potential for inducing flow through use of coupled (injection/withdrawal) suction-cup lysimeters. Numerical studies were run to compliment and extend the ongoing lab work. HYDRUS_2D, a finite element model, was utilized to simulate both water flow and chemical transport within a fine-sediment layer embedded in a coarse-sediment matrix. Published parameter values for the coarse and fine sands used in the laboratory experiments, when applied in HYDRUS_2D, allowed successful reproduction of the laboratory results. Using the sediment-type parameter sets available in HYDRUS_2D, the model has allowed identification of a range of sediment combinations that show promise for inducing and controlling horizontal flow and chemical transport within the vadose zone.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2007 Joint Assembly