HR: 1340h
AN: H13I-1419    [Abstracts]
TI: Modelling the Fate of Heavy Metals in the Vadose Zone: Preferential Flow Effects and the Role of Vegetation
AU: * Roulier, S
EM: Stephanie.Roulier@env.ethz.ch
AF: Soil Protection group, ETHZ, Universitaetstrasse 16, Zurich, 8092 Switzerland
AU: Menon, M
EM: Manoj.Menon@env.ethz.ch
AF: Soil Protection group, ETHZ, Universitaetstrasse 16, Zurich, 8092 Switzerland
AU: Schulin, R
EM: Rainer.Schulin@env.ethz.ch
AF: Soil Protection group, ETHZ, Universitaetstrasse 16, Zurich, 8092 Switzerland
AB: Plant development can be affected by heavy metal stress, resulting in different patterns of root distribution, and in a modification of the soil structure through the genesis of more or less developed root-macropores, acting as preferential flow pathways. Preferential flow is a known process in which contaminants transfer rapidly through the vadose zone, creating a potential risk for the groundwater. Whereas it is commonly assumed that heavy metals are little mobile in soils, very little interest has been shown in the potential preferential leaching of heavy metals, either present in solution, or particle-binded. A sensitivity analysis for the preferential flow model MACRO was performed, prior to the inverse parameterisation of the model using plot scale data. MACRO was then linked to the inverse modelling program SUFI, and calibrated against lysimeter data describing water regime changes and heavy metal behaviour, in a heavy metal contaminated soil, under a young forest ecosystem. Two objectives were pursued: (i) to highlight the modification of the soil structure due to the plant growth strategy in a metal contaminated soil, (ii) to investigate the effects of preferential flow on the mobility of heavy metals through the root zone, at the plot scale. Initial modelling results suggested that in case of heavy metal contamination, the plant water uptake was more distributed in the soil profile than when the soil was not contaminated, as well as a deeper root penetration, resulting in the creation of deep continuous macropores.
DE: 1847 Modeling
DE: 1852 Plant uptake
DE: 1875 Vadose zone
DE: 5104 Fracture and flow
DE: 5139 Transport properties
SC: Hydrology [H]
MN: Fall Meeting 2005