HR: 1330h
AN: H32A-0532    [PDF]
TI: Simulating Water Transfers at a Forest Field Site by Using Pedo-Transfer Functions
AU: * Gerard, F
EM: gerard@nancy.inra.fr
AF: INRA,Biogeochemistry of Forest Ecosystems, Forestry Research Center of Nancy, Champenoux, 54280 France
AU: Tinsley, M
EM: tinsley@nancy.inra.fr
AF: INRA,Biogeochemistry of Forest Ecosystems, Forestry Research Center of Nancy, Champenoux, 54280 France
AU: Mayer, K U
EM: umayer@eos.ubc.ca
AF: University of British Colombia, Department of Earth and Ocean Sciences, Vancouver, V6T 1Z4 Canada
AB: Pedo-transfer functions (PTFs) are an essential building block for the modelling of water flow in soils. Many such functions have been developed for estimating the water retention curve and hydraulic conductivity from measured soil properties. Studies have previously been conducted to evaluate the performance of such functions against independent data sets obtained by laboratory measurements. Three PTFs, which have performed well in such studies, are here compared in the calibration and evaluation of a modified unsaturated flow model for forest soil water dynamics. This flow model is part of the multi-component reactive transport model MIN3P. The three functions perform similarly in reproducing the actual soil moisture data measured by TDR during about 3 years at different soil depths. All functions have difficulty simulating higher soil moisture contents. Improved results could be achieved by considering the presence of preferential flow paths. This has been simulated by implementing preferential flow schemes of varying complexity including an equilibrium flow scheme and a non-equilibrium flow formulation. The equilibrium approach, which involves a single permeability medium and a composite water retention curve, yields statistically the best results and is more flexible for calibration.
DE: 1818 Evapotranspiration
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
SC: Hydrology [H]
MN: 2003 Fall Meeting