Sensitivity of soil parameters in unsaturated zone modelling and the relation between effective, laboratory andin situ estimates

• DOI: 10.1002/hyp.5591
• Publication Date: 2004-12-22T16:53:22Z
• Authors: J. Mertens; H. Madsen; M. Kristensen; D. Jacques; J. Feyen
• Keywords: Infiltrometer; Soil horizon; Infiltration (HVAC); Pedotransfer function; Richards equation

Simulation of soil moisture content requires effective hydraulic parameters that are valid at the modelling scale. This study investigates how these can be estimated by inverse using measurements 25 locations three different depths (at surface, 30 and 60 cm depth) on an 80 20 m hillslope. The presents two global sensitivity analyses to investigate in simulated used a one-dimensional unsaturated zone model based Richards' equation. For estimation shuffled complex evolution algorithm is applied. These compared their measured laboratory situ equivalents. Soil functions were 100 cm3 undisturbed cores collected 115 situated horizons profile pits along Furthermore, field saturated conductivity was 120 single-ring pressure infiltrometer measurements. analysis 13 physical (saturated (Ks), (θs), residual (θr), air-entry value (α), van Genuchten shape parameter (n), Averjanov (N) for both horizons, depth (d) from surface B horizon) two-layer single column showed N least sensitive parameter. Ks θs A horizon d found most parameters. Distributions over all distributions samples estimates significantly 5% level except α horizon. Different reasons discussed explain large differences. Copyright © 2004 John Wiley & Sons, Ltd.