Soil hydraulic modelling outcomes with four parameterization methods: Comparing soil description and data inversion approaches

Different methods for parameterizing soil hydraulic models can lead to substantially varied predictions of soil-plant-atmosphere water fluxes. This study investigated, for a heterogeneous stony soil, 4 methods of soil hydraulic parameterization. Soil drainage, volumetric water content, and evapotranspiration were modeled using HYDRUS-1D for an irrigated pasture in New Zealand. While all methods underpredicted evapotranspiration by 18% to 30% compared with eddy covariance, improvement in drainage estimates with inverse estimation from field data led to decreased capability for modeling evapotranspiration. We suggest this approach for application in other settings to select the most appropriate parameterization approach for a given soil hydraulic model application.