Naslov
Characterizing plot scale soil heterogeneity by effective mass exchange parameters in 1D dual- domain flow and transport models

Autori
Filipović, Vilim ; Coquet, Yves ; Gerke, H. Horst ;

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
German Soil Science Society Annual Meeting

Mjesto i datum
Braunschweig, Njemačka, 06.09.2018. - 07.09.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
dual region flow, upscaling, mass transfer, numerical modeling

Sažetak
In arable soil landscapes, the topsoil is often characterized by spatial and structural heterogeneities related to tillage and trafficking such as compacted or loosened regions. The heterogeneous flow fields created by contrasting hydraulic properties of more- and-less compacted regions require two- or three-dimensional models when accounting for the spatially-distributed soil hydraulic or transport properties explicitly. However, the difficulty lies in the estimation of such properties and its spatial distribution and description in 2D/3D soil continuum at the plot or field scale. The idea was to limit the model complexity by reducing the spatial dimensionality in a model with two flow domains and mass exchange between them. The aim was to test a 1D dual permeability model approach that effectively accounts for sub-plot soil structural variability. The compacted soil was represented by matrix and non-compacted by highly-conductive fracture domains. An additional immobile pore water region in the fracture domain should represent embedded clods that resulted from tillage as sub-pedon scale variability. Model testing was based on simulations of flow and bromide transport of a field tracer experiment. Results of 1D dual- domain approaches with and without an immobile region are comparable with those obtained with representative 2D model simulations. The effective parameters are describing the size and shape of the domains and the mass exchange properties in the plot-scale 1D model. Such scaling approach can be useful in addressing and simplifying plot and field scale soil heterogeneity while retaining the validity of the performed simulations. Still, more research is needed in better estimation of the highly sensitive parameters of the mass transfer term between soil structural features in agricultural soils.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA