Publication Details

Category Text Publication
Reference Category Journals
DOI 10.5194/hess-10-495-2006
Title (Primary) The dominant role of structure for solute transport in soil: experimental evidence and modelling of structure and transport in a field experiment
Author Vogel, H.-J.; Cousin, I.; Ippisch, O.; Bastian, P.
Source Titel Hydrology and Earth System Sciences
Year 2006
Department BOPHY
Volume 10
Issue 4
Page From 495
Page To 506
Language englisch
Abstract A classical transport experiment was performed in a field plot of 2.5 m2 using the dye tracer brilliant blue. The measured tracer distribution demonstrates the dominant role of the heterogeneous soil structure for solute transport. As with many other published experiments, this evidences the need of considering the macroscopic structure of soil to predict flow and transport. We combine three different approaches to represent the relevant structure of the specific situation of our experiment: i) direct measurement, ii) statistical description of heterogeneities and iii) a conceptual model of structure formation. The structure of soil layers was directly obtained from serial sections in the field. The sub-scale heterogeneity within the soil horizons was modelled through correlated random fields with estimated correlation lengths and anisotropy. Earthworm burrows played a dominant role at the transition between the upper soil horizon and the subsoil. A model based on percolation theory is introduced that mimics the geometry of earthworm burrow systems. The hydraulic material properties of the different structural units were obtained by direct measurements where available and by a best estimate otherwise. From the hydraulic structure, the 3-dimensional velocity field of water was calculated by solving Richards' Equation and solute transport was simulated. The simulated tracer distribution compares reasonably well with the experimental data. We conclude that a rough representation of the structure and a rough representation of the hydraulic properties might be sufficient to predict flow and transport, but both elements are definitely required.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=3090
Vogel, H.-J., Cousin, I., Ippisch, O., Bastian, P. (2006):
The dominant role of structure for solute transport in soil: experimental evidence and modelling of structure and transport in a field experiment
Hydrol. Earth Syst. Sci. 10 (4), 495 - 506 10.5194/hess-10-495-2006